GEOLOGIC TIME SCALE
Time Units of the Geologic Time Scale
Eon
Era
Period
Development of
Plants and Animals
Epoch
Holocene
Quaternary
0.01
Pleistocene
1.6
Cenozoic
Tertiary
5.3
Eocene
Cretaceous
Jurassic
145
208
Triassic
33.7
65
“Age
of
Reptiles”
248
Carboniferous
Palaeozoic
410
Silurian
Cambrian
438
505
545
Vendian
650
First reptiles
Large coal swamps
Amphibians abundant
360
Ordovician
Archean Proterozoic
“Age
of
Amphibians”
Mississippian
Devonian
Extinction of dinosaurs
and many other species
First flowering plants
First birds
Dinosaurs dominant
First mammals
Extinction of trilobites and
many other marine animals
286
320
“Age of Mammals”
55
Permian
Pennsylvanian
Earliest hominids
23.8
Oligocene
Palaeocene
Mesozoic
Phanerozoic
Pliocene
Miocene
Earliest Homo sapiens
“Age
of
Fishes
“Age
of
Invertebrates”
“Soft-bodied
faunas”
First amphibians
First insect fossils
Fishes dominant
First land plants
First fishes
Trilobites dominant
First organisms with shells
Abundant Ediacaran faunas
First multicelled organisms
Collectively called
Precambrian
2500
3800
Hadean
4600 Ma
comprises
about 87% of the
geological time scale
First one-celled organisms
Age of oldest rocks
Origin of the earth
Describe the Geological Time Scale with the development of life in the Earth.
Prepared by : Dr. Basanta Raj Adhikari
Tribhuvan University
Institute of Engineering
Pulchowk Campus
Department of Civil Engineering
N
N
Plan View
Block 1
N
Plan View
Block 2
Prepared by: Dr. Basanta Raj Adhikari
Tribhuvan University
Institute of Engineering
Pulchowk Campus
Department of Civil Engineering
N
N
55
55
Plan View
AP
Block 3
N
N
55
55
Plan View
Block 4
AP
Prepared by: Dr. Basanta Raj Adhikari
Tribhuvan University
Institute of Engineering
Pulchowk Campus
Department of Civil Engineering
N
N
27
55
Plan View
AP
Block 5
N
N
27
55
Plan View
Block 6
AP
Prepared by: Dr. Basanta Raj Adhikari
Tribhuvan University
Institute of Engineering
Pulchowk Campus
Department of Civil Engineering
N
N
Plan View
Block 9
N
N
Plan View
Block 10
Prepared by: Dr. Basanta Raj Adhikari
Tribhuvan University
Institute of Engineering
Pulchowk Campus
Department of Civil Engineering
N
N
27
Plan View
Block 7
N
N
27
Plan View
Block 8
Prepared by: Dr. Basanta Raj Adhikari