Lecture 18

Question 1

How far down to the successions of layers in the Earths crust go and what does this demonstrate?

Answer 1

10 000m. Demonstrates that Earth is OLD AF

Question 2

What did John Strachi do?

Answer 2

Made drawings of layer successions in 1745. Discovered facious terminations

Question 3

What are facious terminations?

Answer 3

Things that define the appearance of a layer

Question 4

What are the 5 types of terminations?

Answer 4

Lateral, Faulting and erosion, Pinchout, Intertonguing, Lateral Gradation

Question 5

What are lateral terminations?

Answer 5

When the layer terminates at the edges of the sedimentary basin

Question 6

What is faulting and erosion?

Answer 6

Thing that determines the termination of a layer

Question 7

What is a pinch out termination?

Answer 7

Occurs due to sea level changes through geological time

Question 8

What are the 2 components of a pinch out termination?

Answer 8

Transgression and Regression

Question 9

What are transgressions?

Answer 9

When the shore line moves forward towards the continent

Question 10

What are regressions?

Answer 10

Shoreline moves backwards to ocean. Pinch out termination shows new layers terminate during each transgression and regression cycle.

Question 11

What is intertonguing?

Answer 11

Successive pinch out termination. Demonstrates sea level fluctuations over a period of time,

Question 12

What is lateral gradation?

Answer 12

Gradual facious determination. Crucial for next half century and changes in science.

Question 13

Who published a book claiming that the Earth may be older than previously thought (over 70 000 years) and how did he do it?

Answer 13

Cont Debufont in 1774. Calculated the time of cooling for certain metals. Extrapolated that time to mass of Earth and came up with Earth’s age in hours

Question 14

When did creationism lose influence in science?

Answer 14

1774

Question 15

Who discovered that successions of rocks are either normal or turned upside down?

Answer 15

Thomas (something). Discovered this in the Alps.

Question 16

What are mudcracks?

Answer 16

Structures formed from evaporation of fluid from a wet sediment Always present opening towards upper part of a layer

Question 17

What are burrowings?

Answer 17

Areas where organisms burrowed into the rock for food/protection. Opening is always at the top of the layer

Question 18

What are ripple marks?

Answer 18

Structures formed in a sediment by water. Asymmetrical or symmetrical. Always narrow upwards.

Question 19

What do burrowings, mudcracks, and ripple marks help us to determine?

Answer 19

Recognizing the original position of the sea bottom.

Question 20

What is one of the most important questions with stratigraphy?

Answer 20

How do we compare rock successions from other parts of the world?

Question 21

What are conformable successsions?

Answer 21

Strata without depositional breaks

Question 22

What are non-conformable successions (unconformities)

Answer 22

Strata that are separated by surfaces of discontinuity, encompassing substantial amounts of geological time. At some point, sedimentation stopped and eroded.

Question 23

What are the types of unconformities?

Answer 23

Disconformities, Angular, Non-conformity

Question 24

What is a disconformity?

Answer 24

Existence of sedimentary layers below and above (unconformity). Layering is parallel below and above conformity. LOwer succession is formed and uplifted, then eroded. Top hardened, sank, created sedimentation of upper layers.

Question 25

What is an angular unconformity?

Answer 25

Sedimentary layers below and above form an angle. Succession below unconformity was formed with diagonal layers. Folding and fracturing resulted in layers changing position. Sunken, sedimentation started again horizontally

Question 26

What is a non-conformity?

Answer 26

Below the unconformity=igneous rocks. Above=sedimentary and metamorphic rocks.

Question 27

What did Charles Lyle discover in 1830?

Answer 27

Idea of Unconformity: Dis, angular, and non conformities all formed at the same time, and not different. Non-conformities cannot be used to figure out Earth’s Age.