On a geologic map,if the contacts between sedimentary rock units form a bull's-eye pattern of concentric circles,with the oldest unit in the center,the underlying structure is a(n)________.
A)anticline
B)basin
C)dome
D)syncline

Question

On a geologic map,if the contacts between sedimentary rock units form a bull's-eye pattern of concentric circles,with the oldest unit in the center,the underlying structure is a(n)________. 
A)anticline 
B)basin 
C)dome 
D)syncline

Quizplus · Accepted Answer

A bull's-eye pattern of concentric circles on a geologic map indicates a dome structure, where the oldest rock unit is in the center and the younger units are around the edges. This is because the rock layers are folded upward and away from the center, creating a dome-like shape. Anticlines also have a similar shape, but the oldest rock unit would be on the crest of the fold, not in the center. Basins and synclines have a bowl-like shape, with the youngest rock units in the center.

On a Geologic Map,if the Contacts Between Sedimentary Rock Units