COURSE: GEOMORPHOLOGY-ORIGIN AND EVOLUTION OF EARTH AND RELATED THEORIES LESSON: GEOLOGICAL TIME SCALE-PART1 PRESENTED BY BHUMIKA SAINI
About me .B Tech from MNIT, Jaipur Interests: Reading, Playing Badminton Appeared in CSE interview thrice Three years of experience in teaching .Course fee: CONTRIBUTE Follow me on Unacademy: https://unacademy.in/user/BhumikaSaini me on Unacademy: httpsi//unacademyin/user/BhumikaSaini
THE GEOLOGICAL TIME SCALE . The geological time scale (GTS) is a system of chronological measurement that describes the timing and relationships between events that have occurred throughout Earth's history. . Scientists developed the time scale by studying rock layers and fossils world wide. Radioactive dating helped determine the absolute divisions in the time scale.
DIVISION OF GEOLOGICAL TIME SCALE EPOCH PERIOD EPOCH EPOCH EPOCH EPOCH ERA EON PERIOD ERA PERIOD
APPLICATIONS Illustrate the vast diversity of life that has been present on Earth over time Summarize how scientists study Earth's past environment and diverse life-forms by examining different types of fossils e Summarize how scientists stu . Explains how Earth's history has been influenced by catastrophes that have affected the conditions on Earth and the diversity of its life-forms. ecions on Earth and the diversity of its life-forms
DIVISIONS OF GEOLOGIC TIME- Geological time begins with Precambrian Time. PRE-CAMBRIAN-88% of earth's history Paleozoic (ancient life) . 544 million years ago, lasted 300 million yrs Mesozoic (middle life) 245 million years ago, lasted 180 million yrs Cenozoic (recent life) . 65 million years ago, continues through present day Today we are in the Holocene Epoch of the Quaternary Period of the Cenozoic Era.
Millions of years Era Period Epoch Quaternary 0.o1 Miln Millions of years 1go Pleistocene Eon Era 5.3 Cenozoic oic Cenozoic 85 251 Paleog aleogene Eocene 8 Paleocene 65.5 Neoprot Mesoproterozoi 145.5 Mesozoic 199 Triassic erozoic Permian Pennsyivanian 318 Mississippian Devonian Paleoarchean Paleozoic Goo Situri Eoarchean Ordov ician Preca
EPOCH PLEISTOCENE PLIOCENE MIOCENE EON ERA MYA 0.0 1+-- ICE AGE ENDS 1 .6ICE AGE BEGINS PERIOD QUATERNARY EARLIEST HUMANS 5.3 23.7 36.6 57.8 66 + TERTIARY 2OLIGOCENE FORMATION OF HIMALAYAS EOCENE PALEOCENE 1 DINOSAUR EXTI ROCKY MTS FORMED | CRETACEOUS ION 144 JURASSIC TRIASSIC PERMIAN 208 FIRST MAMMALS PANGEA BREAK UP FIRST DINOSAURS 245 286 320 PENNSYLVANIAN MISSISSIPPIAN 360 FIRST REPTILES FIRST ANPHIBIANS DEVONIAN 408 438 ORDOVICIAN 505 570 | SIL URIAN FIRST SP PLANTS FIRST LAND PLANTS FIRST FISH EARLIEST SHELLED ANIMALS PROTEZOIC EON 2500 AR CHEAN EON LIFE 3800 4600
P CA PE START OF EACH PERIOD (in millions of years) ERA FLORA & FA UNA Modem species of mammals, extinction of large forms, such as mammoth; dominance of human Cenzoic Quarternary Tertiary 54 Rise of birds and placental mamm als Domin ance of flowering plants; extinction of large reptiles and ammonites by end of period Mesozoic Cretaceous 65 Reptiles dominant on land, sea and in air first birds; archaic mammals Jurassic 145 First dinosaurs, turtles, Ichthyosaurs, plesiosaurs; cycads and conifers Triassic 20 Paleozoic Pian Radiation of reptiles, which displace amphibians as dominant group widespread glaciation Paleozoic Permian 245 Fems as dominant plant group; sharks and crinoids abundant; radiation of amphibians; frst reptiles Carboni ferous 286 Devonian A ge of fishes (mostly freshwater): first trees and first amphibians 360 Invasion of the land by plants and arthropods; braciopods; primitive jawless vertebrates Siluriarn 408 Appearance of vertebrates (armoured fishes); brachiopods and cephalopods dominant Ordovician 438 Appeamce of all inv ertebrate phyla and many classes; dominance of trilobites and brachiopods Cambrian 505
B Tech from MNIT, Jaipur. Appeared in CSE interview thrice. Loves teaching and playing badminton.