Geology Exam 1 Review

Carbonate

cation + CO3 - Example: calcite CaCO3 Reactive property: Reacts wth Acid

Sulfide

cation + sulfur - Example: pyrite FeS2

Oxides

cation+oxygen - Example: hematite Fe2O3

Where are the active volcanoes in the U.S.?

- 7 in HI - > 40 in Alaska -Wahington, Oregon -Yellowstone - ~20 in other states

What makes a mineral a mineral?

• Naturally occurring-- formed by geologic processes; not synthesized by humans • Inorganicly occurring-- not created solely by biological processes; does not contain carbon-hydrogen bonds • Solid-- not liquid/gas • Crystalline-- fixed chemical composition with regular internal structure • Have distinct physical properties that can be used to identify Ex: -Steel is synthetic=not a mineral -Wood is organic=not a mineral -Gold is natural and inorganic=is a mineral -Water is liquid=not a mineral -Beach sand is natural and inorganic=made of minerals (mostly quarrtz)

Three main types of plate boundaries

• divergent - plates moving apart • convergent - plates moving toward each other • transform - plates moving side-by-side

Basaltic lava types:

●aa ● pahoehoe ● pillow Lowest silica content, lowest viscosity Common at hot spots and mid-ocean ridges Highest temperature (1000−1200ºC) Form basalt igneous rock (mafic)

Igneous Rocks can be indentified by Composition

- Felsic = high silica content (light color) - Mafic = low silica content (dark color)

Shield volcanoes

- Large, flat, shield-like shape • larger area relative to height - Form basalt lava; thin basalt flows build up over time - Most common at hot spots -Mafic Igneous Rocks - Relatively predictable and "quiet" eruptions- Examples: Hawaiian Islands (Kilauea; Mauna Loa)

Divergent Plate Boundary

- Lithospheric plates move apart • form continental rift zones (continental-continental divergence) - example: East Africa • form mid oceanic ridges (oceanic-oceanic divergence) - Mid-Atlantic Ridge - Upwelling of asthenosphere at plate boundary injects molten mantle material to the surface, forming new oceanic crust • When new crust forms, it forces plates apart

Transform Boundaries

- Plates "slide" past each other, side by side - Can offset oceanic ridges, breaking ridges up into short segments- separate continental plates • Example: San Andreas Fault, California and Mexico

what is planetary differntiation?

- Process by which heavier (denser) metals (Fe, Ni, Mg) sank deeper into the Earth while lighter metals (Si, K, Ca, Na) concentrated at the surface - Created the layering of the Earth

What are hot spots, and what do they tell us about plate movement?

-Hot spots are areas of upwelling magma located in the interior of a plate, not at a plate boundary -Position of volcanic island groups (like Hawaii) trace the direction and speed of the plates over fixed hot spots in the mantle -• under oceanic crust → mafic • under continental crust → intermediate to felsic -Hot spot stays in the same place in the mantle, you can trace the movement of plates over the hotspot

Volcanic Domes

-Composed of rhyolite, but can cause andesite lavas as well• Too viscous to flow - material oozes out to surface (felsic lava) from a tube close to the vent• may explode as nuee ardente: a cloud of gas and ash-Commonly occur at subduction zones after stratovolcano eruptions, hot spots under continents, and continental rifts-Vary in size

What sediment sizes would you expect at high energy depositional locations?

-Continental (on land) -Gravel sizes deposited

What sediment sizes would you expect at low energy depositional locations?

-Marine (sea/ocean) • Clay deposited

How does Convection affect Earth's magnetic field?

-Outer core convection drives the geodynamo: Rapid motion of the liquid outer core stirs up electrical flow in the solid (iron) inner core, causing Earth's magnetic field. -Pole migration is caused by variations of fluid movement in the outer core that affect convection strength -The variations of fluid movement in the outer core also make it possible for Earth's magnetic field to spontaneously reverse itself -Without convection, there is no magnetic field, and radiation from Sun would strip away the atmosphere

Covalent Bond

-Sharing of Electrons • atoms share valence (outermost) electrons • By sharing, each atom then has stable number of electrons • Stronger than ionic bond; makes minerals harder

What sediment sizes would you expect at medium energy depositional locations?

-Shoreline (where land meets water) Sand size deposited

Fractional crystallization

-The process by which the crystals formed in a cooling magma are segregated from the remaining liquid at progressively lower temperatures. -Temperature dependent; the first minerals to crystallize from a cooling magma are the ones that are the last to melt. Mafic=Crystallize at high temp Felsic=Crystalize at low temp

Two main types of Igneous Rocks

1) Plutonic/Intrusive rocks - magma cools within the crust and does not make it to surface; cooling is slow 2) Volcanic/Extrusive rocks - magma reaches the Earth's surface as lava flows or explodes as pyroclastic fragments; cooling is fast

What is the difference between contintnetal and oceanic crust?

1. Oceanic crust = low silica (Si) = high density = faster P-waves (~7 km/s) 2. Continental crust = high silica = low density = slower P-waves (~6 km/s)

pahoehoe

A hot, fast-moving type of lava that hardens to form smooth, ropelike coils

Pangea

A supercontinent containing all of Earth's land that existed about 225 million years ago. -Existed during the late Paleozoic and early Mesozoic eras.

What is shale and how does it's appearance identify a shale?

Any of a group of fine-grained, laminated sedimentary rocks consisting of silt- and clay-sized particles -breaks on bedding planes; laminated -Shale is made from clay

Add

Aphanteritic,

Convergent Plate Boundaries

Areas where plates move toward each other and collide, causing uplift. Three Types:- Lithospheric plates move toward each other • Continental-oceanic (oceanic subducts continental) - examples: Oregon/Washington; Andes Mountains (west coast South America) • Oceanic-oceanic (subduction) - examples: Japan; southern coast of Alaska • Continental-continental (no subduction) - example: Himalaya Mountains (between India/China)

What are the different types of sandstones?

Arkose = feldspar-rich (pink-reddish) Quartz arenite = quartz-rich Lithic = particles of other rocks, rather than minerals Graywacke = a sandstone cemented with clay mineral matrix (kaolinite)

What is the link between volcanism and climate?

Ash and gas entering atmosphere can cause climate changes

What clastic sediments become what clastic sedimentary rocks?

Clay becomes shale or claystone Clay + silt becomes mudstone Silt becomes siltstone Sand becomes sandstone Gravel becomes conglomerate or breccia

What two ways turn sediments into sedimentary rocks?

Compaction - removal of air and water in void space between particles Cementation - addition of minerals into the void space

What are the differences between P-Waves and S-waves?

Compression (P) waves • push-pull motion ➢ travel through both solids and liquids • faster velocity Shear (S) waves • side to side motion ➢ travel only through solids • slower velocity

gneous rocks types are linked to plate tectonics

Divergent plate boundaries • Oceanic-oceanic → mafic, • Continental-continental → felsic Convergent plate boundaries • Oceanic-oceanic → mafic • Oceanic-continental → intermediate • Continental-continental → nothing Hot spots • under oceanic crust → mafic • under continental crust → intermediate to felsic

What are the differences between protons, neutrons, and electrons?

Electrons are a type of subatomic particle with a negative charge. Protons are a type of subatomic particle with a positive charge. Protons are bound together in an atom's nucleus as a result of the strong nuclear force. Neutrons are a type of subatomic particle with no charge

Bioturbation Structures/Trace Fossils

Evidence that living organisims were present with out any remains of the organism

Mineral Composition: Four total compositional groups, based on chemistry of the source magma (mainly silica content):

Felsic igneous rocks (high silica) Intermediate igneous rocks (medium silica) Mafic igneous rocks (low silica) Ultramafic igneous rocks (very low silica)

Mafic Sillicates

Ferromagnesian (higher in Iron and Magnesium, lower in Silicon) -Minerals are gernally darker in color Ex: ➢Olivine ➢Pyroxene ➢Amphiboles ➢Biotite mica

Cross-bedding

bedding on an angle to the main bedding plane

What is the principle of Uniformitariansim?

Geological processes presently occurring on Earth are the same processes that operated throughout Earth's history. So, the past can be understood by modern observations."the present is the key to the past"

Graded bedding

Gradual changes of one sediment size into another; coarser/heavier sediments are deposited first

What are the main sediment sizes?

Gravel (largest) Sand: Silt: Clay: Sedimet (small)

Difference Between Hypothesis and Theory

Hypothesis becomes a theory only after extensive testing of the hypothesis

Anion

Ion that is negataivley charged (gained an electron)

Cation

Ion that is postivley charged (lost an electron in transfer)

How do seismic wave velocities tell us about the layering of the Earth?

Knowing how the waves behave as they move through different materials enables us to learn about the layers that make up the Earth. Seismic waves tell us that the Earth's interior consists of a series of concentric shells, with a thin outer crust, a mantle, a liquid outer core, and a solid inner core. S waves tell us about velocity of mantle. S waves tell us about the outer core because it is liquid. We know whats oceanic and contintnetal crust based off P- Waves.

What is the difference between the Lithosphere and the Athenosphere?

Lithosphere = hard, brittle (rigid) solid made of crust and uppermost portion of mantle • Asthenosphere = soft, ductile (plastic) solid below the lithosphere

Fissures

Long, nearly vertical cracks where basalt lava emerges at large volumes Fissures are where new crust is created at divergent plate boundary

What is the compositional difference between the mantle and the core?

Mantle: a semi-solid magma layer consisting of iron, magnesium, and silicon. Core: centrally located solid mass of metal (inner core) and a liquid mass of iron and nickel (outer core).

What are Silicate minerals? What are the two main types?

Minerals based on silicon and oxygen with cations. Two main types: Mafic and Felsic Silsicates

Cinder Cones

Minor explosive volcano - Mostly pyroclastic discharges of varying sizes - Pyroclastics build up around the vent creating cones - Example: Paricutin, Mexico; Cerro Negro, Nicaragua

Felsic Silicates

Non-Ferromagnesian (lower in Iron and Magneisum, higher in Silicon) -Minerlas are generally lighter in color ➢Quartz ➢Orthoclase feldspar ➢Plagioclase feldspar ➢Muscovite mica

What defines an element?

Number of protons dictates the chemical element

What is the Plate Tectonic System?

Tectonic plates, large slabs of rock that divide Earth's crust, move constantly to reshape the Earth's landscape. The system of ideas behind plate tectonics theory suggests that Earth's outer shell (lithosphere) is divided into several plates that glide over the Earth's rocky inner layer above the soft core (mantle).

What are the 3 main Earth Systems?

The Climate System, The Plate Tectonic System, The Geodynamo System

The Climate System

The climate system is the highly complex global system consisting of 5 major components: the atmosphere, the oceans, the cryosphere (snow and ice), the land surface, the biosphere, and the interactions between them. The interactions of these components determine not only day-to-day weather, but also long-term averages that we refer to as the climate.

What observations led to the continental Drift Hypothesis?

The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations 1. "Jigsaw-puzzle" fit-shapes of continent appear to fit together 2. Rock sequences-similarity of rock assemblages and ages across oceans 3. Fossil assemblages 4. Glacial evidence

What is the Geodynamo System?

The theory describes how Earth's magnetic field is generated and maintained by convective flow in the Earth's fluid outer core. According to physicists, this convection is driven by gravitational energy from secular cooling and differentiation of the Earth.

Theory

Theory formed as accepted explanation for an observation or set of data

What happens to iron minerals at divergent plate boundaries, and what does that tell us about plate movement?

When magnetic iron emerges from the mantle at divergetingplates, it aligns with Earth's magnetic field before solidifying into rock. As the plates spread, rocks move away in both directionsA symmetric pattern occurs on both sides of the boundary, showing magnetic orientation through time

Coquina

broken fragments of shell pieces

Stratovolcanoes / composite volcanoes

built up of layers of lava and pyroclasts- Andesitic lavas plus pyroclastic layers form a tall volcano- Usually associated with subduction zones - Tend to be violent and explosive eruptions -Intermediate Composition - Examples: Mount St. Helens (WA); Cascade Range (WA/OR); Mt Shasta (CA); Fujiyama, Japan

Igneous Rock texture: Phaneritic

coarse/large (slow cooling)

Bowen's reaction series

explains the sequence of fractional crystallization

sedimentary structures (look at diagrams)

features in sediments and sedimentary rocks formed at the time of deposition

Chalk

fine-grained calcite

Igneous Rock texture: Aphanitic

fine/small (fast cooling)

Pillow Basalt lava

form on seafloor

Bedding

formation of parallel layers of sediment as particles are deposited

What is Convection?

hotter, less dense material rises, while cooler, denser material sinks, then the pattern continues

Dike

intrusion crosses (not parallel to) the country rock layers ("against the grain") • Neck = dike exposed at land surface

Sill

intrusion of igneous rocks parallel to the layering of country rock ("with the grain")

What is an ionic bond?

ionic bond, also called electrovalent bond, type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. (transfer of electrons)

What is limestone?

is composed of biologically precipitated carbonate mineral calcite CaCO3. -Reacts with acid

aa lava

lava that hardens into rough, jagged rocks with a crumbly texture

Igneous Rock Texture: Porphyritic

mix of large and small (fst for some minerals, slow for others)

Mineral composition of particles

more = less mineral variety

Rounding of particles

more distance = more rounded

Transport of Sediments: Size of particles

more distance = smaller

Sorting of particles

more distance = well sorted

Igneous Rock Texture: Glassy

no crystals (super fast cooling) -2 types Frothy ( contains air bubbles) and Compact ( no air bubbles)

Oolitic limestone

pearl-like grains (ooids)

What is coal and how is it formed?

solid fossil fuel that is formed in several stages from the reamins of plants buried 300-400 million years ago and then exposed to intense heat/pressure. -Made from swamp plants that die and become compacted

Pyroclasts

solid fragments extruded from volcanic eruption; cause pyroclastic texture Pyroclasts include ash, pumice, fine solidified magma combined into a rock

How is convection related to plate tectonics?

the movement of convection currents in Earth's mantle to the movement of Earth's tectonic plates. The upward current in a convection cell cycle is associated with divergent plate boundaries, as heated magma rises and spreads out beneath the lithosphere plates.

Viscosity

the resistance of a fluid to flow • High viscosity = more resistant to flow- Flows more slowly, thicker- Example: ketchupn (Felsic) • Low viscosity = less resistant to flow - flows more easily, faster- Example: water (Mafic)

Bedding plane

the surface separating one bedding layer from another

Reef limestone

visible coral reef fossils

Fossiliferous limestone

visible fossils

Ripples

wave-shaped features showing direction of movement

What physical properties do we use to identify minerals?

• Color • Luster-Metallic or non metallic? • Streak-color of powder • Crystal Form • Cleavage/Fracture-abilllity to break among flat surfaces • Hardness-scratch test, harder scratchs softer, Mo's hardness • Specific Gravity (Density)

Rhyolitic lavas

• Highest silica content, viscosity • Common where magma melts large quantities of continental crust • Lowest temperature (600-800ºC) Form rhyolite igneous rock (felsic)

Hypothesis

• Hypothesis is formed to explain the observations or data • Conceptual framework or model is developed• Multiple explanations or equations developed • Must be testable and test must be reproducible • Proof of a hypothesis is sought as well as evidence to disprove it• Test the hypothesis repeatedly and systematically• Make set of predictions and perform series of experiments

Andesitic lavas

• Intermediate silica content, viscosity • Common at subduction zones -Form andesite igneous rock (intermediate)