What could be a possible explanation why tectonic plates do not all move in the same direction?
a. the magma moves the plates in the same direction, but slab pull makes them move away from one another.
b. the magma moves in the same circular path, but the plates bounce against each other and change direction.
c. the magma moves in “cells,” which circulate in different directions, moving the plates in more than one direction.
d. the magma’s movement in the mantle is highly erratic and causes the plates to move in circles.

Ageologist is working in an area with exposed sedimentary rocks and finds a well exposed sequence of stratified rocks. as he works through a thick sequence of limestone, he sees abundant large clam fossils that produce an interlocking texture suggesting a reef, but within the limestone section these clams disappear and the overlying limestone is made up primarily of fragments of corals. he now moves 50 km away and finds limestones interbedded with shales, and the limestones contain the same clam fossils he had seen previously 50 km away. as he continues through this section, the rocks become entirely limestone, and the clams disappear again with coral fossils above forming a reef structure. he concludes