If horizontal sedimentary strata overlie tilted strata (and no fault is present),the surface between the horizontal and tilted strata must be a(n)____________.

A)conformable sedimentary contact
B)angular unconformity
C)disconformity
D)nonconformity

Question

If horizontal sedimentary strata overlie tilted strata (and no fault is present),the surface between the horizontal and tilted strata must be a(n)____________.

A)conformable sedimentary contact 
B)angular unconformity 
C)disconformity 
D)nonconformity

Quizplus · Accepted Answer

If horizontal sedimentary strata overlie tilted strata, then there must have been a period of deformation before the horizontal strata were deposited. This means that there was a break, or unconformity, between the two sets of strata. The surface between these two sets of strata is an angular unconformity, which is characterized by the tilted strata underlying the horizontal strata at an angle. A conformable sedimentary contact would indicate that the two sets of strata were deposited continuously without any break, which is not the case here. A disconformity would show flat-lying strata separated by an erosion surface, but without any significant tilt like we see in this scenario. A nonconformity would only be present if the horizontal strata were in contact with a completely different rock type, such as igneous or metamorphic, which is not specified in this scenario.

If Horizontal Sedimentary Strata Overlie Tilted Strata (And No Fault