This document outlines the major geological time periods from the Precambrian Eon 4.5 billion years ago to the present. It describes key events that occurred in each period such as the emergence of life starting with single-celled bacteria, the first land plants in the Silurian Period, the rise of the dinosaurs in the Triassic Period, and the appearance of modern humans in the Holocene Epoch. Major climate and environmental changes are also noted, including ice ages and fluctuations in atmospheric carbon dioxide levels. The text provides a high-level overview of the entire geological history of Earth.
The document summarizes key concepts in geologic time and Earth's history. It describes Earth forming 4.6 billion years ago from a collection of gases and iron. Early atmosphere contained water vapor and carbon dioxide. Geologic time is divided into eons, eras, periods, and epochs to record Earth's history. The Precambrian era saw the earliest life emerge and atmosphere develop oxygen. The Paleozoic era saw hard-shelled animals and plants colonize land. Mass extinctions divide eras, like dinosaurs dying out in the Mesozoic.
The document summarizes key topics in geologic time including:
1) Fossils, their types and classification of organisms. 2) Principles of relative dating such as superposition and cross-cutting relations. 3) Dendrochronology and its use in dating features. 4) An overview of the geologic time scale from the Hadean Eon to periods in the Paleozoic, Mesozoic, and Cenozoic eras.
This document provides an overview of the geologic time scale from the formation of Earth 4.567 billion years ago to the present. It describes important events, lifeforms, landmasses, and tectonic activities that occurred during each eon, era, and period of Earth's history. The timeline is divided into Precambrian, Paleozoic, Mesozoic, and Cenozoic eras. During the Precambrian, the earliest lifeforms emerged and oxygen levels rose. The Paleozoic saw diversification of life on land and sea and formation of the supercontinent Pangaea. During the Mesozoic, dinosaurs and mammals appeared while Pangaea broke up.
The geologic time scale shows the eras and periods of Earth's history. During the Jurassic period of the Mesozoic era, dinosaurs like T-Rex and Velociraptor lived. A meteor wiped out the dinosaurs and allowed mammals to evolve and dominate. Early humans were cavemen that evolved to become smarter and build the first civilizations. The document provides an overview of major events and periods within the geologic time scale.
The document outlines the geologic time scale which divides Earth's history into standardized eon, era, period, and epoch units. It describes the major events that occurred during each period such as the emergence of life, evolution of plants and animals, mass extinction events, and more. The geologic time scale is based on analyzing the fossil record and dating the ages of rocks and sediments to correlate transitions in life forms with absolute time.
This document outlines the major geological time periods from the Precambrian Eon 4.5 billion years ago to the present. It describes key events that occurred in each period such as the emergence of life starting with single-celled bacteria, the first land plants in the Silurian Period, the rise of the dinosaurs in the Triassic Period, and the appearance of modern humans in the Holocene Epoch. Major climate and environmental changes are also noted, including ice ages and fluctuations in atmospheric carbon dioxide levels. The text provides a high-level overview of the entire geological history of Earth.
The document summarizes key concepts in geologic time and Earth's history. It describes Earth forming 4.6 billion years ago from a collection of gases and iron. Early atmosphere contained water vapor and carbon dioxide. Geologic time is divided into eons, eras, periods, and epochs to record Earth's history. The Precambrian era saw the earliest life emerge and atmosphere develop oxygen. The Paleozoic era saw hard-shelled animals and plants colonize land. Mass extinctions divide eras, like dinosaurs dying out in the Mesozoic.
The document summarizes key topics in geologic time including:
1) Fossils, their types and classification of organisms. 2) Principles of relative dating such as superposition and cross-cutting relations. 3) Dendrochronology and its use in dating features. 4) An overview of the geologic time scale from the Hadean Eon to periods in the Paleozoic, Mesozoic, and Cenozoic eras.
This document provides an overview of the geologic time scale from the formation of Earth 4.567 billion years ago to the present. It describes important events, lifeforms, landmasses, and tectonic activities that occurred during each eon, era, and period of Earth's history. The timeline is divided into Precambrian, Paleozoic, Mesozoic, and Cenozoic eras. During the Precambrian, the earliest lifeforms emerged and oxygen levels rose. The Paleozoic saw diversification of life on land and sea and formation of the supercontinent Pangaea. During the Mesozoic, dinosaurs and mammals appeared while Pangaea broke up.
The geologic time scale shows the eras and periods of Earth's history. During the Jurassic period of the Mesozoic era, dinosaurs like T-Rex and Velociraptor lived. A meteor wiped out the dinosaurs and allowed mammals to evolve and dominate. Early humans were cavemen that evolved to become smarter and build the first civilizations. The document provides an overview of major events and periods within the geologic time scale.
The document outlines the geologic time scale which divides Earth's history into standardized eon, era, period, and epoch units. It describes the major events that occurred during each period such as the emergence of life, evolution of plants and animals, mass extinction events, and more. The geologic time scale is based on analyzing the fossil record and dating the ages of rocks and sediments to correlate transitions in life forms with absolute time.
Origin and extiction of phanerozoic eonVarun Durge
Jack Sepkoski compiled data on the stratigraphic ranges of over 4,000 marine skeletonized families and 20,000 genera to study rates of origination and extinction in the Phanerozoic Eon. He concluded that the rates of origination were highest in the Cambrian and Ordovician periods. Generalist species that can survive in a variety of environments are less vulnerable to extinction than specialist species with narrow environmental tolerances. Factors like ecological specialization, population dynamics, and geographic range influence the extinction risk of species.
The document summarizes the Geologic Time Scale which divides Earth's history into units including eons, eras, periods, and epochs. It describes the three main eras:
1) The Paleozoic Era (544-251 million years ago) which was dominated by invertebrates and saw the rise of fish and amphibians on land and sea.
2) The Mesozoic Era (251-65 million years ago) which was dominated by reptiles like dinosaurs and saw the rise of mammals and the breakup of Pangaea.
3) The ongoing Cenozoic Era (past 65 million years) which is the "Age of Mammals" and
The geologic time scale is a system used by scientists to describe Earth's history by dividing it into standardized units of time based on stratigraphy and significant events. The first geologic time scale was proposed in 1913 and has since been refined using data from radiometric dating and revisions to the fossil record. It divides Earth's history into eons, eras, periods, and epochs with the Phanerozoic Eon being the most recent period of time spanning from over 500 million years ago to present day.
The document provides an overview of Earth's geological time scale by dividing it into four eons and their associated eras and periods. Each section includes 3 key points about the dominant conditions, lifeforms, tectonic events of that time period. The time scale ranges from 4.6 billion years ago in the Hadean Eon to the present day Quaternary Period.
1) The document outlines the major geologic periods from the Precambrian era to today. It describes key events, climate conditions, dominant species and organisms, formation and breaking up of continents, and mass extinctions that occurred during each period.
2) The major periods discussed include the Precambrian, Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Tertiary, and Quaternary periods.
3) During each period, the document highlights one or two defining features such as the first appearance of oxygen and land, ice ages, dominant animal groups, and tectonic plate movement.
The document summarizes the geological time scale which divides Earth's history into different eras, periods, and epochs based on fossil and stratigraphic evidence. It describes the four eons of Earth's history starting with the Hadean and Archean eons of the earliest lifeforms like bacteria. It then outlines the major eras - Paleozoic, Mesozoic, and Cenozoic - describing some of the significant lifeforms, events, and environmental changes that occurred during each period within these eras. The largest unit of the geological time scale is the eon, while the smallest is the epoch.
The document discusses the Geologic Time Scale which divides Earth's history into units of time based on fossils and rock layers. It describes the four main eras - Precambrian, Paleozoic, Mesozoic, and Cenozoic. The Paleozoic era saw the rise of invertebrates and fish, the Mesozoic was the age of reptiles including dinosaurs, and the Cenozoic is the current era which began after the extinction of the dinosaurs and saw the rise of mammals and humans.
The document discusses the Geological Time Scale which is used to divide Earth's history into eras, periods and epochs based on fossil and rock evidence. It describes the major eras - Precambrian, Paleozoic, Mesozoic and Cenozoic - along with key environmental conditions and lifeforms that existed during each era, noting major extinction events. The timeline shows how life on Earth has evolved and changed dramatically over its approximately 4.5 billion year history.
The document discusses geological timescales and how fossils found in Grand Canyon National Park and Capitol Reef National Park in Utah provide evidence about periods of the Phanerozoic Eon. Specifically, it notes that during the Phanerozoic Eon the number of species with shells and skeletons dramatically increased, as did the total number of individual organisms, species, and average size of organisms preserved as fossils. The document also mentions a virtual field trip to these two national parks to see fossils from different periods in geological history.
The document summarizes the geological timescale used to divide Earth's history into standardized periods of time. It describes how the timescale is broken down into eons, eras, periods, and epochs. The two main divisions are the Precambrian super eon prior to the Cambrian period and the Phanerozoic eon from the Cambrian period to present day. Precambrian time included the Hadean, Archean, and Proterozoic eons, while the Phanerozoic included the Paleozoic, Mesozoic, and Cenozoic eras. The geological timescale provides a standardized framework for correlating and dating rock formations across periods of Earth's history.
The document discusses several topics related to geology and earth history. It describes petrology as the study of rocks, stratigraphy as the study of rock layers. It also discusses paleontology, which is the study of life from the past through fossils. The document outlines principles of relative and absolute dating that are used to date rocks and geological events. These principles include original horizontality, superposition, cross-cutting relationships, and inclusion. Radiometric dating is described as a method of absolute dating using radioactive isotope decay rates. Fossils are also summarized, including their classification into true form, mold, cast, and trace fossils.
The document outlines the geologic timeline from the formation of Earth to the emergence of early humans. It lists key events in order from oldest to most recent, including the appearance of single-celled organisms, plants, insects, fish, reptiles, mammals, birds, flowers, primates and humans. The timeline is divided into eras - Precambrian, Paleozoic, Mesozoic, and Cenozoic - with brief descriptions and examples provided for each era.
The document outlines the major geological time periods used to describe Earth's history. It divides time into eons, eras, and periods. The four eons are Hadean, Archean, Proterozoic, and Phanerozoic. The three main eras are Precambrian, Paleozoic, and Mesozoic, with the current era being the Cenozoic. Each era is further divided into periods characterized by characteristic organisms and geological events. The document also briefly describes some of the major transitions and events that occurred during these periods, such as the Cambrian explosion and age of dinosaurs.
The document summarizes the geologic time scale which divides Earth's history into sections including eons, eras, periods and epochs. The largest section is the eon, with the Precambrian and Phanerozoic eons covering over 4 billion years of history. Key events mentioned include the first life forms in the Archean era, marine invertebrates in the Proterozoic, and the rise of dinosaurs, mammals and modern life forms in the Phanerozoic. Several important periods are highlighted such as the Carboniferous, Permian, Jurassic and Cretaceous periods.
The document discusses how geologists use rocks and fossils to understand Earth's history. Rock layers and fossils provide evidence about past life forms and environmental conditions. By analyzing things like rock formations, unconformities, and the fossils contained within rocks, geologists have learned that Earth is much older than previously believed and has undergone geological changes over long periods of time. Radiometric dating techniques also allow geologists to estimate the age of rocks and events in Earth's history.
The document summarizes the geologic time scale which divides Earth's history into sections called eons, eras, periods, and epochs based on major changes. The largest eras include Precambrian, Paleozoic, Mesozoic, and Cenozoic. The Precambrian saw the emergence of life. The Paleozoic was dominated by marine invertebrates. The Mesozoic was the 'Age of Reptiles'. The Cenozoic era sees mammals rise to dominance. Mass extinctions marked transitions between eras.
This document provides an overview of geologic history from the Precambrian era to present day. It describes the major eras, periods, events, climate changes, organisms, and theories of evolution that are recorded in the layers of rock and fossil records. The document is organized chronologically, with each era and period summarized in terms of dominant life forms, environmental conditions, and significant developments or extinctions. Major theories like plate tectonics and mass extinction events are also outlined.
The document summarizes the Geologic Time Scale which divides Earth's history into eras and periods based on fossil and biological evidence. The four eras are Pre-Cambrian, Paleozoic, Mesozoic, and Cenozoic. Each era is then divided into periods characterized by evolutionary changes and extinctions of important species. The timeline stretches from the formation of Earth 4.6 billion years ago to the present.
The document discusses the geologic time scale, which divides Earth's history into eons, eras, and periods based on changes in the fossil record found in different rock layers. Scientists use radiometric dating to determine the ages of each rock layer and develop a timeline of life on Earth from single-celled organisms in the Precambrian to mammals becoming dominant in the Cenozoic era.
Prehistory 1: Geologic Timeline- Notes on the geologic & life history of Ear...Robin Seamon
This document provides information about Earth's prehistory and geologic timeline. It discusses how Earth is approximately 4.5 billion years old, and life has changed the planet's chemistry over the past 3/4 of geologic time. Five major extinctions have occurred, including the K-Pg extinction that killed the dinosaurs 65 million years ago. Mass extinctions are caused by long-term stresses combined with short term catastrophic events. Recovery of biodiversity after extinctions can take 5-10 million years as weedy species repopulate the planet. The eras of geologic time - Precambrian, Paleozoic, Mesozoic, and Cenozoic - are summarized along with significant developments in life during each period
The document summarizes the geologic time scale which divides Earth's history into sections called eons, eras, periods, and epochs based on major changes. It describes several important periods including the Precambrian, Paleozoic, Mesozoic, and Cenozoic eras. The Paleozoic era saw the first appearance of hard-shelled animals and plants colonizing land. It ended in a mass extinction event. The Mesozoic era was dominated by reptiles such as dinosaurs, until another mass extinction wiped them out. The current Cenozoic era is when mammals and eventually humans evolved.
The geological time scale records 4.6 billion years of Earth's history divided into eras, periods, and epochs based on studying rock layers and fossils. It begins with the Precambrian era which covers 88% of Earth's history. The timescale includes the Paleozoic era of ancient life dominated by invertebrates like trilobites; the Mesozoic era of middle life dominated by dinosaurs and the breakup of Pangaea; and the ongoing Cenozoic era of recent life dominated by mammals including the evolution of humans.
Origin and extiction of phanerozoic eonVarun Durge
Jack Sepkoski compiled data on the stratigraphic ranges of over 4,000 marine skeletonized families and 20,000 genera to study rates of origination and extinction in the Phanerozoic Eon. He concluded that the rates of origination were highest in the Cambrian and Ordovician periods. Generalist species that can survive in a variety of environments are less vulnerable to extinction than specialist species with narrow environmental tolerances. Factors like ecological specialization, population dynamics, and geographic range influence the extinction risk of species.
The document summarizes the Geologic Time Scale which divides Earth's history into units including eons, eras, periods, and epochs. It describes the three main eras:
1) The Paleozoic Era (544-251 million years ago) which was dominated by invertebrates and saw the rise of fish and amphibians on land and sea.
2) The Mesozoic Era (251-65 million years ago) which was dominated by reptiles like dinosaurs and saw the rise of mammals and the breakup of Pangaea.
3) The ongoing Cenozoic Era (past 65 million years) which is the "Age of Mammals" and
The geologic time scale is a system used by scientists to describe Earth's history by dividing it into standardized units of time based on stratigraphy and significant events. The first geologic time scale was proposed in 1913 and has since been refined using data from radiometric dating and revisions to the fossil record. It divides Earth's history into eons, eras, periods, and epochs with the Phanerozoic Eon being the most recent period of time spanning from over 500 million years ago to present day.
The document provides an overview of Earth's geological time scale by dividing it into four eons and their associated eras and periods. Each section includes 3 key points about the dominant conditions, lifeforms, tectonic events of that time period. The time scale ranges from 4.6 billion years ago in the Hadean Eon to the present day Quaternary Period.
1) The document outlines the major geologic periods from the Precambrian era to today. It describes key events, climate conditions, dominant species and organisms, formation and breaking up of continents, and mass extinctions that occurred during each period.
2) The major periods discussed include the Precambrian, Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Tertiary, and Quaternary periods.
3) During each period, the document highlights one or two defining features such as the first appearance of oxygen and land, ice ages, dominant animal groups, and tectonic plate movement.
The document summarizes the geological time scale which divides Earth's history into different eras, periods, and epochs based on fossil and stratigraphic evidence. It describes the four eons of Earth's history starting with the Hadean and Archean eons of the earliest lifeforms like bacteria. It then outlines the major eras - Paleozoic, Mesozoic, and Cenozoic - describing some of the significant lifeforms, events, and environmental changes that occurred during each period within these eras. The largest unit of the geological time scale is the eon, while the smallest is the epoch.
The document discusses the Geologic Time Scale which divides Earth's history into units of time based on fossils and rock layers. It describes the four main eras - Precambrian, Paleozoic, Mesozoic, and Cenozoic. The Paleozoic era saw the rise of invertebrates and fish, the Mesozoic was the age of reptiles including dinosaurs, and the Cenozoic is the current era which began after the extinction of the dinosaurs and saw the rise of mammals and humans.
The document discusses the Geological Time Scale which is used to divide Earth's history into eras, periods and epochs based on fossil and rock evidence. It describes the major eras - Precambrian, Paleozoic, Mesozoic and Cenozoic - along with key environmental conditions and lifeforms that existed during each era, noting major extinction events. The timeline shows how life on Earth has evolved and changed dramatically over its approximately 4.5 billion year history.
The document discusses geological timescales and how fossils found in Grand Canyon National Park and Capitol Reef National Park in Utah provide evidence about periods of the Phanerozoic Eon. Specifically, it notes that during the Phanerozoic Eon the number of species with shells and skeletons dramatically increased, as did the total number of individual organisms, species, and average size of organisms preserved as fossils. The document also mentions a virtual field trip to these two national parks to see fossils from different periods in geological history.
The document summarizes the geological timescale used to divide Earth's history into standardized periods of time. It describes how the timescale is broken down into eons, eras, periods, and epochs. The two main divisions are the Precambrian super eon prior to the Cambrian period and the Phanerozoic eon from the Cambrian period to present day. Precambrian time included the Hadean, Archean, and Proterozoic eons, while the Phanerozoic included the Paleozoic, Mesozoic, and Cenozoic eras. The geological timescale provides a standardized framework for correlating and dating rock formations across periods of Earth's history.
The document discusses several topics related to geology and earth history. It describes petrology as the study of rocks, stratigraphy as the study of rock layers. It also discusses paleontology, which is the study of life from the past through fossils. The document outlines principles of relative and absolute dating that are used to date rocks and geological events. These principles include original horizontality, superposition, cross-cutting relationships, and inclusion. Radiometric dating is described as a method of absolute dating using radioactive isotope decay rates. Fossils are also summarized, including their classification into true form, mold, cast, and trace fossils.
The document outlines the geologic timeline from the formation of Earth to the emergence of early humans. It lists key events in order from oldest to most recent, including the appearance of single-celled organisms, plants, insects, fish, reptiles, mammals, birds, flowers, primates and humans. The timeline is divided into eras - Precambrian, Paleozoic, Mesozoic, and Cenozoic - with brief descriptions and examples provided for each era.
The document outlines the major geological time periods used to describe Earth's history. It divides time into eons, eras, and periods. The four eons are Hadean, Archean, Proterozoic, and Phanerozoic. The three main eras are Precambrian, Paleozoic, and Mesozoic, with the current era being the Cenozoic. Each era is further divided into periods characterized by characteristic organisms and geological events. The document also briefly describes some of the major transitions and events that occurred during these periods, such as the Cambrian explosion and age of dinosaurs.
The document summarizes the geologic time scale which divides Earth's history into sections including eons, eras, periods and epochs. The largest section is the eon, with the Precambrian and Phanerozoic eons covering over 4 billion years of history. Key events mentioned include the first life forms in the Archean era, marine invertebrates in the Proterozoic, and the rise of dinosaurs, mammals and modern life forms in the Phanerozoic. Several important periods are highlighted such as the Carboniferous, Permian, Jurassic and Cretaceous periods.
The document discusses how geologists use rocks and fossils to understand Earth's history. Rock layers and fossils provide evidence about past life forms and environmental conditions. By analyzing things like rock formations, unconformities, and the fossils contained within rocks, geologists have learned that Earth is much older than previously believed and has undergone geological changes over long periods of time. Radiometric dating techniques also allow geologists to estimate the age of rocks and events in Earth's history.
The document summarizes the geologic time scale which divides Earth's history into sections called eons, eras, periods, and epochs based on major changes. The largest eras include Precambrian, Paleozoic, Mesozoic, and Cenozoic. The Precambrian saw the emergence of life. The Paleozoic was dominated by marine invertebrates. The Mesozoic was the 'Age of Reptiles'. The Cenozoic era sees mammals rise to dominance. Mass extinctions marked transitions between eras.
This document provides an overview of geologic history from the Precambrian era to present day. It describes the major eras, periods, events, climate changes, organisms, and theories of evolution that are recorded in the layers of rock and fossil records. The document is organized chronologically, with each era and period summarized in terms of dominant life forms, environmental conditions, and significant developments or extinctions. Major theories like plate tectonics and mass extinction events are also outlined.
The document summarizes the Geologic Time Scale which divides Earth's history into eras and periods based on fossil and biological evidence. The four eras are Pre-Cambrian, Paleozoic, Mesozoic, and Cenozoic. Each era is then divided into periods characterized by evolutionary changes and extinctions of important species. The timeline stretches from the formation of Earth 4.6 billion years ago to the present.
The document discusses the geologic time scale, which divides Earth's history into eons, eras, and periods based on changes in the fossil record found in different rock layers. Scientists use radiometric dating to determine the ages of each rock layer and develop a timeline of life on Earth from single-celled organisms in the Precambrian to mammals becoming dominant in the Cenozoic era.
Prehistory 1: Geologic Timeline- Notes on the geologic & life history of Ear...Robin Seamon
This document provides information about Earth's prehistory and geologic timeline. It discusses how Earth is approximately 4.5 billion years old, and life has changed the planet's chemistry over the past 3/4 of geologic time. Five major extinctions have occurred, including the K-Pg extinction that killed the dinosaurs 65 million years ago. Mass extinctions are caused by long-term stresses combined with short term catastrophic events. Recovery of biodiversity after extinctions can take 5-10 million years as weedy species repopulate the planet. The eras of geologic time - Precambrian, Paleozoic, Mesozoic, and Cenozoic - are summarized along with significant developments in life during each period
The document summarizes the geologic time scale which divides Earth's history into sections called eons, eras, periods, and epochs based on major changes. It describes several important periods including the Precambrian, Paleozoic, Mesozoic, and Cenozoic eras. The Paleozoic era saw the first appearance of hard-shelled animals and plants colonizing land. It ended in a mass extinction event. The Mesozoic era was dominated by reptiles such as dinosaurs, until another mass extinction wiped them out. The current Cenozoic era is when mammals and eventually humans evolved.
The geological time scale records 4.6 billion years of Earth's history divided into eras, periods, and epochs based on studying rock layers and fossils. It begins with the Precambrian era which covers 88% of Earth's history. The timescale includes the Paleozoic era of ancient life dominated by invertebrates like trilobites; the Mesozoic era of middle life dominated by dinosaurs and the breakup of Pangaea; and the ongoing Cenozoic era of recent life dominated by mammals including the evolution of humans.
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.
Gondwana university prospectus 2016 17 educationiconnect.com 7862004786 (2)00007123
We provide university prospectus student can check all prospectus in any slide Gondwana university prospectus 2016 17 educationiconnect.com 7862004786 Gondwana university
The document divides Earth's geologic history into a time scale consisting of eons, eras, periods, and epochs. Major changes in lifeforms or the environment define the boundaries between these divisions. The Precambrian era spanned from Earth's formation 4.6 billion years ago until 542 million years ago and saw the emergence of early prokaryotic and then eukaryotic life. Mass extinctions, such as those at the ends of the Paleozoic and Mesozoic eras, were often caused by catastrophic asteroid impacts or climate change and marked transitions between eras.
1. The continent of Gondwana formed between 570-510 million years ago through the collision of several continental fragments and microcontinents along orogenies in central Gondwana and East Africa.
2. Gondwana eventually amalgamated into the supercontinent Pangaea before beginning to break apart in the Early Jurassic period around 184 million years ago.
3. The breakup of Gondwana involved the drifting apart of East Gondwana (Antarctica, Australia, India, Madagascar), the opening of the South Atlantic between Africa and South America, and the separation of India from Madagascar during the Cretaceous period.
During construction of canals in the 19th century, scientists discovered many layers of sedimentary rock containing fossils of extinct animals. Finding fossils in sites around the world, including the Grand Canyon, led scientists to realize the Earth was older than previously believed. By piecing together evidence from rock layers and using radioactive dating, scientists developed the Geologic Time Scale which divides Earth's 4.5 billion year history into four eras, with the earliest being the Precambrian Era from 4.5 billion to 600 million years ago when the first life emerged.
The document summarizes the major eras of geological time from the formation of the Earth 4.6 billion years ago to the present. It outlines four eras: Precambrian, Paleozoic, Mesozoic, and Cenozoic. The Precambrian era saw the earliest life forms and atmosphere. The Paleozoic era brought marine diversity and early land plants and animals. Dinosaurs dominated during the Mesozoic before an asteroid caused their extinction. The current Cenozoic era began after this mass extinction and saw the rise of mammals and modern humans.
The document provides information about the geologic timescale including major eras such as the Precambrian, Paleozoic, Mesozoic, and Cenozoic. It lists periods within these eras like the Hadean, Archean, Proterozoic, Cambrian, Ordovician, and others. There are also versions of the timescale shown in different speeds from fast to reverse.
This document outlines the major geological eras and periods relevant to primate and human evolution over the last 570 million years. It describes how continental drift changed global climates, causing temperatures to decline from the warm and wet Eocene period to present. Key events included the breakup of Pangea, the rise of angiosperms during the Mesozoic, mammalian diversification in the Paleogene as new food sources emerged, and hominin emergence in the Neogene as forests retreated due to cooling and drying trends.
The document summarizes Earth's geologic history from its formation 4.6 billion years ago to the present. It is divided into eons, eras, periods, and epochs. The earliest eons included the Hadean and Archean, when Earth was molten and the first life formed. The Proterozoic saw continued formation of continents and oxygen buildup. The Phanerozoic eon saw the rise of complex life, including during the Paleozoic era of the Cambrian, Ordovician, and other periods. During the Mesozoic era, life included dinosaurs and the breakup of Pangaea. The Cenozoic era is the current one including the C
The document discusses the geological time scale, which is a system used by geologists and other earth scientists to describe events in Earth's history. It relates rock layers and the order in which they were formed to specific time periods. The geological time scale is constructed by studying rock strata and using principles like uniformitarianism, as well as fossils, artifacts, and other evidence found in the different layers to determine the relative and absolute ages of formations. It divides Earth's history into eons, eras, periods, epochs, and ages at different timescales from hundreds of millions of years to millions of years.
The geologic time scale is a system used to describe Earth's history by dividing it into units of time based on changes in lifeforms and rock layers. It begins over 4.6 billion years ago with the formation of Earth and extends to the present. Major divisions include eons like the Precambrian and Phanerozoic, eras like the Paleozoic and Cenozoic, and periods like the Jurassic and Quaternary. Life began as single-celled organisms and evolved over billions of years to include complex plants and animals, with major extinction events periodically wiping out many species. The current geologic period is the Quaternary, which began over 2 million years ago and includes the evolution
The document summarizes the geologic time scale, which is divided into eras, periods, and epochs based on fossil evidence showing changes in Earth's organisms over its 4.56 billion year history. The largest divisions are eras, including Precambrian, Paleozoic, Mesozoic, and current Cenozoic. Each era is characterized by the dominant lifeforms and events of that time period. The geologic time scale helps break up Earth's history into more manageable chunks for study.
1) Approximately 6 billion years ago, the Earth formed from a part of the sun that cooled and separated. While the interior remains hot, tectonic forces later caused hills, mountains, and changes to the surface.
2) Around 4 billion years ago, the cooled Earth developed water and an atmosphere, allowing the first living single-celled organisms to form in oceans about 3.5 billion years ago.
3) Multicellular life eventually emerged, followed by more complex organisms like fish, amphibians, reptiles, birds, and later humans. Periods like the ice age were challenging as many species went extinct while others survived.
The document summarizes the geologic time scale and highlights key periods that contain natural resource formations important to XTO Energy. It discusses rock formations from as far back as 3 billion years ago that contain evidence of ancient life and are the origins of today's natural resources. The document then lists several periods within the Paleozoic, Mesozoic, and Cenozoic eras, along with the page numbers where more information can be found about notable fossil findings from each period that are relevant to XTO Energy.
The document provides information about the Jurassic period from approximately 199.6 to 145 million years ago. Key points include:
- The period saw the rise of dinosaurs and other terrestrial reptiles as well as marine reptiles like ichthyosaurs and plesiosaurs. Sauropod dinosaurs were common.
- Atmospheric CO2 levels were high, around 1950 ppm, and temperatures were warmer than today. Forests dominated the landscape.
- The supercontinent Pangaea began to break apart during this period, creating more coastlines with humid climates and rainforests.
Cent and her friends Magnitude and Magnuuz take a tour through Earth's history from planetary formation to the current Cenozoic era. They observe examples of planetary accretion, massive volcanic activity in the Precambrian, red beds and Ediacaran fauna of that time. In the Paleozoic era they see the Burgess Shale, epeiric seas, early plants including ferns and gymnosperms, amniotic eggs, Pangaea formation, and subduction zones. Key events of the Mesozoic include the breakup of Pangaea, the rise of dinosaurs, and bolide impact at the end of the period. The tour concludes with examples of angios
The document provides an outline and overview of Dr. Gary Stilwell's cosmology course, which covers both mythological and scientific cosmology. It summarizes the timeline of events from the Big Bang to the present day, from quantum fluctuations at 10-43 seconds to the formation of galaxies, stars, and life. The course explores our limited knowledge of the earliest moments and the development of the standard models of particles, forces, and the structure of matter in the early universe.
The document summarizes the formation and early history of Earth and life:
1) Around 4.6 billion years ago, Earth formed from a cloud of dust and gas left over from the creation of the Sun.
2) Life first emerged around 3.8-2.5 billion years ago in the form of primitive microbes like cyanobacteria and archea.
3) The first soft-bodied animals appeared around 543 million years ago, marking the end of the Proterozoic Eon and the beginning of complex life on Earth.
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.
The document provides information on geological times, continental drift, and three schools of evolutionary thought. It summarizes key transitions in evolution such as the RNA world, prokaryotes evolving into eukaryotes, the emergence of sex and multicellularity. It also outlines the geological timescale from eons to epochs and provides examples of major events in Earth's history.
Similar to Geologic timescale and natural history of the earth (7)
2. Units in geochronology and stratigraphy
Units in geochronology and stratigraphy
Segments of
rock (strata) Periods of
in time in
chronostratig geochron
raphy ology Notes
Eonothem Eon 4 total, half a billion years or more
Erathem Era 12 total, several hundred million years
System Period
Series Epoch tens of millions of years
Stage Age millions of years
smaller than an age/stage, not used by the ICS
Chronozone Chron timescale
Page 2
3. Eons
Precambrian Supereon
Present
time
18.28 GY
15.2 10 2.2
=4570 Ma
Hadean Archean Proterozoic Phane
770 Ma 1300 Ma 1958 Ma
rozoic
Formation of the Earth and later, Moon (Cryptic Era)
542 Ma
First lifeform and self replicating RNA appears (16 GY, Basin Groups Era)
First simple single-celled life (Prokaryote, Eoarchean Era)
First complex single-celled life
(Eukaryote, Statherian Period)
First multi-cellular animal (Metazoan, Ediacaran Period)
1 GY = 250 Ma Cambrian Explosion (Cambrian Period)
(GY = Galactic Year, the time the Solar System
takes to go round the centre of the Galaxy once;
Ma = Millions of years (ago), Megaanum)
Page 3
4. Hadean & Archean Eon to Eras
18.28 GY
15.2 10 2.2
Phanerozoic
Hadean Archean Proterozoic
50 Ma First known oxygen-producing
bacteria; Oldest cratons on earth
Formation of Moon from Lower
giant impact (4533Ma) 70 Ma Imbrian
Nectarian
Proterozoic
Eon
230 Ma 200 Ma 400 Ma 400 Ma 300 Ma
420 Ma
Basin Eoarchean Paleo Meso Neo
Cryptic
Groups archean archean archean
Solar
Nebula 15.4
16.6 15.68 15.2
14.4 12.8 11.2 10 Paleoproterozoic
18.28 GY
Era
=4570 Ma
First lifeform and
self-replicating First simple single-celled life (bacteria
RNA appears & archaea); Oldest probable microfossils
(4000Ma)
Formation First stromatolites (probably colonial
End of the Late Heavy Bombardment of
of the Earth cyanobacteria); Oldest macrofossils
the inner solar system.
Oldest known mineral, Zircon
Page 4 (4406 Ma)
5. Proterozoic Eon to Eras & Periods
18.28 GY
15.2 10 2.2
Phanerozoic
Hadean Archean Proterozoic
Archean
Phanerozoic
Eon 250 Ma
Rhyacian
200 Ma
Statherian
200 Ma 150 Ma 88 Ma
Eon
Ectasian Tonian Ediacaran
200 Ma 250 Ma 200 Ma 200 Ma 220 Ma
Siderian Orosirian Calymmian Stenian Cryogenian
9.2 8.2 7.2 5.6 4.8 3.4 2.52
Neoarchean 4
Cambrian
2.2
Era 10 GY Paleoproterozoic 6.4
Mesoproterozoic Neoproterozoic Period
900 Ma 600 Ma 458 Ma
Snowball Earth
Period
First complex single-celled life
Green algae colonies in sea
Era (Eukrayote)
First multi-cellular animal (Metazoan);
First sponges, trilobitomorphs
Page 5
6. Phanerozoic Eon to Eras
18.28 GY
15.2 10 2.2
Hadean Archean Proterozoic Phanero
zoic
Precambrian
Supereon &
Proterozoic
Eon
Ediacaran
Period 2.2
Paleozoic 1 Mesozoic 0.26
Cenozoic
291 Ma 186 Ma 65 Ma
(= 65 Ma)
Page 6
7. Paleozoic Era to Periods
Proterozoic
Eon 2.2 GY
Paleozoic 1 Mesozoic 0.26
Cenozoic
(= 65 Ma)
First clubmosses, ferns,
seed-bearing plants, trees,
Cambrian Explosion; insects, aquatic amphibians
Precambrian First chordates appear;
Atmospheric CO2 content
Supereon & 20-35 times present day levels First reptiles, coal forests;
Proterozoic Highest-ever atmospheric O2 level Mesozoic
Eon letting arthropods to flourish
Era
54 Ma 44 Ma 28 Ma 56 Ma 60 Ma 49 Ma
Cambrian Ordovician Silurian Devonian Carboniferous Permian
Ediacaran Period
Triassic
542 Ma 444 416 251 Period
488 360 300
(= 2.2 GY) (= 1 GY)
First green plants Pangea formed; First true seed-plants
& fungi on land (conifers) & mosses replace coal-age flora
First vascular plants, jawed fishes;
First millipedes & arthropleurids on land;
Permian-Triassic Mass Extinction
Sea-scorpions reach large size
(95% life goes extinct)
Page 7
8. Mesozoic Era to Periods
Proterozoic
Eon 2.2 GY Paleozoic 1 Mesozoic 0.26
Cenozoic
(= 65 Ma)
First birds & lizards; ichthyosaurs, plesiosaurs,
gymnosperms (conifers, cycads) diverse; K-T Mass Extinction
Breakup of Pangaea into Gondwana and Laurasia Most large animals (dinosaurs) go extinct
Paleozoic
Era Cenozoic
Era
51 Ma 55 Ma 80 Ma
Triassic Jurassic Cretaceous
Permian Period
Paleogene
251 Ma 200 145 Period
(= 1 GY) 65
(= 0.26 GY)
Archosaurs dominate as dinosaurs, Flowering plants, new insect types,
ichthyosaurs, nothosaurs & pterosaurs; new dinosaur types, new eusuchians, modern sharks,
First mammals, crocodilians, teleosts appears monotremes, marsupials, placental mammals appear;
Primitive birds gradually replace pterosaurs
Page 8
9. Cenozoic Era to Periods and Epochs
Proterozoic
Eon 2.2 GY Paleozoic 1 Mesozoic 0.26
Cenozoic
(= 65 Ma)
First large mammals, Ice Age recedes;
modern plants appear; Rise of human civilization
Evolution of anatomically modern humans;
Indian subcontinent collides with Asia 55Ma Dawn of human stone-age cultures
Mesozoic 2.489 Ma
Era Grass appears; atmospheric Pleistocene
2.8 Ma
CO2 decays
Pliocene
Holocene
9.2 Ma 21.8 Ma 11 Ma 17.7 Ma 0.0114 Ma
Paleocene Eocene Oligocene Miocene
Permian Period
65 Ma
(= 0.26 GY) 55.8
34 2.5
5.3 0.0114
42 Ma 23 23 Ma (=11.4 ka)
Paleogene Neogene
Epoch
Period First apes appear
Major evolution & dispersal
of modern types of Austrapithecines appear;
Page 9 mammals & flowering plants Homo habilis appears;
Present Ice Age begins;