Question

task: fossils
activity 2 of 4
how long ago were dinosaurs walking the earth? around 240 million years ago! paleontologists determined this due to the discovery of a nyasasaurus parringtoni fossil in 1930 in the country of tanzania. the nyasasaurus parringtoni set the record for the oldest dinosaur fossil ever discovered. (adapted from national geographic, 2012)
some rocks contain fossils, which provide clues to the past. how was a rock containing fossils most likely formed?
a. through the process of heating and cooling
b. through the process of sedimentation
c. through the process of volcanic activity
d. through the process of magma cooling

Explanation:

Fossils are typically found in sedimentary rocks. Sedimentation is the process by which sediments (such as sand, silt, clay, and organic matter) accumulate and are compacted and cemented over time to form sedimentary rocks. When organisms die, they can be buried by sediments, and under the right conditions (such as low oxygen levels to prevent decay), their remains can be preserved as fossils within the sedimentary rock.

• Option A (heating and cooling) is more related to igneous rocks (formed from magma or lava) and some metamorphic rocks (but not the typical process for fossil - containing rocks).
• Option C (volcanic activity) is associated with igneous rocks (formed from volcanic eruptions, either as lava on the surface or magma below the surface). Fossils are not typically preserved in volcanic - origin rocks.
• Option D (magma cooling) is also related to igneous rock formation. Magma cools either slowly (intrusive igneous rocks) or quickly (extrusive igneous rocks), and these environments are not conducive to fossil preservation.

Answer:

B. Through the process of sedimentation