What is a transgressive surface?
The transgressive surface is the first major flooding surface following the lowstand systems tract. In depositionally updip areas, the transgressive surface is commonly merged with the sequence boundary, with all of the time represented by the missing lowstand systems tract contained within the unconformity.
What is Lowstand system tract?
Lowstand systems tract (LST) – includes deposits that accumulate after the onset of relative a sea-level rise. This systems tract lies directly on the upper surface of the falling stage systems tract and is capped by the transgressive surface formed when the sediments onlap onto the shelf margin.
What is a Parasequence set?
A parasequence is a set of relatively conformable, genetically interrelated rock strata or stratal set that is bounded by marine flooding surfaces and their correlatable interfaces.
What is TST in sequence stratigraphy?
A transgressive systems tract (TST) is bounded by maximum regressive surface at the base and maximum flooding surface at the top. This systems tracts forms when the rate of sedimentation is outpaced by the rate of sea level rise in the sea level curves.
What does the word transgressive mean?
[ trans-gres-iv, tranz- ] SHOW IPA. / trænsˈgrɛs ɪv, trænz- / PHONETIC RESPELLING. adjective. violating or challenging socially accepted standards of behavior, belief, morality, or taste: We welcome those who are engaged in consensual, albeit transgressive sexualities.
What is transgressive geology?
1. n. [Geology] The migration of shoreline out of a basin and onto land during retrogradation. A transgression can result in sediments characteristic of shallow water being overlain by deeper water sediments. Antonyms: regression.
What is progradational parasequence set?
progradational parasequence set A parasequence set in which successively younger parasequences are deposited farther basinward; overall the rate of deposition is greater than the rate of accommodation.
What are the characteristics of the transgressive systems tract?
It is underlain by the transgressive surface and overlain by the maximum flooding surface. As in any retrogradational set of parasequences, flooding surfaces within the transgressive systems tract are unusually prominent and display strong facies contrasts and pronounced deepening.
What are the components of vertical succession?
In vertical succession, all depositional sequences are composed of the following elements in this order: sequence boundary, lowstand systems tract, transgressive surface, transgressive systems tract, maximum flooding surface, highstand systems tract, and the following sequence boundary.
How can we deduce the origin of barrier transgressive sequences?
Barrier transgressive sequences are demonstrably the result of prolonged sea level rise, but the precision with which the transgression that produced them can be deduced is wholly dependent on the preservation of lagoonal peats that provide dating control.
What do we know about flooding in the transgressive systems tract?
As in any retrogradational set of parasequences, flooding surfaces within the transgressive systems tract are unusually prominent and display strong facies contrasts and pronounced deepening. These flooding surfaces may display variable but commonly strong degrees of sediment starvation, discussed in more detail below.