Graphite is identified in a particular schist.Which one of the following conclusions is justified?
A)The rock also contains diamonds; both are crystalline forms of the element carbon.
B)The schist formed from a quartz-rich, sedimentary limestone.
C)The graphite lubricated shearing movements along a fault, causing a schist to form.
D)The pre-metamorphic rock was a shale or mudstone containing organic matter.

Question

Quizplus · Accepted Answer

Graphite is a form of carbon that typically originates from organic matter, such as shale or mudstone, that has undergone metamorphism. Therefore, the presence of graphite in a schist is a strong indication that the pre-metamorphic rock was a shale or mudstone containing organic matter. Choices A, B, and C are not supported by the information given.

Graphite Is Identified in a Particular Schist