Geo 200 - Chpt 13 (Intro to Landforms)

the most widespread oxides are those that combine with_______

iron - particularly hematite, magnetite, and limonite (all major sources of iron ore and are common rock-forming minerals

when lava on the surface cools, .....

it cools rapidly; therefore, producing a fine-grained texture

when magma cools beneath the surface, ...

it cools slowly; therefore, producing a coarse-grained texture

carbonates

light colored (or colorless) minerals that are common constituents of sedimentary rocks such as limestone (largely made of calcium carbonate in its mineral form, calcite). - carbonates are composed of one or more elements in combo w/ carbon & oxygen

________ are formed from skeletal remains of coral and other lime-secreting sea animals.

limestones

The "plates" in plate tectonics are in the ________.

lithosphere

magma vs lava

magma is molten rock beneath the surface, whereas lava is motion rock that flows out on, or is squeezed up onto, the surface

Mafic igneous rocks

magmas with relatively low amounts of silica generally cool into mafic igneous rocks, which contain large portions of dark-colored, magnesium and iron-rich silicate minerals such as olivine and pyroxene

An inner segment of the Earth which is rigid, dense, and solid and lies directly beneath the Moho is called the ________.

mantle

The thickest of Earth's interior layers is the ________.

mantle

classification of igneous rocks is based largely on ...

mineral composition and texture - which is determined by the "chemistry" of the magma, or particular combination of molten mineral material in the magma

organic sedimentary rocks

organically accumulated sedimentary rocks form from the compacted remains of dead plant material - lignite (soft brown coal) and bituminous coal (soft black coal)

The basic classification of rock types is based on their ________.

origin

examples of minerals that are native elements:

precious metals (gold, silver, platinum) - not combined chemically with another element

which are the most abundant of the silicate minerals?

quartz and feldspar - nonferromagnesian silicates (light)

drainage

refers to the movement of water (rainfall or snowmelt), either over Earth's surface or down into the soil and bedrock

structure of the landscape

refers to the nature, arrangement, and orientation of the materials (rocks) making up a landform.

tuff

rock made from volcanic ash or pyroclastic flow deposits

Detrital/Clastic Sedimentary Rocks

rocks composed of fragments of preexisting rocks in the form of cobbles, gravel, sand, silt, or clay

The most widely distributed type of metamorphic rock is ________.

schist

___________rocks accordingly constitute only a very small proportion (perhaps 4 percent) of the total volume of the crust.

sedimentary

on the continents, ___________rocks compose the most commonly exposed bedrock. - as much as 75%.

sedimentary

the combination of compaction and cementation consolidates and transforms sediments to __________

sedimentary rock

Mohorovicic discontinuity

the boundary between the earth's crust and the upper part of the Asthenosphere where there is a significant change in mineral composition; seismic waves change speed at this boundary

relief

the difference in elevation b/w the highest and lowest points in an area

slope of the landscape

the fundamental aspect of shape for any landform - the angular relationship reflects the balance b/w the structure and process at that time

sulfates mineral family

the group includes minerals such as gypsum that contain sulfur and oxygen in combo with some other element. - calcium is the principal coming element - usually light colored and found in sedimentary rocks

halides

the least widespread mineral family. - name derived from word meaning "salt" - minerals include halite (common table salt- NaCl) and fluorite

Diastrophism

the process of deformation of the Earth's crust which involves folding and faulting.

geomorphology

the study of the characteristics and development of landforms

petrology

the study of the origin and characteristics of rocks

topography

the surface configuration of Earth

lithosphere

the uppermost mantle zone together with the overlying oceanic or continental crust

pyroclastics

tiny pieces of solid volcanic rock, that have been explosively ejected onto the surface by a volcanic eruption and that "weld" to form some igneous rocks

Diastrophism is considered an internal geomorphic process.

true

Granite is a type of rock which has cooled from magma.

true

Plutonic rocks are the same thing as intrusive rocks.

true

although originally deposited and formed in horizontal orientation, the strata may later be uplifted, tilted, and deformed by pressures from within Earth.---- true or false.

true

basalt is a type of rock that has cooled from lava.

true

Organic material such as plants remains and algae remains can also become sedimentary rock. true or false

true - it accumulates over time alongside inorganic sediments.

just eight elements account for more than 98 percent of the mass of earth's crust --- true or false.

true - O and Si make up more than 75%

on magma can produce a number of quite different igneous rocks. True or false.

true - depending on whether the material cools below the surface, on the surface as lava flow, or on the surface as accumulation of pyroclastics.

the distribution of the three principal rock classes on Earth's surface is _______.

uneven - this is a consequence of processes operating on the surface and in the planet's interior

Most processes which shape topography are ________.

very slow

which igneous rocks have a fine-grained texture?

volcanic (extrusive) b/c they cool more rapidly

obsidian

volcanic glass

pumice

volcanic glass with frothy texture

Process of sedimentary rocks

weathering, erosion, deposition, compaction, cementation

the texture of an igneous rock is determined primarily by

where and how the molten material cools.

The most recent Era on the Earth is ________.

Cenozoic

what is the most common component of chemical sedimentary rocks? and was is the most widespread result?

calcium carbonate ; >>limestone

in addition to compaction, __________occurs in forming sedimentary rocks, in which process chemical agents - especially ______, ________, and ________ - precipitate from the water into the pore spaces between sediment grains.

chemical cementation ; silica, calcium carbonate, and iron oxide

chemical sedimentary rocks

chemically accumulated sedimentary rocks usually form by the precipitation of solids from ions in solution, but sometimes by more complicated chemical reactions.

minerals in granite

combination of light and dark quartz, plagioclase feldspar, potassium feldspar (light colored) and hornblende & biotite (dark colored)

sulfides

combo of reduced sulfur with one or more other elements. - many of the important ore minerals (galena-lead, sphalerite-zinc, and chalcopyrite-copper) are sulfides

over long periods of time, sedimentary deposits can build to a remarkable thickness, and the weight of this exerts enormous pressure, which causes individual particles of sediment to adhere to each other and tho interlock though________

compaction

process of the landscape

considers the actions that have combined to produce the landform. - geologic, hydrologic, atmospheric, and biotic - in some cases a landscape results from one process primarily (glaciation)

Earth is probably 14.6 billion years old.

false

Internal forces of the Earth tend to be better understood and more predictable than the external forces of the Earth.

false

Several organic minerals are found in nature.

false

Uniformitarianism is the study of the interior of the Earth.

false

Magma with relatively large amounts of silica generally cool into______ igneous rocks, which contain large portions of light-colored silicate minerals, such as quartz and feldspar.

felsic

bedding planes

flat surfaces separating one layer from the next

igneous rocks origin

formed by the cooling and solidification of molten rock

sediment

fragmented mineral material produced by disintegration caused by mechanical and chemical external processes operating on rocks

the most common plutonic rock is

granite

the bulk of the continents consist of __________, along with an unknown proportion of metamorphic rocks such as ________and _______

granite; gneiss and schist

the bulk of the crust is made up of _________ rocks.

igneous

The original rocks which cooled on the surface of the Earth could be classified as ________.

igneous extrusive

The ________ processes working on Earth's landscapes are energized by heat inside the Earth; they work without any regard to atmospheric influences.

internal

Earth's age is ________ billion years old.

4.6

With respect to minerals, which of the following is TRUE?

Fewer than 20 minerals make up 95% of the crust.

why exactly are silicates the most important mineral family

b/c they combine the two most abundant chemical elements in the lithosphere: oxygen and silicon

the ocean floor is composed almost entirely of ______ and ______

basalt and gabbro (the plutonic equivalent of basalt)

over most of Earth's surface, solid rock exists as a buried layer of ________

bedrock

Uniformitarianism

"the present is the key to the past." means that the processes that shape the landscape today are the same processes that formed the topography of the past - and are the same processes that will shape the topography of the future - James Hutton (1795)

the most common detrital (clastic) sedimentary rocks are:

- shale (or mudstone), which is composed o very fine silt and clay particles, and - sandstone, which is made up of compacted, sand size grains

what are the three sublayers of the mantle?

- upper mantle : thin, rigid and hard, layer under the crust (this plus the crust= lithosphere) - asthenosphere: risks are hot, "plastic" (deformable) - lower mantle: rocks are very hot but largely rigid b/c of higher pressures

The geographer's concern with Earth's interior is restricted primarily to its influence on________.

Earth surface features

The Pleistocene is a part of the ________ period.

Quaternary

rocks

a consolidated mixture of minerals

conglomerate rock

a detrital (clastic) rock composed of rounded, pebble-sized rock fragments

regolith

a layer of broken rock that covers bedrock

asthenosphere

a weak plastic layer of the mantle situated below the lithosphere; the rock within this zone is easily deformed b/c of the heat

oxide

an element combined with oxygen

landform

an individual topographic feature of any size

The proof for the long-doubted idea of drifting continents came in the form of ________.

analysis of magnetic and seismic patterns

Isostasy refers to the recognition that the ________ floats on the denser mantle.

crust

The ________ is a layer comprising less than 1% radius and 0.4% of Earth's mass.

crust

The ________ is the thinnest layer.

crust

ferromagnesian silicates are called _____ silicates.

dark - rich amounts of magnesium and iron.

When tectonic plates subduct it is because ocean crust is ________ than continental crust.

denser

three categories of sedimentary rocks based on how they formed:

detrital (clastic), chemical, and organic

why do most sedimentary rocks form in flat, horizontal layers called strata?

during transportation and disposition, sediments are sorted by size and composition - strata layers vary in thickness and composition

sial

silica and aluminum on the continental crust

the bulk of the crustal rocks are composed of what family of minerals?

silicate

The largest and most important mineral family consists of the ________.

silicates

what are the seven principle "families" of rock-forming minerals?

silicates oxides sulfides sulfates carbonates halides native elements

The rock type which results from metamorphosed shale is ________.

slate

In the formation of igneous rocks, large crystal size is closely related to ________.

slow cooling

when present, _______comprises the upper portion of the regolith

soil

outcrop

solid rock that is found right at the surface

four basic elements of the landscape

structure process slope drainage

what mineral family is pyrite?

sulfide - combo of iron and sulfur