Mineralogy/Petrology Test 3 INFO

true

"At Mahana Bay, along the southern coast of the big island of Hawaii a 49,000 year old tuff ring is eroding along the coastline. Much of this is olivine (containing iron and magnesium) and olivine is heavier than most sand grains. So, as the coastline erodes the olivine stays on the beach longer than most of the rest of the sand (that gets carried away by the waves) and builds up so that the beach appears green. "

powdered

"Dolomite often occurs with calcite, but it only reacts with HCl when _________________."

Their chemical composition will be nearly the same

"Generally speaking, how does the chemical composition of most metamorphic rocks compare to that of the parent rock?"

Garnet Schist

"Of the following rocks, one that is metamorphic is: "

large, medium, small Answer: small

"The calcite group is the CO3 carbonate anionic complex combined with ________ divalent cations (Ca, Mg, Fe, Mn, Zn)"

bladed

"The common crystal forms in the calcite group are rhombohedral, tabular, and _______________."

What is diagenesis?

"The textural, compositional, and other changes that occur to sediments after deposition"

Burial

"________ metamorphism tends to occur in regions where massive amounts of sedimentary or volcanic materials accumulate in a subsiding basin, pushing older rocks further into the interior."

Impact metamorphism

"strike metamorphism" occurs when meteorites strike Earth's surface rocks called impsctiles Ultra high T & P

Saltation particle movement

(intermittent hopping) "Bedload" wind or water larger materials

Hydrothermal Metamorphism

-Chemical alteration caused when hot, ion-rich fluids circulate through fissures and cracks -Most widespread along axis of the mid-ocean ridge system, altering ocean-floor basalt

Subduction zone metamorphism

-High pressure, low temperature -restricted to narrow belts (smaller than regional) -forms at temps below average geothermal gradient, but very high pressure -Accretionary prisms at subduction zones is only site (Blueschist facies)

Contact metamorphism

-Magma invades a host rock -Temperature rises -Zone of alteration forms in rock surrounding the magma (limited areal extent) -High temps, but low pressure -Typically produces massive rocks

Metamorphism

-Metamorphism occurs when a protolith undergoes a solid state (not magma) change in response to a modification of environment -TEMPERATURE, PRESSURE, COMPOSITION OF FLUID

Chert

-Rock name for cryptocrystalline quartz -Occurs in bedded deposits and as nodules in sedimentary sequences. -Precipitates in water, mostly marine -Silica sources include -Some plankton (diatoms and radiolarian) -Sponge spicules

halite (halide mineral)

-most abundant in marine deposits -Mechanically unstable: deforms by flowing when deeply buried. -forms salt dome structures. -extremely restricted basin shows halite

Siliciclastic sedimentary rocks

-most abundant sedimentary rocks. -formed from detritus left over from weathering of igneous and metamorphic & older sedimentary rocks. -pyroclastic materials if close to active volcano -rock composition depends on source region, weathering, and separation of grains/minerals during transport. -most derived from continents (terrestrial siliciclastic sediment)

Chert

-rock name for cryptocrystalline quartz -occurs in bedded deposits and as nodules in sedimentary sequences -precipitates in water, mostly marine -silica sources include some plankton (diatoms/radiolaria) and sponge spicules

sequence of evaporite formation

1. Calcite - begins when seawater 1st starts to evaporate 2. Gypsum- begins when ~75% water removed 3. Halite- begins when ~90% water removed 4. Various Mg/K salts- ~95% removed

sedimentary weathering rates influenced by:

1. Chemical composition and bonding of mineral material (Quartz=high stability, Olivine=low) 2. Structural integrity of mineral; fractures, cleavage (increases particles) 3. Sizes & Impurities of crystals 4. Chemical character of environment (water availability[no soil without water], temperature[polar regions- low weathering]) 5. Areas with high topographic relief promote weathering and transport of sediment. (convergent and divergent plate boundaries)

Mudrocks

2/3 of all sedimentary rocks siltstone, claystone, shales source of organic materials from which oil and gas form. (contain 95% of all organic matter in sed rocks) low permeability, good cap rocks for oil reservoirs and confined aquifers. Silt (mostly quartz-angular bc never at stream bottom) and clay sized mineral may be finely layered (laminated, fall like sheets of paper)

Halite begins to deposit when ~_____% of the original seawater has been removed.

90

Wackes

> 15% mud matrix. Immature. Characteristic of submarine fan, slope, and abyssal deposits.

Porphyroblasts

A crystal in a metamorphic rock that is significantly larger than the other mineral grains in the rock, and commonly euhedral and has grown during metamorphism

Stylolites

A dark irregular line in limestone formed where insoluble residue has accumulated on a surface where solution of the rock has taken place.

Marble

A rock formed from the metamorphism of limestone and composed predominantly of calcite, but it may also contain dolomite.

immature

A sedimentary deposit containing angular sand grains in a clayey matrix would be described as:

Graded Bedding

A sedimentary structure that exhibits coarser grain size at the bottom and finer at the top is called ___________.

ripple mark

A sedimentary structure that is formed as wind or water moves across sand is a ____________.

high

Areas of ___________ topographic relief promote weathering and transport of sediment.

Metamorphic facies derive their names from those metamorphic rocks specifically formed from a ________ parent.

Basaltic

Match the sedimentary rock or mineral example with the type of sedimentary rock or mineral: oolitic limestone.

Biochemical

__________ sedimentary rocks form from sediment derived from organisms.

Biochemical

role of CO2

CO2 gas dissolved in water is KEY to deposition less CO2 in water, more CaCO3 deposits how to get less CO2 in water: Increase temperature Agitate water (more area to lose gas dissolved in water) Increase salinity (through evaporation) (CO2=less soluble) Enhance organic activity (Plants absorb CO2 during day) Expose groundwater saturated with CaCO3 to atmosphere

Carbonate matrix

Calcium carbonate mud that binds allochems together

Rainwater will combine with which atmospheric gas in order to create carbonic acid?

Carbon Dioxide

Which marine depositional environment is characterized by clear water dominated by skeletons of marine organisms?

Carbonate Shelf

Which mineral class is best described by the following statements: Ex: dolomite

Carbonates

"______________ weathering is the decomposition of minerals, with formation of new minerals"

Chemical

______________ weathering is the removal of some material in solution

Chemical

Greenstone

Chlorite gives green color Mafic protolith, such as basalt

Hydrocarbons

Coal- from buried plant material before it oxidizes Oil- burial of animal and plant remains Natural gas- same as oil but higher temperatures

Formation of mudrocks

Compaction is most notable change because porosity loss. (loss bc increasing depth of burial for muds)

Carbonate Minerals

Contains Co32- anion. Cementing agents in clastic sed. rocks and make up shells of many organisms. Minerals will break down in presence of H+ (acid): 2H+Co32 yields H2O+CO2

"Which of the following sedimentary structure can NOT determine the ""up-direction"" in rocks that have been overturned?"

Cross-beds

"In cementation, stable precipitates may replace less stable minerals, and porosity ______________."

Decreases

Transitional

Deltas are included in _______________ depositional environments.

True

Depositional environments have a distinctive set of rock characteristics.

Bedload

Detritus that rolls or intermittently hops on the bottom of a river makes up the rivers

Cambrian

During which period does the rock record indicate an explosion of life (rapid evolution and diversification) of many organisms that contribute to the formation of carbonate sediment?

Which mineral class is best described by the following statements: Ex: gypsum

Evaporite

What is not true about Sedimentary Rocks?

Evaporites are examples of biogenic sedimentary rocks

A ________ describes the observation of successive changes in a laterally continuous sedimentary layer that are visible and are interpreted as a result of many depositional processes taking place over a large area.

Facies transitional environment

Peliods

Fecal pellets formed of carbonate minerals that are produced by many different organisms.

"During hydrolysis, ________ commonly decompose into clay minerals, silica, and soluble constituents."

Feldspars

Schistocity

Geological foliation with medium to large grained flakes in a preferred sheetlike orientation

Gneissic banding

Gneiss appears to be striped in bands

"_______________ is defined as how grains can be classified as spherical, rod-shaped, or disk-shaped"

Grain size

___________ sedimentary rock form from detritus.

Gravel

90

Gypsum begins to deposit when ~_____% of the original seawater has been removed.

Heat as agent in metamorphism

Heat between diagenesis and melting, recrystallization results in new, stable minerals. hotter = faster

Heat from magma, geothermal gradient, radioactive decay Answer: all answers are correct

Heat leading to metamorphism can be provided by which of the following?

Agents of metamorphism

Heat, prograde changes (heating), retrograde changes (cooling), confining pressure, differential stress, hydrothermal fluids.

Calcite Group

Hexagonal minerals created by triangular shape of CO3 structure. -Rhombohedral cleavage. -Common forms: Rhombohedral, tabular, scalendohral "dog tooth"

A sedimentary deposit containing angular sand grains in a clayey matrix would be described as

Immature

Ooids

Inorganic origin. A sub-rounded sand-size grain consisting of concentric layers of carbonate. The argonite or calcite precipitates around a preexisting grain, which forms the nucleus. Most oolitic limestone is made of calcite.

is a biochemical sedimentary rock that often forms in carbonate reefs.

Limestone

______________ allochems are subrounded sand-size particles formed by precipitation of calcite or aragonite in concentric layers around a nucleus grain as it washes back and forth in shallow marine waters

Limestone ooids

Lagoons are included in _______________ depositional environments.

Marine

Turbidites are associated with which type of depositional environment?

Marine

Phosphorites

Marine sedimentary rocks composed mostly of apatite with >20% P2O5 Apatite, Collophane, Chert

Detrital

Match the sedimentary rock or mineral example with the type of sedimentary rock or mineral: quartz arenite.

Gneiss

Medium to coarse grained high-grade metamorphism exhibits gneissic banding (color segregation)

Micrite

Microcrystalline carbonate 1 to 5 microns in size (dull in hand sample) precipitates in low energy environments may recrystallize within few million years to microspar (spar)

Spar

Microspar Micrite that recrystallizes

Which of the following sedimentary structures only occurs in fine-grained sediment?

Mudcracks

Siltstone

Mudrock; commonly layered with fluvial sandstone lithified, non-fissile mudrock smaller than sand particles

Dynamic metamorphism

Occurs at depth and high temperatures along fault zones Pre-existing minerals deform by ductile flow result of shearing (Mylonite) Mylonite- large grains in protolith recrystallize to fine grained

protolith

Parent rock

Organically produced limestone/carbonate sediment

Precambrian- explosion of life Carbonate sediment- forms from hard parts of variety of organisms that are broken by wave/current action or by other organisms on them. gravels to sands to muds

Conglomerates

Predominantly gravel- size particles. Form in high-energy environment (Ex. Fast-flowing rivers or alluvial fans). May be clast-supported or matrix-supported. If angular, called sedimentary breccia.

Allochems

Primary carbonate sedimentary particles that form the framework of a limestone. Ex. shell fragments, ooids, and pellets.

Which of the following is the most common sedimentary mineral?

Quartz

Indicate which metamorphic rock is described. Consists of quartz sandstone grains which have been fused together; is nonfoliated

Quartzite

________ is a widespread type of metamorphism typically associated with mountain building.

Regional Metamorphism

Which of the following methods of transportation will result in the least sorted deposit?

Rock Fall

"_______________ is defined as how angular grains are. It is controlled by grain size, hardness, and environments of transport and deposition."

Roundness

Which rock type can contain fossils?

Sedimentary

__________ are visible features within sedimentary rocks that formed at the time of deposition and represent manifestations of the physical and biological processes that operated in depositional environments.

Sedimentary Structures

"Which rock type, or combination of rock types, makes up the majority of Earth's outermost solid surface?"

Sedimentary, metamorphic

Claystone

Shale- most abundant sedimentary rock, recognized by fissility (split into thin sheets) doesn't grit on teeth

What sediment particle size(s) make up shale?

Silt and Clay sized

"Which low-grade metamorphic rock displays thin, parallel layers and contains very fine grains of mica?"

Slate

Slate

Slate is a hard mudstone that has undergone metamorphosis, and has well-developed cleavage

1. calcite 2. quartz 3. hematite 4. clay

Sort the following from MOST common cement to LEAST common cement.

Which mineral class is best described by the following statements: Ex: gypsum

Sulfates

In stratified glacial meltwater deposits, you might assume that a layer with larger grain size was deposited during

Summer

shock

Tectites are the result of which type of metamorphism?

What is the definition of metasomatism?

The change in chemical composition because hot fluids are bringing or removing ions

Foliation

The property of a rock to break into thin sheets that are bounded by planes along which typically platy minerals are aligned. This alignment may result from sedimentation of clay minerals or from the growth of micas in a preferred orientation in metamorphic rocks.

false

The raw material for coal is dead marine organisms.

false

To get less CO2 in water you need to increase organic activity.

What sedimentary environment do the following statements/key words/rock types belong to? Glacial.

Transitional

"Chalk is a soft, porous rock composed of the hard parts of microscopic marine organisms."

True

Marine

Turbidites are associated with which type of depositional environment?

Water

What fluid is generally responsible for metasomatism?

Heat

What is the most important factor driving metamorphism?

varves

What is the name given to annual deposits of rhythmic layers of coarser and finer sediment reflecting seasonal changes?

Marine

What sedimentary environment do the following statements/key words/rock types belong to? Oozes.

Marine

What sedimentary environment do the following statements/key words/rock types belong to? Turbidites.

uniform stress

What type of stress relates with foliation?

rod-shaped

Which of the following is NOT a type of detrital grain sphericity?

Gabbro, greywacke, rhyolite, Andesite Answer:

Which of the following is a sedimentary rock?

Cross-bedding

Which of the following represents the single most common and characteristic structures in sedimentary rocks?

mudrocks, sandstones, limestones Answer: mudrocks

Which of the following rocks is most abundant?

Shales and mudstones are baked during contact metamorphism.

Which of the following scenarios best describes the formation of hornfels?

Lithic Arenites

Which of the following siliciclastic rocks is submature and do not contain K-feldspar? They are often found at the base of recent uplifts where rock fragments are plentiful.

mudrocks

Which type of sedimentary rock makes up approximately 65% of all sedimentary rocks?

Regional metamorphism

Widespread metamorphic zones, producing greatest quantity of metamorphic rock Associated with mountain building/convergence (folding) temperature very high, associated with depth/igneous activity higher pressure due to overburden weight, plus compression and shearing foliation develops

Regional Metamorphism

Widespread metamorphic zones, producing greatest quantity of metamorphic rocks -Associated with mountain building/convergence -Very high temps associated with depth and/or igneous activity -High pressure due to overburden weight, plus compression and shearing -Foliation develops

Dolomitization

________ is the process where calcium ions in limestone are replaced with magnesium or small amounts of iron.

"well-sorted, poorly sorted"

_________________ sands tend to have higher porosity and permeability than _________________ sands.

Mylonite

a fine-grained metamorphic rock, typically banded, resulting from the grinding or crushing of other rocks.

Migmatites

a rock composed of two intermingled but distinguishable components, typically a granitic rock within a metamorphic host rock.

Which of the following is part of later diagenesis?

all of the above

Continental depositional environment

always above sea level on land or in fresh water; alluvial fans, fluvial (streams), glacial, desert (eolian), and lacustrine (lake)

Marine depositional environment

always below sea level; includes continental shelf, continental slope, and deep marine. Turbidility currents

Compaction

as fluids are expelled from pores, porosity decreases. particles may rotate bc stress. at deposition particles=scattered, during diagenesis particles=aligned parallel

Burial metamorphism

associated with very thick sedimentary strata increasing T & P with additional burial/subsidence typically low grade little to no internal deformation of rocks

Sedimentary structures

bedding (layering)- most common cross bedding graded bedding ripple marks mudcracks tracks/trails burrows

Bedload vs. Suspended load

bedload=faster suspended load= slower effective sorting by grain size results. both contribute to alluvial deposits.

Metasomatism

change in rock's composition by reactions with hydrothermal fluids

Changes to beddings in sandstone (5)

change in: composition size shape orientation packing

Retrogarde

changes that take place during cooling

Prograde

changes that take place during heating

Hydrothermal metamorphism

chemical alteration caused when hot, ion rich fluids circulate through fissures and cracks Most widespread along axis of the mid-ocean ridge system, altering ocean-floor basalt (divergent boundaries)

Sedimentary rock compositions

chemical composition- wide range caused by weathering clastic reflect source rock undergoing erosion (angular or rounded) strongly reflect biochemical environment of deposition

weathering of sedimentary rocks

chemical weathering= decomposition of minerals with formation of new minerals (change composition) removal of some material in solution (oxidation, hydration, hydrolysis, carbonation) Physical= size reduction and increases in surface area without chemical alteration they work together, physical triggers chemical

Limestone Peloids/Pellets

coarse-silt to fine-sand sized carbonate grains that often lack internal structure Origin of most thought to be fecal pellets from burrowing organisms

Graded bedding

coarser grains at bottom, finer at top. forms as sediment heavy currents slow down characteristic of turbidites

Marble

composed mostly of calcite (sometimes dolomite) protolith of limestone or dolostone usually granoblastic foliation may be present

Types of siliciclastic sedimentary rocks

conglomerates, sandstones, mudrocks (shales)

Serpentinites

consists mostly of serpintine

Mudcracks depositional environment

continental

limestone diagenesis

determined by pore water chemistry and rate of water movement (need slow water) most carbonates experience early cementation later dagenesis consists of mechanical(siliclastic sediments), chemical compaction (developes stylolites) and Burial cementation (pressure solution major source for cements)

Products of physical weathering of sedimentary rocks

detritus: loose material and grains resistant minerals more abundant (quartz) can later form rocks if cemented together ex. conglomerate, sandstone, siltstone, shale.

Metamorphic environments based on

different types based on temperature & pressure

Limestone fossils

easiest observed are inequant, biologically determined shapes often broken and hard to see

Carbonate deposition

equation for equilibrium: CaCO3 + CO2 + H2O <-----> Ca+2 + 2H+ + 2CO3+2

Highly fractured rocks will exhibit faster or slower rates of weathering?

faster

________ metamorphism will occur where two blocks of rock are grinding against each other.

fault zone

Which grain size (coarse or fine) tends to exhibit more rounding?

fine

Phyllite

fine-grained Gradational between slate & schist Glossy reflective sheen due to platey mineral grains wavy surfaces

siliciclastic sedimentary rocks

form from detritus: fragments of other rocks- loosely bounded mudrocks sandstones

Limestone allochems

fossils, ooids, peloids/pellets, limeclasts

Limestone Limeclasts

fragments of earlier formed limestones or partially lithified carbonate sediment may have been torn from seafloor by storm and moved

Hornsfels

generic name for fine-grained, granoblastic, contact metamorphic rocks that are typically: hard, dense, baked appearance, gray to brown to black & smooth to touch depends on where magma intruds- changes composition

some sedimentary structures that help determine "up direction" in rocks that have been overturned

graded beds, cross beds, mudcracks, symmetrical ripples, burrows, tracks

Which of the following does NOT control the roundness of detrital grains?

grain size

As sediment matures what happens

grain size reduce by abrasion(sands), breakage, solution, chemical weathering = more rounded

Detrital textures

grains can be spherical, rod shaped, disc shaped coarser= rounder, finer=more angular

high energy= __________ textural maturity

high (mature)

Turbulent flow

high energy, irregular flow path, air (desert) & water (early river stages) always flows turbulently

Detrital grain size

imp. feature in conglomerate and sandstone most rocks have single size; reflects conditions at deposition

Confining pressure in metamorphic rocks

increases with depth applies force equally in all directions may cause recrystallization to more compact crystalline form

Transitional depositional environment

influenced by marine and continental processes; deltas, beaches, and lagoons.

Cross bedding

internal stratification at an angle to main stratification of deposit Most common in sands and silts cross bedding dip downstream

Stylolites

irregular surface or seam in rock developed when chemical compaction where carbonate is removed by pressure solution

Turbidity currents

lakes and ocean basins. rapidly moving suspension of particles. dislodged sediment is taken by current and travels as far downslope as it can go. triggered by slumping or earthquakes graded bedding is characteristic

Porphyroblasts

larger recrystallized grain occurring in a finer groundmass

Detritus

loose material and grains

Physical rotation of platy minerals will contribute most to the development of foliation in ________ grade metamorphism.

low

low energy= __________ textural maturity

low (immature)

Laminar flow

lower energy, predictable, similar to thin sheets sliding over eachother, flow of glacial ice always laminar

Slate (metamorphic)

lowest grade metamorphism of shale/mudstone can't identify grains green/dark colored Growth of very fine-grained chlorite and micas results in slaty cleavage

Hydrothermal fluids in metamorphic rocks

mainly water enhances migration of ions aid in recrystallization of existing minerals

Collophane

massive cryptocrystalline variety of apatite found in phosphorites major source of phosphate used in fertilizer

"Beach environments represent which textural maturity, immature or mature?"

mature

Granoblast textures

may form during recrystallization crystals of roughly the same size:quartzite and marble exhibit polygonal grain boundaries

Schist

medium to coarse grained Conspicuous platy mineral grains exhibits irregular planar foliation of visible mica flakes called schistosity Composition indicated by using mineral names (biotite)

Amphibolites

medium to coarse grained dark colored hornblende and plagioclase metamorhism of mafic rock- gabbro

Contact metamorphism

metamorphism due to contact with or proximity to an igneous intrusion magma invades host rock temperature rises (high T, low P) zone of alteration forms produces massive rock (ex. hornsfeld)

Metaquartzite

metamorphism of quartz arenite and cherts recrystallization with interlocking crystals of quartz rich in water fractures across grain boundaries hard- very stable

Soapstones

mixture of serpentine and talc both typically form by hydrothermal alteration of ultramafic igneous rocks

mudstone

mixture of silt- and clay-sized particles

gypsum (sulfate mineral)

most abundant in marine deposits only common in arid climates soft so easy to identify in outcrop

chemical and biogenic rocks

most commonly carbonates(limestones and dolomites

sediment transport

most moved by fluids responding to stress (wind water & ice) depends on viscosity and velocity Laminar flow= lower energy turbulent flow=high energy (air & water) Particle movement by fluid flow- rolling, saltation(intermittent hopping), suspension by turbulent eddy currents (clay and silt sized particles) (mixed throughout water)

Grains between 1/16 and 2 mm are classified as _____.

mud

common/abundant sedimentary rocks

mudrocks (siltstones and claystones) (65%) sandstones (25%) limestones & dolomites chert

Products of chemical weathering of sedimentary rocks

newly formed minerals can stay at site of weathering ex. clays formed by weathering of feldspars dissolved materials transported in solution can later precipitate to form chemical sedimentary rocks ex. carbonates (limestone), evaporites (gypsum)

Rolling particle movement

on stream bed "bedload" largest materials

"________ are tiny ""seed"" particles created when small sediments or shell fragments are rolled by waves in water supersaturated with calcium carbonate."

ooids

Skarns

originate from contact metamorphism of limestone show evidence of having exchanged constituents with intruding magma (metasomatism) calcium rich- wollostone diopside, plagioclase may form ore deposits

Apatite

phosphate mineral hardness of 5 mined for phosphorite occurs in shallow marine settings

Depositional environments

physical, chemical, biological and geographic conditions under which sediments are deposited. yield distinctive rocks characteristic of various environments Marine, Continental, and Transitional

Mudcracks

polygonal pattern of cracks produced when mud dries suspended load deposited in floodplains fine grained and clay rich form 3 fractures at 120 degree angles

Limestone diagenesis is determined primarily by ____________________ and rate of water movement.

pore water chemistry

Metamorphic rocks

pressure, heat

Dolomitization

process by which limestone is altered into dolomite Diagenetic replacement solutions dissolve CaCO3 and precipitate dolomite Mg substitutes Ca

Ripple marks

produced as wind or water moves across sand finer particles=faster; coarser particles= slower alluvial, beach, stream bottoms, deserts go in direction of flow wavy appearance symmetrical= back & forth (beaches) asymmetrical= one flow direction (alluvial)

Trace fossils

provide us with indirect evidence of life in the past tracks, trails, or burrows determining "up direction"

Which of the following best describes the appearance and composition of a conglomerate?

rounded fragments; poorly sorted

how do sedimentary rocks form

sediments are transported, deposited, and lithified. -preexsiting rocks weathered -directly by organisms -as a direct chemical precipitate

debris flows

sediments loaded down with water (boulders to clays) travel downslope at various speeds. called mudflow if particles travel quickly in mud matrix. common around volcanoes and alluvial fans.

types of mudrocks

siltstone, claystone, mudstone, slate, and shale

Chemically produced sediment

some weathering products may be removed in solution, and these ions may end up in the ocean, a lake, or a rift basin.

Metamorphic Grade

somewhat informal way to indicate intensity of metamorphism Yield different mineral assemblages Metamorphic index minerals can approximate grade Increasing grade= grain size coarsens, stable at higher temp and pressure (slate, phylilite, schist, gniess)

Slaty cleavage

splitting into thin sheets along foliation Found in the rocks slate and phyllite

Limestone Ooids

subrounded sand-sized particles fromed by precipitation of calcite or aragonate in concentric layers around a nucleus grain as it washes back and forth in shallow marine waters. looks like bullseye when cut in half more rounded than sandstone aragonite over time converts to calcite pisoliths are >2mm

"In stratified glacial meltwater deposits, you might assume that a layer with larger grain size was deposited during:" (summer or winter)

summer

Foliation

the process of being split into thin sheets or laminae

Limestone depositional environment

transitional

Carbonates tend to deposit in very deep marine locations.

true

deposits of turbidity currents

turbidites

Water almost always flows __________.

turbulent

Which type of flow follows an irregular flow path in both the vertical and horizontal direction?

turbulent

Suspension particle movement

turbulent eddy currents, suspended load clay and silt sized particles, mixed throughout water, doesn't settle. smallest materials

Limestone textures described by:

types of grains (allochems) forming framework of rock carbonate mud matrix- fine grained presence or absence of coarsely crystalline calcite cement texture and structures

differential stress in metamorphic rocks

unequal in different directions can result in preferred orientation of mineral grains (ex. convergent plate boundaries)

Till

unsorted material deposited from glacial ice.

Sedimentary deposits with ________ grains would likely make better reservoirs for petroleum, natural gas, or groundwater because they tend to have a higher porosity and permeability

well-sorted