Rock sample analysis is a critical component in the field of geology, providing insights into the composition, structure, and history of geological materials. Through systematic examination and testing, geologists can interpret the Earth’s processes and make informed decisions regarding resource management, environmental protection, and hazard assessment. Below are three diverse examples of rock sample analysis lab reports, showcasing various contexts and methodologies used in geological studies.
In this example, we analyze a granite rock sample collected from the Sierra Nevada mountains. This analysis aims to understand the mineral composition and texture of the rock, which can provide insights into the geological history of the region.
The granite sample was subjected to thin section petrography and X-ray diffraction (XRD) to determine its mineralogical makeup. The thin section revealed a coarse-grained texture with visible crystals of quartz, feldspar, and biotite. XRD analysis confirmed the presence of quartz (35%), plagioclase (50%), and biotite (15%).
This analysis highlights the formation of granite from the slow cooling of magma beneath the Earth’s surface, indicating a plutonic origin. The results can be useful for assessing the area’s geological history and potential for mineral resources.
This report focuses on a limestone sample obtained from a coastal region. The objective is to analyze the fossil content and sedimentary structures to interpret the depositional environment.
The limestone sample was subjected to a combination of visual examination, acid reaction tests, and scanning electron microscopy (SEM). Visual examination revealed numerous fossilized shells and corals, indicating a rich marine environment. The acid test confirmed the carbonate composition, while SEM analysis provided detailed images of the microstructure, showing fine layering typical of sedimentary formations.
The findings suggest that this limestone was formed in a shallow marine environment, supporting a diverse ecosystem. Such insights are crucial for understanding past climate conditions and guiding conservation efforts in similar ecosystems.
This example analyzes a schist sample collected from a mountain range, aiming to identify the mineralogical changes resulting from metamorphism.
The schist sample underwent polarized light microscopy and electron microprobe analysis to determine its mineral composition and texture. The microscopy revealed a foliated texture with abundant mica, garnet, and quartz. Electron microprobe analysis quantified the mineral percentages, showing 40% mica, 30% garnet, and 30% quartz.
This analysis provides evidence of high-grade metamorphism, indicating that the original rock was subjected to significant heat and pressure. The results can inform geological mapping and help predict the location of potential mineral deposits in the area.