The Deccan Traps in India
The Deccan Traps in India are primarily formedfrom multiple layers of this rock. Early geologistsstudying continental drift used the term“sima”[SIM-uh]for crust made primarily of this rock, andtheorized that a layer of it may have extendedunderneath continents. As this rock’s lava cools, itmay form columns such as those in Devils PostpileNational Monument in California.A’a [ah-AH]andpahoehoe [puh-HOY-hoy]are terms for flows of lavamade of this typically dark rock, which also existsat mid-ocean ridges in a form nicknamed “MORB”.Name this extrusive igneous rock, the primaryconstituent of oceanic crust