Week 2 Rock cycle Flashcards
Types of rocks
Igneous
Sedimentary
Metamorphic
Igneous rocks
Made from the melting of rocks in hot, deep crust and upper mantle. This process is called crystallization (solidification of magma)
Crystallization
Solidification of magma into rocks
Sedimentary rocks are made by
Made from the weathering and erosion of rocks exposed at surface. Sedimentary rocks are made from processes of deposition, burial, and lithification.
Metamorphic rocks
Sourced from rocks under high temperatures and pressures in deep crust and upper mantle. Metamorphic rocks are made during the process of recrystallization in solid-state of new minerals.
Magma
A mass of molten rock originates from deep within the crust and upper mantle at temperatures above 1200 celsius. When magma cools beneath the earth’s surface, microscopic crystals begin to form.
Intrusive rocks
As magma cools and forms microscopic crystals into larger ones, it forms a coarse-grained igneous rock.
Extrusive rocks
When magma erupts from a volcano onto Earth’s surface, it cools and solidifies rapidly not giving time to form large crystals. Many tiny crystals form simultaneously, forming a fine grained igneous rock.
Two types of igneous rock
Mafic and Felsic
Porphyritic crystals
Crystals which start to grow beneath the earth’s surface. Some crystals grow large, but the remaining melt cools after, forming smaller crystals, either because it erupts to the surface or because it is intruded close to Earth’s surface.
Types of Volcanism
Ocean-ocean convergence, spreading center, hot spot, ocean-continental coveragence
Extrusive Mafic rock is called
Basalt
Extrusive Felsic rock is called
Rhyolite
Intrusive Mafic rock is called
Gabbro
Intrusive Felsic rock is called
Granite
Sediments
Found on earth as loose particles, such as sand, silt, and clay.
Three types of sediments
Clastic, lithification, chemical/biochemical
Clastic sediments
Loose particles such as sand, silt, and clay are physically deposited by running water, wind, or ice.
Lithification
The process of compacting and cementing clastic sediments. THey will form sandstone, siltstone, and shale.
Chemical/ Biocemical sedimintation
Sediment or new mineral grains are formed by precipitation from water after a state of supersaturation is achieved.
Rock formation stages
- Weathering breaks down rocks physically and chemically
- Erosion carries away particles produced by weathering.
- Transportation via streams, glaciers, and wind moves particles downhill.
- Deposition (sedimentation) occurs when particles settle out or dissolved minerals precipitate.
- Burial occurs as layers of sediment accumulate and compact previous payers.
- Diagenesis lithifies the sediment to make sedimentary rocks
Bowen’s Reaction
A system that determines melt/crystalization order in igneous rocks.- in general, minerals formed at high T and or P at depth are unstable at the Earth’s surface
Mud forms
Shale
Sand forms
Sandstone
Gravel forms
Conglomerate
Limestone
Forms through chemical sedimentation, by calcium and carbonate ions forming calcite
Metamorphism
Metamorphic rocks are produced when high temperatures and pressures deep into the Earth’s crust cause existing rocks to change their mineralogy, texture, or composition while in solid form.
Regional metamorphism
Occurs when high pressure and temperature over large regions (like in mountain building).
Contact metamorphism
Where high temperatures are restricted to smaller areas, rocks are transformed.
Types of Metamorphism
Regional High pressure contatct shock seafloor burial
Regional metamorphism
occurs at moderate to deep levels under moderate to ultra-high pressures and high temperatures.
Shock metamorphism
the result from the heat and shock waves of a meteorite impact, transforms rock at impact site
High-pressure metamorphism
Along linear belts of volcanic arcs, produced by continent-continent collision, occur at high pressures.
Contact metamorphism
affects thin zone of country rock around an igneous intrusion
Seafloor metamorphism
occurs at mid-ocean ridges, where intruding magma drives seawater circulation through extruded basalts.
Burial metamorphism
transforms sedimentary rocks at progressively increasing temperature and pressure
Changes in levels of atmospheric carbon dioxide (CO2) lead to changes in the rate of _____
weathering (weathering of silicates such as feldspar removes CO2 from the atmosphere
Link between the rock cycle and climate change
weathering of silicates such as feldspar removes CO2 from the atmosphere
