To better understand the paleoenvironments of the lower-middle Santonian, dinocyst data were obtained from the Santa Marta Formation, Larsen Basin, James Ross Island, Antarctic Peninsula. This study provides the first available quantitative dinocyst data for the Santa Marta Formation, which should more clearly reflect detailed changes in paleoenvironments, as recorded by fluctuations in diversity and abundance. To record the Santonian dinocyst assemblages from the Larsen Basin, 30 samples from an outcrop of the Lachman Crags Member (LC section) were analyzed. These assemblages are dominated by peridiniacean dinocysts typical of the Isabelidinium flora. A lower-middle Santonian age was determined after the recognition of Odontochitina poriferaand... |