Physical Geology Exam 3

How rocks can change in the rock cycle (diagram on quiz 2, #10)

1. weathering, transport, and deposition 2. burial and heating 3. melting

a water molecule in the atmospheric reservoir has a residence time of approximately

10 days

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Biochemical sedimentary rocks are made up of shells. Chemical sedimentary rocks form by precipitation from a solution. Intrusive rocks are a type of igneous rock, formed by the freezing of magma.

sedimentary rocks form

By grains being cemented together

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Coal is a carbon-rich organic sedimentary rock that is made from compacted plant matter.

Explain the transition path of a rock that first experienced melting and cooling, then burial to deep depths during mountain building, and finally uplift and weathering

Igneous, metamorphic, sedimentary

This statement is true about a reservoir

It is a component in the Earth System that holds material for a period of time

Which of the following statements is true?

Pieces of broken rock produced by physical weathering are called clasts. Conglomerates are made up of various grain sizes, not just one. A well-sorted rock is made up of uniform particle sizes. Rounding and sphericity are different: A clast may be well-rounded but not have the shape of a sphere.

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Shell material is biochemical sediment. Evaporation of seawater produces evaporite deposits. Deposition of quartz sand on a beach or accumulation of mud on the seafloor produces clastic sediment, which must be cemented together to form clastic (not biochemical) sedimentary rock.

Characteristics of all rocks

They are collection of minerals or a body of glass

As clastic sediment is transported downstream, away from its point of origin, what happens to the clasts?

They become smaller in size Clastic sediments become smaller, more rounded, and more uniform in size (well sorted) as they are transported farther from their point of origin.

These statements are true about igneous rocks

They were molten and have frozen into a solid form they may form from lava they may form around volcanoes

The feature that may form where a stream enters a lake or ocean is called

a delta Deltas are accumulations of clastic sediment that form where rivers deposit their sediment into an ocean or lake. Reefs form offshore in areas of little to no clastic input, alluvial fans form when rivers exit mountains, and a sedimentary basin is a tectonic feature that has nothing to do with streams entering lakes.

A sedimentary basin that forms when continental lithosphere is stretched, causing down-dropped crustal blocks bordered by narrow mountain ranges and alluvial fans, is called

a rift basin Rift basins are a result of crustal stretching, and typically have bordering mountain ranges and alluvial fans. Passive-margin basins form on the edges of continents and continue long after rifting has ended. Intracontinental basins are similar to rift basins but form over much larger areas for much longer time periods. Foreland basins lie on the continent side of a mountain belt formed as a result of continental collision.

The feature in the photo is an apron of gravel and sand deposited at the mouth of a streambed that is leaving the mountains and entering a flat plain. This type of feature is called

an alluvial fan This photo shows an alluvial fan. Deltas form where a stream enters a lake or ocean, turbidites form in deep water, and reefs are offshore features made of biochemical sediment.

Coal is a form of

biochemical sedimentary rock.

A nonmarine clastic sedimentary rock composed of angular pebbles surrounded by matrix would be a(n)

breccia Conglomerate fragments are rounded, turbidities are marine rocks, and arkose is a type of sandstone.

shale, a sedimentary rock, can be metamorphosed to schist through

burial during continental collision

Which of the following processes forms biochemical sedimentary rock?

cementing together of shell fragments

these are true statements

chemical weathering is fastest where surface area is low weathering happens fastest on the flat faces of broken blocks of rock spheroidal weathering is due to faster rates of weathering along corners and edges of a rock

Which of the following rock types contains the mineral quartz?

chert Chert is composed of the mineral quartz (i.e., it is siliceous). The others are examples of biochemical limestone, all composed of the mineral calcite or its polymorph aragonite.

Which of the following classes of sedimentary rock is produced by weathering and erosion of pre-existing rocks?

clastic

Evapotranspiration

describes the release of water to the atmosphere from the surface, plants, or animals.

The sandstone in this photo was most likely deposited in what type of environment?

desert sand dunes The size of these cross beds indicates that they were deposited in desert sand dunes. A floodplain environment deposits mostly mud and silt, deep-marine environments deposit fine-grained sediment and turbidites with graded beds, and a reef deposit would be made of limestone, not sandstone.

Which of the following is a general term used to describe all the physical, chemical, and biological processes that make a sedimentary rock from sediments?

diagenesis Diagenesis includes all the physical, chemical, and biological processes that transform sediment into sedimentary rock or alter existing sedimentary rock.

South of the Himalayan mountain range, the crust of the Indian subcontinent has been bent downward and covered by a thick succession of sediment eroded from the mountains. This sedimentary basin is a type of

foreland basin The Ganges basin, described in this question, is a foreland basin caused by the weight of the Himalayas pushing down on the crust of India.

The named intervals in this photo of the Grand Canyon are ________, and the yellow lines between them are called ________.

formations, contacts Beds are individual layers of sedimentary rock. These larger groupings of rock, called formations, consist of many individual beds that are similar in character. Formations are continuous and of large enough scale to be drawn on a map. Beds are separated by bedding planes, and formations are separated by contacts.

what source(s) of energy makes it possible to move matter through the rock cycle?

gravity, the Earth's internal heat, and solar energy

Which of the following minerals or rock types is associated with evaporite deposits?

gypsum only gypsum is a common evaporite mineral. Quartz and feldspar are common constituents of clastic sediment, and chert precipitates biochemically or chemically.

metamorphic rock

has changed physical characteristics while remaining solid

which of the following chemical reactions breaks down feldspars into clay

hydrolysis

the rock cycle indicates that

input of new melt into the crust enters the rock cycle as a igneous rock

Natural cracks in rock that form due to exhumation (erosion of overburden) of deeply buried rock are called

joints

Which of the following features is a bed-surface marking, meaning that it appears on the surface of a bed as a result of events during or soon after sediment deposition?

mud cracks Mud cracks form on a bed surface after a mud layer dries up following deposition. The other choices describe sedimentary structures that are seen in cross section, but not on a bedding surface.

Which of the following lists accurately reflects an increase in grain size from smallest to largest?

mud, silt, sand From smallest to largest, clastic particle sizes range from mud, silt, sand, and pebbles, to cobbles.

The organic sedimentary rock that is composed of mud-sized particles and partially decayed organic matter derived from plankton and algal remains is called

oil shale. Coal is partially decayed particles, larger than mud-sized, and derived from swamp plants, not plankton and algae. The other rocks are not composed of decayed organic matter.

In which of the following environments, or by which process, was this sedimentary structure most likely produced?

on a floodplain This photo shows mud cracks. Mud cracks develop only if a muddy surface dries up sufficiently to crack into roughly hexagonal plates. In deep-marine settings, where turbidites occur, drying cannot happen.

The various geologic settings in which rocks can melt, metamorphose, or becomes sediment are ultimately generated by

plate tectonics

most of the minerals in granite weather to clay except for

quartz

A deposit contains very little sand and mud, but instead a lot of broken-up carbonate shells of marine organisms. What was the likely depositional environment?

reef In warm areas of the ocean where very little sand or mud is deposited, marine organisms of reefs deposit their calcite (limestone) shells to form limestone. Rivers, deltas, and alluvial fans are all clastic environments where gravel, sand, silt, and mud are deposited.

The hydrologic cycle involves

reservoirs above, below, and at the Earth's surface

Which of the following sedimentary structures indicates that the sediments were deposited by a moving fluid?

ripple marks Of the choices listed, only ripple marks form as a result of sediment being moved by a current.

Formation of a clastic sedimentary rock involves five stages. Of these stages, erosion is the

separation of rock or regolith from its substrate The process by which bedrock separates into particles is weathering. Compaction and cementation are processes involved in lithification. The settling of particles out of a transport medium is deposition.

A clastic sedimentary rock with clay and silt-sized grains that is finely laminated and breaks into thin sheets is called

shale Only mudstone and shale are rocks made of silt and mud-sized pieces, and mudstone does not break into thin sheets.

Which of the following might be considered sediment

shell fragments washed up on a beach

What physical characteristics can be used to distinguish individual rock types?

texture, the size and shape of grains that compose the rock, and composition

which of the following energy sources drives landscape evolution

the force of gravity

identify the statement that is true about atoms as they pass through the rock cycle

they do not move through the rock cycle at the same rate. the rocks found at the Earth's surface can be of very different ages.

In this image, the fact that shoreline beach deposits occur on top of terrestrial swamp and floodplain deposits indicates that ________ has occurred.

transgression This is an example of transgression. In regression, sea level falls and terrestrial sediments are deposited on top of marine sediments. Uplifting would produce erosion, and rifting does not explain the sequence of depositional environments given in the question.

this statement is true according to the rock cycle

uplift, weathering, burial, and heating/ melting can transform one rock type into another.

agents of erosion

water, ice, and/ or air