SEM Imaging of Rocks of the Finger Lakes Region

Sean Maksimuk, Chemical Engineering, University of Rochester

Enfield Glen

Enfield Glen is located inside Treman State Park, several miles southwest of Ithaca. The samples were collected from and above the area of Lucifer Falls, and these rocks are assigned to the Sonyea group of the late Devonian Age, which is about 370 million years ago.

Sample 1

The first sample was taken from the entrance of the glen. As with most samples, the specimen was taken from an area with layer of rocks stacked on top of one another. It is interesting to note that the microstructure of the rocks, as seen on the bottom right SEM image, also has a lamellar structure. The EDX spectrum suggests it is some kind of Aluminosilicate with traces of iron and magnesium.

Sample 2

This sample was taken from the walls right after entering the upper entrance. The walls were typically oriented 90 degrees to each other. Some layered morphology can be observed in the SEM image, but not to the extent of the first sample.

Sample 3

This sample was taken from the middle region; between the upper entrance and the top of Lucifer Falls. The EDX spectrum (not shown) suggests an aluminosilicate, typical of most rocks observed in this area.

Sample 4

This rock was taken from an area that was equal in height to about the middle of Lucifer Falls.

Sample 5

This sample was also taken from an area that was equal in height to about the middle of Lucifer Falls. However the appearance was somewhat different in that brownish colors can be observed between the layers of rocks. It happens that the brownish areas consist mostly of iron, sulfur, and oxygen, suggesting some kind of mineral with iron sulfate as its main component (bottom picture and spectrum). Some microcrystals of calcium sulfate can be observed (top picture and spectrum). It is most likely that these crystals grew after the formation of the original layer of rocks (gray region of the picture on right) as they can be seen only between the small layers and the delicate morphology is preserved.