Offlap

offlap

[′ȯf‚lap]
(geology)
The successive lateral contraction extent of strata (in an upward sequence) due to their deposition in a shrinking sea or on the margin of a rising landmass. Also known as regressive overlap.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Offlap

 

(also regressive offlap), the deposit of strata of sedimentary rock as a result of regression of the sea. In cross section, an offlap is characterized by an alternation, from the bottom to the top, of fine detrital rocks (clays) and increasingly coarse-grained rocks (aleurites, sands, and gravels). There is a decrease in the area occupied by rocks of marine origin. The arrangement of the layers is used to reconstruct the geological history of ancient sea basins and the history of vertical movements of the earth’s crust.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
Mentioned in ?
References in periodicals archive ?
Over-lain by a red bed of the Gercus Fm, the Beciraman represents a marine offlap corresponding to continental beds related to extensive uplifts to the north and east.
Turkey's Geology
The sand percentage within the Agbada Formation varies from 30 to 70%, which results from the large number of depositional offlap cycles.
Integration of seismic and petrophysics to characterize reservoirs in "ALA" oil field, Niger Delta
Drag is also increased significantly by whorl offlap (Chamberlain, 1976).
Functional morphology at the mall
This drop in sea level within Hudson Bay and James Bay will lead to an offlap of water and an outward migration of shorelines.
Post-glacial isostatic adjustment and global warming in subarctic Canada: implications for islands of the James Bay region

Encyclopedia browser ?
Full browser ?