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Benthic foraminiferal community changes across the Miocene climatic optimum Identified by SHEBI analysis (SHE analysis for biozone identification), Calvert Cliffs, Maryland, USA

April 15, 2024

The Calvert Cliffs, MD, an iconic section of Middle Miocene strata, have been well studied both paleontologically and stratigraphically for over a century. However, few studies of the Calvert Cliffs have looked at the benthic foraminifera. This study uses SHEBI analysis (SHE analysis for biozone identification) of benthic foraminiferal assemblages to analyze community change in the Calvert and Choptank formations of the Calvert Cliffs deposited during the Miocene Climatic Optimum (MCO; 17–14.8 Ma) and the Middle Miocene Climate Transition (MMCT; 14.8–13.8 Ma). SHE analysis differs from traditional analytical methods by defining communities based on changes in diversity rather than the relative abundance of individual species. This study uses SHE analysis on a composite section of benthic foraminiferal assemblages from three vertical transects that span the MCO and MMCT. Two communities were identified from the studied strata. Community 1 was deposited during the MCO and includes incised valley fill (IVF), transgressive system tract (TST), and highstand system tract (HST) deposits. Community 2, deposited during the MMCT, is composed of samples from TST, HST, IVF, and another HST. The assemblages of community 1 are representative of an inner to middle shelf environment whereas those of community 2 are representative of an inner shelf environment. The two foraminiferal communities differentiated by SHE analysis indicate a high relative sea level in the Salisbury Embayment during the warm MCO followed by a decrease in sea level during the subsequent cooler MMCT.

Publication Year 2024
Title Benthic foraminiferal community changes across the Miocene climatic optimum Identified by SHEBI analysis (SHE analysis for biozone identification), Calvert Cliffs, Maryland, USA
DOI 10.61551/gsjfr.54.2.188
Authors Seth R. Sutton, Stephen J. Culver, Lee-Ann Hayek, David J. Mallinson, Marci M. Robinson, Harry J. Dowsett, Martin A. Buzas
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Foraminiferal Research
Index ID 70252797
Record Source USGS Publications Warehouse
USGS Organization Florence Bascom Geoscience Center
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