Video Transcript
Which of the following is a
biogenic rock? (A) Fossiliferous limestone, (B)
laminated mudstone, (C) shale, (D) sandstone.
All of the answer choices are
examples of sedimentary rocks. We need to determine which of these
sedimentary rocks is a biogenic rock. The word “biogenic” can be split
into two parts. Bio- means life and -genic means to
produce or generate. So, we can infer that the word
“biogenic” means produced from life or living organisms. In fact, a biogenic rock is a rock
that is formed by biological processes and is primarily formed of organic
remains. These organic remains include plant
material, shell fragments, or minerals created by organisms.
Of the options given in the
question, the only one that fits the description of a biogenic rock is fossiliferous
limestone. Fossiliferous limestone is a
biologically formed limestone that is composed of fossils or fragments of fossils
that represent ancient marine organisms such as corals and bivalves. These fossils form when an organism
dies and its hard parts, such as its shell, fall to the seafloor and are
preserved. These shells can accumulate on the
seafloor, become buried, compacted, and eventually form fossiliferous limestone.
In conclusion, the answer choice
that is a biogenic rock is fossiliferous limestone.
