The document discusses biostratigraphic classification and units. It defines biostratigraphy as correlating and assigning relative ages of rock strata based on fossil assemblages. The purpose is to systematically organize rock strata into named units based on fossil content and distribution. Biostratigraphic units are distinguished by differences in fossil content. Common types of biostratigraphic units include range zones defined by the range of a taxon, assemblage zones based on an assemblage of fossil taxa, and lineage zones representing a segment of an evolutionary lineage.
Precambrian cambrian boundary with reference to indiaPramoda Raj
This document summarizes a seminar on the Precambrian period covering its evolution on Earth, important fossils and terrains in India, paleogeography and the breakup of a late Proterozoic supercontinent, stratigraphy of basins in India, and the Precambrian-Cambrian boundary. Key points include: Earth's atmosphere formed via outgassing; stromatolites and microplankton are common Precambrian fossils; a late Proterozoic supercontinent broke up during the period; and the Precambrian-Cambrian boundary marks major biotic changes in Earth's history.
Ostracods are bivalved crustaceans that are commonly used in micropaleontology and paleoecology research. They have a complex morphology and are found in both marine and freshwater environments around the world. Key aspects of ostracod anatomy include their carapace, hinge patterns, and ornamentation, which are important for classifying and interpreting species. Ostracods first appeared in the late Cambrian and have adapted to occupy nearly all aquatic habitats, with over 2000 known living species today. Their fossil record allows them to be used for biostratigraphy and paleoenvironmental reconstruction.
The document provides an overview of foraminifera including:
- Their morphology, wall structure, and chamber development which can be unilocular or multilocular in various arrangements.
- Their importance for biostratigraphy, paleoecology, and paleoceanography making them useful tools for dating rocks and reconstructing past environments.
- Their global geological distribution through time from Cambrian to Recent, reaching their maximum diversity in the Tertiary and present.
This document discusses seismic stratigraphy, which uses seismic data to extract stratigraphic information about subsurface rock layers. It defines seismic waves and methods, including refraction and reflection. Reflection seismic is more commonly used to identify structures like folds and faults beneath the surface. Key parameters for interpretation are reflection configuration, continuity, amplitude, frequency, and interval velocity. Depositional environments are also identified based on their relationship to the wave base.
Chronostratigraphic units Geology By Misson Choudhury Misson Choudhury
This document defines and describes various chronostratigraphic units used to organize rock layers based on their age. It discusses the hierarchy of units from smallest to largest: chronozone, stage, series, system, erathem, eonothem. Chronozones correspond to short intervals within named rock units. Stages are the basic working units, ranging from 3-10 million years. Larger units like series and systems contain multiple stages and span longer periods of geologic time. The largest units, erathems and eonothems, encompass multiple systems and span eras and eons, respectively.
Boundary problems between :-
Precambrian/Cambrian
Permian/Triassic
Cretaceous/Tertiary
Neogene/Quaternary
Stratigraphic boundaries are determined by one or more of geological events such as volcanic activity, sedimentation, tectonism, paleo-environments & evolution of life.
Faunal records have played major role in determining the boundaries of the Phanerozoic units.
The other geological events are dated on the evidence of fossil records.
Ichnology,classification & significance of trace fossilUjjavalPatel16
Ichnology,classification& significance of trace fossil
Most trace fossils are largely facies dependant.
No secondary displacement or transport.
Trace fossils are common in rocks that otherwise are unfossiliferous. (siliciclastics, shorelines)
Non-preservation of the causative organism.
Multiple architects may produce a single structure.
The same individual can produce different structures corresponding to different behavior.
The same individual may produce different structures corresponding with identical behavior but in different substrates.
Identical structures may be produced by the activity of systematically different organisms where behavior is similar.
Abundance - one animal, especially if mobile, can make many traces during its lifetime, whereas it may or may not have its body preserved in the fossil record.
Microfossils are very small remains of organisms 0.001 mm (1 micron) to 1 mm, that require magnification for study.
They are abundant, can be recovered from small samples.
Provide the main evidence for organic evolution through the time
They classified into two groups:
Organic-walled; Acritarchs, Dinoflagellate, Spores and Pollen grains … etc.
Foraminifera Each chamber interconnected by an opening (foramen) or several openings (foramina).
Known from Early Cambrian through to recent times, and has reached its acme during the Cenozoic.
Have a wide environmental range from terrestrial to deep sea and from polar to the tropical region.
Depending on the species, the shell may be made of organic compounds, sand grains and other particles cemented together, or from crystalline calcite.
Inorganic walled; Diatoms, Silicoflagellates, Ostracods, Conodonts, and Foraminifera
Precambrian cambrian boundary with reference to indiaPramoda Raj
This document summarizes a seminar on the Precambrian period covering its evolution on Earth, important fossils and terrains in India, paleogeography and the breakup of a late Proterozoic supercontinent, stratigraphy of basins in India, and the Precambrian-Cambrian boundary. Key points include: Earth's atmosphere formed via outgassing; stromatolites and microplankton are common Precambrian fossils; a late Proterozoic supercontinent broke up during the period; and the Precambrian-Cambrian boundary marks major biotic changes in Earth's history.
Ostracods are bivalved crustaceans that are commonly used in micropaleontology and paleoecology research. They have a complex morphology and are found in both marine and freshwater environments around the world. Key aspects of ostracod anatomy include their carapace, hinge patterns, and ornamentation, which are important for classifying and interpreting species. Ostracods first appeared in the late Cambrian and have adapted to occupy nearly all aquatic habitats, with over 2000 known living species today. Their fossil record allows them to be used for biostratigraphy and paleoenvironmental reconstruction.
The document provides an overview of foraminifera including:
- Their morphology, wall structure, and chamber development which can be unilocular or multilocular in various arrangements.
- Their importance for biostratigraphy, paleoecology, and paleoceanography making them useful tools for dating rocks and reconstructing past environments.
- Their global geological distribution through time from Cambrian to Recent, reaching their maximum diversity in the Tertiary and present.
This document discusses seismic stratigraphy, which uses seismic data to extract stratigraphic information about subsurface rock layers. It defines seismic waves and methods, including refraction and reflection. Reflection seismic is more commonly used to identify structures like folds and faults beneath the surface. Key parameters for interpretation are reflection configuration, continuity, amplitude, frequency, and interval velocity. Depositional environments are also identified based on their relationship to the wave base.
Chronostratigraphic units Geology By Misson Choudhury Misson Choudhury
This document defines and describes various chronostratigraphic units used to organize rock layers based on their age. It discusses the hierarchy of units from smallest to largest: chronozone, stage, series, system, erathem, eonothem. Chronozones correspond to short intervals within named rock units. Stages are the basic working units, ranging from 3-10 million years. Larger units like series and systems contain multiple stages and span longer periods of geologic time. The largest units, erathems and eonothems, encompass multiple systems and span eras and eons, respectively.
Boundary problems between :-
Precambrian/Cambrian
Permian/Triassic
Cretaceous/Tertiary
Neogene/Quaternary
Stratigraphic boundaries are determined by one or more of geological events such as volcanic activity, sedimentation, tectonism, paleo-environments & evolution of life.
Faunal records have played major role in determining the boundaries of the Phanerozoic units.
The other geological events are dated on the evidence of fossil records.
Ichnology,classification & significance of trace fossilUjjavalPatel16
Ichnology,classification& significance of trace fossil
Most trace fossils are largely facies dependant.
No secondary displacement or transport.
Trace fossils are common in rocks that otherwise are unfossiliferous. (siliciclastics, shorelines)
Non-preservation of the causative organism.
Multiple architects may produce a single structure.
The same individual can produce different structures corresponding to different behavior.
The same individual may produce different structures corresponding with identical behavior but in different substrates.
Identical structures may be produced by the activity of systematically different organisms where behavior is similar.
Abundance - one animal, especially if mobile, can make many traces during its lifetime, whereas it may or may not have its body preserved in the fossil record.
Microfossils are very small remains of organisms 0.001 mm (1 micron) to 1 mm, that require magnification for study.
They are abundant, can be recovered from small samples.
Provide the main evidence for organic evolution through the time
They classified into two groups:
Organic-walled; Acritarchs, Dinoflagellate, Spores and Pollen grains … etc.
Foraminifera Each chamber interconnected by an opening (foramen) or several openings (foramina).
Known from Early Cambrian through to recent times, and has reached its acme during the Cenozoic.
Have a wide environmental range from terrestrial to deep sea and from polar to the tropical region.
Depending on the species, the shell may be made of organic compounds, sand grains and other particles cemented together, or from crystalline calcite.
Inorganic walled; Diatoms, Silicoflagellates, Ostracods, Conodonts, and Foraminifera
The document summarizes the geology of the Vindhyan Basin located in central India. It describes the basin's stratigraphy, consisting of the lower and upper Vindhyan groups composed of sandstone, shale, and carbonate deposits. Key economic minerals found in the basin include diamonds, pyrite, coal, and limestone. The Vindhyan Supergroup represents one of India's most important Precambrian sedimentary basins.
The document summarizes the Jurassic stratigraphy of the Kutch region in India. It describes the key geological formations that date from the Middle Jurassic to Lower Cretaceous periods, including the Pachcham Formation consisting of limestones and corals, the Chari Formation containing sandy limestones and marls, the Katrol Formation made up of shales, limestones and sandstones, and the Umia Formation comprising sandstone, shale and conglomerate. It provides context that these sedimentary rocks formed during a phase of marine transgression in the western part of India during the Jurassic Period.
Biostratigraphy is the branch of stratigraphy that deals with the distribution of fossils in rock layers and uses fossils to divide rock formations into biostratigraphic units. The key types of biostratigraphic units are biozones, which are defined by characteristic fossil assemblages. Common biozones include range biozones defined by the first and last appearances of an index fossil, and interval biozones defined between two significant fossil horizons. Together, biozones allow rock formations to be correlated between areas and their relative ages to be determined based on principles of evolution and succession of fossil taxa.
The document discusses sedimentary facies and their relationship to sea level changes. It defines sedimentary facies as aspects of rock units defined by their composition, texture, and fossil content that indicate the environment of deposition. There are two main types of facies - lithofacies defined by composition and texture, and biofacies defined by fossil content. Sedimentary facies change laterally and vertically according to sea level changes - during transgression facies shift onshore and during regression facies shift offshore. Vertical sequences of facies represent once laterally continuous environments (Walther's Law). Major causes of sea level change include continental glaciation, plate tectonics, and local geological changes.
Sequence stratigraphy and its applicationsPramoda Raj
Sequence stratigraphy is the study of rock strata in terms of depositional sequences that are genetically related and bounded by unconformities or correlative conformities. It was pioneered by James Hutton in 1788 and further developed by researchers like Sloss and Vail to understand global eustatic sea level changes and their control on sediment deposition. Key concepts include systems tracts like transgressive, highstand, and parasequences which are building blocks of sequences. Sequence stratigraphy is useful for basin analysis, hydrocarbon exploration, and understanding past sea level fluctuations. Case studies have applied it to outcrops and subsurface sediments.
The Stratigraphic Code establishes rules for naming and defining stratigraphic units. There are two versions of the code from the North American and International commissions. Stratigraphic units are categorized based on physical characteristics and time, and include lithostratigraphic, biostratigraphic, magnetostratigraphic, and others. Proper naming of a new unit requires publication and establishing type sections and boundaries.
Stratigraphy establishes relationships between rock layers by classifying them into mappable units called formations, which can be subdivided into members and grouped into units called groups. Correlating rocks means establishing their equivalency using physical stratigraphy techniques like lithostratigraphy (comparing rock types), magnetostratigraphy (comparing magnetic polarity sequences), and sequence stratigraphy (using sea level curves), or biostratigraphy techniques like comparing fossil zones, evolutionary lineages, and index fossils to determine the relative or absolute ages of rock layers.
Applications of micro-fossil in bio statigraphy Pramoda Raj
This document provides an overview of biostratigraphy and microfossils. It defines biostratigraphy as using fossils to determine the relative age of rock strata. Microfossils, which are fossils less than 0.5mm in size, are commonly used for biostratigraphy. Various types of microfossils like foraminifera, radiolaria, and diatoms are described. Biostratigraphic units defined by fossil occurrences like zones, assemblage zones, and interval zones are also outlined. The document discusses uses of biostratigraphy in fields like stratigraphy, correlation, and sequence stratigraphy. Microfossils are concluded to be very useful for reconstructing past environments from deep sea sediments and in the
The document summarizes the Cudappah Supergroup, an important Proterozoic sedimentary basin in India. It describes the basin's lithostratigraphy, which includes groups like the Papaghni, Chitravati, Nallamalai, and Srisailam quartzites. The basin provides economic resources like barytes, chrysotile, asbestos, steatite, diamonds, uranium, and building/ornamental stones. Radiometric dating indicates the basin formed between 1500-1800 million years ago. The Cudappah Supergroup is a significant paleo-Mesoproterozoic basin that records much of India's early geological history.
This document discusses the Precambrian geology of the Southern Granulite Terrain of India. It describes the terrain as being composed of several blocks separated by shear zones, which experienced high-grade metamorphism and multiple periods of folding and faulting. The metamorphic history involved ultra-high temperature conditions in some areas, as evidenced by mineral assemblages. The document also outlines two competing tectonic models to explain the evolution of the related Pandyan Mobile Belt: a subduction-collision model and an accretion model.
The document summarizes the Mesozoic Era stratigraphy in three periods: Triassic, Jurassic, and Cretaceous. It describes the lithology and fossil content of formations from these periods found in various regions of India, including the Himalayas, Kashmir, Spiti, and the Indian peninsula. Key points include the marine deposits of the Triassic in Spiti and Kashmir characterized by limestones and shales, and the Jurassic rock units of Spiti, Kashmir, and Kutch divided into named members.
Contact metasomatism forms new minerals through reactions between intrusive rocks and escaping gases from magma chambers. Important requirements include a magma source of ore ingredients and intrusion into reactive host rocks. Metals like Fe, Cu, Zn, and W can be deposited through this process. Hydrothermal deposits are formed when hot, mineral-laden waters circulate through fractures, leaching and redepositing metals. Sedimentary deposits can form through evaporation, biochemical processes, or mechanical concentration of minerals in placer deposits.
Stratigraphy is the chronological study of sedimentary rocks to understand the history of the Earth. It involves correlating and arranging rock formations based on principles like lithology, order of superposition, and fossil content. The geological time scale divides Earth's history into Eras, Periods, and Epochs as a framework for studying and comparing rock sequences globally. Today we are in the Holocene Epoch of the Quaternary Period within the Cenozoic Era.
The document provides an overview of the Paleozoic era, which began approximately 542 million years ago and lasted around 290 million years. Some key points:
- Suitable time for organic evolution of both flora and fauna. Rocks from this era are less deformed, providing good sections for research.
- In India, Paleozoic rocks are mainly found in the Himalayan region and isolated basins in the peninsula. Stratigraphy has been determined along river sections in the Himalayas.
- Life included early plants, foraminifera, corals, brachiopods, pelecypods, gastropods, cephalopods, ostracods
The document discusses the Precambrian-Cambrian boundary, which saw major biotic changes like the emergence and extinction of soft-bodied Ediacaran fauna and the emergence of organisms with hard parts. Trace fossils from this period provide important stratigraphic information. In India, sections in Kashmir and Spiti Valley contain microbiota and trace fossils that help delineate the boundary. The Precambrian-Cambrian transition witnessed an evolutionary explosion of life and the emergence of many new animal phyla. Detailed study of sections in the Himalayas continues to provide insights into this important period in Earth's history.
This document discusses different types of metasomatism classified based on metasomatic processes and geological position. There are two main types of metasomatic processes - diffusional metasomatism which occurs through diffusion, and infiltrational metasomatism which occurs through the transfer of materials in solution. The geological positions discussed include autometasomatism near magmatic bodies, contact metasomatism at contacts between bodies, and regional metasomatism over large areas. Specific metasomatic rock types are also summarized like fenite, greisens, and skarns, which are important in studying ore deposits.
The Siwalik Group originated from sediments deposited in the Tethys Sea during the middle Miocene to lower Pleistocene periods. It is distributed across the outer foothills of the Himalayas from Pakistan to Arunachal Pradesh, India. The stratigraphy includes lower, middle, and upper Siwalik subgroups composed of sandstone, shale and conglomerate deposited in fluvial and lacustrine environments. Fossils found in the Siwalik Group provide important evidence for the evolution of mammals in South Asia.
This document discusses the Dharwar Super Group found in the Dharwar Craton of India. The Dharwar Craton is divided into the Western and Eastern Dharwar cratons, separated by the Chitradurga shear zone. The Western Dharwar craton contains two prominent super belts: the Bababudan-Western Ghats-Shimoga super belt and the Chitradurga-Gadag super belt, which are part of the Dharwar super group. The Eastern Dharwar craton also contains formations from the Dharwar super group, divided into the Kolar and Yashwantanagar formations. The document concludes that the Dharwar super
There are two main forms of igneous rocks:
1) Extrusive rocks form from lava erupted at the Earth's surface and cool rapidly. They include lava flows, pyroclastic deposits like volcanic ash and tuff.
2) Intrusive rocks form from magma that cools below the surface. They can be concordant, forming sheets and domes parallel to layers, like sills and laccoliths, or discordant and cutting across layers, like dikes, batholiths, and volcanic necks.
SIGNIFICANCE OF CONODONTS IN MICROFOSSIL HISTORY Pramoda Raj
Conodonts are an extinct group of microscopic fossils that are significant in microfossil history. They are composed of calcium phosphate and resemble eel-like creatures. Conodonts first appeared in the Late Cambrian period and became extinct in the Late Triassic. They are useful for correlating strata and determining environmental factors like climate and water depth due to their abundance and wide geographic range during the Paleozoic era. Their tooth-like elements are prepared and studied using acid treatment and microscopy. Conodonts have been important for biostratigraphy and tracing evolutionary relationships.
Biostratigraphic units Geology By Misson Choudhury Misson Choudhury
The document defines and describes different types of biostratigraphic units used for organizing rock strata based on their fossil content. The main types discussed are assemblage-zones, range-zones, acme-zones, and interval-zones. Assemblage-zones group strata based on the fossil assemblages present. Range-zones represent the stratigraphic range of a taxon or group of taxa. Acme-zones denote intervals of maximum abundance of a taxon. Interval-zones are the strata between two distinctive biostratigraphic horizons. Together these biostratigraphic units allow for the systematic classification and correlation of rock sequences based on paleontological features.
This document provides an overview of biostratigraphy, which uses fossil assemblages to correlate and date rock layers. It discusses key concepts like the principle of faunal succession, stages, zones, and ranks of biostratigraphic units. Barriers to organism dispersal are also covered, as well as preservation potential and common marine macrofossils used in biostratigraphy. The overall goal of biostratigraphy is differentiation, correlation and interpretation of Earth's history through analysis of fossil records.
The document summarizes the geology of the Vindhyan Basin located in central India. It describes the basin's stratigraphy, consisting of the lower and upper Vindhyan groups composed of sandstone, shale, and carbonate deposits. Key economic minerals found in the basin include diamonds, pyrite, coal, and limestone. The Vindhyan Supergroup represents one of India's most important Precambrian sedimentary basins.
The document summarizes the Jurassic stratigraphy of the Kutch region in India. It describes the key geological formations that date from the Middle Jurassic to Lower Cretaceous periods, including the Pachcham Formation consisting of limestones and corals, the Chari Formation containing sandy limestones and marls, the Katrol Formation made up of shales, limestones and sandstones, and the Umia Formation comprising sandstone, shale and conglomerate. It provides context that these sedimentary rocks formed during a phase of marine transgression in the western part of India during the Jurassic Period.
Biostratigraphy is the branch of stratigraphy that deals with the distribution of fossils in rock layers and uses fossils to divide rock formations into biostratigraphic units. The key types of biostratigraphic units are biozones, which are defined by characteristic fossil assemblages. Common biozones include range biozones defined by the first and last appearances of an index fossil, and interval biozones defined between two significant fossil horizons. Together, biozones allow rock formations to be correlated between areas and their relative ages to be determined based on principles of evolution and succession of fossil taxa.
The document discusses sedimentary facies and their relationship to sea level changes. It defines sedimentary facies as aspects of rock units defined by their composition, texture, and fossil content that indicate the environment of deposition. There are two main types of facies - lithofacies defined by composition and texture, and biofacies defined by fossil content. Sedimentary facies change laterally and vertically according to sea level changes - during transgression facies shift onshore and during regression facies shift offshore. Vertical sequences of facies represent once laterally continuous environments (Walther's Law). Major causes of sea level change include continental glaciation, plate tectonics, and local geological changes.
Sequence stratigraphy and its applicationsPramoda Raj
Sequence stratigraphy is the study of rock strata in terms of depositional sequences that are genetically related and bounded by unconformities or correlative conformities. It was pioneered by James Hutton in 1788 and further developed by researchers like Sloss and Vail to understand global eustatic sea level changes and their control on sediment deposition. Key concepts include systems tracts like transgressive, highstand, and parasequences which are building blocks of sequences. Sequence stratigraphy is useful for basin analysis, hydrocarbon exploration, and understanding past sea level fluctuations. Case studies have applied it to outcrops and subsurface sediments.
The Stratigraphic Code establishes rules for naming and defining stratigraphic units. There are two versions of the code from the North American and International commissions. Stratigraphic units are categorized based on physical characteristics and time, and include lithostratigraphic, biostratigraphic, magnetostratigraphic, and others. Proper naming of a new unit requires publication and establishing type sections and boundaries.
Stratigraphy establishes relationships between rock layers by classifying them into mappable units called formations, which can be subdivided into members and grouped into units called groups. Correlating rocks means establishing their equivalency using physical stratigraphy techniques like lithostratigraphy (comparing rock types), magnetostratigraphy (comparing magnetic polarity sequences), and sequence stratigraphy (using sea level curves), or biostratigraphy techniques like comparing fossil zones, evolutionary lineages, and index fossils to determine the relative or absolute ages of rock layers.
Applications of micro-fossil in bio statigraphy Pramoda Raj
This document provides an overview of biostratigraphy and microfossils. It defines biostratigraphy as using fossils to determine the relative age of rock strata. Microfossils, which are fossils less than 0.5mm in size, are commonly used for biostratigraphy. Various types of microfossils like foraminifera, radiolaria, and diatoms are described. Biostratigraphic units defined by fossil occurrences like zones, assemblage zones, and interval zones are also outlined. The document discusses uses of biostratigraphy in fields like stratigraphy, correlation, and sequence stratigraphy. Microfossils are concluded to be very useful for reconstructing past environments from deep sea sediments and in the
The document summarizes the Cudappah Supergroup, an important Proterozoic sedimentary basin in India. It describes the basin's lithostratigraphy, which includes groups like the Papaghni, Chitravati, Nallamalai, and Srisailam quartzites. The basin provides economic resources like barytes, chrysotile, asbestos, steatite, diamonds, uranium, and building/ornamental stones. Radiometric dating indicates the basin formed between 1500-1800 million years ago. The Cudappah Supergroup is a significant paleo-Mesoproterozoic basin that records much of India's early geological history.
This document discusses the Precambrian geology of the Southern Granulite Terrain of India. It describes the terrain as being composed of several blocks separated by shear zones, which experienced high-grade metamorphism and multiple periods of folding and faulting. The metamorphic history involved ultra-high temperature conditions in some areas, as evidenced by mineral assemblages. The document also outlines two competing tectonic models to explain the evolution of the related Pandyan Mobile Belt: a subduction-collision model and an accretion model.
The document summarizes the Mesozoic Era stratigraphy in three periods: Triassic, Jurassic, and Cretaceous. It describes the lithology and fossil content of formations from these periods found in various regions of India, including the Himalayas, Kashmir, Spiti, and the Indian peninsula. Key points include the marine deposits of the Triassic in Spiti and Kashmir characterized by limestones and shales, and the Jurassic rock units of Spiti, Kashmir, and Kutch divided into named members.
Contact metasomatism forms new minerals through reactions between intrusive rocks and escaping gases from magma chambers. Important requirements include a magma source of ore ingredients and intrusion into reactive host rocks. Metals like Fe, Cu, Zn, and W can be deposited through this process. Hydrothermal deposits are formed when hot, mineral-laden waters circulate through fractures, leaching and redepositing metals. Sedimentary deposits can form through evaporation, biochemical processes, or mechanical concentration of minerals in placer deposits.
Stratigraphy is the chronological study of sedimentary rocks to understand the history of the Earth. It involves correlating and arranging rock formations based on principles like lithology, order of superposition, and fossil content. The geological time scale divides Earth's history into Eras, Periods, and Epochs as a framework for studying and comparing rock sequences globally. Today we are in the Holocene Epoch of the Quaternary Period within the Cenozoic Era.
The document provides an overview of the Paleozoic era, which began approximately 542 million years ago and lasted around 290 million years. Some key points:
- Suitable time for organic evolution of both flora and fauna. Rocks from this era are less deformed, providing good sections for research.
- In India, Paleozoic rocks are mainly found in the Himalayan region and isolated basins in the peninsula. Stratigraphy has been determined along river sections in the Himalayas.
- Life included early plants, foraminifera, corals, brachiopods, pelecypods, gastropods, cephalopods, ostracods
The document discusses the Precambrian-Cambrian boundary, which saw major biotic changes like the emergence and extinction of soft-bodied Ediacaran fauna and the emergence of organisms with hard parts. Trace fossils from this period provide important stratigraphic information. In India, sections in Kashmir and Spiti Valley contain microbiota and trace fossils that help delineate the boundary. The Precambrian-Cambrian transition witnessed an evolutionary explosion of life and the emergence of many new animal phyla. Detailed study of sections in the Himalayas continues to provide insights into this important period in Earth's history.
This document discusses different types of metasomatism classified based on metasomatic processes and geological position. There are two main types of metasomatic processes - diffusional metasomatism which occurs through diffusion, and infiltrational metasomatism which occurs through the transfer of materials in solution. The geological positions discussed include autometasomatism near magmatic bodies, contact metasomatism at contacts between bodies, and regional metasomatism over large areas. Specific metasomatic rock types are also summarized like fenite, greisens, and skarns, which are important in studying ore deposits.
The Siwalik Group originated from sediments deposited in the Tethys Sea during the middle Miocene to lower Pleistocene periods. It is distributed across the outer foothills of the Himalayas from Pakistan to Arunachal Pradesh, India. The stratigraphy includes lower, middle, and upper Siwalik subgroups composed of sandstone, shale and conglomerate deposited in fluvial and lacustrine environments. Fossils found in the Siwalik Group provide important evidence for the evolution of mammals in South Asia.
This document discusses the Dharwar Super Group found in the Dharwar Craton of India. The Dharwar Craton is divided into the Western and Eastern Dharwar cratons, separated by the Chitradurga shear zone. The Western Dharwar craton contains two prominent super belts: the Bababudan-Western Ghats-Shimoga super belt and the Chitradurga-Gadag super belt, which are part of the Dharwar super group. The Eastern Dharwar craton also contains formations from the Dharwar super group, divided into the Kolar and Yashwantanagar formations. The document concludes that the Dharwar super
There are two main forms of igneous rocks:
1) Extrusive rocks form from lava erupted at the Earth's surface and cool rapidly. They include lava flows, pyroclastic deposits like volcanic ash and tuff.
2) Intrusive rocks form from magma that cools below the surface. They can be concordant, forming sheets and domes parallel to layers, like sills and laccoliths, or discordant and cutting across layers, like dikes, batholiths, and volcanic necks.
SIGNIFICANCE OF CONODONTS IN MICROFOSSIL HISTORY Pramoda Raj
Conodonts are an extinct group of microscopic fossils that are significant in microfossil history. They are composed of calcium phosphate and resemble eel-like creatures. Conodonts first appeared in the Late Cambrian period and became extinct in the Late Triassic. They are useful for correlating strata and determining environmental factors like climate and water depth due to their abundance and wide geographic range during the Paleozoic era. Their tooth-like elements are prepared and studied using acid treatment and microscopy. Conodonts have been important for biostratigraphy and tracing evolutionary relationships.
Biostratigraphic units Geology By Misson Choudhury Misson Choudhury
The document defines and describes different types of biostratigraphic units used for organizing rock strata based on their fossil content. The main types discussed are assemblage-zones, range-zones, acme-zones, and interval-zones. Assemblage-zones group strata based on the fossil assemblages present. Range-zones represent the stratigraphic range of a taxon or group of taxa. Acme-zones denote intervals of maximum abundance of a taxon. Interval-zones are the strata between two distinctive biostratigraphic horizons. Together these biostratigraphic units allow for the systematic classification and correlation of rock sequences based on paleontological features.
This document provides an overview of biostratigraphy, which uses fossil assemblages to correlate and date rock layers. It discusses key concepts like the principle of faunal succession, stages, zones, and ranks of biostratigraphic units. Barriers to organism dispersal are also covered, as well as preservation potential and common marine macrofossils used in biostratigraphy. The overall goal of biostratigraphy is differentiation, correlation and interpretation of Earth's history through analysis of fossil records.
Introduction of foraminifera in oil explorationPurvaPandey3
This document discusses the application of foraminifera in oil exploration. It begins with an introduction to foraminifera and their importance in oil exploration due to their sensitivity to environmental changes. It then covers the conditions required for oil formation, concepts in using foraminifera for oil exploration like biostratigraphy and paleoenvironment interpretation, and micropaleontological techniques. Foraminifera are useful for biostratigraphic correlation, interpreting depositional environments, and reconstructing the geologic history of sedimentary basins to aid in oil exploration.
This document discusses the principles of stratigraphy used to determine the relative ages of rock layers and geological structures. It describes key stratigraphic principles like superposition, lateral continuity, inclusion and cross-cutting relationships. It also discusses methods of correlation like lithostratigraphy, chronostratigraphy and biostratigraphy which use rock characteristics, magnetic polarity or fossil evidence respectively to correlate rock formations across different locations. In conclusion, it states that stratigraphic principles are important geological tools to analyze rock sequences, estimate the order of geological events and understand field relationships.
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The document discusses dams, including their history, types, parts, failures, and site selection criteria. Dams are constructed across rivers and streams to store water for uses like electricity, irrigation, flood control, and fisheries. The earliest known dams date to 3000 BC in Jordan and the 2nd century in India. Dams are typically classified as concrete (e.g. gravity, buttress, arch), earth/embankment (e.g. earthfill, rockfill), or composite. Critical factors in dam site selection include stable geologic conditions, adequate water flow, and minimizing human displacement. Geological investigations evaluate factors like rock strength, drainage, seismic activity, and environmental hazards. Dams provide important benefits but must
The document summarizes the exam pattern and syllabus for the UPSC Geologist exam, which consists of two parts. Part 1 is a written exam worth 700 marks covering subjects like geology, hydrology, and English. It involves 3 papers of 200 marks each. Part 2 is an interview worth 200 marks for shortlisted candidates. The syllabus for the written exam includes subjects like geomorphology, structural geology, geotectonics, stratigraphy, and paleontology. Candidates are advised to thoroughly prepare the exam pattern and syllabus in order to improve their chances of success.
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Disaster Management System in India - Notes Pramoda Raj
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2) Disaster management involves preparing for, responding to, and recovering from disasters to minimize impacts. It aims to make India resilient to disasters and reduce losses of life and assets.
3) International organizations like the UN Office for Disaster Risk Reduction coordinate global efforts in disaster risk reduction, with the Sendai Framework as the guiding document following the Hyogo Framework.
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Multiple hazard mapping (MHM) combines information about different natural hazards affecting an area into a single map. This provides a comprehensive picture of hazards for planning purposes. It is more concise than individual hazard maps and allows common risk reduction strategies to be identified. Developing an MHM involves translating hazard data on location, likelihood, and severity into a consistent format. Information is compiled from various sources and overlaid on a base map at an appropriate scale. Symbols are used to represent different hazards. An MHM can improve risk assessment and guide more rational land use and development decisions.
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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.
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Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
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Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
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This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
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বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
2. CONTENTSCONTENTS
INTRODUCTIONINTRODUCTION
PURPOSE OF BIOSTRATIGRAPHIC CLASSIFICATIONPURPOSE OF BIOSTRATIGRAPHIC CLASSIFICATION
DISTINCTIVE NATURE OF UNITSDISTINCTIVE NATURE OF UNITS
SIGNIFICANCE OF FOSSILSSIGNIFICANCE OF FOSSILS
KINDS OF BIOSTRATIGRAPHIC UNITSKINDS OF BIOSTRATIGRAPHIC UNITS
PROCEDURES FOR EXTENDING BIOSTRATIGRAPHIC UNITS -PROCEDURES FOR EXTENDING BIOSTRATIGRAPHIC UNITS -
BIOSTRATIGRAPHIC CORRELATIONBIOSTRATIGRAPHIC CORRELATION
CONCLUSIONCONCLUSION
REFERENCEREFERENCE
Dated,11/27/2010 2
3. INTRODUCTIONINTRODUCTION
• Stratigraphy is also known as the historical geology and is a
systematic study of the rocks of the earth’s crust aimed at
answering vital question like-
When they are formed
What happen to them subsequent to their formation and
What is the eventual relationship of rocks formed at
various places and times since the beginning of the
geological history of the earth.
• The history of the earth is mostly written in the sedimentary
rocks, hence sedimentary rocks are described as ‘pages of
the earth history’.
• There are different branches of stratigraphy, Among them;
“BIOSTRATIGRAPHY is the branch of stratigraphy which
focuses on correlating and assigning relative ages of rock
strata by using the fossil assemblages contained within
them”.
Dated,11/27/2010
3
4. The purpose of Biostratigraphic classification is to organise rock strata
systematically into named units based on content and distribution of fossils.
NATURE OF BIOSTRATIGRAPHIC UNITS
Bases for units
Rock strata are classified Biostratigraphically by dividing them into units
distinguished by differences in their fossil content. A Biostratigraphic Unit may be
based simply-
•On the presence of fossils as contrasted with their absenceOn the presence of fossils as contrasted with their absence
•On all kinds of fossils taken together or only on fossil of a certain kindOn all kinds of fossils taken together or only on fossil of a certain kind
•On the complete assemblage of fossils characterising a certain stratigraphicOn the complete assemblage of fossils characterising a certain stratigraphic
intervals or only on selected taxons.intervals or only on selected taxons.
•On a particular natural association of fossils.On a particular natural association of fossils.
•On the range of a fossil taxon or fossil taxons.On the range of a fossil taxon or fossil taxons.
•On frequency and abundance of fossil specimen.On frequency and abundance of fossil specimen.
•On certain morphological feature of fossils.On certain morphological feature of fossils.
•On stage of evolutionary development. orOn stage of evolutionary development. or
•On variation in any of the many other features related to the fossil content ofOn variation in any of the many other features related to the fossil content of
strata, etc.strata, etc.
PurPose of BiostratigraPhicPurPose of BiostratigraPhic
classificationclassification
Dated,11/27/2010 4
5. Biostratigraphic UnitsBiostratigraphic Units are distinct from many other kinds of
stratigraphic units in that they are based on distinct particles in the
rocks of almost infinite variety which are disseminated in widely
different degrees of density throughout much, but not all, of the
earths stratigraphic sequence. They are also distinctive in that, as
whole, they show significant evolutionary changes in character with
geologic time.
significance of fossilssignificance of fossils
•1. Value of fossils. Fossils were once living organisms and as such are
sensitive indicators of past environments, sedimentation patterns,
and their distributions.
•In addition, because of the irreversibility of evolution, fossils are
particularly useful in working out the relative times of origin of
sedimentary strata.
DISTINCTIVE NATURE OF UNITSDISTINCTIVE NATURE OF UNITS
Dated,11/27/2010 5
6. • 2. Fossil assemblages. Four kinds of intervals are found in sedimentary rocks:
strata without fossils; strata containing organisms that lived and were buried in the
area (biocoenosis); strata containing organisms that lived somewhere else and
were brought into the area after death (thanatocoenosis); and strata that contain
organisms transported alive away from their normal environment.
• These may be mixed or interbedded in any proportion. All categories of fossil-
bearing strata may be the basis for biostratigraphic zonation.
• Intervals lacking identifiable fossils or entirely without fossils are not subject to
biostratigraphic classification.
• 3. Reworked fossils. Fossils from rocks of one age that have been eroded,
transported, and redeposited in sediments of a younger age. Because of the
difference in their significance with respect to age and environment, they should
be treated apart from those believed to be indigenous.
• 4. Introduced or infiltrated fossils. Fossils introduced into older or younger rocks
by fluids, through animal burrows or root cavities, or by sedimentary dikes or
diapirs. They should be distinguished from indigenous fossils in biostratigraphic
zonation.
• 5. Effects of stratigraphic condensation. Extremely low rates of sedimentation
may result in fossils of different ages and different environments being mingled or
very intimately associated in a very thin stratigraphic interval, even in a single bed.
Dated,11/27/2010 6
7. DEFINITIONDEFINITION
SS
According to International Stratigraphic Guide, Biostratigraphy may be defined as “the element of
stratigraphy that deals with the remains or evidences of former life in strata and with the
organization of strata into units based on their fossil content”.
Biostratigraphic classification- The systematic subdivision and organization of the
stratigraphic section into named units based on their fossil content.
Biostratigraphic zone (Biozone)- A general term for any kind of biostratigraphic unit
regardless of thickness or geographic extent e.g. Globerigina brevis Zone. Biozones vary
greatly in thickness, geographic extent, and represented time span.
Biostratigraphic horizon (Biohorizon)- A stratigraphic boundary, surface, or interface
across which there is a significant change in biostratigraphic character.
•A biohorizon has no thickness and should not be used to describe very thin stratigraphic
units that are especially distinctive.
Subbiozone (Subzone)- A subdivision of a biozone.
Superbiozone (Superzone)- A grouping of two or more biozones with related
biostratigraphic attributes.
Zonule- The use of this term is discouraged.
•It has received different meanings and is now generally used as a subdivision of a biozone
or subbiozone.
Barren intervals- Stratigraphic intervals with no fossils common in the stratigraphic
section.
Dated,11/27/2010
7
9. Kinds of Biostratigraphic UnitsKinds of Biostratigraphic Units
Five kinds of Biozones are in common use : Range zones,
Interval zones, Assemblage zones, Abundance zones,
and Lineage zones.
1. Assemblage Zone:1. Assemblage Zone:
a. Definition. The body of strata characterized by an
assemblage of three or more fossil taxa that, taken
together, distinguishes it in Biostratigraphic character
from adjacent strata.
b. Boundaries. The boundaries of an assemblage zone
are drawn at Biohorizons marking the limits of
occurrence of the specified assemblage that is
characteristic of the unit. Not all members of the
assemblage need to occur in order for a section to be
assigned to an assemblage zone, and the total range of
any of its constituents may extend beyond the
boundaries of the zone.Dated,11/27/2010
9
11. 2. Range Zone: The body of strata representing the known
stratigraphic and geographic range of occurrence of a particular taxon or
combination of two taxa of any rank.
There are different types of range zones namely:-
Taxon-Range Zone:
• i). Definition. The body of strata representing the known range of
stratigraphic and geographic occurrence of specimens of a particular taxon.
It is the sum of the documented occurrences in all individual sections and
localities from which the particular taxon has been identified.
• ii). Boundaries. The boundaries of a taxon-range zone are Biohorizons
marking the outermost limits of known occurrence in every local section of
specimens whose range is to be represented by the zone. The boundaries of
a taxon-range zone in any one section are the horizons of lowest
stratigraphic occurrence and highest stratigraphic occurrence of the
specified taxon in that section.
• iii. Name. The taxon-range zone is named from the taxon whose range it
expresses.
• iv. Local Range of a Taxon. The local range of a taxon may be specified in
some local section, area, or region as long as the context is clear.
Dated,11/27/2010
11
13. Concurrent-Range Zone:
• i. Definition. The body of strata including the
overlapping parts of the range zones of two specified
taxa.
• This type of zone may include taxa additional to those
specified as characterizing elements of the zone, but
only the two specified taxa are used to define the
boundaries of the zone.
• ii. Boundaries. The boundaries of a concurrent-range
zone are defined in any particular stratigraphic section
by the lowest stratigraphic occurrence of the higher-
ranging of the two defining taxa and the highest
stratigraphic occurrence of the lower-ranging of the
two defining taxa.
• iii. Name. A concurrent-range zone is named from
both the taxa that define and characterize the Biozone
by their concurrence.
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15. Lineage Zone:
Lineage zones are discussed as a separate category because they require for
their definition and recognition not only the identification of specific taxa
but the assurance that the taxa chosen for their definition represent
successive segments of an evolutionary lineage.
• a. Definition. The body of strata containing specimens representing a
specific segment of an evolutionary lineage.
• It may represent the entire range of a taxon within a lineage or only that
part of the range of the taxon below the appearance of a descendant
taxon.
• The boundaries of lineage zones approach the boundaries of
Chronostratigraphic units.
• However, a lineage zone differs from a Chronostratigraphic unit in being
restricted, as all Biostratigraphic units are, to the actual spatial
distribution of the fossils.
• Lineage zones are the most reliable means of correlation of relative time
by use of the Biostratigraphic method.
• b. Boundaries. The boundaries of a lineage zone are determined by the
Biohorizons representing the lowest occurrence of successive elements of
the evolutionary lineage under consideration.
• c. Name. A lineage zone is named for the taxon in the lineage whose
range or partial range it represents.
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17. 3. Acme(Abundance) zone
• a. Definition. The body of strata in which the abundance
of a particular taxon or specified group of taxa is
significantly greater than is usual in the adjacent parts of
the section.
• Unusual abundance of a taxon or taxa in the
stratigraphic record may result from a number of
processes that are of local extent, but may be repeated
in different places at different times. For this reason, the
only sure way to identify an abundance zone is to trace it
laterally.
• b. Boundaries. The boundaries of an abundance zone are
defined by the Biohorizons across which there is notable
change in the abundance of the specified taxon or taxa
that characterize the zone.
• c. Name. The abundance zone takes its name from the
taxon or taxa whose significantly greater abundance it
represents.
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19. Interval Zone:
• a. Definition. The body of Fossiliferous strata between two specified
Biohorizons.
• Such a zone is not itself necessarily the range zone of a taxon or
concurrence of taxa; it is defined and identified only on the basis of its
bounding Biohorizons.
• This type of interval zone has been called "last-occurrence zone" but
should preferably be called "highest-occurrence zone".
• Interval zones defined as the stratigraphic section comprised between
the lowest occurrence of two specified taxa ("lowest-occurrence
zone") are also useful, preferably in surface work.
• b. Boundaries. The boundaries of an interval zone are defined by the
occurrence of the Biohorizons selected for its definition.
• c. Name. The names given to interval zones may be derived from the
names of the boundary horizons, the name of the basal boundary
preceding that of the upper boundary; e.g. Globigerinoides sicanus-
Orbulina suturalis Interval Zone.
• In the definition of an interval zone, it is desirable to specify the
criteria for the selection of the bounding Biohorizons, e.g. lowest
occurrence, highest occurrence etc.
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21. HierarcHy in BiostratigrapHicHierarcHy in BiostratigrapHic
UnitsUnits
• The different kinds of Biostratigraphic units described above do not
represent different ranks of a Biostratigraphic hierarchy, except in
the case of Subzones and Super zones, where the prefix indicates
the position in a hierarchy.
• With respect to taxon-range zones, there is no need for a hierarchy
of Biozone terms because the hierarchical system of biological
taxonomy extends also to these Biostratigraphic units in the sense
that the range zone of a species is subsidiary to the range zone of
the genus to which it belongs, and so on.
procedUres for estaBlisHing BiostratigrapHicprocedUres for estaBlisHing BiostratigrapHic
UnitsUnits
• It is recommended that the definition or characterization of a
Biostratigraphic unit include the designation of one or more specific
reference sections that demonstrate the stratigraphic context of
the taxon or taxa diagnostic of the unit.Dated,11/27/2010 21
22. Procedures for extendingProcedures for extending
BiostratigraPhic units -BiostratigraPhic units -
BiostratigraPhic correlationBiostratigraPhic correlation
•Biostratigraphic units are extended away from the areas where they
were defined or from their reference sections by Biostratigraphic
correlation, which is the establishment of correspondence in
Biostratigraphic character and position between geographically
separated sections or outcrops based on their fossil content.
Biostratigraphic correlation is not necessarily time-correlation.
•It may approximate time correlation, or it may be the identification of
the same biofacies.
naming of BiostratigraPhic unitsnaming of BiostratigraPhic units
•The formal name of a Biostratigraphic unit should be formed from the
names of one, or no more than two, appropriate fossils combined with
the appropriate term for the kind of unit in question. The function of a
name is to provide a unique designation for the biozone. Thus, any
taxon in the characteristic assemblage of a Biozone may serve as
name-bearer so long as it is not already employed.
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23. • The term ‘Biostratigraphy’ was used first by Dollo in 1910.
• Biostratigraphy is the branch of stratigraphy which focuses on
correlating and assigning relative ages of rock strata by using the
fossil assemblages contained within them.
• Usually the aim is correlation, demonstrating that a particular
horizon in one geological section represents the same period of time
as another horizon at some other section.
• The fossils are useful because sediments of the same age can look
completely different because of local variations in the sedimentary
environment. For example, one section might have been made up of
clays and marls while another has more chalky limestones, but if the
fossil species recorded are similar, the two sediments are likely to
have been laid down at the same time.
• The Biostratigraphy is also significant as an indicator of environment.
It is also a general indicator of geologic age.
• It is also applicable in sedimentology, sub- surface studies etc.
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24. Books:Books:
Hollis D. Hedberg, ‘INTERNATIONAL STRATIGRAPHIC GUIDE’
Edition: 1976, Page No. 45 to 65. International Sub commission on
Stratigraphic Classification of IUGS Commission on Stratigraphy.
Parbin Singh, ‘Engineering And General Geology’
Edition: 2008, Page No. 349-350. S.K. KATARIA AND SONS.
Surendra Kumar, ‘EARTH SCIENCE’ Edition:2010, Page No. 218,
219, 220, R. GUPTA’S PUBLISHING HOUSE.
Website:Website:
• www.answer.com
• www.wikipedia.com
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