Eons may be further divided into smaller chunks called eras, and each era is divided into periods. Figure 12.1 shows you what the geologic time scale looks like ...Cenozoic Era, third of the major eras of Earth’s history, beginning about 66 million years ago and extending to the present. It was the interval of time during which the continents assumed their modern configuration and geographic positions and during which Earth’s flora and fauna evolved toward those of the present.What are the 4 main geologic period? The Precambrian, Paleozoic, Mesozoic, and Cenozoic Eras. The Geologic Time Scale is the history of the Earth broken down into four spans of time marked by various events, such as the emergence of certain species, their evolution, and their extinction, that help distinguish one era from another.The Precambrian, Paleozoic, Mesozoic, and Cenozoic Eras The Geologic Time Scale is the history of the Earth broken down into four spans of time marked byIt was a time that witnessed the most rapid development and diversification of multi-cellular organisms in earth history -- an event that signaled the beginning of the famed Cambrian Explosion. The Paleozoic lasted for nearly 290 million years… from 541 to 252 million years ago. Science has chosen to divide that incomprehensible length of ...Geologists have mapped out a time scale that is a “calendar” of Earth’s geologic history. The scale of geologic time starts some 4 billion years ago, when Earth’s crust was formed. Earth itself is slightly older than this, but when it was first formed the planet was in a hot and thick liquid form. As it cooled, the surface of the planet ... Geologic time scale Take a journey back through the history of the Earth — jump to a specific time period using the time scale below and examine ancient life, climates, and geography. You might wish to start in the Cenozoic Era (65.5 million years ago to the present) and work back through time, or start with Hadean time (4.6 to 4 billion ... The Pre-Nectarian period is defined from the point at which the lunar crust formed, to the time of the Nectaris impact event. Nectaris is a multi-ring impact basin that formed on the near side of the Moon, and its ejecta blanket serves as a useful stratigraphic marker. 30 impact basins from this period are recognized, the oldest of which is the South Pole–Aitken basin.1 мар. 2018 г. ... Fossilized Lycoptera sp. from Jurassic Period of the Mesozoic Era. The geologic time scale breaks down the earth's history into time spans ...Earth's 4.6-billion-year history is divided into Precambrian time and three eras: Paleozoic, Mesozoic, & Cenozoic. Each era is subdivided into a number of ...Earth's 4.6-billion-year history is divided into Precambrian time and three eras: Paleozoic, Mesozoic, & Cenozoic. Each era is subdivided into a number of ...Results 1 - 24 of 100+ ... Browse eras of geologic time scale resources on Teachers Pay Teachers, a marketplace trusted by millions of teachers for original ...Mar 8, 2020 · One important moment in geologic time was the transition from the Mesozoic era to the Cenozoic era about 65 million years ago. The change was spurred by the asteroid impact that eventually killed ... ... eras: Coenozoic, Mesozoic, paleozoic, Proterozoic and Archezoic. Each era is divided into periods and each period is divided into epochs. It is as follows ...Name 3 geologic era Earth's history since Precambrian times? The 3 geological eras since Precambrian super-eon :-Paleozoic Era (542 - 251 Ma)Mesozoic …... time period using the time scale below and examine ancient life, climates, and geography. You might wish to start in the Cenozoic Era (65.5 million years ...Which division of the geologic time scale includes most of Earth's history?, How are eras and periods of the geologic time scale named?, Fill in the blank to complete the statement about the geologic time scale. On the geologic time scale, scientists use the terms era and period to describe lengths of time _____ Precambrian time. and more. ...The Geological Time Scale. Now that you have learned about the hierarchical components of the geological time scale--eons, eras, periods, and epochs--consider again how all of these parts fit together. Note that some boundaries (those that follow horizontal lines on the time scale) are equivalent in age.The Phanerozoic is the current and the latest of the four geologic eons in the Earth's geologic time scale, covering the time period from 538.8 million years ago to the present. It is the eon during which abundant animal and plant life has proliferated, diversified and colonized various niches on the Earth's surface, beginning with the Cambrian period …Era, a very long span of geological time; in formal usage, the second longest portion of geologic time after an eon. Ten eras are recognized by the International Union of Geological Sciences. An era is composed of one or more geological periods. The stratigraphic, or rock, term that corresponds to ‘era’ is ‘erathem.’An interactive project on geologic time, for those who want to explore in more detail. Although the Geologic Column was developed as a relative time scale, geologists wanted to figure out the numerical age dates for Era-Era boundaries and other events. Discovered various techniques: Main one: Radiometric datingPaleoproterozoic – The Paleoproterozoic Era, spanning the time period from 2,500 to 1,600 million years ago, is the first of the three sub-divisions of the Proterozoic Eon. The Paleoproterozoic is also the longest era of the Earth’s geological history. It was during this era that the continents first stabilized.Geologists divide the time between Precambrian and the present into three long units called eras (Paleozoic, Mesozoic, Cenozoic). Eras are divided into periods.Things to Ponder ⮚ Geologic time scale is a timeline that illustrates Earth’s past. ⮚ Geologic time scale describes the order of duration of major events on Earth for the last 4 billion years. ⮚ Geologic time scale was …Based on geologic events. ➢ the ancient period from earth's history is formulated into eons-eras-periods-epochs. ➢ Each division in the geological ...Their fossil record allows geologists to date and compare rocks across geological time. For example, dinosaur fossils are only found during the Mesozoic era ...Epoch, unit of geological time during which a rock series is deposited. It is a subdivision of a geological period, and the word is capitalized when employed in a formal sense (e.g., Pleistocene Epoch). Additional distinctions can be made by appending relative time terms, such as early, middle, and. to 0.0082 Ma, Northgrippian from 0.0082 to 0.0042 Ma, and Meghalayan from 0.0042 to present. The geologic community broadly recognizes the Anthropocene as a proposed new time interval of Earth history, partly coincident with the Holocene. Currently, the Anthropocene has an informal You can see them in the geologic time scale below and in our worksheets. Reminder: we go into the Paleozoic, Mesozoic, and Cenozoic eras into more detail in Montessori Great Lesson: Coming of Life and Timeline of Life. In the worksheets below, we focus on the basic elements of the Clock of Eras / Geologic Time Scale.The history of the earth is broken up into a hierarchical set of divisions for describing geologic time. As increasingly smaller units of time, the generally accepted divisions are eon, era, period, epoch, age. In the time scale shown at left, only the two highest levels of this hierarchy are represented. The Phanerozoic Eon is shown along the ...Based on geologic events. ➢ the ancient period from earth's history is formulated into eons-eras-periods-epochs. ➢ Each division in the geological ...Jan 15, 2017 - Geologic Time - Eon and Eras Introduction ActivitiesIntroduce students to Geologic Time in this Activity Pack:Precambrian Eon - Paleozoic Era ...Paleoproterozoic – The Paleoproterozoic Era, spanning the time period from 2,500 to 1,600 million years ago, is the first of the three sub-divisions of the Proterozoic Eon. The Paleoproterozoic is also the longest era of the Earth’s geological history. It was during this era that the continents first stabilized.The history of the earth is broken up into a hierarchical set of divisions for describing geologic time. As increasingly smaller units of time, the generally accepted divisions are eon, era, period, epoch, age. In the time scale shown at left, only the two highest levels of this hierarchy are represented. The Phanerozoic Eon is shown along the ... The modern geologic time scale was formulated in 1911 by Arthur Holmes. But ancient Greek philosophers like Xenophanes and Aristotle had put forth observations about rock beds, fossils, and changes in the positions of lands and seas. The geologic time scale is a way of representing deep time based on events that have occurred throughout Earth ...shown on the poster.The largest time span of the geologic time scaleis the eon.It is an indefinitely long period of time that contains at least two eras.Geologic time is divided into two eons.The more ancient eon is called the Precambrian, and the more recent is the Phanerozoic.Each eon is subdivided into smaller spans called eras.The Geologic Time – Period prior to humans. 4.6 billion to 3 million years ago. (See "prehistoric periods" for more detail into this.) Primatomorphid Era – Period prior to the existence of Primatomorpha, before this point, no …The time between the Precambrian Time and the present is divided into three long units called eras: the Paleozoic Era, Mesozoic Era, and Cenozoic Era. Likewise, ...Eras. Eras are divisions of geologic time shorter than eons but longer than periods. In terms of geochronological units, there are 10 defined eras that generally span several hundred million years. For example, the Paleozoic, Mesozoic, and Cenozoic eras are within the Phanerozoic Eon.Earth’s history is divided into a hierarchical series of smaller chunks of time, referred to as the geologic time scale. These divisions, in descending length of time, are called eons, eras, periods, epochs, and ages. These units are classified based on Earth’s rock layers, or strata, and the fossils found within them. From examining these ...Detailed geologic time scale: The United States Geological Survey has published "Divisions of Geologic Time: Major Chronostratigraphic and Geochronologic Units." It is …AboutTranscript. Earth's 4.6 billion-year history has distinct periods. Learn about the four eons - Hadean, Archean, Proterozoic, and Phanerozoic - and how they mark different stages of Earth's history. Discover how geologists use these periods to understand Earth's past and present. Created by Big History Project.It is the latest of three geological eras, preceded by the Mesozoic and Paleozoic. The Cenozoic started with the Cretaceous–Paleogene extinction event , when many species, including the non-avian dinosaurs , became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor . to 0.0082 Ma, Northgrippian from 0.0082 to 0.0042 Ma, and Meghalayan from 0.0042 to present. The geologic community broadly recognizes the Anthropocene as a proposed new time interval of Earth history, partly coincident with the Holocene. Currently, the Anthropocene has an informalDiagrama de la escala de tiempo geológico. El tiempo geológico abarca toda la historia de la Tierra y se mide por medio de una escala del tiempo geológica: ETG o GTS de sus siglas en inglés: Geological Time Scale [1] . Esta escala de tiempo geológico se divide y en intervalos caracterizados por acontecimientos importantes de la historia de la Tierra y de la vida que se registraron en ...... eras: Coenozoic, Mesozoic, paleozoic, Proterozoic and Archezoic. Each era is divided into periods and each period is divided into epochs. It is as follows ...The Crossword Solver found 30 answers to "A geological time span", 3 letters crossword clue. The Crossword Solver finds answers to classic crosswords and cryptic crossword puzzles. Enter the length or pattern for better results. Click the answer to find similar crossword clues . Enter a Crossword Clue Sort by Length # of Letters or PatternGeologic Time Scale. Today, the geologic time scale is divided into major chunks of time called eons. Eons may be further divided into smaller chunks called eras, and each era is divided into periods. Figure 12.1 shows you what the geologic time scale looks like. We now live in the Phanerozoic eon, the Cenozoic era, and the Quarternary period. Eon, Long span of geologic time. In formal usage, eons are the longest portions of geologic time (eras are the second-longest). Three eons are recognized: the Phanerozoic Eon (dating from the present back to the beginning of the Cambrian Period), the Proterozoic Eon, and the Archean Eon. 17 сент. 2019 г. ... A geological era is a formal geochronological unit of the geological time scale that represents the time corresponding to the duration of an era ...The Crossword Solver found 30 answers to "A geological time span", 3 letters crossword clue. The Crossword Solver finds answers to classic crosswords and cryptic crossword puzzles. Enter the length or pattern for better results. Click the answer to find similar crossword clues . Enter a Crossword Clue Sort by Length # of Letters or PatternSince of the Earth's atmosphere is out-of-balance with the conditions expected from simple chemical equilibrium, it is very hard to say what precisely sets the level of the carbon dioxide content in the air throughout geologic time. While scientists are fairly certain that a 100 million years ago carbon dioxide values were many times higher ...period, in geology, the basic unit of the geologic time scale; during these spans of time specific systems of rocks were formed. Originally, the sequential nature of defining periods was a relative one, originating from the superposition of corresponding …Eons are the largest time segments. These are each broken down into Eras which in turn are divided into Periods. The periods are further divided into Epochs.May 2, 2018 · Geologic time scales divide geologic time into eons; eons into eras; and eras into periods, epochs and ages. Photograph: Mark Carnall. Lost worlds revisited Science. The Crossword Solver found 30 answers to "A geological time span", 3 letters crossword clue. The Crossword Solver finds answers to classic crosswords and cryptic crossword puzzles. Enter the length or pattern for better results. Click the answer to find similar crossword clues . Enter a Crossword Clue Sort by Length # of Letters or PatternThe Geologic Time Scale. The geologic time scale. Image by Jonathan R. Hendricks for the Earth@Home project. Note that the geologic time scale above is not scaled to time and mostly represents the Phanerozoic Eon. Mosts of geologic history (88%) happened during the Precambrian, which is represented by Hadean, Archean, and Proterozoic eons.The Cenozoic Era (66 million years ago through today) is the "Age of Mammals." Birds and mammals rose in prominence after the extinction of giant reptiles. Common Cenozoic fossils include cat-like carnivores and early horses, as well as ice age fossils like wooly mammoths. Caves can preserve the remains of ice-age animals that died in them or ...The U.S. Geological Survey offers opportunities to volunteers interested in natural science. Read about volunteer ideas through the U.S. Geological Survey. Advertisement From collecting native plant seeds in Alaska's Denali National Park to...What era of geologic time scale did humans emerge? Hominins first appear by around 6 million years ago, in the Miocene epoch, which ended about 5.3 million years ago. Our evolutionary path takes us through the Pliocene, the Pleistocene, and finally into the Holocene, starting about 12,000 years ago. What are geological materials?Geologists have mapped out a time scale that is a “calendar” of Earth’s geologic history. The scale of geologic time starts some 4 billion years ago, when Earth’s crust was formed. Earth itself is slightly older than this, but when it was first formed the planet was in a hot and thick liquid form. As it cooled, the surface of the planet ... The Geological Time Scale. Now that you have learned about the hierarchical components of the geological time scale--eons, eras, periods, and epochs--consider again how all of these parts fit together. Note that some boundaries (those that follow horizontal lines on the time scale) are equivalent in age.Tune in to International Observe the Moon Night! Catch up on lunar exploration and science from the past year, discover what's on the horizon and explore...15 февр. 2018 г. ... Eons are the largest slices of time, ranging from a half-billion to nearly 2 billion years long. And the earliest Eon is known as the Hadean. It ...The Mesozoic era is an interval of geological time from about 252 to 66 million years ago which is deemed as the age of reptiles. True | False. 8. The Pleistocene epoch is the current epoch which ...The scale divides all geologic time into a series of named intervals or units according to the order in which rocks and fossils were formed. From longest to shortest in relative length, those units are eons, eras, periods, and epochs. The units form a hierarchy in which each type of unit encompasses one or more smaller units—an eon contains ... The Clock Of Eras And Geologic Time. The Clock of Eras is a graphic aid to help us visualize geologic time. It is nearly impossible for the human mind to comprehend the amount of time that it has taken for the Earth to develop to its present state, yet we try to imagine each stage of its unfolding and the time that passed during each phase of ...May 12, 2021 · There are three eras in the Phanerozoic Eon: the Paleozoic, the Mesozoic, and the Cenozoic era. These eras like all geologic times are delineated by the specific rock types or fossil abundant here. Eras within the Phanerozoic eon are replete with fossil remains of organisms. Paleoproterozoic Era. This era is the widest era on the geologic time ... Mesozoic Era, second of Earth’s three major geologic eras of Phanerozoic time. Its name is derived from the Greek term for “middle life.” The Mesozoic Era began 252.2 million years ago, following the conclusion of the Paleozoic Era, and ended 66 million years ago, at the dawn of the Cenozoic Era. Earth's 4.6-billion-year history is divided into Precambrian time and three eras: Paleozoic, Mesozoic, & Cenozoic. Each era is subdivided into a number of ...The Crossword Solver found 30 answers to "A geological time span", 3 letters crossword clue. The Crossword Solver finds answers to classic crosswords and cryptic crossword puzzles. Enter the length or pattern for better results. Click the answer to find similar crossword clues . Enter a Crossword Clue Sort by Length # of Letters or PatternEven while ice sheets covered more and more of Earth’s surface, tectonic plates continued to drift and collide, so volcanic activity also continued. Volcanoes emit the greenhouse gas carbon dioxide. In our current, mostly ice-free world, the natural weathering of silicate rock by rainfall consumes carbon dioxide over geologic time scales.Geologic time on Earth, is represented circularly, to show the individual time divisions and important events. Ga=billion years ago, Ma=million years ago. Geologic time has been subdivided into a series of divisions by geologists. Eon is the largest division of time, followed by era, period, epoch, and age. The students will also be interacting with their journals using INB templates for the geologic time scale. Each INB activity is designed to help students compartmentalize information for a greater understanding of the concept. The geologic time scale INB templates allow students to focus their notes on the Geologic Time Eras. •The geologic history of the North American craton may be divide into two parts - the first dealing with the relatively stable continental interior over which epeiric seas transgressed and regressed, - and the other dealing with the mobile belts where mountain building occurred • In 1963 American geologist Laurence Sloss proposed - that the ...One way to distinguish and define each segment of time is by the occurrence of major geologic events and the appearance (and disappearance) of significant life-forms, starting with the formation of Earth’s crust followed by the appearance of ever-changing forms of life on Earth.Students will be working in pairs to better understand the geologic time scale. Students will be examining a number models of different layers of the earth. From the models, …7.4.5 Geologic Time Scale Figure 7.52: Geologic time on Earth, represented circularly, to show the individual time divisions and important events. Ga=billion years ago, Ma=million years ago. Geologic time has been subdivided into a series of divisions by geologists. Eon is the largest division of time, followed by era, period, epoch, and age.Geologic time period: TOR: Geologic feature: STRATA: Geologic layers: EPOCH: Geologic time unit: MESA: Mexican geologic feature: CENE: End of geologic time? ERA: Unit of geologic time: JURASSIC: Pre-Cretaceous, in geologic history: HOLOCENE: Echelon "0" of a geologic timeEven while ice sheets covered more and more of Earth’s surface, tectonic plates continued to drift and collide, so volcanic activity also continued. Volcanoes emit the greenhouse gas carbon dioxide. In our current, mostly ice-free world, the natural weathering of silicate rock by rainfall consumes carbon dioxide over geologic time scales.Aug 16, 2022 · Era: noun; one of the five major divisions of geologic time. Period: noun; a division of geologic time longer than an epoch and included in an era. Epoch: noun; a division of geologic time less than a period and greater than an age. Precambrian: noun; the earliest era of geological history extending to the beginning of the Phanerozoic eon about ... The geologic time scale is a system used to divide Earth's history into different time intervals. These intervals are categorized into four groups: eons, eras, periods, and epochs. Eons are the largest divisions of time, followed by …The Clock Of Eras And Geologic Time. The Clock of Eras is a graphic aid to help us visualize geologic time. It is nearly impossible for the human mind to comprehend the amount of time that it has taken for the Earth to develop to its present state, yet we try to imagine each stage of its unfolding and the time that passed during each phase of ...One of the warmest times was during the geologic period known as the Neoproterozoic, between 600 and 800 million years ago. Conditions were also frequently sweltering between 500 million and 250 million years ago. And within the last 100 million years, two major heat spikes occurred: the Cretaceous Hot Greenhouse (about 92 million …Results 1 - 24 of 100+ ... Browse eras of geologic time scale resources on Teachers Pay Teachers, a marketplace trusted by millions of teachers for original ...Fossils Through Geologic Time. Fossils are found in the rocks, museum collections, and cultural contexts of more than 260 National Park Service areas and span every period of geologic time from billion-year-old stromatolites to Ice Age mammals that lived a few thousand years ago. Visit the parks that preserve fossils from each major time period.Best Answer. Copy. The 3 eras of geologic time is Palezozoic era, Mesozoic era, and Cecozoic era. Wiki User. ∙ 15y ago. This answer is:Results 1 - 24 of 100+ ... Browse eras of geologic time scale resources on Teachers Pay Teachers, a marketplace trusted by millions of teachers for original ...The Geological Time Scale. Now that you have learned about the hierarchical components of the geological time scale--eons, eras, periods, and epochs--consider again how all of these parts fit together. Note that some boundaries (those that follow horizontal lines on the time scale) are equivalent in age.May 12, 2021 · There are three eras in the Phanerozoic Eon: the Paleozoic, the Mesozoic, and the Cenozoic era. These eras like all geologic times are delineated by the specific rock types or fossil abundant here. Eras within the Phanerozoic eon are replete with fossil remains of organisms. Paleoproterozoic Era. This era is the widest era on the geologic time ... You can see geological toadstools in the Badlands of Nebraska. HowStuffWorks explains how and why these rocky mushrooms form over time. Advertisement You don't go to Toadstool Geologic Park to look at mushrooms. Strange topography is the ma...
Eons may be further divided into smaller chunks called eras, and each era is divided into periods. Figure 12.1 shows you what the geologic time scale looks like .... Puzzle ball math playground
Get familiar with the most important geologic eons, eras, periods and epochs. *Eons and Eras.shown on the poster.The largest time span of the geologic time scaleis the eon.It is an indefinitely long period of time that contains at least two eras.Geologic time is divided into two eons.The more ancient eon is called the Precambrian, and the more recent is the Phanerozoic.Each eon is subdivided into smaller spans called eras.TheA Brief History of Geologic Time | Eons. Video Grades: 9-12. Collection: EONS. About. By looking at the layers beneath our feet, geologists have been able to ...Eras. Eons are divided into smaller time intervals known as eras. In the time scale above you can see that the Phanerozoic is divided into three eras: Cenozoic, Mesozoic and Paleozoic. Very significant events in Earth's history are used to determine the boundaries of the eras. Periods. Eras are subdivided into periods. The events that bound the ...7 окт. 2016 г. ... It marked the end of the Mesozoic Era and the beginning of the Cenozoic Era. All of the dinosaurs and half of the other animals & plants went ...This last point in time is the start of a division of geological time called the Phanerozoic Eon. Phanerozoic means “visible life”, and is the time in which fossils are abundant. Phanerozoic Eon. The Phanerozoic Eon is divided into three eras, the Paleozoic, Mesozoic and Cenozoic eras. These were named for the kinds of fossils that were ... Geologic Time Scale. Another tool for understanding the history of Earth and its life is the geologic time scale. You can see this time scale in Figure below. It divides Earth’s history into eons, eras, and periods. These divisions are based on major changes in geology, climate, and the evolution of life.An interactive project on geologic time, for those who want to explore in more detail. Although the Geologic Column was developed as a relative time scale, geologists wanted to figure out the numerical age dates for Era-Era boundaries and other events. Discovered various techniques: Main one: Radiometric datingto 0.0082 Ma, Northgrippian from 0.0082 to 0.0042 Ma, and Meghalayan from 0.0042 to present. The geologic community broadly recognizes the Anthropocene as a proposed new time interval of Earth history, partly coincident with the Holocene. Currently, the Anthropocene has an informalEon, Long span of geologic time. In formal usage, eons are the longest portions of geologic time (eras are the second-longest). Three eons are recognized: the Phanerozoic Eon (dating from the present back to the beginning of the Cambrian Period), the Proterozoic Eon, and the Archean Eon. Apr 16, 2022 · What are the 4 main geologic period? The Precambrian, Paleozoic, Mesozoic, and Cenozoic Eras. The Geologic Time Scale is the history of the Earth broken down into four spans of time marked by various events, such as the emergence of certain species, their evolution, and their extinction, that help distinguish one era from another. shown on the poster.The largest time span of the geologic time scaleis the eon.It is an indefinitely long period of time that contains at least two eras.Geologic time is divided into two eons.The more ancient eon is called the Precambrian, and the more recent is the Phanerozoic.Each eon is subdivided into smaller spans called eras.The Earth's 4.6-billion-year history is divided into Precambrian time and three eras: Paleozoic, Mesozoic, & Cenozoic. Each era is subdivided into a number of ...Cretaceous Period, in geologic time, the last of the three periods of the Mesozoic Era. The Cretaceous began 145.0 million years ago and ended 66 million years ago; it followed the Jurassic Period and... Tertiary Period. Tertiary Period, former official interval of geologic time lasting from approximately 66 million to 2.6 million years ago.Generally, the eras used to describe the modern Earth are the Quaternary geological era and the Cenozoic evolutionary era. In the future, there may also be a historical era that the current time period, the 21st century, will belong to.Precambrian, period of time extending from about 4.6 billion years ago (the point at which Earth began to form) to the beginning of the Cambrian Period, 541 million years ago. The Precambrian encompasses the Archean and Proterozoic eons, which are formal geologic intervals that lasted from 4 billion to about 541 million years ago, and the ...The Cenozoic Era (66 million years ago through today) is the "Age of Mammals." Birds and mammals rose in prominence after the extinction of giant reptiles. Common Cenozoic fossils include cat-like carnivores and early horses, as well as ice age fossils like wooly mammoths. Caves can preserve the remains of ice-age animals that …The primary objective of the International Commission on Stratigraphy (ICS) is to precisely define global units (systems, series, and stages) of the International Chronostratigraphic Chart that, in turn, are the basis for the units (periods, epochs, and age) of the International Geologic Time Scale .