Physical Sciences and Mathematics Commons^™

Last Interglacial Climate From Dendostrea Frons Oysters, Verrill Island, Bermuda, Lillian Minnebo

Student Summer Scholars Manuscripts

The Bermuda Islands preserve carbonates recording many past changes in sea level, including multiple warm and cool geologic intervals. Several localities expose shell-rich deposits from the Last Interglacial (~125,000 years ago), a time broadly similar to climate today that can potentially serve as an analog for future conditions. Here, we use δ18O analyses of fossil mollusks to estimate past temperatures and seasonality and compare our data with those from other species.

Eight Dendostrea frons oysters were sampled along their growth axes to reconstruct seasonal temperature curves. We report a mean δ18O value of -0.51 ± 0.17‰, corresponding to a temperature …

Biodiversity And Distribution Of Benthic Foraminifera In Harrington Sound, Bermuda: The Effects Of Physical And Geochemical Factors On Dominant Taxa, Nam Le

Honors Theses

Harrington Sound, Bermuda, is a nearly enclosed lagoon acting as a subtropical/tropical, carbonate-rich basin in which carbonate sediments, reef patches, and carbonate-producing organisms accumulate. Here, one of the most important calcareous groups is the Foraminifera. Analyses of common benthic orders, including miliolids (Quinqueloculina and Triloculina spp.) and rotaliids (Homotrema rubrum, Elphidium spp., and Ammonia beccarii), are essential in understanding past and present environmental conditions affecting the island's coastal environment. These taxa have been studied previously; however, factors explaining their individual patterns of abundance in the Sound are not well detailed. The goal of this study is …

Anthropogenic Infilling Of A Bermudian Sinkhole And Its Impact On Sedimentation And Benthic Foraminifera In The Adjacent Anchialine Cave Environment, Jacquelyn N. Cresswell, Peter J. Van Hengstum, Thomas M. Iliffe, Bruce E. Williams, Gil Nolan

International Journal of Speleology

In the mid-20^th century, an inland brackish pond from Bermuda, known as Eve’s Pond, was filled with marine sediment from an adjacent coastal lagoon. At this time, an eyewitness reported “…sediment billowing out of the Green Bay Cave for days…”, which is a marine-dominated anchialine cave located proximal to the former location of Eve’s Pond (~200 m). The purpose of this study was to evaluate the potential impact of this infilling event on cave sedimentation and benthic meiofaunal communities, as proxied by the unicellular protists foraminifera that remain preserved in the sediment record. Eight sediment cores were collected from …

Mantle Transition Zone Discontinuities Beneath The Contiguous United States, Stephen S. Gao, Kelly H. Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Using over 310,000 high-quality radial receiver functions recorded by the USArray and other seismic stations in the contiguous United States, the depths of the 410 km and 660 km discontinuities (d410 and d660) are mapped in over 1,000 consecutive overlapping circles with a radius of 1⁰. The average mantle transition zone (MTZ) thickness for both the western and central/eastern U.S. is within 3 km from the global average of 250 km, suggesting an overall normal MTZ temperature beneath both areas. The Pacific Coast Ranges and the southern Basin and Range Province are underlain by a depressed d410, indicating higher-than-normal temperature …