Sediment Core Analysis Using Visual and Numeric Datasets for Interpretation of Paleoenvironments
Advisor: Dr. Jillian Maloney
Monday, May 10, 2021
watch Matthew’s talk
In 2017 and 2018, 27 sediment cores were collected from the Santa Cruz Passage offshore from the Northern Channel Islands in order to reconstruct the paleolandscape during times of lower sea level. We used a suite of geophysical and geologic data (e.g., grain size and XRF data) collected from the shelf to identify these deposits. By identifying a possible terrestrial signature in these data, it will help future geologists identify terrestrial deposits in a marine environment. The identification of these deposits is important for archaeological research on early human migration into the Americas. If the first people migrated into North America along the Pacific coast during the last glacial period, evidence of this migration could now be submerged on the continental shelf. Identification of environments and resources valuable to early humans (e.g., estuaries, seeps, rivers) can help to refine the search for submerged archaeological sites. Furthermore, the identification of these environments can improve management of offshore energy development to avoid development in regions that are likely to contain archaeological sites. Our results show that grain size alone is not sufficient to characterize marine vs. terrestrial deposits as both have multiple sub-environments that are characterized by variable grain size distributions. XRF data indicates terrestrial deposits typically have high counts of mainly Fe and Ti, while marine deposits typically have high counts of Ca and Sr. In conclusion, a variety of data types are needed to identify terrestrial deposits on the continental shelf.