Lecture 2 - Geographical Time Scale and Stratigraphy

Question 1

epochs of the Cenzoic

Paleocence

Answer 1

66.0 ma
non-avian dinos become extinct

Question 2

What was the Cenzoic

Answer 2

age of mammals
past 65 million years

Question 3

epochs of the Cenzoic

Eocene

Answer 3

56 ma
first true primates

Question 4

epochs of the Cenzoic

Oligocene

Answer 4

33.9 ma
anthropoid primates

Question 5

epochs of the Cenzoic

Miocence

Answer 5

23.02 ma
early apes

Question 6

epochs of the Cenzoic

Pliocene

Answer 6

5.33 ma
early apes

Question 7

epochs of the Cenzoic

Pleistocene

Answer 7

2.58 ma
early hominins

Question 8

epochs of the Cenzoic

Holocene

Answer 8

0.1 ma
early humans

Question 9

types of rocks

igneous formation

Answer 9

cooling of magma (molten rock underground)

Question 10

types of rocks

forms of igneous rock

Answer 10

intrusive - cool slowly within earth (large crystals like granite)
extrusive - cool fast on surface (small crystals like basalt)

Question 11

types of rocks

sedimentary formation

Answer 11

formed by accumulation of particles

Question 12

types of rocks

clastic sedimentary rocks

Answer 12

weathered bits of other rocks
- occurs due to filling of low lying areas, water action/flow is key
- 90% of fossils found here

Question 13

types of rocks

types of clastic sedimentary

Answer 13

sandstone - particles = rocks that are sand sized
breccia - sharp, angular pieces
conglomerate - lots of sizes

Question 14

types of rocks

organic sedimentary

Answer 14

animal and plant debris
- produced through accumulation of organic debris (CaCO3)
- esp. in shallow ocean

Question 15

types of rocks

chemical sedimentary

Answer 15

dissolved minerals precipitate directly from water suspension
- “hard” water

Question 16

types of rocks

Metamorphic

Answer 16

rock modified by heat and pressure from original form
- usually formed deep underground

Question 17

Fossil Formation

What is a Fossil?

Answer 17

mineralized remains of an organism, or impression of the organism
- often occurs in clastic sedimentary rock

Question 18

Fossil Formation

Steps of fossil formation

Answer 18

1. death
2. neglect
3. burial
4. fossilization

Question 19

Fossil Formation

factors of neglect in fossil form.

Answer 19

neglect from typical factors that prevent fossil from entering fossil record
- predators, weathering from UV radiation, microbes

Question 20

Fossil Formation

process of burial for fossil form

Answer 20

burial aids neglect
occurs in clastic sediments

Question 21

Fossil Formation

process of fossilization in fossil form.

Answer 21

replacement of biogenic minerals with minerals in groundwater
- some fossils preserve as casts (e.g. brains)
- takes LONG time to form

Question 22

first appears

Homo appears

Answer 22

2.8 ma

Question 23

first appears

first hominins

Answer 23

6-7 ma

Question 24

first appears

early apes

Answer 24

25 ma

Question 25

first appears

early primates

Answer 25

55 ma