Chapter 5 (part 2) Flashcards
The characteristics of sediment deposited in an area depend on:
- 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
In regard to Tectonics, an area may be in one of these 4 states:
- 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>
Sediments and sedimentary rocks may be ____ or ____ In Origin.
• 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>
What are three broad categories of depositional environments:
- Marine
- Transitional
- Continental
The 4 components of Marine Depositional Environments are:
- Continental Shelf
- Continental Slope
- Continental Rise
- Abyssal Plain
The types of Transitional Depositional Environments at or near the transition between the land and the sea are:
- Deltas
- Beaches
- Barrier Islands
- Lagoons
- Tidal Flats
- Estuaries
The 5 types of Continental Environments are:
- Fluvial
- Alluvial Fans
- Lacustrine
- Glacial
- Eolian
The three “textural components” to most clastic sedimentary rocks are:
- Clasts
- Matrix
- Cement
What are 3 sedimentary structures that form after deposition?
- Footprints
- Worm Trails
- Mudcracks
The 4 major types of sandstone are:
Quartz
Arkose
Graywacke
Lithic
The characteristics of most marine carbonate environments include:
- Warm Water
- Shallow Water
- Tropical Climate
- Clear Water
- Sunlight
The 3 causes of Transgressions are:
- Melting of Polar Ice Caps
- Displacement of Ocean Water by Undersea Volcanism
- Localized Sinking or Subsidence of the Land in Coastal Areas.
The 3 causes of Regressions are:
Buildup of ice in the polar caps
Formation of Glaciers
Localized uplift of land in coastal areas
Walther’s Principle explains that:
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.
The two basic types of contacts between rock units are:
- Conformable
- Unconformable
