Clastic Shorelines

Question 1

Name 7 Transitional environments?

Answer 1

marsh,swamp
chenier
estuary
tidal flat
Beach
Barrier bars
Lagoon

Question 2

grain size decreases with water depth in coastal depositional environments: T or F?

Answer 2

TRUE

Question 3

Where do coastal depositional systems form?

Answer 3

in proximity to shorelines

Question 4

What are the 3 fluid flow transport methods and deposition for coastal depositional systems?

Answer 4

1. Fluvial input
2. Wave action
3. Current action

Question 5

Define progradation and retrogradation

Answer 5

progradation: sediment deposition that build forward ocean-wards
retrogradation: sediment deposition that build backwards land-ward

Question 6

What is a swamp?

Answer 6

shallow lake, water stagnant or contain very feeble current, filled with vegetation, bordered by trees

Question 7

What is found in-situ in a swamp environment?

Answer 7

Peat and 3 grades of coal (lignite, bituminous, anthracite)

Question 8

What are Cheniers?

Answer 8

Exposed beach ridges, composed of sand or shells within marshes on a coastal plain

Question 9

Where are Cheniers formed?

Answer 9

near estuaries and in mudflats with low wave energy but effective long shore currents

Question 10

Example of a chenier?

Answer 10

St Phillips Island, SC

Question 11

What is an estuary?

Answer 11

semi enclosed body of water, in which fresh water mixes with sea water. Typically, old river valleys that have been drowned by marine transgression.

Question 12

What is the facies of an estuary system?

Answer 12

extremely complex mix of lithology’s and sedimentary structures.

Question 13

Do sediments coarsen upward or downward from marine shales in an estuary system?

Answer 13

coarsen upward

Question 14

Are the sand bodies in an estuary system perpendicular or parallel to a basin margin?

Answer 14

perpendicular

Question 15

What are tidal flats?

Answer 15

marshy or muddy land areas which are covered and uncovered by the rise and fall of the tide in the absence of string wave action.

Question 16

What two setting do tidal flats occur in?

Answer 16

open coast(low relief, low energy)
Protected areas (high energy including bays, estuaries and fiords (glacial origin))

Question 17

Where are tidal flats present?

Answer 17

where part of shoreline periodically covered

by seawater at high tide and then exposed at low tide.

Question 18

Do most tidal flats prograde or regress seaward?

Answer 18

prograde (from sand to mud)

Question 19

What is one of the most distinctive features of tidal flats?

Answer 19

herringbone cross-bedding

Question 20

Tidal flats are divided into what 2 environments that control facies development?

Answer 20

1. intertidal

2. subtidal

Question 21

what is an intertidal tidal flat?

Answer 21

refers to the tidal flat lying between the high and low tide range.

Question 22

what is a subtidal flat?

Answer 22

area of the tidal flats that are more likely to be preserved in the geological record.

Question 23

Define shoreline, fore shore, shore face

Answer 23

shoreline: line of intersection of the sea with the land

fore shore: the narrow zone between the high and low tide shorelines

shoreface: the narrow zone seaward from the low tide shoreline permanently covered by water, over which sands and gravels oscillate with changing wave conditions

Question 24

Define a beach

Answer 24

deposit of unconsolidated sediment extending landward from low tide to a change in topography such as a line of sand dunes, or the point where permanent vegetation begins

Question 25

What is a lagoon?

Answer 25

body of shallow water, particularly one with a restricted access to the open coean

Question 26

Where do lagoons occur?

Answer 26

landward of barriers bars and reefs within atolls