REVIEW FOR TEST 2

Question 1

Stromatolites

Answer 1

Flat or hemispherically laminated structured of fine caebonate, fine organic matter, and clay/silt
Formed by trapping and binding of cyanobacteria
Formed today by mainly in shallow tidal zones
Oldest fossil
Occur in carbonate limestones

Question 2

chemical processes
Metamorphic

Answer 2

recrystallization
remobilization
pressure solution

Question 3

Physical appearance of lava domes

Answer 3

dome feature- plugging of vent due to high viscosity
small to moderate in size

Question 4

Inorganic Sedimentary Rock- Travertine

Answer 4

calcite slowly precipitate from water, leaving thin band/layer (caves and hot spring)

Question 5

Fossiliferous limestone

Answer 5

abundant visible fossiles (marine invertebrates)
Coral reefs, shallow ocean setting, lakes

Question 6

Deep Marine

Answer 6

Relatively flat plain, low energy
Dominated by ocean currents
Main sediment0 very fine grains mud and oozes
Rocks: chert, shale, carbonate, mudstone

Question 7

Ripples

Answer 7

Small ridges in the sands creates as sand piles up

Cm scale bedforms

Asymmetrical- unidirectional flow- rivers

Symmetrical- Bidirectional flow- waves, tides

Question 8

Shallow Marine

Answer 8

Continental shelf- Marine
Moderate energy, storms
Important transport process- waves and tidal current s
Main sediment- fine sand and mud
Main rock- mudstone, sandstone, carbonates
Structures- planar bedding, cross beds, storm influence
Main fossils- bioturbation, few marine invertebrates, fish

Question 9

Bedding Planes

Answer 9

Sedimentary material or deposition in horizontal layers forming beds

Beds are bigger than 1 cm thick

Defined by differene in color, sediment size, and/or resistance to erosion

A different bed incidactes change in sediment deposition conditions

Question 10

Physical processes metamorphism

Answer 10

Deformation of objects
Rotation
Shearing

Question 11

Beach

Answer 11

Transitional
Important transport process- wave and tidal current
Main sediment- sand
Main rock- sandstone
Main strucute- plane bed, large cross beds
Constant wave activgity, little to no structure preserved
Main fossils- bioturbation, marine invertebrates, rare vertebrates, some corals

Question 12

Inorganic Sedimentary- Banded Ions Formations

Answer 12

iron oxide precipitated from ocean water depositing on ocean floor in concentration bands, alternating with chert

Question 13

Deltas

Answer 13

Transitional - Where rivers enters oceans

Three types- river delta, wave delta, tide dominated delta
Main sediment: channelized sand, mud, organic matter (swamp)
Main rock- clastic rocks, coal/organic sedimentary rocks (swamps)
Main structure- cross bed, delta seidments, sequence (muds to fine sand to coarse sands and organic rich rocks)
Main fossils- many to few fossils

Question 14

Physical appearance of Calderas

Answer 14

moderate to very large circular, steep-walled depressions

Question 15

Chalk

Answer 15

Soft powdery, brittle limestone, Composed mostly of calcite
Accumulation of calcium- rich shells of microorganisms and algae in deep ocean

Question 16

Bed Forms

Answer 16

Sedimentary structures formed from a current (water or wind) working on sandy sediment

Ripples

Dunes

Question 17

Magma compositions of Calderas

Answer 17

Intermediate to felsic comp

Question 18

Inorganic Sedimentary Rocks - Inorganic Chert

Answer 18

Microcrysyalline quartz precipitated out of silica rich groundwater
Jasper, Flint, Onyx, Agate

Question 19

Lacustrine

Answer 19

Continental- Lakes
Low energy environment
Main sediment- fine-grained
Main rock- shale
Main structure- lamination
Main fossil- freshwater organisms

Question 20

Physical appearance of shield volcano

Answer 20

long angles, broad flanks
small vents and craters at top
can be largest of volcano- size varies

Question 21

Dunes

Answer 21

Meter Scale Ripples

Question 22

Inorganic Sedimentary rocks high evaporation rate

Answer 22

cause bodies of water to dry up
Dissolved ions precipitation out of solution
Forming evaporate minerals
Salt, calcite, gypsum, halite

Question 23

Chalk is considered a biochemical sedimentary rock because

Answer 23

It’s a carbonate that formed from the calcium-rich skeletons of microorganisms that had accumulated on the seafloor

Question 24

Inorganic

Answer 24

evaporates/precipitates from water (by chemical reactions)
Classified by composition

Question 25

Aeolian

Answer 25

Continental - Wind-blown Sand dragged along surface or briefly lifted- silt and clay blown away and carried long distances Main sediment- very well sorted sant and silt Main rock- sandstone Main strucute- large cross beds Main fossils- rare

Question 26

Continental Rift has what type of igneous rock comp

Answer 26

Felsic rock- intermediate magma

Question 27

Subduction Zone

Answer 27

Convergence SUBDUCTION and REGIONAL metamorphism Reverse/Thrust Faulting FAULT metamorphism and BURIAL metamorphism CONTACT metamorphism- magma intrusion into continental crust

Question 28

Fluvial

Answer 28

Continental- Rivers High low energy, water transport Meandering and braided rivers Meandering- 1 single channel Braided- multiple channels Main sediments- sand, mud, coarse grains Main rocks- sandstone, conglomerates, siltstone Main structure- cross beds, asymmetric ripples, channels Main fossils- bone beds,

Question 29

Bioturbation

Answer 29

Reworking of soft sediment by burrowing organisms SHALLOW MARINE environments Used to indicate WATER DEPTH

Question 30

Laccoliths

Answer 30

lens shaped, cause surface doming

Question 31

Laminations

Answer 31

Parallel layers, less than 1 cm thick, fine grained sediments Fine grained sediment deposited in QUIET, LOW energy environment Lake, deep ocean

Question 32

Biochemical

Answer 32

formed from shells/skeletons of marine/freshwater organisms Organisms extract dissolved material out of water to form shells, when dies, the hard parts deposit on sea floor as sediment that lithifies when buried fossiliferous limestone chalk biogenic chert stromatolites

Question 33

Graded Bedding

Answer 33

Change in grain size within a sediment bed Trends from coarse to finer; or finer to coarser Caused by changes in currents speed Events like FLOOD, LANDSLIDES, SUBMARINE LANDSLIDES

Question 34

What are the metamorphic rock textures produced from directed stresses?

Answer 34

Shistosity- schist Shearing- mylonite Foliation- Gneiss

Question 35

Inorganic Sedimentary rocks- rich groundwater

Answer 35

abundant dissolved ions precipiate out of solution- lakes streams hot spring, caves stalagmaite and stalactite

Question 36

Mudcracks and raindrop impressions

Answer 36

When wet-logged clay rich sediment dries out Shrinking mud forms cracks- get preserved if sediment fills in cracks Can form TIDAL FLATS; DRIED LAKES: SHORELINES

Question 37

Cross-Beds

Answer 37

How do ripples and Dunes Migrate Wind or water transport grains on upstream side and deposits grains on downstream side Migrating dune/ripple erodes, the crest in front of it , leaving base as layer behind with crossbedding Downstream migration of ripples produce crossbedding Paleocurrent direction Crossbeds tilt down- current and thus indicate DIRECTION OF FLOW

Question 38

Biogenic Chert

Answer 38

Microcyralline quartz made of shells from microorganisms (plankton) Siliceous ooze in deep ocean, lakes

Question 39

Hot Spot has what type of igneous rock comp

Answer 39

oceanic- mafic to intermediate continetal- mafic to felsic