The Solid Earth - Chapter 1: Sedimentary Rocks Flashcards
____ begins the process of the origin of sedimentary rocks
Weathering
Running water, wind, waves, and glacial ice are examples of ______ agents
erosional
True or false: the particles are not broken down further during the transport phase
False
Following deposition, the sediment is ____ (turned into rock)
Lithified
Weathered debris is constantly being swept from bedrock and carried away by ____ and ____
Water
Wind
As piles of sediment accumulate, the materials near the bottom are compacted by the weight of the overlying layers. Over long periods, these sediments are cemented together by _____ matter deposited in the spaces between particles to form solid rock
Mineral
__ percent of all rock outcrops on the continents are sedimentary
75
Sediment accumulates at the ___ of the earth
Surface
Sedimentary rocks contain ____ which are vital in studying the geological past
Fossils
True or false: coal is considered to be a sedimentary rock
True
Deposits of sedimentary materials are referred to as ____
detrital
The second major source of sediment is soluble material produced by ____ weathering
Chemical
When the dissolved substances are precipitated by either organic or inorganic processes, the rocks formed are called ____
chemical sedimentary rocks
_____ and _____ are the chief constituents of most sedimentary rocks that are detrital
Clay
Quartz
Give two qualities of quartz that make it abundant
Durable
Resistant to chemical weathering
When gravel sized particles predominate in rock it is called
congolomerate
Gravel size particles make a rock ___
conglomerate
Sand size particles make a rock
Sandstone
Silt sized particles make a rock
Siltstone
Clay sized particles make a rock
Shale
The name of a sandstone like rock with angled edges
Breccia
True or false: angular fragments indicate that particles were not transported far from their source for deposition
True
The stronger the current, the (larger/smaller) the particle size carried
Larger
Silts and clay settle very (slowly/quickly), and these accumulations are associated with the waters of a lake, lagoon, swamp, or marine environment
Slowly
When notable amounts of ____ are present in sandstone, they are called arkose
Feldspar
Chemical sediments derive from materials that are carried in ___ in bodies of water
Solution
Sediment formed by chemical processes are said to have a ___ origin
biochemical
Give a large example of chemical sediments forming a large unit
Lake or ocean floor
What is the most common chemical sedimentary rock?
Limestone
Which mineral primarily makes up limestone?
Calcite (CaCO3)
As much as ___ percent of the world’s limestone may have originated as accumulations of biochemical sediment
90
An easily identified biochemical limestone composed of poorly cemented shells
Coquina
A soft porous rock made up almost entirely of the hard parts of microscopic organisms no larger than the head of a pin
Chalk
An example of inorganic origin limestone
Travertine
What is the source of travertine that is deposited in caves?
Groundwater
Dissolved ___ precipitates to form varieties of microcrystalline quartz
Silica
Give four examples of quartz variety from chemical sedimentary rock formations
Agate
Chert
Flint
Jasper
What is very often the mechanism triggering deposition of chemical precipitates
Evaporation
List two minerals commonly precipitated through evaporation
Gypsum
Halite
What is the chief component of rock salt?
Halite
Deposits that formed under the condition of shallower arms of the sea which constantly required water moving to replace evaporated water
Evaporites
____ marks may indicate a beach or stream channel environment
Ripple
______ form when wet mud or clay dries and shrinks, perhaps signifying a tidal flat or desert basin
Mud cracks
The _______ in a sandstone might indicate it was once a sand dune
Cross-bedding
____ is most significant as a lithification process in fine grained sedimentary rocks like shale
Compaction
____ materials are carried in solution by water percolating through the open spaces between particles
Cementated
The most common cements
Calcite
Iron Oxide
Silica
True or false: calcite cement will effervesce with dilute hydrochloric acid
True
___ is the hardest cement
Silica
When a sedimentary rock has an orange or red color, this usually means _____ ______ is present
Iron oxide
Two names for the layers of sediment deposited
Beds
Strata
What separates the strata?
Bedding planes
A conglomerate could indicate a (high/low) energy environment where only course materials could settle out
High
A rock that is arkose might indicate a (dry/wet) climatee where feldspar would not be altered
Dry
Carbonaceous shale is a sign of a low energy organic rich environment such as a ____ or _____
lagoon
Swamp
The traces or remains of prehistoric life
Fossils
