Question

In the interior of continents the earth's crust is typically about 40km thick and the elevation is near sea level. Most earth materials expand when heated, lowering their density. During rifting continental margins are heated but cool as sea floor spreading moves offshore from the continent. Thus, basic isostasy suggests that after rifting, a continental margin will ________. rise slowly as erosion removes uplifted rocks uplift remain near sea level subside

Answer 1

Subside

Step-by-step explanation:

New York's continental boundary consists of a dense series of mostly shallow-water sediments of at least 4.8 km.

The impact of sediment loading alone can not create these large thicknesses of shallow-water sediments.

COST B-2 biostratigraphic information was used to analyze the source of this margin's subsidence.

The sediment loading contribution to the subsidence was measured and eliminated. Corrections were also included for consequences of compaction, water depth and sea level shifts.

The remaining subsidence for the cooling lithosphere was interpreted as a basic thermal template.

Answer 2

Move vertically to maintain a balanced crust.

Step-by-step explanation:

Isostasy is a natural process of adjustment of balance maintained by blocks of crusts of different thickness. So after rifting, the blocks will rise and drop following a line that equals the sea level. This allows to keep a balance and maintain the continental margins on place.