(TEST 1) Earth Science, Lecture pt 2 (ch 3) Flashcards
What are the three broad classifications of rocks?
Igneous
Sedimentary
Metamorphic
What is a sediment?
Loose fragments of rocks or minerals broken off bedrock
How are sediments produced?
Through weathering
What is weathering?
The physical or mechanical and/or chemical breakdown of pre-existing rocks
What is physical weathering?
The breakdown of intact rock into unconnected clasts (grains or rock fragments)
What are the three ways which rocks can be physically weathered?
- Abrasion
- Jointing
- Wedging
What is abrasion?
Breakdown of rocks due to material falling or washing down slopes
What is jointing?
Natural cracks that form in rocks due to the removal of overburden or due to cooling
What is exfoliation jointing?
A type of jointing where rocks can break into thin sheets along pre-dominantly flat-lying parallel joints
What is wedging?
Expansion slowly forces open cracks in rocks
What are the types of wedging?
Frost wedging
Salt wedging
What is chemical weathering?
The decomposition of minerals in rocks via chemical reactions
What are the types of chemical weathering?
- Dissolution
- Hydrolysis
- Oxidation
What is dissolution?
Dissolving of minerals into water
What is hydrolysis?
A reaction between water and mineral in which water itself is broken down (typically into a weak acid)
What is oxidation?
Loss of electrons from an ion (typically ion) to oxygen. Also know as the “rusting” process
What are sedimentary rocks?
Rocks formed through the accumulation of sediment or new minerals formed through chemical precipitation or organic
activity
What are the 4 classes of sedimentary rocks?
- Clastic
- Biochemical
- Chemical
- Organic
What are igneous rocks?
Rocks that were formed from originally molten states
How do igneous rocks form?
They form when minerals crystallize from a cooling
body of magma (molten rock)
What two physical properties are igneous rocks characterized by?
- Texture (grain size)
- Chemical composition
Igneous rocks are also characterized by composition, what does composition mean?
Composition describes the minerals that make up the rock
What are the four major magma types?
- Felsic
- Intermediate
- Mafic
- Ultramafic
What are metamorphic rocks?
Pre-existing rocks that are affected by pressure, substantial changes in temperature, or by chemically active fluids (i.e. hot water), but do not melt!
What is metamorphism?
The process by which rocks are altered by some combination of heat, pressure, and/or fluids, producing metamorphic rocks
What is prolith?
The name of a rock before it was metamorphosed
What are two primary environments of metamorphism?
- Contact
- Regional
What does a slate rock look like?
Fine-grained, low-grade metamorphic rock
What does a schist rock look like?
Fine- to coarse-grained, intermediate grade rock
What does gneiss rock look like?
Distinct compositional bands of felsic (light) and mafic (dark) minerals
What does the nucleus contain?
Protons and neutrons
Atoms that have the same # of protons are called
Elements
Elements with different # of neutrons are called
Isotopes
What are ions?
Charged atoms that have either gained or lost an electron
