Concepts on eustasy

Raghubeer rai

eustasy is something which is related to change of sea level throughout the world, caused typically by movements of parts of the earth's crust or melting of glaciers. in simple terms "Eustasy"refers to a globally uniform change in sea level. Removal or addition of water to oceans during glacial/interglacial cycles was a fundamental cause of this phenomenon.Now the thing is how can we know that in a particular area there is Eustasy phenomenon happened in past ? we can tell about Eustasy by Study the fossil record in that particular area where we are curious about whether Eustasy happened or not ,like suppose we do a field trip of certain region and there we get some organisms fossil (which is mainly of sea origin,like bivalve, brachiopod,stromatolites etc.)and also some special kind of features which is characteristics of marine environment or which form generally in marine environment (in shallow depth environment )so we can easily say that here once a time Marine transgressions phenomenon occur and the result is many organisms came to the continental part after that marine regression happened suddenly although sea water regressed but the organisms couldn't go in there habitable environment that's why we are getting this fossil here in present time. Eustasy deals not only with change in sea level but also what are the mechanisms responsible for that and we study all the things under the Eustasy.