Fossilized Traces: the Search for a Window into the Past
For Mary Langworthy ’17 and Mary Margaret Allen ’17, the geology trip to Turkana, Kenya, was not only a great research experience, but also a true adventure. Supervised by Assistant Professor of Geosciences Catherine Beck, they visited East African Rift and described sedimentary rock sequences and collected sample that will be used for further analysis back at school.
The Turkana Basin is part of the East African Rift System, a complex north-south trending rift that contains key clues about how humans and their ancestors evolved. The sediments accumulated over millions of years in subsiding basins and left a detailed archive of past environments and climates in East Africa. By studying these sediments, geologists provide valuable information about how changes in the environment and climate impacted our evolution as a species.
The team travelled to various locations throughout West Turkana to participate in several projects lead by Beck and collaborators from other universities. The research included measuring and describing sections of sedimentary rocks from outcrop exposures and collecting a variety of samples, such as a core from the shore of a small volcanic crater lake.
The team visited a 17 million year old Lower Miocene rock sequence that records shifts back and forth between lake and soil-forming environment. Fossils of plants, vertebrates (including now-extinct primates), and invertebrates were found in the sequence. Langworthy collected samples of ostracods, microscopic aquatic crustaceans, which will be analyzed for stable isotope values using the mass spectrometer at Hamilton College. The oxygen isotope ratios provide clues to water chemistry, temperature, and circulation.
In addition to isotope geochemistry, Langworthy will describe the morphology of the ostracods and assess the species diversity of the assemblage. She is excited to discover new information about how the climate and environment fluctuated in the Miocene. “This is important because not a lot is known about the Lower Miocene in Turkana, and my paleoenvironmental description can contribute to a greater understanding of the conditions which precipitated hominoid evolution,” she remarked.
In addition to collecting data, the team made sure to take some time to enjoy Kenya’s natural beauty. The group hiked along the rim of a volcanic lake full of crocodiles, and explored remote areas on foot and Land Cruiser. They also got to visit famous archaeological sites, including Lomekwi 3, the site where the oldest stone tools dated to 3.3 million years were discovered, and worked alongside a diverse range of experienced geologists and archaeologists.