Geology Test 2 Review Flashcards

Questions and Answers

What is a craton, and how does tectonic activity help explain the formation of new continental crust along the edges of a craton?

A craton is the ancient nucleus of a continent, and new continental crust is added along its margins as oceanic plate is subducted, resulting in volcanic activity that adds igneous rock. Terranes are fragments of crust accreted onto the continent.

What is an anticline and a syncline, and how are they thought to form?

An anticline is an upward fold in bedrock, whereas a syncline is a downward fold. They form due to the interactions of continental plates that compress and deform the rock.

What is a fault and how are faults thought to form?

A fault is a break in bedrock where movement occurs, forming due to tectonic activity that pulls rock apart or compresses it.

Where is the Basin and Range Province, and how does the landscape of this region show the influence of faulting?

The Basin and Range Province is located in the interior of the American West, mainly Nevada and Utah, where tension has created a series of valleys and mountains due to downward-faulted blocks (grabens) and upward-faulted blocks (horsts). Signup and view all the answers

What is orogenesis?

Mountain building. Signup and view all the answers

How does the interaction of tectonic plates explain how orogenesis occurs?

Plate interactions cause volcanic activity and crustal deformation (folding and faulting) which build mountains. Signup and view all the answers

What is denudation?

Processes that wear down or rearrange landforms. Signup and view all the answers

What is weathering?

Processes that break down bedrock into smaller particles or dissolve rocks. Signup and view all the answers

How does physical weathering differ from chemical weathering?

Physical weathering involves the breakage of rocks without chemical change, while chemical weathering involves chemical reactions that alter the minerals in the rocks. Signup and view all the answers

What are mass movements, and what causes them?

Mass movements, or mass wasting, are downslope movements of weathered material caused by gravity. Signup and view all the answers

Characterize the following types of mass movement by speed and water content:

Rockfall = Rapid, dry Debris avalanche = Rapid, moderately wet Soil creep = Slow, dry Solifluction = Slow, wet Signup and view all the answers

Study Notes

Cratons and Continental Crust Formation

Craton: ancient, stable part of a continent, exposed in the continental shield.
New continental crust forms at craton margins via subduction of oceanic plates.
Subduction leads to volcanic activity, adding igneous rock to the continent.
Terranes: fragments of crust, like islands, accreted to craton edges during tectonic activity.

Anticlines and Synclines

Anticline: upward fold in bedrock, indicating compression forces.
Syncline: downward fold in bedrock, also formed from compression.
Formation linked to interactions of continental plates that cause rock deformation.

Faults

Fault: break in bedrock with movement occurring along its plane.
Formed through tectonic activity: pulling apart (causing fault drops) or compressing (creating folds).

Basin and Range Province

Located in the American West, primarily Nevada and Utah.
Characterized by faulting that results in grabens (downward-faulted blocks) and horsts (upward-faulted blocks).
Landscape features alternating valleys and mountains.

Orogenesis

Orogenesis: the process of mountain building caused by plate tectonics.

Tectonic Plates and Orogenesis

Mountain building arises from volcanic activity and crustal deformation due to plate interactions.
Deformation includes folding and faulting of the Earth's crust.

Denudation

Denudation: processes that wear down or rearrange landforms, critical in geomorphology.
Involves weathering and erosion that strips down landscape features.

Weathering

Weathering: breakdown of bedrock into smaller particles, can involve dissolution of rocks.

Physical vs. Chemical Weathering

Physical Weathering: mechanical breakage of rocks, no chemical change occur.
Chemical Weathering: alters rock minerals through chemical reactions, e.g., limestone forming karst terrain.

Mass Movements

Mass movements, or mass wasting: downslope movement of weathered material due to gravity.

Types of Mass Movement

Rockfall: rapid movement of dry material.
Debris avalanche: rapid movement of moderately wet material.
Soil creep: slow movement of dry material.
Solifluction: slow, water-saturated movement in regions with freezing and thawing.

Description

Prepare for your geology test with these review flashcards focusing on cratons and tectonic activity. This set includes definitions and discussions surrounding the formation of new continental crust and the role of terranes. Enhance your understanding of fundamental geological concepts.