ASBOG Practice Exam 2025 – Complete Preparation Guide

The number of fossils within a sample is a key feature used to narrow down the relative age of geological samples due to the principles of biostratigraphy. Fossils serve as important indicators of specific time periods in Earth's history because they evolve at different rates and are found in distinct layers of sedimentary rocks. By examining the types and abundance of fossils present, geologists can compare them with known fossil records to establish a relative age.

For instance, many species are known to have existed only during certain geological eras, so finding a particular fossil can help correlate the rock layer with its corresponding time period. Moreover, the presence of specific fossil assemblages can indicate a broader ecological history and help stratigraphers understand the depositional environment. This application of fossil data to understand relative ages is crucial in fields such as paleontology and geology.

Other options, while relevant to geological studies, do not provide as directly useful information for establishing relative ages. The type of rock composition can be indicative of certain geological processes, but it does not pinpoint the age without additional contextual information. The presence of minerals might suggest specific conditions of formation but lacks the temporal resolution that fossils provide. Similarly, geographical location can help understand the context of geological formations but does not inherently reveal the relative age