Geology Midterm

Matter

Any substance that has mass and takes up space by having volume

Elementary Particles

Basic indivisible components of all matter (smallest known particles)

Protons, Electrons, Neutrons

Subatomic particles made of 3ish elementary particles (components of atoms)

Atoms (elements)

Smallest unit of matter that can take part in a chemical reactions- cannot be broken down (metals, nonmetals, and metalloids)

Silicate minerals

Quartz
Feldspars
Micas
Amphibole
Pyroxene
Olivine
Clay

Calcite, aragonite, and dolomite

Carbonate Mineral

Hematite and Limonite

Oxide Minerals

Pyrite, gypsum, and anhydrite

Sulfur-bearing minerals

Halite

Mineral Salts

Minerals

Form as a result of geologic process, which causes specific elements to combine

5 defining characteristics of minerals

1. Naturally occurring
2. Homogeneous
3. Solid
4. Definite chemical composition
5. Characteristic crystal structure

Sedimentary rocks

formed by the lithification of sediment

Clastic Sed. Rock

made of fragments of previous rock

Conglomerate

Sed. rock with the biggest fragments

Sandstone

Sed. rock with the sand sized fragments

Siltstone

Sed. rock with very small grains, can't be seen with the naked eye

Shale

Sed. rock with the smallest fragments

Biogenic Sed. Rock

Life is involved in the making of the rock

Chemical Sed. Rock

Formed by direct chemical precipitation

3 Main Depositional Environments

Continental, costal, and marine

High energy

Bigger pieces

Low energy

Small pieces

Shallow marine (high energy)

Biogenic limestone

Deep marine (low energy)

Shale

Beach or delta (high energy)

Sandstone

Tidal flat (moderate energy)

Siltstone

Lagoon (low energy)

Shale

Fluvial

Streams or rivers

Fluvial (various energy)

Conglomerate, sandstone, siltstone

Eolian

Wind

Eolian (high energy)

Sandstone

Lacustrine

Lake

Lacustrine (low energy)

Shale

Glacial (various energy)

All clastic types

Sedimentary structures

Cross-bedding, ripple marks, mud cracks, fossils

Cross-bedding

Big\= eolian (high energy)
Smaller\= fluvial (high energy)

Ripple marks

Shallow water (slower energy)

Mud cracks

Occasionally exposed above water

Symmetric ripples

Coast

Asymmetric ripples

Rivers

Metamorphism

The change of the rock or the texture or a change of shape due to minerals in the rocks (without melting the protolith to magma)

Causes of Metamorphism

1. Heat
2. Pressure
3. Chemical activity

Foliation

Mineral grains in a line/parallel

Foliated (lowest temp/pressure)

Slate

Foliated (Medium temp/pressure)

Phyllite

Foliated (high temp/pressure)

Schist

Foliated (highest temp/pressure)

Gneiss

Nonfoliated (protolith: limestone)

Marble

Nonfoliated (protolith: sandstone)

Quartzite

Nonfoliated (protolith: conglomerate)

Metaconglomerate

Nonfoliated with the lowest pressure (protolith: any sed. rock)

Hornfels

Metamorphic rocks in order

Mud/clay
Shale
Slate
Phyllite
Schist
Gneiss

Mafic

Dark

Felsic

Light

Aphanitic

Crystals too small to see

Phaneritic

Crystals that are visible

Porphyritic

Visible mineral crystals in an aphanitic matrix

Glassy

No visible crystal formation

Vesicular

Gas bubbles

Pegmatitic

Extremely large crystals

Intrusive

Phaneritic, pegmatitic, porphyritic

Extrusive

Aphanitic, glassy, vesicular, porphyritic

Ultramafic
Mafic
Intermediate
Felsic

Darkest to lightest

Felsic and phaneritic

Granite

Intermediate and phaneritic

DIorite

Mafic and phaneritic

Gabbro

Ultramafic and phaneritic

Peridotite

Felsic and aphanitic

Rhyolite

Intermediate and aphanitic

Andesite

Mafic and aphanitic

Basalt

Slate becomes

Phyllite

Mud becomes

Shale

Shale becomes

Slate

Slate becomes

Phyllite

Mechanical Weathering: Pressure release fracturing (unloading)

Caused when overlying material is removed and intrusive igneous rock explands

Mechanical Weathering: Frost wedging

Water gets into cracks and freezes and expands (tends to be vertical)

Mechanical Weathering: Abrasion

Friction/impacts when water, wind, ice carrying debris past by

Mechanical Weathering: Organic Activity

When plants grow and expand within cracks

Mechanical Weathering: Thermal expansion and contraction

Heating and cooling of rocks

Chemical Weathering: Dissolution

Disolves

Chemical Weathering: Hydrolysis

H20 in the chemical

Chemical Weathering: Oxidation

Rusting

Soil profiles (residual)

If the material has formed in 1 place

Soil profiles (transported)

If the material was transported and then modified as a soil

6 major agents of erosion

Surface water/streams (Saltation)
Underground water (dissolution)
Glaciers (abrasion)
Wind (abrasion)
Waves (abrasion)
Gravity (collapse of over-steep slopes)

Gravity

Mass wasting

Direction of dripping rocks

parallel to the slope of the ground will generate more mass wasting than opposite to the slope of the ground

Angle of repose

the angle at which the material on a slope is in equilibrium

Slow mass wasting

Creep and solifluction

Soilfluction

Frozen ground sliding down

Mass wasting fall

Sudden vertical drop of material

Mass wasting slide

Rapid displacement of mass downslope

Mass wasting flow

Flowing where pores filled with water/air

Mass wasting rock

Bedrock

Mass wasting debris

Bedrock and/or regolith

Mass wasting mud

Fine grained regolith only

Mass wasting with debris and slide

Slump

Big Bang

13.8 Billion yrs ago

~7 Ba

Red Giant star exploded (supernova)

~4.6 Ba

The remnants of that particular supernova forms our solar system