This document provides an overview of structural geology and geologic map interpretation. It discusses key topics such as rock deformation, folding, faulting, joints, continental tectonic landform units, and the geomorphology of folded terrain. Specifically, it describes how rocks can deform through plastic, elastic, or brittle mechanisms in response to stress. It also explains different types of folds and faults that form due to compression and tension. The relationships between rock structures, erosion rates, and resulting landforms are explored.
This document provides an overview of structural geology and folds. It defines structural geology as the study of geological structures like folds, faults, unconformities and joints. Folds occur when rock layers bend due to compressive forces, and come in different forms like anticlines and synclines. The key parts of a fold are identified as the crest, trough, limbs, hinge and axial plane. Folds can be classified based on their symmetry, plunge, bed thickness changes and other characteristics. Examples of different fold types include symmetrical, asymmetrical, isoclinal, overturned and plunging folds. Considerations for engineering projects involving folded rock formations are also outlined.
Igneous structure and genesis (structural geology)Shivam Jain
This presentation summarizes igneous rock structures formed from the cooling and solidification of magma. It describes both intrusive and extrusive igneous rock structures. Intrusive structures include concordant structures like laccoliths, lopoliths, sills, and discordant structures like batholiths, stocks, dikes, and volcanic necks. Extrusive structures include primary structures like pillow structures, lava flow structures, vesicular structures, and columnar structures. The presentation provides examples and diagrams to illustrate different igneous rock formations and the geological processes that create their characteristic shapes and features.
Rocks are divided into three main types based on their origin: igneous, sedimentary, and metamorphic. Igneous rocks form from the cooling and solidification of magma either underground (intrusive/plutonic rocks like granite) or on the surface (extrusive/volcanic rocks like rhyolite and basalt). Sedimentary rocks form from the compaction and cementation of sediments. Metamorphic rocks form from the alteration of existing rocks via heat, pressure, and chemical reactions. Rocks continuously cycle between these three types through geological processes like erosion, deposition, and tectonic activity.
The document discusses different types of metamorphism including contact metamorphism, regional metamorphism, and cataclastic metamorphism. It also describes the agents of metamorphism including temperature, pressure, and water. Temperature can come from magma or increasing depth, while pressure includes lithostatic pressure from overburden and stress from tectonic forces. Metamorphism results in changes to mineral composition and texture of rocks.
This document discusses different types of igneous rocks. It begins by explaining that igneous rocks form from lava or magma and can be extrusive or intrusive. Extrusive rocks form from lava at the surface, while intrusive rocks form from magma underground. Intrusive rocks can take various forms depending on factors like the viscosity of the magma and the structure of the surrounding rock layers. Common intrusive rock forms include dykes, sills, laccoliths, lopoliths, and batholiths. Extrusive rocks include lava flows. The document provides detailed descriptions of these different igneous rock types and their characteristic features.
Rocks weather and break down into soil particles through various physical, chemical, and biological processes. There are three main types of rocks - igneous, sedimentary, and metamorphic - which are the source materials for various soil formations. Residual soils form in place from weathered parent rock, while transported soils are eroded, carried by agents like water or wind, and deposited in new locations. Understanding the geological processes that produce, transport, and deposit soils helps engineers evaluate a soil's properties and potential behavior.
The document discusses different types of intrusive igneous rock bodies, known as plutons. It describes concordant plutons, which include sills, laccoliths, lopoliths, phacoliths, and bysmaliths. Sills are thin, tabular bodies that spread parallel to bedding planes. Laccoliths have a flat floor and domed roof, causing folding of overlying rock layers. Lopoliths are large, basin-shaped bodies with nearly flat tops and convex bottoms. Phacoliths and bysmaliths are also concordant bodies that form along folded strata. The document provides diagrams and examples of each type of concordant
Geological structures- التراكيب الجيولوجيه
Geological Structures
What are Geologic Structures?
إيه هيا التراكيب الجيولوجيه؟
Division of Structures
تقسيم للتراكيب الجيولوجيه
A- Primary structures
Ripple marks
Mud cracks
Cross bedding
Graded bedding
Burrows
B- Secondary Structures
Folds
Faults
Joints
Unconformities
What are Geologic Structures?
إيه هيا التراكيب الجيولوجيه؟
Geologic structure is any feature in rocks that results from deformation, such as folds, joints, and faults.
اى شكل فى الصخر ينتج من خلال عملية التشويه مثل : الصدوع والطيات
هى التشققات والتصدعات الضخمة والالتواءات العنيفة التى تشوه صخور القشرة الارضية .
Geologic structures are usually the result of the powerful tectonic forces that occur within the earth. These forces fold and break rocks, form deep faults, and build mountains .
Division of Structures
• Primary (or sedimentary) structures: such as ripple marks, cross-bedding, and mud cracks form in sediments during or shortly after deposition.
هى التراكيب الناتجة من تدخل العمليات الخارجية أثناء الترسيب
• Secondary structures: is that structures formed after the formations of any kind of rocks, such as folds, faults, or unconformities.
Primary structures
They are any structures in sedimentary rock formed at or shortly after the time of deposition: such as:
هى الاشكال التى تتخلف بالصخور تحت تأثير عوامل مناخية وبيئية خاصة مثل الجفاف والحرارة وتأثير الرياح والتيارات المائية وغيرها وبدون أى تدخل من جانب القوى والحركات الارضية أمثلة ذلك:
Ripple marks
علامات النيم: هي تموجات رملية صغيرة تنشأ على سطح الطبقات الرسوبية بواسطة حركة الماء أو الهواء و تكون حروف علامات النيم متعامدة على اتجاه الحركة.
They are wavelike (undulating) structures produced in granular sediment such as sand by unidirectional wind and water currents or by oscillating wave currents.
Wind and current ripples. (Asymmetric
Wave ripples. (Symmetric
Mud cracks
التشققات فى الرواسب الطينية : حيث ينكمش سطح الرسوبيات الطينية مخلفة شقوقا مميزة فى فترات الجفاف
Mud crack is a crack in clay-rich sediment that has dried out.
Cross bedding
التطبق المتقاطع هو النمط الذي تسلكه الرسوبيات الجديدة المتراكمة عند تأثرها بأي من التيارات المائية أو الهوائية. عندما تستق
This document provides an overview of structural geology and folds. It defines structural geology as the study of geological structures like folds, faults, unconformities and joints. Folds occur when rock layers bend due to compressive forces, and come in different forms like anticlines and synclines. The key parts of a fold are identified as the crest, trough, limbs, hinge and axial plane. Folds can be classified based on their symmetry, plunge, bed thickness changes and other characteristics. Examples of different fold types include symmetrical, asymmetrical, isoclinal, overturned and plunging folds. Considerations for engineering projects involving folded rock formations are also outlined.
Igneous structure and genesis (structural geology)Shivam Jain
This presentation summarizes igneous rock structures formed from the cooling and solidification of magma. It describes both intrusive and extrusive igneous rock structures. Intrusive structures include concordant structures like laccoliths, lopoliths, sills, and discordant structures like batholiths, stocks, dikes, and volcanic necks. Extrusive structures include primary structures like pillow structures, lava flow structures, vesicular structures, and columnar structures. The presentation provides examples and diagrams to illustrate different igneous rock formations and the geological processes that create their characteristic shapes and features.
Rocks are divided into three main types based on their origin: igneous, sedimentary, and metamorphic. Igneous rocks form from the cooling and solidification of magma either underground (intrusive/plutonic rocks like granite) or on the surface (extrusive/volcanic rocks like rhyolite and basalt). Sedimentary rocks form from the compaction and cementation of sediments. Metamorphic rocks form from the alteration of existing rocks via heat, pressure, and chemical reactions. Rocks continuously cycle between these three types through geological processes like erosion, deposition, and tectonic activity.
The document discusses different types of metamorphism including contact metamorphism, regional metamorphism, and cataclastic metamorphism. It also describes the agents of metamorphism including temperature, pressure, and water. Temperature can come from magma or increasing depth, while pressure includes lithostatic pressure from overburden and stress from tectonic forces. Metamorphism results in changes to mineral composition and texture of rocks.
This document discusses different types of igneous rocks. It begins by explaining that igneous rocks form from lava or magma and can be extrusive or intrusive. Extrusive rocks form from lava at the surface, while intrusive rocks form from magma underground. Intrusive rocks can take various forms depending on factors like the viscosity of the magma and the structure of the surrounding rock layers. Common intrusive rock forms include dykes, sills, laccoliths, lopoliths, and batholiths. Extrusive rocks include lava flows. The document provides detailed descriptions of these different igneous rock types and their characteristic features.
Rocks weather and break down into soil particles through various physical, chemical, and biological processes. There are three main types of rocks - igneous, sedimentary, and metamorphic - which are the source materials for various soil formations. Residual soils form in place from weathered parent rock, while transported soils are eroded, carried by agents like water or wind, and deposited in new locations. Understanding the geological processes that produce, transport, and deposit soils helps engineers evaluate a soil's properties and potential behavior.
The document discusses different types of intrusive igneous rock bodies, known as plutons. It describes concordant plutons, which include sills, laccoliths, lopoliths, phacoliths, and bysmaliths. Sills are thin, tabular bodies that spread parallel to bedding planes. Laccoliths have a flat floor and domed roof, causing folding of overlying rock layers. Lopoliths are large, basin-shaped bodies with nearly flat tops and convex bottoms. Phacoliths and bysmaliths are also concordant bodies that form along folded strata. The document provides diagrams and examples of each type of concordant
Geological structures- التراكيب الجيولوجيه
Geological Structures
What are Geologic Structures?
إيه هيا التراكيب الجيولوجيه؟
Division of Structures
تقسيم للتراكيب الجيولوجيه
A- Primary structures
Ripple marks
Mud cracks
Cross bedding
Graded bedding
Burrows
B- Secondary Structures
Folds
Faults
Joints
Unconformities
What are Geologic Structures?
إيه هيا التراكيب الجيولوجيه؟
Geologic structure is any feature in rocks that results from deformation, such as folds, joints, and faults.
اى شكل فى الصخر ينتج من خلال عملية التشويه مثل : الصدوع والطيات
هى التشققات والتصدعات الضخمة والالتواءات العنيفة التى تشوه صخور القشرة الارضية .
Geologic structures are usually the result of the powerful tectonic forces that occur within the earth. These forces fold and break rocks, form deep faults, and build mountains .
Division of Structures
• Primary (or sedimentary) structures: such as ripple marks, cross-bedding, and mud cracks form in sediments during or shortly after deposition.
هى التراكيب الناتجة من تدخل العمليات الخارجية أثناء الترسيب
• Secondary structures: is that structures formed after the formations of any kind of rocks, such as folds, faults, or unconformities.
Primary structures
They are any structures in sedimentary rock formed at or shortly after the time of deposition: such as:
هى الاشكال التى تتخلف بالصخور تحت تأثير عوامل مناخية وبيئية خاصة مثل الجفاف والحرارة وتأثير الرياح والتيارات المائية وغيرها وبدون أى تدخل من جانب القوى والحركات الارضية أمثلة ذلك:
Ripple marks
علامات النيم: هي تموجات رملية صغيرة تنشأ على سطح الطبقات الرسوبية بواسطة حركة الماء أو الهواء و تكون حروف علامات النيم متعامدة على اتجاه الحركة.
They are wavelike (undulating) structures produced in granular sediment such as sand by unidirectional wind and water currents or by oscillating wave currents.
Wind and current ripples. (Asymmetric
Wave ripples. (Symmetric
Mud cracks
التشققات فى الرواسب الطينية : حيث ينكمش سطح الرسوبيات الطينية مخلفة شقوقا مميزة فى فترات الجفاف
Mud crack is a crack in clay-rich sediment that has dried out.
Cross bedding
التطبق المتقاطع هو النمط الذي تسلكه الرسوبيات الجديدة المتراكمة عند تأثرها بأي من التيارات المائية أو الهوائية. عندما تستق
This document describes different types of intrusive volcanic rocks. It defines batholiths as large irregular reservoirs of magma that cool slowly underground. Laccoliths are dome-shaped intrusions that push up rock layers as magma is blocked below. Sills are horizontal sheets that form between bedding planes, while dikes are vertical or diagonal intrusions that cut across bedding planes. In conclusion, intrusive volcanism occurs when magma enters and solidifies in weaknesses or chambers in the earth's crust.
This document defines and describes various primary structures found in sedimentary and igneous rocks. Primary structures form during or shortly after the formation of a rock and include features like bedding, cross-bedding, graded bedding, ripple marks, mud cracks, and unconformities in sedimentary rocks. In igneous rocks, primary structures include intrusive features like dykes, sills, batholiths, and extrusive features like pillow lava, ropy lava, and pyroclastic flows. Secondary structures form after the rocks solidify due to tectonic forces and include folds, faults, joints, and lineations.
This document describes different types of intrusive igneous rocks based on their shape and relationship to existing bedrock structures. It defines dykes as vertically intruded bodies that cut across bedding planes in a discordant manner. Sills are described as intrusions that spread parallel to bedding plans in a concordant way. Laccoliths and lopoliths are both concordant bodies of differing dome or basin shapes that intrude between layers of existing rock.
This document discusses metamorphic textures, which refer to the physical appearance or arrangement of minerals in metamorphic rocks at the microscopic level. There are several types of textures that can form during metamorphism due to factors like heat, pressure, and chemically active fluids. Typomorphic textures are characteristic of metamorphism and include porphyroblastic, mortar, and granoblastic textures. Relict textures are inherited from the original rock, such as ophitic or porphyritic textures. Reaction textures involve chemical reactions between minerals, forming textures like coronas or reaction rims. The document provides examples of different textures and concludes that textures provide information about the metamorphic conditions and original rock type.
Structural geology is the study of the three-dimensional of the rock units with respect to their deformational histories, Structure is spatial and geometrical configuration of rock components.
Structures are classified into two types:
Primary structures.
Secondary structures
Primary structures
Structures that form during deposition or crystallization of the rock, are the result of two processes:
Settling of solid particles from fluid medium in which they have been suspended, in most of the sedimentary rocks.
Crystallization of mineral grains from a liquid in which they have been dissolved as in igneous rocks.
Joints are cracks or fractures in rocks that divide the rock mass into blocks. They form due to tensile and compressive stresses from processes like cooling/crystallization of igneous rocks, erosion, seismic activity, and tectonic plate movement. Joints can be systematic or non-systematic, and are classified by their orientation, geometry, and origin. Joints are important both geologically and economically, as they influence groundwater flow, quarrying, tunnel construction, and more.
Mountain building, or orogenesis, involves the deformation, uplift, and erosion of mountain belts. It results from tectonic plate interactions that cause crustal thickening, folding, faulting, and metamorphism. Key aspects of mountain building discussed in the document include the results of deformation like translation, rotation, and strain; different types of geologic structures such as faults, folds, and foliation that form during deformation; and the processes of orogenesis such as uplift, erosion, and isostatic rebound that shape mountain belts over time. The document uses the Appalachian Mountains as a case study of an ancient orogenic belt formed through multiple tectonic events over one billion years.
A fabric describes the spatial and geometric relationships that make up a rock at the microscopic to centimeter scale. It includes planar structures like bedding and cleavage, as well as the preferred orientation of minerals. There are different types of fabric including linear fabric formed by elongate minerals, planar fabric formed by platy minerals, and random fabric with no orientation. Foliation specifically refers to any planar arrangement of minerals or structures in a rock. Foliation can be primary, forming during rock formation, or secondary, resulting from deformation. Common types of secondary foliation include cleavage, schistosity, and mylonitic foliation. Lineation describes a preferred linear orientation of features in a rock, often related to deformation processes like intersection of planar
Contact metamorphism occurs where cooler country rocks are thermally altered by nearby intrusive bodies. The textures that develop under these low-pressure conditions typically lack strain and preserve relict features. Common textures include granoblastic polygonal textures in isotropic minerals like quartz, decussate textures in anisotropic minerals, and porphyroblasts. With increasing metamorphic grade, recrystallization becomes more prominent, grains grow larger, and evidence of strain decreases.
This document defines and describes different types of lineations found in deformed rocks, which are linear structures that occur repetitively. It discusses three main types of lineations: form lineations related to geological structures like folds, boudins, and slickenlines; surface lineations defined by intersections or slip; and mineral lineations caused by the preferred orientation of mineral grains or aggregates. Specific examples of each lineation type are provided, and the usefulness of lineations in structural analysis to determine strain and slip directions is explained.
Joints are fractures in rock without displacement. They form due to tension, shear, or compressive stresses. Joints can be classified based on their orientation relative to bedding, their geometry, genesis, and dip. Systematic joints are parallel while nonsystematic joints have irregular distributions. Joints influence groundwater flow, construction, and are important in mining and resource exploration. They provide pathways for fluid migration and impact slope stability.
This document discusses various criteria that can be used to determine the top and bottom of sedimentary beds and identify the relative age of rock layers. Some key criteria mentioned include unconformities, fossils, ripple marks, cross-bedding, graded bedding, and the position of cleavage in folded rocks. Law of superposition, which states that older beds are deposited first and therefore located lower in the stratigraphic column, is also discussed. Together, these criteria can be used to deduce the order of deposition and effects of tilting, folding, or other deformation on sedimentary beds.
The document provides information about petrology, which is the study of rocks. It discusses the structure of the Earth and defines rocks as aggregates of minerals. Rocks are classified based on their geological origin as igneous, sedimentary or metamorphic. Igneous rocks form from the solidification of magma or lava and include intrusive and extrusive types. Sedimentary rocks form from the compaction or cementation of sediments derived from pre-existing rocks by weathering processes. The document outlines the formation of magma from heat and pressure conditions in the Earth's interior and how magma crystallizes into igneous rocks as it cools on the surface or in the crust.
This document discusses unconformities, which are surfaces that separate younger rock strata from older rocks. Unconformities form due to erosion during periods of tectonic uplift or subsidence. There are several types of unconformities including angular unconformities, non-conformities, and disconformities. Unconformities are important geological features that can indicate past tectonic activity and paleogeography. They also represent gaps in the geological record where deposition did not occur.
Fractures are weaknesses in rock where separation can occur. They form due to stress from tectonic and other geological forces. There are two main types of fractures: faults where adjacent blocks are displaced parallel to the fracture surface from shearing; and joints where blocks move perpendicular with no displacement. Fractures are important for fluid migration, understanding geology and tectonics, and engineering projects. They are classified based on displacement and can be identified through field evidence like offset strata, slickensides and fault rocks.
Foliation and cleavage are planar rock fabrics that form through various geological processes. Foliation can be primary, forming during rock deposition or formation, or secondary, forming through tectonic deformation. Cleavage specifically refers to a rock's ability to split into parallel surfaces and develops through compaction, tectonic stress, and pressure solution. The grade of metamorphism influences the development of cleavage, from pencil cleavage to slaty cleavage and eventually to schistosity at higher grades. Cleavage orientation provides clues about the strain history and kinematics of deformation in the rock.
This document is the 2009 revision of the Geological Society of America Rock-Color Chart, which provides color chips to aid in describing rock colors. It notes that the chart covers the typical range of colors seen in rocks and recommends replacing the chart every two years to maintain consistent color references over time. The document provides instructions on using the chart for different grain sizes and wet vs dry rocks, and notes the chart is designed primarily for field use in rock color identification.
Map showing the counties located in the Delaware River Basin and therefore (unfortunately) subject to the Delaware River Basin Commission's years-long and ongoing moratorium on Marcellus Shale drilling. It is a particuarly onerous moratorium for those living in Pennsylvania counties like Wayne and Pike in northeastern PA where there is a lot of drilling activity. Those landowners have been and continue to be screwed by not allowing drilling.
This document describes different types of intrusive volcanic rocks. It defines batholiths as large irregular reservoirs of magma that cool slowly underground. Laccoliths are dome-shaped intrusions that push up rock layers as magma is blocked below. Sills are horizontal sheets that form between bedding planes, while dikes are vertical or diagonal intrusions that cut across bedding planes. In conclusion, intrusive volcanism occurs when magma enters and solidifies in weaknesses or chambers in the earth's crust.
This document defines and describes various primary structures found in sedimentary and igneous rocks. Primary structures form during or shortly after the formation of a rock and include features like bedding, cross-bedding, graded bedding, ripple marks, mud cracks, and unconformities in sedimentary rocks. In igneous rocks, primary structures include intrusive features like dykes, sills, batholiths, and extrusive features like pillow lava, ropy lava, and pyroclastic flows. Secondary structures form after the rocks solidify due to tectonic forces and include folds, faults, joints, and lineations.
This document describes different types of intrusive igneous rocks based on their shape and relationship to existing bedrock structures. It defines dykes as vertically intruded bodies that cut across bedding planes in a discordant manner. Sills are described as intrusions that spread parallel to bedding plans in a concordant way. Laccoliths and lopoliths are both concordant bodies of differing dome or basin shapes that intrude between layers of existing rock.
This document discusses metamorphic textures, which refer to the physical appearance or arrangement of minerals in metamorphic rocks at the microscopic level. There are several types of textures that can form during metamorphism due to factors like heat, pressure, and chemically active fluids. Typomorphic textures are characteristic of metamorphism and include porphyroblastic, mortar, and granoblastic textures. Relict textures are inherited from the original rock, such as ophitic or porphyritic textures. Reaction textures involve chemical reactions between minerals, forming textures like coronas or reaction rims. The document provides examples of different textures and concludes that textures provide information about the metamorphic conditions and original rock type.
Structural geology is the study of the three-dimensional of the rock units with respect to their deformational histories, Structure is spatial and geometrical configuration of rock components.
Structures are classified into two types:
Primary structures.
Secondary structures
Primary structures
Structures that form during deposition or crystallization of the rock, are the result of two processes:
Settling of solid particles from fluid medium in which they have been suspended, in most of the sedimentary rocks.
Crystallization of mineral grains from a liquid in which they have been dissolved as in igneous rocks.
Joints are cracks or fractures in rocks that divide the rock mass into blocks. They form due to tensile and compressive stresses from processes like cooling/crystallization of igneous rocks, erosion, seismic activity, and tectonic plate movement. Joints can be systematic or non-systematic, and are classified by their orientation, geometry, and origin. Joints are important both geologically and economically, as they influence groundwater flow, quarrying, tunnel construction, and more.
Mountain building, or orogenesis, involves the deformation, uplift, and erosion of mountain belts. It results from tectonic plate interactions that cause crustal thickening, folding, faulting, and metamorphism. Key aspects of mountain building discussed in the document include the results of deformation like translation, rotation, and strain; different types of geologic structures such as faults, folds, and foliation that form during deformation; and the processes of orogenesis such as uplift, erosion, and isostatic rebound that shape mountain belts over time. The document uses the Appalachian Mountains as a case study of an ancient orogenic belt formed through multiple tectonic events over one billion years.
A fabric describes the spatial and geometric relationships that make up a rock at the microscopic to centimeter scale. It includes planar structures like bedding and cleavage, as well as the preferred orientation of minerals. There are different types of fabric including linear fabric formed by elongate minerals, planar fabric formed by platy minerals, and random fabric with no orientation. Foliation specifically refers to any planar arrangement of minerals or structures in a rock. Foliation can be primary, forming during rock formation, or secondary, resulting from deformation. Common types of secondary foliation include cleavage, schistosity, and mylonitic foliation. Lineation describes a preferred linear orientation of features in a rock, often related to deformation processes like intersection of planar
Contact metamorphism occurs where cooler country rocks are thermally altered by nearby intrusive bodies. The textures that develop under these low-pressure conditions typically lack strain and preserve relict features. Common textures include granoblastic polygonal textures in isotropic minerals like quartz, decussate textures in anisotropic minerals, and porphyroblasts. With increasing metamorphic grade, recrystallization becomes more prominent, grains grow larger, and evidence of strain decreases.
This document defines and describes different types of lineations found in deformed rocks, which are linear structures that occur repetitively. It discusses three main types of lineations: form lineations related to geological structures like folds, boudins, and slickenlines; surface lineations defined by intersections or slip; and mineral lineations caused by the preferred orientation of mineral grains or aggregates. Specific examples of each lineation type are provided, and the usefulness of lineations in structural analysis to determine strain and slip directions is explained.
Joints are fractures in rock without displacement. They form due to tension, shear, or compressive stresses. Joints can be classified based on their orientation relative to bedding, their geometry, genesis, and dip. Systematic joints are parallel while nonsystematic joints have irregular distributions. Joints influence groundwater flow, construction, and are important in mining and resource exploration. They provide pathways for fluid migration and impact slope stability.
This document discusses various criteria that can be used to determine the top and bottom of sedimentary beds and identify the relative age of rock layers. Some key criteria mentioned include unconformities, fossils, ripple marks, cross-bedding, graded bedding, and the position of cleavage in folded rocks. Law of superposition, which states that older beds are deposited first and therefore located lower in the stratigraphic column, is also discussed. Together, these criteria can be used to deduce the order of deposition and effects of tilting, folding, or other deformation on sedimentary beds.
The document provides information about petrology, which is the study of rocks. It discusses the structure of the Earth and defines rocks as aggregates of minerals. Rocks are classified based on their geological origin as igneous, sedimentary or metamorphic. Igneous rocks form from the solidification of magma or lava and include intrusive and extrusive types. Sedimentary rocks form from the compaction or cementation of sediments derived from pre-existing rocks by weathering processes. The document outlines the formation of magma from heat and pressure conditions in the Earth's interior and how magma crystallizes into igneous rocks as it cools on the surface or in the crust.
This document discusses unconformities, which are surfaces that separate younger rock strata from older rocks. Unconformities form due to erosion during periods of tectonic uplift or subsidence. There are several types of unconformities including angular unconformities, non-conformities, and disconformities. Unconformities are important geological features that can indicate past tectonic activity and paleogeography. They also represent gaps in the geological record where deposition did not occur.
Fractures are weaknesses in rock where separation can occur. They form due to stress from tectonic and other geological forces. There are two main types of fractures: faults where adjacent blocks are displaced parallel to the fracture surface from shearing; and joints where blocks move perpendicular with no displacement. Fractures are important for fluid migration, understanding geology and tectonics, and engineering projects. They are classified based on displacement and can be identified through field evidence like offset strata, slickensides and fault rocks.
Foliation and cleavage are planar rock fabrics that form through various geological processes. Foliation can be primary, forming during rock deposition or formation, or secondary, forming through tectonic deformation. Cleavage specifically refers to a rock's ability to split into parallel surfaces and develops through compaction, tectonic stress, and pressure solution. The grade of metamorphism influences the development of cleavage, from pencil cleavage to slaty cleavage and eventually to schistosity at higher grades. Cleavage orientation provides clues about the strain history and kinematics of deformation in the rock.
This document is the 2009 revision of the Geological Society of America Rock-Color Chart, which provides color chips to aid in describing rock colors. It notes that the chart covers the typical range of colors seen in rocks and recommends replacing the chart every two years to maintain consistent color references over time. The document provides instructions on using the chart for different grain sizes and wet vs dry rocks, and notes the chart is designed primarily for field use in rock color identification.
Map showing the counties located in the Delaware River Basin and therefore (unfortunately) subject to the Delaware River Basin Commission's years-long and ongoing moratorium on Marcellus Shale drilling. It is a particuarly onerous moratorium for those living in Pennsylvania counties like Wayne and Pike in northeastern PA where there is a lot of drilling activity. Those landowners have been and continue to be screwed by not allowing drilling.
The document summarizes the structural geology and tectonic development of the Delaware Basin and Central Basin Platform in West Texas and Southeastern New Mexico. It finds that the basins have a complex structure influenced by inherited rifting from 1.3-1.1 billion years ago. Movements during the Ancestral Rocky Mountains uplifts were accommodated along these preexisting weaknesses, resulting in geometries that do not align with expected patterns. Flexural subsidence in the Delaware Basin represents a superposition of profiles from the Central Basin Platform and Ouachita Mountains thrust belt. Interpretations of the basin's structure account for observed features and compare consistency.
Bert Vandiver attended Baylor University, where he earned his bachelor of business administration in marketing and management. Today, as founder and CEO of LR Commercial Construction, Inc., Bert Vandiver develops fossil-fuel pipeline projects throughout the Permian Basin.
The document summarizes an upcoming conference on using geological and geophysical data to optimize drilling and completions strategies in unconventional plays in the Permian Basin. The two-day conference in Houston, Texas will feature over 20 expert speakers from leading Permian Basin energy companies. Day one will focus on using data to optimize strategies in key plays like the Wolfcamp, Bone Spring, and Spraberry formations. Day two will focus on using well logs, core samples, and reservoir data to improve productivity. Topics will include seismic analysis, mapping faults and fractures, geosteering, and integrating petrophysical properties to predict productivity.
The document summarizes key information about the Permian Basin, including its structural setting, drilling zones, and potential. It describes how the basin was formed through uplifts and subsidence, filling with thick Paleozoic sediments containing oil and gas reservoirs. Traditionally carbonates dominated production, but unconventional techniques now exploit lower permeability shale and tight sand reservoirs, transforming the basin into a shale development hotspot. Drilling often accesses multiple stacked pay zones from a single well, enhancing economics. Significant potential remains through infill drilling and developing unconventional plays.
This document provides an overview of recruitment in the oil and gas industry, including:
- Definitions of the upstream, midstream, and downstream sectors.
- The differences between service companies and operators.
- The types of jobs available based on degree level, from BS to PhD.
- An overview of recruiting companies that visited the University of Houston in 2014.
- Tips for resume writing, interviewing, and networking to help secure a position in the oil and gas industry.
Bone Spring 2 porosity distribution in Lea Co New Mexico.pdfJerry Beets
The document discusses the Permian paleogeography and stratigraphy of the Delaware Basin in New Mexico. It analyzes porosity log data from the Bone Spring 2 formation which indicates thicker zones of higher porosity oriented in a NE-SW direction, suggesting deposition from channels sourced from structural highlands to the north, east and west. Core data shows higher porosity corresponds to higher permeability. Mapping porosity trends can help define production sweet spots and maximize the economic potential of the Bone Spring 2 play.
1) The document identifies 5 different rocks: slate, sandstone (identified for 3 different rocks), and pumice.
2) For each rock, the document describes the texture, color, and sometimes location where the rock was found to help identify what type of rock it is.
3) Additional context is provided about the geological background of the Santa Monica Mountains and areas around Pyramid Lake where some of the rocks were discovered.
The document provides guidance on describing clastic cuttings from drilling operations. It outlines 12 aspects that should be included in a cutting description, in a specific order: 1) rock type, 2) colour, 3) hardness, 4) fracture and texture, 5) grain size, 6) sorting, 7) angularity/roundness, 8) sphericity, 9) matrix, 10) cementation, 11) accessories and fossils, 12) porosity, and 13) hydrocarbon indications. Descriptions of arenaceous and argillaceous rocks are also provided, along with guidelines on determining lithology, colour, hardness, texture, and other characteristics. Proper terminology and methods for accurate cutting descriptions are emphasized
production Bone Spring-Wolfcamp vs other resource plays.pptJerry Beets
The document contains various charts and data about oil and gas production, costs, and forecasts in major North American shale plays such as the Permian Basin, focusing on the Delaware Basin, Midland Basin, and Wolfcamp and Bone Spring formations. Metrics discussed include lateral lengths, proppant usage, well costs, production rates, break-even prices, rig counts, permits, drilled uncompleted wells, and forecasts for production and prices out to 2040. Recent acquisition costs in the Delaware and Midland basins are also mentioned.
Permian Delaware and Midland basins play.pptJerry Beets
The document discusses the geology and production of the Permian Basin across the Midland and Delaware Basins. It covers the stratigraphy, depositional systems, structure, productive areas, key formations like the Wolfcamp and Bone Spring, resource play polygons, and production type curves. Maps show attributes like thickness, porosity, gas-oil ratios, and acreage ownership across the Permian Basin provinces in Texas.
Metamorphic rocks are rocks that have changed from one type to another due to high heat and pressure underground over millions of years. This process of metamorphism can change a rock's texture, chemical composition, and internal structure. Jade rock specifically forms where tectonic plates meet in areas with high underground heat and pressure, as this environment transforms pyroxene rock into crystalline jade over long periods of time.
The document discusses advances in gas data acquisition systems and gas ratio analysis that enable more accurate interpretation of hydrocarbon zones from drilling mud gas returns. Key points:
- New constant volume degassers extract gas samples more representative of formation fluids, improving consistency. Improved detection also provides high-resolution analysis.
- Gas ratio analysis, comparing quantities of heavier and lighter hydrocarbon fractions, effectively identifies fluid types when validated data is carefully applied. Ratios like LH, LM, and HM have exceptional results determining reservoirs in Southeast Asia.
- Presenting basic gas data alongside ratios and variables affecting the data brings out features to characterize fluids and reach final judgments through cut-offs and comparisons. These advances enable more reliable real-
Definition, metamorphism.
limits and type of metamorphic agents.
Metamorphic processes.
Types of Metamorphism
Classification of metamorphic rocks and textures of metamorphic rocks
Mineral assemblages and Metamorphic grade and facies of metamorphic rocks.
Graphic representation of metamorphic mineral parageneses.
This document provides an overview of geophysics and its various applications. It discusses how geophysics studies the physics of the Earth and its atmosphere. Key methods described include seismic reflection and refraction techniques to map subsurface structures. These methods make use of the travel times of seismic waves to determine depths and detect features like faults and folds. The document also outlines how geophysics has various applications in mineral and oil/gas exploration to locate deposits and structures below the surface using physical property measurements.
Well logging and interpretation techniques asin b000bhl7ouAhmed Raafat
This document provides an introduction to sedimentary rock properties for well log interpretation. It discusses how sedimentary rocks form from the weathering and alteration of existing rocks. Sedimentary rocks are composed mainly of minerals stable under normal surface conditions and may be classified as mechanically or chemically derived. Mechanical rocks include sandstones and conglomerates, while chemical rocks include carbonates and evaporites. Well logs are useful for characterizing sedimentary rocks and pore fluids in order to understand petroleum reservoirs.
This document provides an overview of petroleum geology, including:
1) It discusses the key components of petroleum geology - geochemistry, geophysics, and biology.
2) It explains the process of formation of an oil accumulation, which requires a source rock, reservoir rock, seal, and trap.
3) It describes the basic components of organic matter in sediments and how they are transformed into kerogen and then oil and gas through burial and heating over time.
Formation evaluation and well logging are processes used to determine the properties of subsurface reservoirs and identify commercially viable oil and gas fields. Key logging tools developed over time include resistivity logs in the 1920s, dipmeters in the 1940s, gamma ray and neutron logs in the 1940s, sonic logs in the 1950s, density logs in the 1960s, and logging while drilling was introduced, allowing real-time data acquisition. The document provides a historical overview of the development of various openhole well logging tools and techniques.
This document discusses crustal deformation and geologic structures. It describes the different types of stresses that cause deformation, including compressional, tensional, and shear stresses associated with convergent, divergent, and transform plate boundaries. It also explains how rocks deform through folding, faulting, and fracturing in response to these stresses. Specific structures covered include folds like anticlines and synclines, as well as normal, reverse, thrust, and strike-slip faults. The document concludes by discussing how geologists measure and map the orientation of rock layers and faults.
This document discusses crustal deformation and geologic structures. It describes the different types of stresses that cause deformation, including compressional, tensional, and shear stresses associated with convergent, divergent, and transform plate boundaries. It also explains how rocks deform through folding, faulting, and fracturing in response to these stresses. Specific structures covered include folds like anticlines and synclines, as well as normal, reverse, thrust, and strike-slip faults. The document concludes by discussing how geologists measure and map the orientation of rock layers and faults.
Geological structures folds faults joints types of folds jointsAmjad Ali Soomro
This document discusses different types of geological structures including folds, faults, and joints. It defines key terms related to these structures and provides examples. Specifically, it describes:
1) Different types of folds such as anticlines, synclines, symmetrical, asymmetrical, overturned, and recumbent folds.
2) Fault types including normal, reverse, strike-slip, oblique-slip, and blind faults. It explains the movement and features of each.
3) Joints as fractures with no displacement that form due to stresses and rock movements, and classifies them as tension or shear joints.
GEOHAZARDS03 - Earthquakes Causes and Measurements.pdfraincabcaban
This document discusses earthquakes, their causes, and how they are measured. It begins by explaining that most earthquakes occur along faults in the earth's crust where tectonic forces cause deformation. It then describes how rocks deform under stress, the different types of stresses that can occur, and how materials respond as either brittle or ductile. Evidence of past deformation is discussed, including how the orientation of inclined rock layers is defined and measured. The document concludes by describing the different types of faults like normal, reverse, strike-slip and transform faults, and explains that earthquakes are caused by a sudden release of elastic strain energy built up along fault zones.
MOVEMENT OF PLATES AND FORMATION OF FOLDS AND.pptxmarionboyka
This document discusses various types of rock deformation processes including metamorphism, plate tectonics, folds, faults, and joints. It describes contact and regional metamorphism, the four main types of stresses that cause rock deformation, and plate tectonic theory including the three types of plate boundaries. The document also defines common geological structures such as anticlines, synclines, monoclines and the four basic types of folds. Finally, it explains joints, faults, and the four main fault types.
This document discusses various types of rock deformation processes including metamorphism, plate tectonics, folds, faults, and joints. It describes contact and regional metamorphism, the four main types of stresses that cause rock deformation, and plate tectonic theory including the three types of plate boundaries. The document also defines common geological structures such as anticlines, synclines, and the four basic types of folds. Finally, it explains joints, faults, and the four main fault types.
The document discusses the formation and types of mountains. It begins by explaining the general model of mountain formation, which involves accumulation of sediments, deformation and uplift during plate convergence, and isostatic rebound after erosion. It then describes the five main types of mountains: folded mountains from plate collisions, volcanic mountains from magma erupting, fault-block mountains from faults vertically displacing crustal blocks, erosion volcanic mountains formed by erosion, and dome mountains pushed up from underground magma. Finally, it compares characteristics of young, mature, and old mountains.
Earthquakes originate from a focus point within the earth and seismic waves travel outward, reaching the surface at the epicenter above the focus. Body waves including P-waves and S-waves originate at the focus and travel through the earth, while surface waves cause more damage when they reach the epicenter. Faults occur along tectonic plate boundaries and are classified as normal, reverse, or strike-slip depending on whether the rocks above the fault plane move down, up, or sideways relative to the other side.
Deformation of the crust occurs along tectonic plate margins and produces geologic structures like folds and faults. Folds form as bent layers of rock in response to compressional forces, and the main types are anticlines, synclines, and monoclines. Faults form when stresses exceed a rock's strength, causing fractures. The main types of faults are normal, reverse, strike-slip, and oblique-slip faults. Evidence for seafloor spreading includes drilling samples from the ocean floor that show the oldest rocks farthest from mid-ocean ridges and the youngest rocks closest.
1. Structural geology is the study of secondary geological structures like folds, faults, joints that form in rocks after their initial formation.
2. Folds form as a result of stresses that cause bending or undulations of layered rocks. Folds can be classified based on their geometry and orientation.
3. Faults form when rocks fracture and move relative to each other along a fracture surface due to stresses. Faults are classified based on the type and direction of movement between rock blocks.
4. Joints form when rocks fracture but there is no relative movement between the fractured pieces. Joints often form extensive fracture systems.
This document discusses various geological processes that shape Earth's surface over long periods of time. It describes how stress and strain lead to folding and faulting in the crust. It also explains how volcanic activity, earthquakes, and plate tectonics result in mountain building and other surface features. Key points include how the principle of uniformity helps us understand slow, gradual changes versus sudden catastrophic events, and how different rock types respond to stress depending on temperature, pressure, and time.
Normal faults occur when rocks pull apart, causing the rock on one side of the fault to move down relative to the other side. Reverse faults occur when rocks are pushed together, causing the rock on one side to move up. Transform faults cause horizontal movement between blocks of rock on either side. Oblique faults involve a combination of these movements. Faults represent zones of weakness where future earthquakes and surface rupturing are most likely to occur. Infrastructure like buildings and transportation corridors in fault zones faces damage during seismic activity.
Normal faults occur when rocks pull apart, causing the rock on one side of the fault to move down relative to the other side. Reverse faults occur when rocks are pushed together, causing the rock on one side to move up. Transform faults cause horizontal movement between blocks of rock on either side. Oblique faults involve a combination of these movements. Faults represent zones of weakness where future earthquakes and surface rupturing are most likely to occur. Infrastructure like buildings and transportation corridors in fault zones faces damage during seismic activity.
This document provides an overview of geological structures and the forces that cause them. It discusses stress, strain and rock strength, and how rocks deform through elastic, plastic and brittle mechanisms. The main types of stresses are described as tensional, compressional and shear. Geological structures include folds, fractures, joints and faults, which form through buckling or fracturing of rocks in response to these stresses. Specific fold types like anticlines and synclines are defined. Fractures include joints and faults, with joints involving no displacement and faults involving relative displacement of rock layers.
This document provides an overview of key concepts related to cleavage, foliation, and lineation in metamorphic rocks. It defines different types of cleavage based on scale, including slaty, phyllitic, and schistosity. It also discusses crenulation and spaced cleavage. Examples are provided of slate, phyllite, schistosity, and crenulation cleavage in metamorphic rocks. The document also discusses concepts such as boudinage, gneissic structure, migmatization, mylonite, and different types of lineations. It provides examples of strain markers and describes analyzing strain in strongly deformed rocks. Finally, it discusses relationships between deformation, metamorphism, pl
The document provides information about folds and faults. It defines folds as bent or curved rock layers, and describes common fold types like anticlines and synclines. It also defines various fault types including normal faults, thrust faults, strike-slip faults, and oblique faults. Specific structures are described like the San Andreas Fault, which is a major strike-slip fault in California. Dip, strike, heave and throw are also defined in relation to describing the orientation and movement of geological structures.
Geological structures form in the Earth's crust due to geological causes. There are many types of structures including folds, faults, and joints. Folds form when rock layers bend under stress rather than breaking. Common fold types include anticlines, synclines, domes, and basins. Faults form when rock layers fracture and move relative to each other, and include normal, reverse, and strike-slip faults. Joints are fractures where the rock splits but there is no relative movement, and can form due to processes like cooling, tectonics, and unloading.
Structural Geology for petroleum Egineering GeologyKamal Abdurahman
Structural geology is the study of geological structures like faults, folds, and joints. It provides important information for fields like engineering geology, economic geology, and plate tectonics. Folds form when rock layers bend under pressure and heat. The limbs of folds dip inward or outward forming anticlines and synclines. Faults form when rocks break under stress, producing displacement along a fracture. The hanging wall moves relative to the footwall. Joints are fractures without displacement that form to relieve stress. Unconformities represent gaps in the geological record due to erosion. They provide evidence about past environmental conditions. Structural features must be considered for engineering projects due to their effects on rock strength and fluid flow. Plate t
Structural geology is the study of rock structures and deformations within the Earth's crust. There are several types of rock structures that provide evidence of past deformation, including folds, faults, joints, and foliations. Folds occur when rock layers are bent, and there are different types such as anticlines, synclines, tight folds, overfolds, recumbent folds, and nappe folds. Understanding rock structures provides insight into the stress fields and tectonic processes that shaped the geological past.
The document discusses faults and folds in the Earth's crust. It defines faults as fractures where rocks have moved relative to each other due to stress, strain and deformation. The three main types of faults are reverse, normal, and strike-slip faults. Folds are deformations in rock layers caused by pressure that result in structures like anticlines and synclines. Examples are given of famous mountain ranges formed by folding and faulting at tectonic plate boundaries, like the Himalayas and Alps.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Training: ISO/IEC 27001 Information Security Management System - EN | PECB
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Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
Communicating effectively and consistently with students can help them feel at ease during their learning experience and provide the instructor with a communication trail to track the course's progress. This workshop will take you through constructing an engaging course container to facilitate effective communication.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
1. Overview of Structural Geology and Geologic Map Interpretation
I. Rock Deformation and Structural Geology- process of rocks becoming physically deformed
as they are subjected to tectonic/crustal stress
A. Plastic vs. elastic vs. brittle deformation of rocks: rocks may respond to stress in
the form of folding like paper (plastic deformation) or fracturing into blocks (brittle
deformation) or may deform elastically (i.e. given volume of rock will return to its original
size and shape after stress is removed)
1. brittle deformation of rocks is rather easy to recognize, analogous to hitting
concrete with sledge hammer. Conditions of stress result in fracturing or
rupturing of rocks.
2. elastic: stress is applied slowly under constant pressure, rocks return to original
size and shape after stress is removed.
3. plastic deformation: a set of conditions must be met before rocks will deform
plastically
a. relative heat, constant pressure, and time
4. Generally: as stress is applied to rocks at low temp, and low press, rocks will first
deform elastically (with ability to return to original size and shape once stress is
removed), once the level of stress exceeds the elastic limit of a given type of rock
(i.e. the point or strength of a rock, with stress beyond which rock will fail), it will
then either deform plastically or brittally.
B. Folding of Rock Strata
1. Under components of horizontal stress: flat-lying layers of sedimentary/volcanic
rocks may become bent into a series of folds (analogous to pushing and folding
sheet of paper).
a. folding process results in shortening and thickening the crust
2. Fold Types
a. Anticlines-upfolded forms, results in older rocks becoming enclosed
within younger strata
b. synclines-downfolded forms, results in younger rocks becoming enclosed
within older strata.
c. symmetrical folds - both limbs of the fold dipping at same angle away
from fold axis
d. asymmetrical folds - both limbs of the fold not dipping at same angle
away from fold axis
e. overturned folds - one limb of fold has been tilted beyond vertical
1
2. f. plunging folds- axis of fold is tilted
g. Domes- more or less circular equivalent of anticline, oldest rocks exposed
in center of dome
h. Structural Basin- more or less circular equivalent of syncline, youngest
rocks exposed in center of dome (not to be confused with depositional
basin)
3. Outcrops Patterns Associated with Folded Rocks
a. As rocks are folded, and subsequently subjected to erosion, regular
patterns become evident in relation to type of rock that outcrops and age
of the rock that outcrops in an area of folded strata. In essence, erosion
exposes the interiors of the folds
b. Non-plunging Folds- axis of fold is horizontal, results in parallel bands of
dipping strata about the fold axis
(1) anticlines- oldest strata exposed along fold axis
(2) synclines- youngest strata exposed along fold axis
c. Plunging Folds-axis of fold is tilted, results in alternating V-shaped bands
of dipping strata oriented about the fold axis.
(1) anticlines- oldest strata exposed in the center of the V, V points in
direction of plunge of fold axis
(2) syncline- youngest strata exposed in the center of the V, V points in
opposite direction of plunge of fold axis.
d. Doubly Plunging Folds- fold axis is plunging in two opposite directions,
results in a flattened oval pattern, or a double V-shaped pattern <<<>>>>.
(1) anticlines- oldest strata exposed in center of flattened oval
(2) synclines-youngest strata exposed in center of flattened oval.
C. Faulting and Related Structures
1. Faults - fractures within the earth's crust along which movement or offset of
crustal blocks has occurred.
a. Dip-slip faults- movement is vertical down the plane of the fault,
movement along the inclination or dip of fault plane hence "dip-slip".
2
3. b. Normal Faults-faults in which crustal block above the fault plane (hanging
wall) move down relative to crustal block below the fault plane (foot wall)
c. Reverse Faults- faults in which crustal block above the fault plane
(hanging wall) moves up relative to crustal block below the fault plane
(foot wall).
(1) Thrust Fault- reverse fault with very low angle, or very gently
inclined (<30o) fault plane.
(a) associated with strong, horizontally oriented, compressional
stresses.
d. Strike-slip faults- movement along fault is horizontal along the fault
(similar to notion of transform faults in plate tectonics), i.e. offset is parallel
to the trend or strike of the fault plane.
(1) Strike - the trend or compass direction of the line formed between
the intersection of a horizontal plane with any inclined plane.
e. Oblique-slip faults- faults which have both vertical and horizontal
components of movement.
2. Stress Regimes and Style of Faulting
a. Reverse/Thrust Faults- often associated with compression or squeezing of
crustal blocks, rupture results when stress>strength of rocks. E.g. in
association with convergent tectonic zones.
b. Normal Faults- associated with "pulling apart" or tensional forces exerted
on crustal blocks. E.g. in association with rift zones or spreading centers in
plate tectonics.
(1) Grabens- crustal block bounded by two inward-dipping normal
faults, crustal block downdrops to form a graben.
(2) Horst- relatively uplifted crustal block flanked by two adjacent
grabens.
3. Joints-in contrast to faults- fractures along which no appreciable movement has
taken place.
a. joints - accommodate stress during tensional and shear stresses
associated with crustal movements.
b. joints often occur in very low-stress regimes, with broad, gentle warping of
earth's crust.
c. joints often serve as sights of enhanced weathering processes, may result
in streams and rivers following their trends.
3
4. II. Continental Tectonic Landform Units
A. Craton- low-relief core of continent
1. Cratonic Shields: complexly deformed and metamorphosed crystalline
basement rocks, generally of Precambrian age
a. E.g. Canadian Shield = Precambrian granitic core of North America
b. Stable Platform: sedimentary cover overlying Cratonic Shields
(1) "Stable" = relatively undeformed/broad upwarping
B. Folded Mountain Belts (aka "complex mountains")
1. Mountain relief a result of erosion and dissection of portions of the earth's crust
that has been folded and thickened.
a. Product of tectonic convergence
2. Fold belts are also commonly associated with faulting, metamorphism, and
igneous intrusion; although folding is the most conspicuous deformation style.
a. E.g. Alps, Himalaya's, Appalachian Mountains
C. Fault-Block Mountains
1. Associated with erosion and dissection of portions of the earth's crust that has
been displaced and tilted along high-angle normal faults (in association with
tensional stresses)
2. E.g. Basin and Range Province of Nevada, Utah, Eastern CA, SE Oregon, AZ.
a. Often associated with precursory volcanic activity.
D. Continental Rift Zones
1. Zones of continental extension and pull-apart (rifting) of crust
a. Sites of intense extensional faulting and pursuant volcanism
b. represents early stage of oceanic spreading center development
(1) "Pangaea" breakup initiated by continental rifting, with subsequent
evolution of seafloor spreading centers
4
5. 2. "Triple Point Junctions": rift geometry is such that triple fracture systems
radiates outward from central locus of stretching
a. E.g. Red Sea-East Africa-Afar Triangle Triple Point
3. Aulacogens: failed arms of rift systems
a. Rift process initiated, however one or more rifts in triple-point junction fail
to successfully undergo continued extension
(1) E.g. Gulf Coast-Mississippi Valley Rift/Aulacogen System
E. Upwarped Mountains
1. produced in association with broad arching or upwarping of the crust or of vertical
uplift along high angle reverse faults.
a. e.g. Black Hills of S.D. and Adirondack Mtns. of NY e.g. of broad arching
or uplift
2. Rocky Mtns of CO, NM result of vertical uplift, leave front range in which mantle
of sed. rocks are tilted upward along high angle faults.
a. results in hogbacks or flat-irons of front range
F. Volcanic Mountains
1. Volcanic Arc Complexes
a. Linear volcanic mountain chain formed on over-riding plate of subduction
complex
(1) e.g. Andes, Cascades
2. "Intraplate" Volcanic Complexes
a. Hawaii Hot Spot
b. Yellowstone Hot Spot
c. Extensional-volcanism of SW U.S.
3. "Leaky Transform" volcanic systems
a. volcanism associated with transform faulting
(1) e.g. New Zealand
III. GEOMORPHOLOGY OF FOLDED TERRAIN: BEDROCK ATTITUDE AND LANDFORMS
A. Controlling Factors
1. Rate of Crustal Deformation
a. Influenced by Tectonic Process
b. Measured deformation rates: avg. 5-20 mm/yr
2. Three-dimensional Geometry of Rock Structure
a. Influenced by Stress-Strain Relationships
3. Differential Erosion of Rock
a. Influenced by climate, rock type and structural weakness
(1) e.g. Sandstone = resistant, Shale = nonresistant
5
6. 4. Balance Between Deformation and Erosion
a. If rate erosion < rate deformation....
(1) Topographic Form = Structural Form
(a) e.g. Anticlinal Ridges: topographic and structural highs
(b) Synclinal Valleys: topographic and structural lows
b. If rate erosion > rate deformation....
(1) Structural Form Modified by Erosion
(a) Topographic and Structural Relationships Dependent on 3
controlling factors above
B. Differential Erosion, Rock Structure and Topographic Expression
1. Differential Erosion: variable rates of rock weathering associated with
resistance of rock to weathering
a. Non-resistant Rocks: easily etched and eroded in landscape
(1) e.g. Shale, Limestone (humid climates): commonly underlies
valleys/lowlands
b. Resistant Rocks: resistant to weathering and erosion
(1) e.g. Conglomerate, Sandstone, Limestone (in arid climates):
commonly ridge formers, standing resistant to erosion
(2) Others: Quartzite, chert, lava flows, sills, dikes
c. Stream/Erosion Patterns: conform to rock resistance to erosion
2. Topographic Expression: Flat-rock and Homogeneous Terrain
a. Characterized by uniform resistance to erosion
b. Dendritic Drainage Patterns Commonly Developed
(1) Uniform Distribution of Erosional Topography
c. Landscape Dissection: vertical down-cutting
(1) Cliff and Bench Topography: Grand Canyon like topography
(a) sharp cliffs punctuated by flat topographic benches
i) Benches formed by resistant rock
ii) Common in arid climates
iii) Flat-rock country
iv) Parallel slope retreat over time
a) Resistant benches "undermined" by erosion of
less resistant rock, with subsequent collapse
and slope retreat.
(b) Humid Climate: "cliff and benches" subdued with rounded
hillslopes, thick weathering profile, vegetation, creep
(2) Butte and Mesa Topography: common to Cliff and Bench Terrain
(a) Butte: rounded flat-topped erosional remnants
(b) Mesa: elongated, table-like, flat-topped erosional remanents
i) Product of differential erosion, parallel slope retreat,
6
7. and resistant cap rock.
3. Topographic Expression of Tilted Strata
a. Homoclinal Structure: Homo = same, Cline = inclination; homoclinal
structure = uniformly tilted beds
(1) Differential Erosion Processes: Strike and dip of homocline provide
preferred directions of weakness, and hence preferred directions of
stream orientation
(a) Selective Headward Erosion: cuts "strike valleys" along non-
resistant rock layers
(b) Resistant Strata: "strike ridges" standing above valleys
(c) Net Result: Topography of parallel ridges (resistant strata)
and valleys (non-resistant strata)
(2) Homoclinal Ridges: erosionally-resistant "strike ridges" in tilted
rock terrain
(a) Asymmetric Cross-Sectional Ridge Profile
i) Scarp Face: more steeply inclined "bed" face
ii) Dip Slope: topographic slope formed along dip-plane
or bedding plane of resistant unit
(scarp faces > steepness than dip slopes)
b. Cuestas: homoclinal ridges formed in gently tilted homoclinal sections
(1) <25-30o dip
c. Hogbacks: homoclinal ridges formed in more steeply tilted homoclinal
sections
(1) >30-40o dip
d. Homoclinal Stream Shifting: as initial streams begin cutting rock on newly
formed homoclinal surface, down-cut the more easily eroded layers (e.g.
shale) along strike.
(1) Vertical Limit of Downcutting: underlying resistant bed
(2) Dip-slope forces streams to "shift" laterally down dip laterally
carving the more easily eroded strata
e. Erosional Retreat of Homoclinal Ridge
(1) Scarp-face Retreat: because scarp faces are more high angle than
dip slopes, the scarp face is more energetically eroded over time
(a) Scarp face retreats laterally in down-dip direction
7
8. (2) Homoclinal Shifting: homoclinal valleys migrate laterally in down-dip
direction, and vertically along dip slope
(3) V-shaped Notches
(a) Where streams incise homoclinal ridges perpendicular to
strike, via headward erosion, V-shaped notches are cut
through the scarp face
(b) Law of V's: In the case of a v-shaped notch, the apex of the
"V" points down dip in the direction of dip.
(4) Determining Angle of Dip in Homoclinal Topography
(a) Examine contour pattern along dip slope
(b) Dip = topographic slope of dip slope
i) Dip = Slope = rise/run = vertical relief/horizontal
distance
ii) Tan (theta) = V/H; where theta = dip angle
a) "Inv" Tan (V/H) on calculator = dip angle
4. Topographic Expression of Folded Strata: Processes and forms of eroded
structural folds
a. Anticlinal Ridge: structural anticline mirrored in surface form of a ridge or
hill
(1) "Unbreached" anticline: resistant folded layers undissected along
axial plane of fold
(2) "Breached" anticline: folded layers along axial plane of fold are
incised by erosion and down-cutting streams
b. Anticlinal Valley: Breached anticline- structural anticline eroded in form of
topographic valley along axis of fold
(1) result of easily eroded lithologies along axial plane of fold
(2) Topographic Inversion- sense of structural relief opposite of that of
topographic relief
(a) e.g. Anticlinal Valleys, Synclinal Ridges
c. Synclinal Valley: sense of structural relief = sense of topographic relief
d. Synclinal Ridge: topographic ridge formed along axis of syncline
8
9. (1) Result of erosionally resistant strata along axial plane of fold, with
easily eroded strata on flanks
e. Non-plunging Fold Patterns
(1) Parallel sets of hogbacks oriented symmetrical about fold axis
(a) Anticlines: oldest strata exposed along axis
(b) Synclines: youngest strata exposed along axis
(2) Scarp face and dip slope relations apply as above
f. Plunging Folds and "Zig-Zag" Mountains
(1) Plunging Folds result in alternating V or Zig-Zag shaped
topography
(a) Plunging Anticlines
i) Homoclinal ridges converge to apex in direction of
plunge
ii) "V" of pattern points down plunge
(b) Plunging Synclines
i) Homoclinal ridges diverge in direction of plunge,
converge in "up plunge" direction
ii) "V" of pattern points up plunge
g. Monoclinal Structure: structures in which strata dip in one direction, but
displays local steepening and flattening of dip along "monoclinal flexures".
5. Stream Development and Geologic Structures
a. Consequent: stream patterns formed synchronously as beds are tilted,
and drainage flows in direction of dip
(1) Stream courses are "consequence" of initial slope of surface
b. Subsequent: stream pattern developed in accordance to erosional
resistance of folded or tilted strata.
(1) Form "subsequent" to structural deformation
c. Antecedent: streams maintain stream course (pattern) that was
established prior to structural deformation (unaltered by deformation
patterns)
(1) e.g. Susquehana River cutting through Valley and Ridge near
Harrisburg
(a) Entrenched meander pattern cutting through Valley and
Ridge
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10. IV. GEOMORPHOLOGY OF FRACTURED TERRAIN: JOINTING, FAULTING AND
LANDFORMS
A. Jointing
1. Fractures along which no movement has occurred
a. Brittle rock deformation
(1) crustal (tectonic) stress
(a) Tensional stress (pull apart)
(b) Compressional stress (squeezing)
(c) Shear stress (sliding motion)
(2) shrinkage/cooling phenomena (volcanics)
(3) Occurs in all rock types
(a) Degree of fracturing function of:
i) rock type
a) Sandstone: brittle, readily fractured, heavily
influenced by joint patterns
b) Shale: less brittle, undergoes more "plastic" or
pliable deformation, does not readily display
joint patterns
c) Crystalline igneous and metamorphic rock:
brittle and readily displays joint deformation
ii) strength (resistance to breaking)
iii) degree of stress
(b) Geometry of fracturing function of:
i) stress orientation
a) Tensional Stress: fractures form perpendicular
to direction of maximum tension
b) Shear/compressional stress: fractures form
within 30-45 degrees of maximum compression
direction
i) Conjugate joint sets
ii) Secondary jointing
a) secondary by-product of rock folding
B. Topographic Expression of Joints (Paths of Least Resistance)
1. Joints: represent fractures and zones of weakness easily exploited by the
weathering and erosion process (physical and chemical)
a. Avenues of increased permeability and chemical weathering
b. Differential erosion phenomena
10
11. 2. Joints provide sites of weakness and erosion: strongly influence stream erosion
patterns
a. Rectangular Drainage Patterns
b. Angular Drainage Patterns
3. Joints Identified from maps and air photos
a. "joint" lineaments: linear, geometric patterns observable in map analysis
(1) Identifiable by:
(a) geometric drainage patterns
(b) vegetative growth patterns
(c) Linear "topographic grain"
C. Faulting
1. Erosional Phenomena
a. Faults represent relatively narrow, linear zones of crustal deformation
(1) Zones of lithologic weakness
(2) Avenues of enhanced physical and chemical weathering
(a) Differential weathering phenomena
2. Scarps: word derived from "escarpment" which represents a sharp inclination in
topographic grade
a. Fault Scarps: escarpments along fault zone that result from direct offset
of land surface by fault movement
(1) Linear form in plan view
(2) May erosionally degrade with time
(a) Further tectonic deformation will rejuvenate scarp
b. Fault Line Scarps: escarpments along fault zone that result from
differential erosion of rocks of contrasting resistance juxtaposed by
displacement
(1) Less resistant rock: rapid erosion
(2) More resistant rock: comprises scarp-face
c. Composite Fault Scarp: combination of processes of direct land
displacement and differential erosion
3. Fault Displacement and Fault-Scarp Geomorphology
a. Structural Morphology and Processes
(1) Land Displacement
(a) Fault offset creates scarp, linear front to uplifted mountains
11
12. i) Land displacement: instantaneous rupture of ground
surface, offset of rock and/or unconsolidated surface
materials
a) accompanied by earthquake/seismic activity
b) Single event scarps range from inches to feet
to 50 Ft of vertical offset of land surface
(2) Fault Splays: displacement along interwoven network of fault
strands
(3) Fault Slices: en echelon offset along sets of parallel faults
(a) aka "step faulting"
(4) Fault Segmentation and Differential Stress
(a) Faults of any significant length, rarely undergo uniform
offset along entire lengths
i) Differential stress distribution along fault zone results
in differential displacement at various geographic
locations and times.
ii) Fault may become segmented into definable linear
domains which may become active and inactive
according to stress-strain relationships
(5) Earthquakes: fault rupture and offset is most common cause of
earthquakes and seismic activity; related to brittle deformation and
"elastic rebound" of rock material immediately following rupture
(a) Slope failure: quake-related seismic activity (ground
shaking) may trigger slope failure and mass wasting activity
(slumping, earthflow, liquefaction)
(b) Tsunami: "seismic sea waves" formed from the passage of
seismic waves through ocean water
b. Fault Scarp Landforms
(1) Triangular Facets: headward erosion results in V-shaped valleys
cut through the fault scarp
(a) Rock remanents left between erosional valleys form
triangular-shaped faces (or "facets") of rock exposed along
the fault scarp
(b) Erosion over time will result in degrading the fault scarp and
facets (youth-mature-old age progression)
12
13. i) Renewed uplift/offset on fault will result in
rejuvenating the fault-scarp geomorphic topography
(2) Scarp-notches-"Wineglass" structure
(a) Streams transecting the displaced fault zone impacted by
relatively instant changes in local base level and
development of displacement-related knickpoints
i) Streams draining from upthrown block, down scarp,
erode "hanging valleys", create water falls, and erode
to form a Y-shaped cross-sectional profile
(3) Drainage Disruption
(a) Land displacement associated with faulting may cause local
damming of drainage systems, resulting in ponding and
establishment of local base level
(b) Fault-sag ponding: fault zones commonly form low-lying
zones via differential erosion, may form sites of elongated
ponds, and linear series of ponds along length of fault zone
(4) Spring Development
(a) Linear, aligned springs commonly form along fault zone
(b) Spring formation result of:
i) Creation of zone of high permeability fault breccia
through which groundwater may reach the surface
ii) Juxtaposition of high permeability and low
permeability rocks along fault zone, forcing
groundwater to surface as spring
(5) Surface Uplift/Marine Terracing
(a) Erosion Surfaces
i) Wave-cut terraces and stream terraces may become
displaced by fault offset
ii) Uplift of land surface results in elevating the erosional
surface above active level of erosion
4. Scarp Erosion: Fault-Line Scarp Geomorphology
a. Differential Erosion: fault-line scarps form from differential erosion of less
resistant rock along fault zone
b. Fault Scarp Degradation with Time
(1) Free Faces: steep initially formed fault scarps of 45-90 degrees
13
14. inclination
(2) Progressive erosional degradation via erosion-mass wasting
processes
(a) debris fall
(b) slope wash
(3) Time-dependent degradational process
(a) Scarp height diminishes with time
(b) Scarp slope lessens with time
(4) Can be quantitatively defined via detailed topographic profiling
across fault scarps
(a) Semi-log regression establishes time-decay relationships
i) function of initial scarp slope, time, vegetation,
climate, material
c. Stages of Fault-line Scarp Erosion
(1) Stage 1: Initial Offset- Height of fault scarp = height of fault-line
scarp, erosionally degradation of scarp little to non-existent
(2) Stage 2: Scarp-front retreat via headward erosion, retreat of fault-
line scarp away from fault and line of rupture (Fault scarp does not
equal fault-line scarp)
(3) Stage 3: Obsequent Fault-line Scarp: uplifted block eroded below
grade of downthrown block, fault-line scarp dips in direction
opposite that of original fault plane
(4) Stage 4: total degradation and erosional flattening of scarp, no to
little relief along fault zone
(5) Stage 5: Resequent Fault-line Scarp: rejuvenated uplift along fault,
fault-scarp rejuvenated, however rocks offset along fault are from
lower stratigraphic position
5. Block Fault Topography: essentially fault-bounded mountains and lowlands of
the Basin and Range Province
a. Fault-Block Mountains: fault bounded uplift along mountain fronts,
alternating with fault-bounded down-dropping of structural basins
(1) Up to thousands of feet of fault displacement
(a) e.g. Teton Range, WY; Sierra Nevada, Calif., Sandia
Mountains of NM.
(2) Fault Segmentation: Segmented Mountain Fronts
(a) Uplift along fault-bounded mountain front not an exact or
constant process, scarp-front evolution proceeds as
14
15. differential tectonic deformation as stresses are distributed
sporadically along mountain front according to stress-strain
conditions
b. Horst and Grabens
(1) Horsts: Uplifted fault blocks
(2) Grabens: Down-dropped fault blocks
(a) Half-grabens: asymmetric faulting on one side of graben
(b) Tilted Fault-block Mountains: asymmetric faulting on one
side of mountain block
c. Strike-slip Faults: primary sense of displacement is horizontal, along
strike of fault plane (e.g. San Andreas Transform Zone)
(1) Recognition
(a) Offset Streams
(b) Sag Ponds
(c) Mismatched topography/bedrock with intervening lineament
(2) Transpression and Transtension
(a) Oblique strike slip motion with components of tension and
compression accompanying strike slip motion
i) Transpressional mountains: uplifted blocks and
slivers within strike-slip fault zone (e.g. Transverse
Ranges of Southern Calif.)
ii) Transtensional Basins: down-dropped blocks and
slivers within strike-slip fault zone (e.g. San Gabriel
Basin of Southern Calif... associated with oil and gas
entrapment)
d. Thrust Faults: low-angle reverse faults, < 30 degrees dip
(1) Commonly occurring as low-angle thrust sheets, faults may be flat
to undulating to gently dipping
(a) Displacements along thrust sheets may be up to 10's to 100'
of miles
i) Result of highly detached, low friction fault zone
ii) Extreme compressive tectonic force
iii) Divided into:
a) Upper Thrust Sheet: above fault
b) Lower Thrust Sheet: below fault (floor)
15
16. (b) May be accompanied by secondary drag folding and
general fold deformation
(c) e.g. Northern Rocky thrust sheets of Montana
(2) Klippes: erosional remnants of Upper Thrust Sheet, stranded and
surrounded by rocks of lower thrust sheet
(a) base of klippe marks location of thrust fault
(b) e.g. Chief Mountain, Montana
(3) Fensters: erosional windows cut through Upper Thrust Sheet,
showing rocks of lower thrust sheet surrounded by rocks of upper
thrust sheet.
16