Chapter 7 GEO

A mudstone is composed of particles ranging in size from less than ______ mm to ______ mm.

0.004, 0.06 mm

Sand is cohesionless sediment ranging in size between ______ mm and ______ mm.

0.06 and 2

Beds are thicker than _________ cm.

1

What is a contact?

A contact is a 3D surface separating rocks of differing lithological aspect.

What is the significance of cross beds and ripples?

Cross beds and ripples are sedimentary structures that indicate the general direction of wind or water currents during deposition

How would you describe the property of fissility?

Fissility refers to the characteristic of parting into even parallel sheets when struck with a rock hammer.

What do mud cracks signify?

Mudcracks signify the evaporation of water and the drying out of a sedimentary environment.

How does shale differ from a mudstone?

Shale exhibits fissility while a mudstone does not.

Where are sumarine fans found?

Submarine fans are common features of continental rise environments.

What is chemical weathering?

The chemical alteration of weathered material brought on by reactions with the hydrosphere, biosphere, and atmosphere

What is physical weathering?

The in situ mechanical break down of rock material by plants, animals, abrasion, and feezing and thawing

What does the term sorting refer to?

The range in grain size of sediment in a given sample.

Gravels (including pebbles) are pieces of older rock material greater than a. 2 mm b. 4 mm c. 64 mm d. 256 mm e. 0.06 mm

a. 2

Formations are generally considered to be mappable at a scale of a. 1:48000 b. 1:24000 c. 1:12000 d. 1:6000 e. None of the above

b. 1:24000

Sediment dragged, pushed, or bounced along the river bed is classified as the a. solution load b. bed load c. suspended load d. episodic load e. continuous load

b. bedload

If a sandstone includes less than 15 percent matrix, and is composed of >90 percent quartz then it is called a

b. quartz arenite

A ________ is a strip of sand and gravel extending from the low- to high-tide line.

beach

What would you call a carbonate rock composed of calcite and abundant pieces of clam shells?

bioclastic limestone

A sedimentary rock composed of angular gravel is called a ________________.

breccia

Strips of sand and gravel lying above sea level and paralleling the adjacent coastline but separated from it by a narrow body of water are called a. alluvial fans b. submarine fans c. barrier islands d. deltas e. none of the above

c. barrier islands

What would you call sandstone with the following characteristics: (a) a framework composed of greater than 25 percent feldspar, (b) the proportion of rock fragments to feldspar + rock fragments in the framework is greater than 50%, and (b) the matrix is less than 15 percent?

c. lithic arenite

Alluvial fans develop at the base of a. the continental shelf b. the continental slope c. mountain fronts d. fault scarp e. none of the above

c. mountain fronts

The angularity of the edges and corners of grains in a sedimentary rock is referred to as a. roughness b. smoothness c. rounding d. abruptness e. none of the above

c. rounding

Sediment always carried above the river bed in the moving current is classified as the a. solution load b. bed load c. suspended load d. episodic load e. continuous load

c. suspended load

Sand that is cemented with calcite is called ________________.

calcareous sandstone or just simply sandstone

A common mineral found in carbonate sedimentary rocks is a. quartz b. K-feldspar c. plagioclase d. calcite e. gypsum

calcite

What is the name of the clastic sedimentary rock composed of particles less than 0.004 mm in size?

claystone

Rock that is the result of compaction of variably decayed plant matter is referred to as __________.

coal

A sedimentary rock composed of rounded gravel is called a __________________.

conglomerate

The largest clast size in the range of gravel is a. pebble b. cobble c. very coarse sand d. boulder e. none of the above

d. boulder

An example of a siliceous chemical sedimentary rock is a. quartz siltstone b. quartz sandstone c. quartz mudstone d. chert e. siliceous argillite

d. chert

Microfossils found in chalk are a. radiolaria b. porifera c. rudistids d. coccolithophore e. foraminifera

d. coccolithophore

The process of reducing pore space by depositing younger sediments on top of older material is referred to as a. dilation b. reduction c. contraction d. compaction e. none of the above

d. compaction

When rivers enter large bodies of standing water they typically debouche their loads forming a. alluvial fans b. submarine fans c. barrier islands d. deltas e. none of the above

d. deltas

What would you call sandstone with the following characteristics: (a) a framework composed of greater than 25 percent feldspar, (b) the proportion of feldspar to feldspar + rock fragments in the framework is greater than 50%, and (b) the matrix is more than 15 percent?

d. feldspathic wacke

A mound shaped feature composed chiefly of the calcareous remains of sedentary marine organisms is a a. limestone mound b. fossil mound c. fossil burial ground d. reef e. none of the above

d. reef

Graded beds are the result of deposition by a. rivers b. blowing wind c. moving ice d. turbidity currents e. none of the above

d. turbidity currents

A dolostone is composed mostly of the mineral _______________.

dolomite

What do you call accumulations of sand that are the result of blowing wind?

dunes or sand dunes

Siltstones are coarser grained than a. sandstones b. very fine grained sandstones c. very fine grained siltstones d. mudstones e. claystones

e. claystones

The cement in a sandstone is typically the result of the precipitation of minerals like quartz and calcite from a. the atmosphere b. organisms c. fauna d. flora e. solutions

e. solution

Laminations are thicker then beds. True or false

false

Oolitic limestone is an example of an organic carbonate rock. True or false

false

The current adjacent to the cut bank is moving __________ than the current along the point bar side.

faster

All clastic sedimentary rocks display a ______________________ or _____________ texture.

fragmental, clastic

Grains of sand make up one component of a sandstone while grains smaller than sand make up another. The former is called the ___________________ while the latter is called the _____________.

framework, matrix

Clastic sedimentary rocks are composed of _____________ and _________ ______________ derived from pre-existing material.

minerals, rock fragments

NaCl when found in rock form is referred to as ________ _________.

rock salt

The pores of clastic sedimentary rocks are the ___________ between grains.

voids or empty space

In general the greater the distance sediment is transported the more ______ _________ and _________ sediment becomes.

well sorted, rounded

What are the three major agents of erosion?

wind, water, and ice