geology assignment 2

A ________ is a tabular, concordant pluton that is nearly horizontal and forms when magma exploits a weakness between sedimentary layers.

sill

What is a marine environment example?

deep ocean floors

A _____________ results when magma collects or ponds due to its density being higher than that of overlaying materials

magma chamber

how does magma differ from lava?

magma exists strictly below Earth's surface, whereas lava is found on Earth's surface

Order the natural events that occurred in the Cotopaxi area from first occurrence to last occurrence

-Cotopaxi volcano formed -the pyroclastic flow occurred -the lahar flow occurred -erosion occurred

What is the difference between extrusive igneous rocks and intrusive igneous rocks?

-Extrusive igneous rocks cool and solidify on the Earth's surface -Intrusive igneous rocks cool and solidify beneath the Earth's surface

The three basic sedimentary rock categories are...

-detrital rocks (solid particles) -chemical rocks (ions that precipitated from solution) -organic rocks (form from the carbon-rich remains of organisms)

Lahar volcanic outcrops characteristics:

-is created when a mixture of water and ash flow down the sides of the volcano -contains large rounded boulders -is dark in color

Pyroclastic flow volcanic outcrops characteristics:

-often crystallize to form a pink rock -contains ash and pumice fragments -forms a deposit called ignimbrite

mafic igneous rocks silica content

50% of silica content

intermediate igneous rocks silica content

60% of silica content

felsic igneous rocks silica content

70% of silica content

Match the sedimentary composition with its textural description: Organic

Black, fibrous material. Some layering

Match the sedimentary composition with its textural description: Chemical

Crystalline appearance

The ring of fire is a narrow zone of composite cone volcanoes rimming the ________ Ocean

Pacific

From top to bottom, label five soil horizons

O horizon, A horizon, E horizon, B horizon, C horizon

Match the various grades of coal in order from lowest to highest grade: Bituminous coal, peat, lignite, anthracite coal

Peat Lignite Bituminous coal Anthracite coal

Welded tuff consists of ash surrounding large, jagged, irregularly-shaped pieces of material. What is this material and where does it come from?

Rock fragments that erupted from the volcano

What does a porphyritic texture indicate about the cooling history of an igneous rock?

The rock began cooling under the Earth's surface, but then was moved to above the Earth's surface where it finished cooling

What geologic environments has lead to the formation of the Andes mountains and Cotopaxi Volcano?

a continental volcanic arc created due to the subduction of the Nazca Plate beneath the South American Plate

What is a lahar?

a mudflow of volcanic debris saturated with water

Define B horizon

accumulation of clay particles from upper layers

Examples of a continental environment

alluvial fan, swamp, stream, lakes

Match the intrusive igneous rock with its extrusive equivalent Diorite

andesite

examples of porphyritic igneous rocks

andesite porphyry

what are the six major igneous rock textures?

aphanitic, phaneritic, porphyritic, vesicular, glassy, and pyroclastic

Match the intrusive igneous rock with its extrusive equivalent Gabbro

basalt

Depletion of the upper part of a magma chamber during a volcanic eruption can result in gravitational collapse of the volcanic summit to form a __________

caldera

Match the sediment size with the appropriate rock. Claystone

clay

Define A horizon

composted of a mixture of humus and mineral material

The pipelike feature through which magma travels upward from an underground magma chamber is called a ________

conduit

Examples of a marine environment

deep marine, reef

What is a continental environment example?

deserts

Define frost wedging (mechanical weathering process)

expansion of ice forces a rock apart

examples of intrusive igneous rocks

granite and diorite

List the four basic compositional groups of igneous rocks (high to low silica content)

granitic, andesitic, basaltic, ultramafic

Match the sediment size with the appropriate rock: Breccia

gravel

________ processes, such as evaporation or precipitation, can precipitate chemical sediments

inorganic

aa flows exhibit...

jagged surfaces with sharp edges

What type of deposit represents the greatest hazard to people living farther away from the volcano during an eruption?

lahar

A caldera is a...

large depression that has a diameter of over 1 km

Define E horizon

light-colored, depleted of soluble materials, little organic material

Define biological activity (mechanical weathering process)

living materials beak down a rock

What are the two basic categories of weathering?

mechanical and chemical

Define salt crystal growth (mechanical weathering process)

mineral crystal development forces a rock apart

Define O horizon

mostly organic material, identifiable in uppermost layer

Examples of a transitional environment

mudflat, beach

a crater is formed...

on the volcano summit by explosive eruptions and is composed of accumulated volcanic debris

Define C horizon

partially altered parent material that is easily identifiable

The primary basis for classifying detrital rocks is ________, whereas the primary basis for classifying chemical rocks is ________

particle size; mineral composition

________ has a large percentage of voids and is lightweight, so therefore has the ability to float in water

pumice

Define sheeting (mechanical weathering process)

reduction of pressure on a pluton results in concentric layers breaking off

Match the intrusive igneous rock with its extrusive equivalent Granite

rhyolite

example of extrusive igneous rocks

rhyolite

List magmas from most silica-rich to least silica-rich

rhyolitic, andesitic, basaltic

Which is an example of a sedimentary rock composed of solid masses of intergrown crystals?

rock salt

Which of the following best describes the appearance and composition of a conglomerate?

rounded fragments; poorly sorted

Match the sediment size with the appropriate rock. Arkose

sand

Match the sediment size with the appropriate rock. Quartz sandstone

sand

Match the sediment size with the appropriate rock. Siltstone

silt

A crater is a...

small, funnel-shaped depression

Pahoehoe flows exhibit...

smooth surfaces, are hotter, and are more fluid

Match the sedimentary composition with its textural description: Detrital

subangular clasts, poor sorting

what are the three components of magma?

the liquid portion (melt), the solid portion (silicate mineral crystals), and the gaseous portion (volatiles)

Chemical sedimentary rocks form from _______

the precipitation of ions in solution

what does the presence of mudcracks indicate about the paleoenvironment?

there was a wet environment that is drying up

What is a transitional environment example?

tidal flats

a ______ is an opening where volcanic materials erupt at the Earth's surface, and can form on the flanks of a larger volcano in the case of a ________

vent, parasitic cone

The formation of sedimentary rock requires ________

weathering and erosion of pre-existing rocks

Which of the following agents is capable of moving sediment from the site of formation to the site of deposition?

wind, ice, running water, waves