Geology Chapter 6

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Terms in this set (...)

Breccia
Sedementary rock made of angular fragments
Conglomerate
a coarse-grained sedimentary rock made of rounded pebbles cemented together
sandstone
Gritty can see grains, IMMATURE has many sizes, rounded lots of different minerals, stay where it started, greywacke, like conglomerate rocks MATURE has all the same size, angular, just quartz, traveled a lot, quartz sandstone, like breccia rocks
Shale
rock made of compressed clay
coal
sedimentary rock made of organic materials
Limestone
Made of calcite. You can often find fossils in them, fizzes with hydrochloric acid
sediment
fragments of rock that have settled and cemented
lithification
the process of things being made into rock, cemented the fragments or compressed under their own way
compaction
the consolidation of sediments resulting from the overlying deposits.
detrital clastic sedimentary rocks
rock in small particles or other material worn or broken away from a mass, as by the action of water or glacial ice. Rocks fragmented together
graywacke
dirty sandstone (immature sandstone)
arkose
intermediate sandstone. Sandstone with feldspar
quartz sandstone
a pure quartz sandstone
siltstone
sedimentary rock made of silt
silt
larger particles than clay but smaller than sand
chalk
very soft limestone
coquina limestone
porus limestone made of crushed shells (petrified granola)
lithografic limestone
is a very fine grained limestone that is used in lithography
travertine
layered limestone with holes in it
cave onyx
...dripstone stalactites
dolomite
a very common mineral, calcium magnesium carbonate, CaMg(CO 3 ) 2 , occurring in crystals and in masses.
Silica
can hold grains together, quartz, 7 in hardness, lower class gemstones are made of this
Chert
is a fine grained chemical sedimentary rock made of silica; it is often associated with limestone.
This material usually has a dull surface in contrast to the waxy appearance of flint.
Flint
is a chemical sedimentary rock of cryptocrystalline quartz; similar to chert but with a waxy surface.
This material chips with a conchoidal fracture, making it an ideal material for creating arrowheads,
spear points, and scrapers.
Jasper
is a form of chert or flint that is strongly colored by iron oxides.
Agate
can be polished
Evaporites
Calcite, dolomite, gypsum, iron oxides, salt. When water evaporates, it creates these
salt
is is the mineral halite, sodium chloride
Gypsum
calcium sulfate minerals, makes plaster o paris, and sheet rock, number 2 on hardness.
borax minerals
are a group of borate minerals formed as evaporites. Death Valley, California is a famous borax
deposit.
coal
organic material that has become rock
peat
is dark brown to black organic debris left from plants that grow in swampy areas. It is the parent
material for coal.
lignite
is soft, brown coal.
bituminus coal
is soft coal.
anthracite
is hard coal.
Primary Sedimentary structures
-are structural features found in sedimentary rocks that were created while the sediments were still
unconsolidated. Examples include mud cracks, cross bedding, graded bedding, layering, ripple
marks, etc.
Mudcracks
...As mud dries out, some of the water between clay particles evaporates, causing the surface of
the layer of mud to shrink and crack
Strata
...are layers of sedimentary rock
Crossbedding
...is a primary sedimentary structure in which one set of inclined sedimentary layers is beveled off
by an erosional process and a new set of sedimentary layers is deposited on top of the truncated
original layers; this type of primary sedimentary structure is common in stream sediments and
sand dunes.
Gradded bedding
...is a layer of sediment in which the largest particles occur at the bottom of the layer and grade
upwards into finer materials
Ripple marks
...are small parallel ridges of sand formed by flowing water or wind
Fossils
...is evidence of ancient life embedded in rock