Geologic Time:
Group 1: You have been assigned the entire geologic timescale. Please plot the major
Eon boundaries and the following events:
Event
Earth forms
Formation of the moon
Oldest known zircon
Oldest known rocks
Period of major impact events on moon
Oldest known banded iron formation (free oxygen in the ocean)
Major interval of banded iron formations
Snowball Earth events
Ediacaran fauna
Cambrian explosion (abundant marine organisms in the geologic record)
Formation of Pangea (supercontinent)
Gondwana glaciation and major coal deposits
Largest Mass extinction in Earth history and outpouring of the Siberian Traps
Rifting of Pangea (Triassic basins, e.g. Palisade sill; Central Atlantic Magmatic
Province CAMP)
Extinction of the Dinosaurs and outpouring of Deccan Traps
Most recent glaciation of New York city
Time in billions of years before
present
4.56
4.45
4.4
4.0
3.9
3.8
2.4-1.8
0.713, 0.635, and 0.580
0.549-0.543
0.542
0.300
0.320-0.290
0.251
0.200
0.065
0.00002
**Note to all: The Deccan and Siberian Traps are examples of Large Igneous Provinces. Both are large volume
outpourings of basaltic magma onto the surface of the Earth that are believed to have altered the chemistry and
transparency of Earth's atmosphere.
Group 2: You have been assigned the Paleozoic. Please plot the major Period boundaries and the
following events:
Event
Precambrian-Cambrian boundary (~time of deposition of sedimentary and volcanic
rocks in Central Park)
Early fish
Taconic Mountains (~time of high grade metamorphism of rocks in Central Park)
Earliest land plants
Deposition of Shawangunk Quartzite (rock climbing cliffs in New Paltz)
Earliest fossil amphibians (i.e first animals on land!)
Acadian Mountains (second period of high grade metamorphism in Central Parkformation of small granite bodies); deposition of sediments that form the Catskills
Early trees, formation of coal deposits
Reptiles!
Alleghenian Mountains (Himalayan size mountains along current east coast of North
America, major sedimentary deposits in Pittsburg PA)
Gondwana glaciation and major coal deposits
Final assemblage of Pangaea super-continent
Emplacement of the Siberian Traps and the largest Mass Extinction event in Earth
history! (Paleozoic-Mesozoic boundary)
Time in millions of years
before present
542
490
450
430
416
370
370-360
363-300
325
300
320-290
300-290
251
Group 3: You have been assigned the Mesozoic. Please plot the major Period boundaries and the
following events:
Event
Paleozoic-Mesozoic boundary
First crocodiles
Rifting that eventually led to opening of the Atlantic Ocean begins (Triassic/Jurassic
rift basins- local examples are Newark and Hartford Basins, these are the sources
of "brownstone" building material)
Palisade Sill emplaced (CAMP)- this is approximately the Triassic-Jurassic boundary
Early Mammals (shrew-like, rodents)
North America separates from Africa- beginning of North Atlantic Ocean
First bird, Archaeopteryx
Earliest flowering plant, Archaefructus
South America separates from Africa- beginning of South Atlantic
Tyrannosaurus Rex and Velociraptors roam
Extinction of the dinosaurs and outpouring of the Deccan Traps basalt (MesozoicCenozoic boundary)
Time in millions of years
before present
251
240
220
200
200
190
155
130
100
70
65
Group 4: You have been assigned the Cenozoic. Please plot the Epoch boundaries and the following
events:
Event
Mesozoic-Cenozoic boundary
First Primates
Crocodiles in Canadian Arctic
First horses
India begins to collide with Asia
Antarctic Circumpolar Current forms
Antarctic Ice caps form
First evidence of North Atlantic Deep Water forming
Alps form (restriction of Tethyan seaway, formation of Mediterranean Sea)
Panama passage closes, linking of North and South America
Early hominids (Australopithecus)
Initiation of major Northern Hemisphere glaciation
Beginning of prominent 100 ky glacial cycles
First use of fire
Last time glaciers covered New York City (last glacial maximum or LGM, (pCO2 180
ppmv)
Last major cold snap in Greenland
Modern man
Medieval Warm Period (Vikings settle Greenland)
Little Ice Age (Viking settlements collapse)
Death of King Tutankhamen
Beginning of Industrial revolution (pCO2 280 ppmv)
Today (pCO2 380 ppmv)
Time in millions of years
before present
65
60
55
55
40
35
35
35
20
4
3
2.7
0.7
0.5
0.018
0.013
0.01
0.0007-0.0010
0.0035-0.0015
0.003
0.0001
0