How sedimentary basins are formed?
Basin Formation Sedimentary basins are formed over hundreds of millions of years by the combined action of deposition of eroded material and precipitation of chemicals and organic debris within water environment (Figure 1.2).
What are basins in geology?
A basin is a depression, or dip, in the Earth’s surface. Basins are shaped like bowls, with sides higher than the bottom. They can be oval or circular in shape, similar to a sink or tub you might have in your own bathroom. Some are filled with water.
How many sedimentary basins are there in India?
26 sedimentary basins
India has 26 sedimentary basins covering an area of 3.14 million square kilometres. The sedimentary basins of India, onland and offshore up to the 200m isobath, have an areal extent of about 1.79 million sq. km.
What is Intracratonic basin?
Intracratonic basins are broad, shallow, saucer-shaped basins. A major division can be made between terrigenous and carbonate intracratonic basins. The former are dominated by continental clastics, with negligible or no marine shales; the latter are more marine, although they may also be evaporitic.
How many sedimentary basins are in Nigeria?
three sedimentary basins
The three sedimentary basins in Nigeria are underlain by continental crust except in the Niger delta, where the basement rock is interpreted to be oceanic crust. Most of the wells that penetrated the basement are in the Eastern Dahomey embayment of western Nigeria.
What are domes and basins?
Domes and basins are structures with approximately circular or slightly elongate, closed outcrop patterns. Domes are convex upward; basins are concave upward. Dome and basins have several origins.
What is Vindhyan basin?
The Vindhyan basin is a classic example of Proterozoic intracontinental basin that developed in the central part of the Indian shield along with several other basins such as Cuddapah, Chattisgarh, etc. The strata are exposed in three major sectors: Son valley, Bundelkhand and Rajasthan.
What is epeirogeny and how does it form?
Andrew Alden is a geologist based in Oakland, California. He works as a research guide for the U.S. Geological Survey. Epeirogeny (“EPP-ir-rod-geny”) is strictly vertical movement of a continent rather than horizontal movement that compresses it to form mountains ( orogeny) or stretches it to form rifts (taphrogeny).
Is epeirogeny associated with intrusive intrusion and regional metamorphism?
Igneous intrusion and regional metamorphism rarely, if ever, are associated with epeirogeny. The causes of epeirogeny are not well known but may include large-scale adjustments of the continental crust to phase transitions in the Earth’s mantle.
What are cratons and epeirogeny?
The broad central parts of continents are called cratons, and are subject to epeirogeny. The movement may be one of subsidence toward, or of uplift from, the centre of the Earth. The movement is caused by a set of forces acting along an Earth radius, such as those contributing to isostasy and faulting in the lithosphere.
What are some examples of epeirogenic movements that create drainage divides?
Epeirogenic movements may divert rivers and create drainage divides by upwarping of the crust along axes. Example of this is the deflection of Eridanos River in the Pliocene Epoch by the uplift of the South Swedish Dome or the present-day drainage divides between Limpopo and Zambezi rivers in southern Africa.