Earth History

Question 1

Geological Time Scale

Answer 1

Calendar of events of the history of the earth that expands from different time period

Question 2

Law of Superposition

Answer 2

A basic law of geochronology, stating that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and oldest on bottom, each layer being younger than the one beneath it and older than the one above it

Question 3

Law of crosscut

Answer 3

An igneous rock, fault, or other geologic feature must be younger than any rock across which it cuts.

Question 4

Horizontality

Answer 4

The Principle of Original Horizontality states that layers of sediment are originally deposited horizontally under the action of gravity. It is a relative dating technique. The principle is important to the analysis of folded and tilted strata. It was first proposed by the Danish geological pioneer Nicholas Steno.

Question 5

Geological changes

Answer 5

Geological changes due to erosion, weathering, tectonic plate movement, earthquakes, volcanic eruptions, land slides, etc.

Question 6

Earthquakes

Answer 6

A sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth’s crust or volcanic action.

Question 7

Volcano

Answer 7

A mountain or hill, typically conical, having a crater or vent through which lava, rock fragments, hot vapor, and gas are being or have been erupted from the earth’s crust.

Question 8

Meteor impacts

Answer 8

When a meteor strikes the a planet causing geological changes.

Question 9

Landslides

Answer 9

The movement of a mass of rock, debris, or earth down a slope.

Question 10

Plate motions

Answer 10

The constant movement of the tectonic plates.

Question 11

Ocean structure

Answer 11

Continental Shelves - The area of seabed around a large landmass where the sea is relatively shallow compared with the open ocean. The continental shelf is geologically part of the continental crust.
●12. Ridges - An underwater mountain system formed by plate tectonics.
●13. Fracture Zones- A long, narrow rift on the ocean floor, separating areas of differing depth: where such a zone crosses a mid-ocean ridge, it displaces the ridge by faulting.
●14. Trenches – Long, narrow depressions on the seafloor.

Question 12

Pangea

Answer 12

A supercontinent that incorporated almost all the landmasses on Earth.

Question 13

Continental drift

Answer 13

The gradual movement of the continents across the earth’s surface through geological time.

Question 14

Alfred Wagner

Answer 14

German meteorologist and geophysicist who formulated the first complete statement of the continental drift hypothesis.

Question 15

Relative dating

Answer 15

Used to arrange geological events, and the rocks they leave behind, in a sequence.

Question 16

Fossils

Answer 16

Remnant, impression, or trace of an animal or plant of a past geologic age that has been preserved in Earth’s crust.

Question 17

Plate boundaries

Answer 17

Subduction - A geological term for one of Earth’s tectonic plates sinking under another.
●21. Collision – Continental collision is a phenomenon of the plate tectonics of Earth that occurs at convergent boundaries. Continental collision is a variation on the fundamental process of subduction, whereby the subduction zone is destroyed, mountains produced, and two continents sutured together.
●22. Divergent - A tectonic boundary where two plates are moving away from each other and new crust is forming from magma that rises to the Earth’s surface between the two plates.