What is progradation in stratigraphy?
Progradation is the diagnostic depositional trend for regressions, and is defined as the building forward or outward toward the sea of a shoreline or coastline (as of a beach, delta, or fan) by nearshore deposition of river-borne sediments or by continuous accumulation of beach material thrown up by waves or moved by …
What is deltaic progradation?
In sedimentary geology and geomorphology, the term progradation refers to the growth of a river delta farther out into the sea over time. Progradation can be caused by: Periods of sea-level fall which result in marine regression.
What is progradation process?
1. n. [Geology] The accumulation of sequences by deposition in which beds are deposited successively basinward because sediment supply exceeds accommodation. Thus, the position of the shoreline migrates into the basin during episodes of progradation, a process called regression. Antonyms: retrogradation.
What happens retrogradation?
Retrogradation is an ongoing process, which initially involves rapid recrystallization of amylose molecules followed by a slow recrystallization of amylopectin molecules. Amylose retrogradation determines the initial hardness of a starch gel and the stickiness and digestibility of processed foods.
Which of the following is an example of the Aggradation process?
Aggradation can be caused by changes in climate, land use, and geologic activity, such as volcanic eruption, earthquakes, and faulting. For example, volcanic eruptions may lead to rivers carrying more sediment than the flow can transport:this leads to the burial of the old channel and its floodplain.
What is fining upward sequence?
A complete fining-upwards sequence consists of 1) an erosional base, 2) a coarse basal shell layer representing the winnowed lag of the eroded, preexisting grass-stabilized platform, 3) a ripple-laminated, well-sorted, medium-grained sand zone representing the mobile sand on the leeward slope of the blowout, and 4) a …
What is the progradation of stratigraphic sequences?
If sea level is constant, progradation is extreme. Stratigraphic sequences consist of a succession of genetically related strata, meaning they: were deposited during a single cycle of relative sea level change obeyed Walther’s law.
What does progradation mean in geology?
Progradation. Progradation is the diagnostic depositional trend for regressions, and is defined as the building forward or outward toward the sea of a shoreline or coastline (as of a beach, delta, or fan) by nearshore deposition of river-borne sediments or by continuous accumulation of beach material thrown up by waves or moved by longshore
What is the difference between retrograde and regressive oceanic deposition?
Regression: ocean moves away from shore; result of sea level fall Progradational: shore and nearshore deposits move outward into the ocean and overlie deeper water deposits Retrogradational: deeper water deposits move towards land and overlie shallow water deposits
What is the difference between progradational and retrogradational deposits?
Progradational: shore and nearshore deposits move outward into the ocean and overlie deeper water deposits Retrogradational: deeper water deposits move towards land and overlie shallow water deposits Aggradational: facies remain in the same general location and stack atop others of the same facies