What are heterogeneities?

Question

What are heterogeneities?

Answer 1

homogeneities are where a rock is made up of a single, consistent suite of minerals, that do not vary in composition; or a structure made up of single rock units.  In a heterogeneity, the composition varies widely.  Basalt or granite may be relatively homogeneous, but an igneous intrusion containing many irregular inclusions will be heterogeneous.  Similarly, sandstone may be very homogeneous, made up nearly entirely of quartz, but a conglomerate comprised of many different rock fragments will be heterogeneous.

Therefore a heterogeneity is an inconsistent or widely varying composition