What is seismic stratigraphy in geology?
Seismic stratigraphy, the science of interpreting or modeling stratigraphy, sedimentary facies, and geologic history from seismic reflection data, has been practiced for at least three decades. Seismic stratigraphy has initiated a revolution in stratigraphic analysis as profound as that caused by plate tectonics.
What is Stratal termination?
Seismic reflection terminations, also termed “lapout”, are stratal discontinuities recognized on seismic sections that separate apparently conformable sedimentary units from non-conformable units, forming the basis of seismic sequence stratigraphy.
What is the purpose of seismic stratigraphy?
Seismic stratigraphy techniques help us for stratigraphic interpretation of seismic reflectors. It is important because geological concepts of stratigraphy can be applied on seismic data and hence, seismic stratigraphy can be used as a predictive tool for petroleum system elements like reservoir, seal and source rock.
What is seismic stratigraphy used for?
The methods of seismic stratigraphy are used to correlate sedimentary strata at depth, and they also reveal unconformity-bounded seismic sequences that provide the keys to the analysis of regional geologic history.
What is the meaning of Chronostratigraphy?
In earth science, chronostratigraphy defines rock strata by their temporal relations, reconciling stratigraphy with relative and chronometric dating in the historical discipline of geology. With some differences in scale and evidence, chronostratigraphy is also applied to cultural material left by humans.
What is Onlap and Offlap?
It is generally associated with a marine transgression. It is a more general term than overstep, in which the younger beds overlap onto successively older beds. The opposite is offlap, in which each younger rock bed pinches out short of the full extent of the underlying older bed, typically due to a marine regression.
What stratigraphy involves?
stratigraphy, scientific discipline concerned with the description of rock successions and their interpretation in terms of a general time scale. It provides a basis for historical geology, and its principles and methods have found application in such fields as petroleum geology and archaeology.
Why is sequence stratigraphy important?
Sequence stratigraphy can be used to develop more accurate surfaces for mapping and correlating facies; predict reservoir, source and sealing facies; identify stratigraphic traps; and project reservoir trends into areas with limited data.
What is Chronostratigraphy unit?
Chronostratigraphic units are bodies of rocks, layered or unlayered, that were formed during a specified interval of geologic time. The units of geologic time during which chronostratigraphic units were formed are called geochronologic units.
What is the difference between geochronology and Chronostratigraphy?
Chronostratigraphy—“The element of stratigraphy that deals with the relative time relations and ages of rock bodies.” Geochronology—“The science of dating and determining the time sequence of events in the history of the Earth.”
What is Offlap?
: the progressive withdrawal of a sea from the land also : the arrangement of the strata deposited on the floor of such a sea during its regression — compare onlap, overlap.
What does onlap stand for?
1 : progressive submergence of land by an advancing sea. 2 : the arrangement of strata deposited on the floor of an advancing sea during its advance — compare offlap, overlap.
How is offlap related to erosional truncation?
Offlap cannot be attributed solely to erosional truncation, but instead implies that sequence boundaries develop over a finite interval of time.
Where do you find downlap and TOPLAP in New Zealand?
Downlap and toplap revealed by seismic reflection in the Plio-Pleistocene Giant Foresets Formation, offshore Taranaki, New Zealand. The succession is strongly progradational; the shelf-edge trajectory almost horizontal. A smaller-scale, outcrop example of downlap in prograding outer shelf-slope mudstones.
Where does the downlap of a clinoform occur?
Downlap units must have a dip greater than the surface at which they terminate. Clinoform profile is typically progradational. In this case, downlap commonly occurs across a depositional surface that represents the end of transgression – the surface of maximum flooding.
Which is the mirror image of downlap and TOPLAP?
Toplap: From a geometric perspective, toplap is the mirror-image of downlap such that clinoforms or other stratal packages terminate beneath a surface. Toplap units must have a dip greater than the surface at which they terminate. Toplap completes the characteristic sinusoidal clinoform or stratal geometry typical of progradational successions.