Sedimentary Structures & Environments

Question 1

Clastic - Sedimentary Rocks

Answer 1

Rocks made up of other rocks and sediments that have cemented together.

Question 2

Biochemical - Sedimentary Rocks

Answer 2

Made up of shells and fossils.

e.g. Limestone

Question 3

Organic - Sedimentary Rocks

Answer 3

Rocks made up of carbon based materials.

e.g. coal

Question 4

Chemical - Sedimentary Rocks

Answer 4

Rocks that have a lot of salts in them from evaporation.

Question 5

Rock Beds

Answer 5

Layers of rock. A common formation for sedimentary rocks.

Question 6

Strata

Answer 6

Several beds of rock layered on top of eachother.

Question 7

Contact

Answer 7

When two beds of different rock types are layered and touching.

Question 8

Ripples

Answer 8

These occur in sandy environments and form perpendicular to the flow of water or wind that created them.

Question 9

Crossbedding

Answer 9

Sediments that flow and roll to create beds of old dune material. Usually seen as dunes are created and move around over time.

Question 10

Turbidity Currents

Answer 10

Fast moving currents of sediment laden water that move down slope. Often created by underwater movements like marine avalanches.

Question 11

Turbidite

Answer 11

Are deposits of sediment that end up layered from course grains to fine grains.

Question 12

Depositional Environments

Answer 12

Locations where sediments accumulate.

Question 13

Terrestrial - Depositional Environments (4 types)

Answer 13

Where sediments accumulate on land. Still involves WATER processes.

1. Glacial - Glacial till (unsorted, unstratified)
2. Fluvial - Rivers, mountain streams to flood plains.
3. Lacustrine - Lakes, finely laminated sediments.
4. Deserts - Sand dunes and Red beds (heavily oxidized)

Question 14

Marine - Depositional Environments

Answer 14

Where sediments accumulate in bodies of water.

Question 15

Sedimentary Basins

Answer 15

Places where the land has sunk and has been filled up by sediments.

Question 16

Subsidence

Answer 16

Places where the land has sunk.

Question 17

Foreland Basin - Sedimentary Basin type

Answer 17

These form at the bases of mountain belts

Question 18

Transgression - Sea level Rise

Answer 18

When the depositional environment shifts landwards

Question 19

Regression - Sea level Fall

Answer 19

When the depositional environment shifts towards the basin.

Question 20

Diagenesis - Post Depositional Procress

Answer 20

The sum total of all the physical, chemical and biological changes to a sediment AFTER it is deposited.

Note: Involves changes in temps and pressure but not to the same extent as metamorphizing.

Question 21

Replacement Sedimentary Rock

Answer 21

Diagenetic process - when one material in a rock is substituted by another.

e.g. petrified wood

Question 22

Rift Basins - Sedimentary Basin Type

Answer 22

These sediment basins form at divergent plate boundaries.

Question 23

Intracontinental Basins - Sedimentary Basin Type

Answer 23

These sedimentary basins form in random places on land that are not near any plate boundaries.

Question 24

Passive Margins - Sedimentary Basin Type

Answer 24

There sediment basins form at the edges of continents that are NOT tectonic plate boundaries.

Question 25

Marine Delta - Depositional Environment

Answer 25

When moving water meets still water.

Question 26

Shallow Water Carbonate - Depositional Environment

Answer 26

Lagoons: Tropical, warm, clear, shallow marine water

Question 27

Deep Marine Deposits - Depositional Environments

Answer 27

Fine sediments that settle far out from land. Clays, chalks and plankton ooze.