Chapter 5 (part 2)

Question 1

The characteristics of sediment deposited in an area depend on:

Answer 1

• Tectonic setting
• Physical, chemical, and biological processes in the depositional environment
• Method of sediment transport
• Rocks in the source area from which the sediment is derived
• Climate ^{_{<em>(and its effect on weathering)</em>}}
• Post-depositional processes of lithification ^{_{<em>(cementation, compaction)</em>}}
• Time

Question 2

In regard to Tectonics, an area may be in one of these 4 states:

Answer 2

• Tectonically Stable ^{_{<em>(e.g., midwestern U.S.)</em>}}
• Subsiding ^{_{<em>(or sinking e.g., New Orleans or Mexico City)</em>}}
• Rising Gently ^{_{<em>(e.g., New England and parts of Canada after glacial retreat)</em>}}
• Rising Actively ^{_{<em>(to produce mountains and plateaus e.g., parts of Oregon in the Cascade mountains)</em>}}

Question 3

Sediments and sedimentary rocks may be ____ or ____ In Origin.

Answer 3

• Extrabasinal
^{_{<em>(formed from the weathering of pre-existing rocks outside the basin, and transported to the environment of deposition.)</em>}}
• Intrabasinal
^{_{<em>(formed inside the basin; includes chemical precipitates, most carbonate rocks, and coal.)</em>}}

Question 4

What are three broad categories of depositional environments:

Answer 4

• Marine
• Transitional
• Continental

Question 5

The 4 components of Marine Depositional Environments are:

Answer 5

• Continental Shelf
• Continental Slope
• Continental Rise
• Abyssal Plain

Question 6

The types of Transitional Depositional Environments at or near the transition between the land and the sea are:

Answer 6

• Deltas
• Beaches
• Barrier Islands
• Lagoons
• Tidal Flats
• Estuaries

Question 7

The 5 types of Continental Environments are:

Answer 7

• Fluvial
• Alluvial Fans
• Lacustrine
• Glacial
• Eolian

Question 8

The three “textural components” to most clastic sedimentary rocks are:

Answer 8

• Clasts
• Matrix
• Cement

Question 9

What are 3 sedimentary structures that form after deposition?

Answer 9

• Footprints
• Worm Trails
• Mudcracks

Question 10

The 4 major types of sandstone are:

Answer 10

Quartz
Arkose
Graywacke
Lithic

Question 11

The characteristics of most marine carbonate environments include:

Answer 11

• Warm Water
• Shallow Water
• Tropical Climate
• Clear Water
• Sunlight

Question 12

The 3 causes of Transgressions are:

Answer 12

• Melting of Polar Ice Caps
• Displacement of Ocean Water by Undersea Volcanism
• Localized Sinking or Subsidence of the Land in Coastal Areas.

Question 13

The 3 causes of Regressions are:

Answer 13

Buildup of ice in the polar caps
Formation of Glaciers
Localized uplift of land in coastal areas

Question 14

Walther’s Principle explains that:

Answer 14

Sedimentary Environments that started out side-by-side will end up overlapping one anotherover time due to sea level change. The Vertical Sequence of Facies mirrors the Original Lateral Distribution of Sedimentary Environments.

Question 15

The two basic types of contacts between rock units are:

Answer 15

• Conformable
• Unconformable

Question 16

Conformable contacts between beds of sedimentary rocks may be either:

Answer 16

Abrupt or Gradational

Question 17

Unconformable contacts (or unconformities) are surfaces which represent a gap in the geologic record, because of either:

Answer 17

Erosion or Nondeposition

Question 18

The 3 types of unconformities are:

Answer 18

• Angular Unconformity
• Nonconformity
• Disconformity

Question 19

The various ways in which the distribution of rocks can be depicted are:

Answer 19

• Geologic Columns
• Stratigraphic Cross-Sections
• Structural Cross-Sections
• Geologic Maps
• Paleogeographic Maps
• Isopach Maps
• Lithofacies Maps