Rocks Flashcards
(25 cards)
What are the layers of the earth and the depths of each
Crust <100km
Mantle 2,800 km
Core 3,500 km radius
What rock types are in the crust
Various solid silicates
What rock types are in the mantle
Hot plastic iron silicates
What is the lithosphere
The first 100km of earth-similar to the crust
The lithosphere is broken up into ____ plates
Tectonic
What are the three types of plate boundaries
Convergent
Divergent
Transform
What is a convergent plate boundary
Two plates heading towards each other which results in plate destruction
What is a divergent plate boundary
When two plates are moving away from each other resulting in new crust
What is a transform plate boundary
When two plates are moving alongside each other
What are the three types of rocks
Igneous
Sedimentary
Metamorphic
What is an igneous rock and give some examples
Igneous rocks are rocks formed by magma in the earths mantle cooling
Examples: basalt, andesite, tuff, rhyolite
What is a sedimentary rock and give some examples
Rocks formed by breakdown and deposition of other rocks
These are then compacted and cemented using water
What is the process of compaction and cementation of sedimentary rocks called
Lithification
What are metamorphic rocks
Rocks that are formed by undergoing one of three changes:
Thermal metamorphism
Dynamic metamorphism
Regional metamorphism
What is the conditions for thermal metamorphism
High temperatures
Relatively low temperatures
Adjacent to igneous intrusions
What is the conditions for dynamic metamorphism
Extreme pressure
Minerals ground up and resistant material left
Usually in fault zones
What is the conditions for regional metamorphism
High temperature AND pressure
Slow formation
Very large rock mass affected-mountains
What are some types of metamorphic rocks (bonus points if you put them in order of increasing metamorphism
Least: shale,
slate,
phylitte,
schist,
Most: gneiss
What is weathering
The natural decay and breakdown of rocks and eventually soil
What is the unconfined compressive test (UCS)
Cylinder of 50mm diameter and 100mm height
is compressed from top and bottom with slowly increasing force until failure
What is triaxial test
Cylinder of 50mm diameter and 100mm height
is pressed from top bottom and sides to simulate real ground conditions
with slowly increasing force until failure is reached
What is the Brazilian disk test
A disk of rock of diameter 54mm and thickness 27mm is
crushed across the circular face
What is the rock degradability test
Samples are dried and weighed
then tumbled in water,
dried and tumbled again
and then finally weighed to find how much has come off
What is a fold
When a rock deforms under pressure
