15 special fossils that indicate to geologists the boundaries of geological time. a index fossils b trace…

15 special fossils that indicate to geologists the boundaries of geological time. a index fossils b trace fossils c mold fossils d cast fossils

15 special fossils that indicate to geologists the boundaries of geological time. a index fossils b trace fossils c mold fossils d cast fossils

Answer

Answer:

A. index fossils

Brief Explanations:

Index fossils are used to date rock layers and mark geological - time boundaries due to their short - lived and wide - spread nature. Trace fossils show organism activity, mold fossils are impressions, and cast fossils are filled - in molds, none of which are specifically for indicating geological time boundaries like index fossils.