Chapter 06 Vocab Flashcards
Bed
Layering or stratification in sedimentary rocks.
Biochemical sedimentary rock
Sedimentary rock formed from material (such as shells) produced by living organisms.
Breccia
Coarse sedimentary rock consisting of angular fragments; or rock broken into angular fragments by faulting.
Cementation
The phase of lithification in which cement, consisting of minerals that precipitate from groundwater, partially or completely fills the spaces between clasts and attaches each grain to its neighbor.
Chemical Sedimentary Rock
Sedimentary rocks made up of minerals that precipitate directly from water solution.
Clastic Sedimentary Rock
Sedimentary rock consisting of cemented-together detritus derived from the weathering of preexisting rock.
Coal
A black, organic rock consisting of greater than 50% carbon; it forms from the buried and altered remains of plant material.
Compaction
The phase of lithification in which the pressure of the overburden on the buried rock squeezes out water and air that was trapped between clasts, and the clasts press tightly together.
Conglomerate
Very coarse-grained sedimentary rock consisting of rounded clasts.
Delta
A wedge of sediment formed at a river mouth when the running water of the stream enters standing water, the current slows, the stream loses competence, and sediment settles out.
Deposition
The process by which sediment settles out of a transporting medium.
Depositional environment
A setting in which sediments accumulate; its character (fluvial, deltaic, reef, glacial, etc.) reflects local conditions.
Detritus
The chunks and smaller grains of rock broken off outcrops by physical weathering.
Erosion
The grinding away and removal of Earth’s surface materials by moving water, air, or ice.
Geologic map
A map showing the distribution of rock units and structures across a region.
Limestone
Sedimentary rock composed of calcite.
Lithification
The transformation of loose sediment into solid rock through compaction and cementation.
Mudstone
Very fine-grained sedimentary rock that will not easily split into sheets.
Organic Sedimentary Rock
Sedimentary rock (such as coal) formed from carbon-rich relicts of organisms.
Regression
The seaward migration of a shoreline caused by a lowering of sea level.
Sandstone
Coarse-grained sedimentary rock consisting almost entirely of quartz.
Sedimentary basin
A depression, created as a consequence of subsidence, that fills with sediment.
Sedimentary rock
Rock that forms either by the cementing together of fragments broken off preexisting rock or by the precipitation of mineral crystals out of water solutions at or near the Earth’s surface.
Siltstone
Fine-grained sedimentary rock generally composed of very small quartz grains.
Sorting
(1) The range of clast sizes in a collection of sediment; (2) the degree to which sediment has been separated by flowing currents into different-size fractions.
Stratigraphic formation
A recognizable layer of a specific sedimentary rock type or set of rock types, deposited during a certain time interval, that can be traced over a broad region.
Subsidence
The vertical sinking of the Earth’s surface in a region, relative to a reference plane.
Transgression
The inland migration of shoreline resulting from a rise in sea level.
Turbidity current
A submarine avalanche of sediment and water that speeds down a submarine slope.
