A scientist discovers a deep bowl-like divot under the ocean off the coast of eastern Mexico that is many kilometers across. The layers of the ground all around the continent from around the time that structure formed contain large amounts of iridium and a larger number of fossils than is normally found. What most likely caused the bowl-like structure?

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).