Sedimentary Rocks

Flashcards about sedimentary rocks

Clastic sedimentary rocks in order from coarsest to finest: Conglomerate/breccia, sandstone, siltstone, shale/mudstone

Clastic Sedimentary Rock Order

Coal typically forms in swamps, marine shale in deep marine environments, red beds in terrestrial environments, and marine sandstone in shallow marine environments.

Rock formation by environment

Limestone is made of calcite, reacts with dilute acid, and forms from coccolithophores and foraminifera. Chert is made of quartz (cryptocrystalline), does not react with dilute acid, and forms from radiolaria and diatoms.

Limestone vs. Chert

Alluvial-fan deposits are wedge-shaped, consist of coarse sediments and feldspar, typically at the foot of an eroding mountain range, whereas deep-marine deposits consist mostly of clay and the skeletons of planktonic microorganisms.

Alluvial-fan vs. Deep-marine deposits

Evaporites form as ions (minerals) precipitate out of an evaporating solution.

Evaporite Formation

Alluvial fan deposits are likely laid down in Death Valley National Park.

Death Valley Sedimentary Rock Location

A sedimentary structure that is a single layer of sediment or sedimentary rock with a recognizable top and bottom is called a bed; The overall division of sediment into a sequence of beds is called bedding

Beds and Bedding

During transgression, a mud layer accumulates over a sand layer, sea level rises, and the coastline migrates inland.

Transgression Effects

Argillaceous means made of mostly clay minerals, siliceous means made of mostly quartz, and carbonate means made of mostly calcite and/or dolomite.

Sedimentary Rock Descriptors

During a transgression of the sea, the location at which beach sand accumulates moves inland.

Beach Sand Accumulation During Sea Transgression

The geologic processes in order to form sedimentary rock: Rock is weathered to produce sediments, sediments are buried, compaction removes air from pore spaces, chemically rich groundwater flows through pore spaces, minerals precipitate in pore spaces, sediments are glued together by cement to form sedimentary rock.

Steps for Sedimentary Rock Formation

Travertine can form near hot springs and in caves.

Travertine Formation Locations

When viewing sandstone cross beds, the cross-bed orientation indicates wind direction at the time of deposition.

Wind Direction from Cross Beds

Dolostone is composed of the mineral dolomite, which is similar to calcite in limestone, except that dolomite contains magnesium.

Composition of Dolostone

Replacement chert forms as silica replaces other minerals in a rock, and biochemical chert forms from the accumulation of silica shells from plankton.

Replacement vs. Biochemical Chert

Sediment is initially deposited in horizontal layers.

Sediment Deposition

Layers of sedimentary rocks, called beds, form a cover that buries the underlying basement of igneous and/or metamorphic rock.

Sedimentary Cover vs. Basement Rock

Water, ice, and wind can move sediment.

Transporting Media for Sediment

The faster a fluid flows, the larger the clasts it can carry.

Fluid Velocity and Sediment Size

A sedimentary rock that precipitates from water solutions is chemical.

Chemical Sedimentary Rocks

Biochemical rocks form from the shells of dead marine organisms.

Biochemical Rocks Composition

Clastic rocks are solid fragments and grains broken off of pre-existing rocks that are cemented together. Biochemical rocks consists of shells grown by organisms. Organic rocks are carbon-rich remains of plants or other organism. Chemical rocks consists of minerals precipitated from surface-water solutions.

Four Major Classes of Sedimentary Rocks

Turbidity currents transport sediment.

Turbidity currents

Typically, bedding in sandstone is defined by a change in grain size or mineralogy.

Defining Bedding in Sandstone

Biochemical sedimentary rocks are composed of the shells of dead organisms, but organic sedimentary rocks are composed of organic material/compounds of dead organisms.

Biochemical vs. Organic Sedimentary Rocks

Oil shale and coal are organic sedimentary rocks.

Organic Sedimentary Rock Examples

A conglomerate has rounded grains, whereas a breccia has angular grains.

Conglomerate vs. Breccia

Quartz sandstone consists of quartz grains only, arkose consists of quartz and feldspar, lithic sandstone consists of sand-sized rock fragments, and wacke consists of sand and rock fragments in a clay-rich matrix.

Compositions of Sandstones

Cementation and compaction take place during lithification.

Lithification Processes

The material in cement forms as ions precipitate out of the water in the pore spaces between grains.

Source of Cement Material

The steps in forming a clastic sedimentary rock from its pre-existing parent rock are: weathering, erosion, transportation, deposition, lithification.

Clastic Rock Formation Steps

During transgression, coastline migrates inland, position of beach moves inland, and it involves a relative rise in sea level, and regression involves a relative fall in sea level.

Transgression vs. Regression

Foreland basin, rift basin, intracontinental basin, and passive-margin basin are types of sedimentary basins.

Types of sedimentary basins

Clastic sedimentary rocks in order from coarsest to finest: Conglomerate/breccia, sandstone, siltstone, shale/mudstone

Clastic Sedimentary Rock Order

Coal typically forms in swamps, marine shale in deep marine environments, red beds in terrestrial environments, and marine sandstone in shallow marine environments.

Rock formation by environment

Limestone is made of calcite, reacts with dilute acid, and forms from coccolithophores and foraminifera. Chert is made of quartz (cryptocrystalline), does not react with dilute acid, and forms from radiolaria and diatoms.

Limestone vs. Chert

Alluvial-fan deposits are wedge-shaped, consist of coarse sediments and feldspar, typically at the foot of an eroding mountain range, whereas deep-marine deposits consist mostly of clay and the skeletons of planktonic microorganisms.

Alluvial-fan vs. Deep-marine deposits

Evaporites form as ions (minerals) precipitate out of an evaporating solution.

Evaporite Formation

Alluvial fan deposits are likely laid down in Death Valley National Park.

Death Valley Sedimentary Rock Location

A sedimentary structure that is a single layer of sediment or sedimentary rock with a recognizable top and bottom is called a bed; The overall division of sediment into a sequence of beds is called bedding

Beds and Bedding

During transgression, a mud layer accumulates over a sand layer, sea level rises, and the coastline migrates inland.

Transgression Effects

Argillaceous means made of mostly clay minerals, siliceous means made of mostly quartz, and carbonate means made of mostly calcite and/or dolomite.

Sedimentary Rock Descriptors

During a transgression of the sea, the location at which beach sand accumulates moves inland.

Beach Sand Accumulation During Sea Transgression

The geologic processes in order to form sedimentary rock: Rock is weathered to produce sediments, sediments are buried, compaction removes air from pore spaces, chemically rich groundwater flows through pore spaces, minerals precipitate in pore spaces, sediments are glued together by cement to form sedimentary rock.

Steps for Sedimentary Rock Formation

Travertine can form near hot springs and in caves.

Travertine Formation Locations

When viewing sandstone cross beds, the cross-bed orientation indicates wind direction at the time of deposition.

Wind Direction from Cross Beds

Dolostone is composed of the mineral dolomite, which is similar to calcite in limestone, except that dolomite contains magnesium.

Composition of Dolostone

Replacement chert forms as silica replaces other minerals in a rock, and biochemical chert forms from the accumulation of silica shells from plankton.

Replacement vs. Biochemical Chert

Sediment is initially deposited in horizontal layers.

Sediment Deposition

Layers of sedimentary rocks, called beds, form a cover that buries the underlying basement of igneous and/or metamorphic rock.

Sedimentary Cover vs. Basement Rock

Water, ice, and wind can move sediment.

Transporting Media for Sediment

The faster a fluid flows, the larger the clasts it can carry.

Fluid Velocity and Sediment Size

A sedimentary rock that precipitates from water solutions is chemical.

Chemical Sedimentary Rocks

Biochemical rocks form from the shells of dead marine organisms.

Biochemical Rocks Composition

Clastic rocks are solid fragments and grains broken off of pre-existing rocks that are cemented together. Biochemical rocks consists of shells grown by organisms. Organic rocks are carbon-rich remains of plants or other organism. Chemical rocks consists of minerals precipitated from surface-water solutions.

Four Major Classes of Sedimentary Rocks

Turbidity currents transport sediment.

Turbidity currents

Typically, bedding in sandstone is defined by a change in grain size or mineralogy.

Defining Bedding in Sandstone

Biochemical sedimentary rocks are composed of the shells of dead organisms, but organic sedimentary rocks are composed of organic material/compounds of dead organisms.

Biochemical vs. Organic Sedimentary Rocks

Oil shale and coal are organic sedimentary rocks.

Organic Sedimentary Rock Examples

A conglomerate has rounded grains, whereas a breccia has angular grains.

Conglomerate vs. Breccia

Quartz sandstone consists of quartz grains only, arkose consists of quartz and feldspar, lithic sandstone consists of sand-sized rock fragments, and wacke consists of sand and rock fragments in a clay-rich matrix.

Compositions of Sandstones

Cementation and compaction take place during lithification.

Lithification Processes

The material in cement forms as ions precipitate out of the water in the pore spaces between grains.

Source of Cement Material

The steps in forming a clastic sedimentary rock from its pre-existing parent rock are: weathering, erosion, transportation, deposition, lithification.

Clastic Rock Formation Steps

During transgression, coastline migrates inland, position of beach moves inland, and it involves a relative rise in sea level, and regression involves a relative fall in sea level.

Transgression vs. Regression

Foreland basin, rift basin, intracontinental basin, and passive-margin basin are types of sedimentary basins.

Types of sedimentary basins