Lecture 3 - When did Dinos live?

Question 1

The geologic time scale is the “_____” of events in Earth’s history.

Answer 1

calendar

Question 2

During what era did the dinosaurs live?

Answer 2

Mesozoic

Question 3

What are the 3 time periods within the Mesozoic Era

Answer 3

Cretaceuos (Last Dinos) 145 to 65.5
Jurassic 200 to 145
Triassic (First Dinos) 252 to 200

Question 4

How is the geological time scale built?

Answer 4

By studying rocks and the fossils within them

Question 5

Igneous

Answer 5

Solidify from melted rocks (magma)

Question 6

Metamorphic

Answer 6

Heated and squeezed rocks

Question 7

Which rock type will we most likely find dinos?

Answer 7

Clastic

Question 8

Clastic sedimentary rocks

Answer 8

Sediments deposited on land/beaches/in rivers, buried, and then glued together to make a rock

Question 9

Chemical Sedimentary Rocks

Answer 9

Limestone, salt
Sediments crystallize out of water
Form in lakes/seas due, sometimes to evaporation

Question 10

What happens to grain size as sediment is moved away from the source?

Answer 10

Decreased

Question 11

As water slows down it will deposit ___ and ___ sediment

Answer 11

finer and finer

Question 12

The WCSB formed bc the heavy load of mountains in BC caused the plate to sink down. Why did mountains form here?

Answer 12

Isostasy. Converging tectonics = subduction

Question 13

Imbricated

Answer 13

point in direction of flow

Question 14

Bentonite

Answer 14

Eruptions leave clouds of ash

Question 15

Lithostratigraphy

Answer 15

Relative dating of tocks

Question 16

Biostratigraphy

Answer 16

Relative dating of fossils

Question 17

Strata

Answer 17

Layers of sedimentary rocks

Question 18

Principle of Superposition

Answer 18

Oldest sediments are usually on the bottom

Question 19

Is the dike older or younger than the surrounding srtate

Answer 19

younger. Strata had to be there before

Question 20

A rock inclusion is ___ that is host

Answer 20

older. The inclusion had to exist first in order to be incorporated into another unit

Question 21

Rocks above an uncomformity (erosional surface) are ____ than the rocks below

Answer 21

younger

Question 22

Fauna

Answer 22

Diversity of life at a given time

Question 23

The principle of faunal succession

Answer 23

Extinct animals will only appear in rocks that formed when it was alvie

Question 24

What makes a good index fossil?

Answer 24

Widespread geographically
Exsited for a short range of geological time

Question 25

Isoptopes

Answer 25

Same number of protons diff neutrons

Question 26

Stable isotpoes do not _____

Answer 26

spont breakdown

Question 27

Radioactive isoptopes

Answer 27

(parent isotopes) are not stable and break down into daughter isotopes over time

Question 28

How is radiometric dating measure?

Answer 28

Using half life: the amount of time it takes for half of the sample to break down

Question 29

Radiometric dating is based on…

Answer 29

known rates of radioactive decay to estimate the age of geological samples

Question 30

How can we calculate the age of the dample with radioactive decay?

Answer 30

Measure the ratio of parent to daughter isotope and we know the half life

Question 31

Two conditions for selecting an appropriate radioisotope when dating a sample

Answer 31

The isotope must be present in the sample to begin with
There must be measurble quantities of both the parent and the daughter in the rock

Question 32

Is carbon an appropriate isotope for dating dinos?

Answer 32

C14 is not reliable because the half life is too fast

Question 33

Sed rocks contain radioactive isotopes but the ages represent the age of the mineral and not the rock

Question 34

The geological time scale is divided into smaller units

Answer 34

eons, eras, periods