3. Suppose you have a fossil in your coquina layer, on top of a mountain in that area. This
fossil is an ocean sea slug. However, the current environment in this area is a desert.
Explain how you could have a sea fossil layer in a desert.
One possible explanation for having a sea fossil layer in a desert is through geological processes such as plate tectonics and uplift.
Plate tectonics involves the movement and interaction of Earth's rigid plates, which can result in the formation of mountains. Over millions of years, the area where the desert is now located could have been underwater, part of an ocean or a sea.
During this time, sea slugs and other marine organisms living in the ocean would have deposited their remains on the ocean floor. Sediments containing these fossilized remains could have accumulated and eventually become compacted and cemented to form a layer of rock.
However, due to tectonic movements, the area may have gradually undergone uplift, causing the sea floor to rise and eventually become a part of a mountain range. As the landmass rose and the ocean receded, the area transitioned from being underwater to becoming a dry desert environment.
Although the current environment is now a desert, the layer of rock that contains the sea slug fossil remains preserved from its previous existence as a sea floor. These rock layers could have been exposed through erosion, revealing the fossil embedded within the coquina layer.
Additionally, it's important to note that the concept of "desert" doesn't necessarily mean an absence of water. Deserts can have intermittent or seasonal water bodies such as oasis, rivers, or lakes. The presence of water bodies in the desert could have provided an opportunity for certain marine organisms like sea slugs to survive and leave behind their remains.
Therefore, the presence of a sea slug fossil in a desert area could be attributed to the area's geological history, where it was once underwater and later uplifted to become a mountainous desert.