Lecture 1

Question 1

Superposition

Answer 1

Strata are deposited sequentially, so that in an undisturbed sedimentary succession each layer is younger than the layer beneath it

Question 2

Biostratigraphy

Answer 2

Branch of stratigraphy that involves the use of fossil plants and animals in the dating and correlation of stratigraphic sequences of rocks in which they are discovered.

Question 3

Uniformitarianism

Answer 3

An attempt to explain the former changes of the Earth’s surface, by reference to causes in operation  described as an oversimplification:

Question 4

Biological proxies:

Answer 4

Micro-fossils (pollen, phytoliths, diatoms) and macro-fossils (bones, seeds, wood)

Question 5

Physical proxies

Answer 5

Sediment properties (colour, chemistry) and isotopes (oxygen, carbon)

Question 6

Age estimates:

Answer 6

radiometric & incremental

Question 7

Radiometric

Answer 7

radioactive decay occurs and is time-dependent
- Radiocarbon dating
- Uranium series dating
- Potassium-argon dating
- Thermoluminescence dating

Question 8

Incremental

Answer 8

regular accumulation of a biotic or abiotic material (tree rings, laminated lake sediments, lichen growth, ice layer accumulation)

Question 9

Relative ages

Answer 9

a thing changes through time:
- Pottery typology
- Biogeochemistry of amino acids
- Fluorine, uranium and nitrogen content of fossils
- Obsidian hydration
- Weathering and soil formation

Question 10

Age- equivalence

Answer 10

event is recorded simultaneously in multiple locations:
- Tephrochronology (volcanic ash layers)
- Palaeomagnetism

Question 11

Circle around the sun

Answer 11

eccentricity - 100.000 years

Question 12

tilt of the earth’s axis relative to the sun

Answer 12

obliquity - 41.000 years

Question 13

wobble of the earth upon its axis

Answer 13

precession - 25.000 years

Question 14

Sunspot

Answer 14

Sunspots are phenomena on the Sun’s photosphere that appear as temporary spots that are darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic flux that inhibit convection

Question 15

The K-T boundary mass extinction

Answer 15

• Disappearance of large marine and terrestrial fossils 65 million years ago
• Peak of iridium in a peculiar clay layer

Question 16

Concept earth system services

Answer 16

Earth system science is the study of how scientific data stemming from various fields of research, such as the atmosphere, oceans, land ice and others, fit together to form the current picture of our planet as a whole, including its changing climate.

Question 17

Climate teleconnections

Answer 17

“spatially and temporally large scale anomalies that influence the variablility of the atmospheric circulation”

Question 18

el nino

Answer 18

warmer ocean patterns, dryer amazon, high rainfall in the Andes

Question 19

la nina

Answer 19

a climate pattern that describes the cooling of surface ocean waters along the tropical west coast of South America