The top of unit-3 hosts closely spaced three unconformities
demarcated as U1, U2 and U3.
With Tertiary and Upper Cretaceous shales forming the major source rocks, much of the oil must have leaked across unconformities
into geologically older strata.
The space agency said that the image, which shows a cluster of steeply inclined light-toned layers bounded above and below by "unconformities
," is indicative of a "break" during which erosion of pre-existing layers was taking place at a higher rate than deposition of new materials.
The individual string-beads-like seismic reflection has been interpreted as the evidences of "epigenic karst system" in the Tarim Basin in the published papers, which is always linked with the terms "unconformities
, weathering crusts, exposure, etc." (Guo et al.
The authors describe the characteristics of unconformities
, which are discontinuities in a pile of sedimentary rocks that have resulted from temporary nondeposition of sediment, erosion of previously deposited sediment, changes in the rate of sedimentation, changes in the composition of sediment being deposited, or combinations of those factors.
This is suggested by tens of metres-thick, unconformable conglomeratic levels evidencing unconformities
that are located at the base of the sparsely distributed remains of Carboniferous, Permian and Triassic successions that are well-dated (Cassinis et al., 2000 and references therein; Cassinis and Ronchi, 2002; Ronchi et al., 2008).
In his essay, the curator of the exhibition J.D.Talasek discusses engravings of unconformities
, in particular John Clerk's celebrated engraving of Hutton's unconformity at Jedburgh, Scotland:
According to seismic data, these were interrupted by subtle angular unconformities
, the Paleogene mid-Brookian unconformity in one and the Pliocene-Pleistocene in four.
: Bardic Poetry in the Industrial Age
Therefore an applicable layer thickness is adjustable by taking the amount of erosion by the presence of regional unconformities
The three-dimensional geological modelling has helped SUCO identify unconformities
in the stratigraphic section, construct a new set of maps at reservoir levels, which will be used as the basis for building a new static and dynamic model for the Ras Budran field, and identify several infill target locations for further drilling, the study stated.