Geo 1 Flashcards
Material geology
materials composing Earth and seeks to understand the many processes that operate beneath and upon its surface
Historical geology
the origin of Earth and its development through time.
Catastrophism
Thinking the Earth’s landscapes were shaped primarily by great catastrophes to affirm the belief that the Earth was only a few thousand years old
Uniformitarianism
Jame Hutton saying the physical, chemical, and biological laws that operate today have also operated in the geologic past
What are Earth’s spheres?
Hydrosphere
Biosphere
Solid Earth
Atmosphere
What % of our water is freshwater?
2.5 % 0.75 of this is groundwater
What “powers” Earth?
The sun and it’s internal heat
How long ago was the big bang?
13.7 million years
How did the Earth’s layers form?
Metals sank to the center and molten rock rose to create our first, primitive crust. Chemical differentiation created the basic layers. (1.5)
Describe the crust
thin, outer shell
Oceanic is made of basalt (ig)
Continental is made of lots of different rocks, and is much thicker than the oceanic crust.
Describe the mantle
A rocky shell that makes up 82% of the Earth’s volume. Split into upper & lower
What are the parts of the upper mantle?
Lithosphere-the entire crust plus the uppermost mantle
Asthenosphere- weak layer w little melting
Transition zone- lowest part
Describe the core
Made of iron–nickel alloy, with a liquid outer layer and a solid inner layer (solid due to immense pressure)
Simple rundown of the rock cycle
Magma/lava cools and solidifies into igneous rock which weathers and erodes into sediments, which lithify, compact, and cement into sedimentary rock which is buried and exposed to high heat and pressure which turns it into metamorphic rock, which then melts into magma
What is a mineral?
- Naturally Occurring
- Solid
3.Inorganic - Orderly Crystalline Structure
- Definite Chemical Composition
Rate the bonding types by order of strength
- Covalent
2.Ionic
3.Hydrogen
Metallic is weak as well
What is diaphaneity?
The mineral’s ability to transmit light, translucent, transparent, etc.
What is a crystal habit?
The common or characteristic shape of individual crystals or aggregates of crystals, like fibrous, banded, cubed etc.
Which elements are most abundant in the continental crust?
Oxygen, silicon, and aluminum
Describe the light silicates
Generally 2.7 specific gravity
lacks iron and magnesium
Describe the dark silicates
From 3.2 and 3.6 in specific gravity with iron and magnesium
What is a silicate?
A mineral with silicon and oxygen, , made of the silicon-oxygen tetrahedron
Name some common silicate minerals
Olivine, Micas (biotite, muscovite), Feldspars (potassium, plagioclase), Quartz, Pyroxene (Augite) etc.
What is the most abundant silicate group in the Earth’s crust?
Feldspar! because they can form under a wide range of pressures and temperatures. Quartz is second btw.
Name some important nonsilicates
Gypsum, calcite, and halite
What is the difference between lava and magma?
Lava is at the Earth’s surface, Magma is underneath the Earth
How does an igneous rock form?
Magma rises to the surface
What are volatiles?
Components of magma, they vaporize (form a gas) at surface pressures
What are the 3 parts of magma?
Liquid- melt
Gaseous- volatiles
Solid- crystalized silicate minerals
What is the difference between extrusive and intrusive igneous rock?
Extrusive is formed by lava at the surface, Intrusive is formed by magma at depth (aka plutonic)
Texture in igneous rock is determined by ______
size and arrangement of minerals
Granitic vs Basaltic
Granitic: light-colored silicates, Felsic, High amounts of silica, makes up continental crust
Basaltic: dark-colored silicates, Mafic, Denser, make up the ocean floor
What is ultramafic composition?
Rare composition of super dark rocks with high magnesium and iron, like peridotite
Dissect the words felsic and mafic.
Felsic= FELdspar and SILica (light)
Mafic= MAgnesium and iron (Fe) (dark)
What does texture mean?
It is appearance of a mineral NOT the feel of a mineral.
What does aphanitic texture mean?
Fine-grained,
phan in latin means visible so A-phanitic is not visible!
This represents rapid cooling
What does phaneritic mean?
Coarse (large) grained
This represents slow cooling (grains had time to form)
What does porphyritic mean?
Large crystals embedded in a matrix of small minerals. the crystals are called phenocrysts.
How does a vesicular igneous rock form?
When lava cools so fast that the openings that the gas bubbles are preserved. Extrusive process,
How does a glassy igneous rock form?
When molten rock is ejected into the atmosphere by a volcano and very quickly cooled, like obsidian
What factors affect crystal size?
rate of cooling
amt. of silica present
amt of dissolved gases
Describe granite
Igneous rock, phaneritic, mostly feldspar some quartz, very abundant. Rhyolite is its extrusive version
What are the igneous rock pairings?
Phan-Aphan
Intrusive- ex
felsic-mafic
Granite-Rhyolite
Diorite-Andesite
Gabbro-Basalt
Periodite- Komatite
What does Bowen’s reaction series demonstrate?
as a magma cools, minerals crystallize in a systematic fashion based on their melting points. So like from high to low temps, mafic melts at high and felsic melts at low.
What is magmatic differentiation?
Generating more than one type of rock from one magma
What is assimilation?
Changing a magma’s composition by incorporating
surrounding rocks into a magma
What is magma mixing?
Exactly what it sounds like, just another way for magma composition to be changed
Basaltic magma is made of what?
magmas migrate upward, confining pressure
decreases, which reduces the melting temperature, common at the Earth’s surface
What is an intrusion/ pluton?
The structures that result from the emplacement of magma into preexisting rocks
What is a dike?
A tabular, discordant pluton
What is a sill?
A tabular, concordant pluton
Whats some of the vocabulary to describe plutons?
Tabular- table-like
Massive- blob shaped
Discordant- cut across existing structures
Concordant-inject parallel to existing features
What is a batholith?
large linear structures several hundred kilometers long and more than 100 kilometers wide
What is a stock?
Smaller than a batholith but very similar
How does mechanical weathering help chemical weathering?
Mechanical creates more surface area to be weathered chemically
How is water helpful in chemical weathering?
oxidation, rain mixing with co2 to make carbonic acid,
What mineral is really resistant to weathering?
Quartz
What factors affect weathering
Climate- temperature & rain
Rock characteristics
What is soil made of?
mineral and organic matter, water, and air
What factors affect soil composition?
Parent rock, time, climate, animals and plants, topography
What are the soil horizons?
O.A.E.B.C.R
How do sedimentary rocks form?
Sediments are deposited then buried then lithified into rock
What is a detrital rock?
form from sediments that have been weathered and transported, distinguished by particle size fr
What is a chemical sedimentary rock?
When ions in solution are precipitated from like evaporation
What’s the difference between a conglomerate and breccia
Conglomerate is rounded, breccia is sharp, poorly sorted
What is the distinguishing thing for sedimentary rocks?
Particle size, (gravel, sand, mud)
Describe shale
A fine-grained detrital rock, very common, has fissility (can break into layers) dark shale will have fossilized plants sometimes
Describe limestone
most abundant chemical sedimentary rock, mostly made of the mineral calcite, ex: coquina and chalk
What is inorganic limestone?
when chemical changes increase the calcium carbonate content of the water until it
precipitates, like travertine or ooids
Steps of coal formation
Peat to lignite to bituminous to anthracite
What is diagenesis
Changes that happen after the sediment are deposited and buried, like lithification or recrystallization
What are the parts of lithification?
Compaction and cementation
Ripple marks
Small waves of sand that develop on the surface of a sediment layer through the action of moving water or air
Nonmetallic mineral resources
Earth materials that are not used as fuels or processed for the metals, like asbestos, graphite, gems
What are the types of coal traps?
Anticline- arched series of sedimentary strata, gas oil water
Fault trap-strata are displaced so that a dipping reservoir rock abuts an impermeable bed,
Salt dome- salt rises bc increase in pressure and deforms the strata above, pushing oil and gas
What does an oil trap need?
Pourous permeable resevoir rock
impermeable cap rock like shale
Talk about carbon in all of the places in the carbon cycle
Atmosphere- CO2 is a greenhouse gase
Biosphere- photosynthesis or vegetation
