Scallop Hill Formation, Brown Peninsula, McMurdo Sound, Antarctica

Abstract

Abstract Scallop Hill Formation was sampled at the northern end of Brown Peninsula, in the McMurdo Sound area, Antarctica. This paper describes the stratigraphy and age relationships, paleoecology, petrography, and genesis of the formation. The formation consists of palagonitic tuffs and poorly sorted volcanic breccias of basaltic composition. Zeolites commonly fill vesicles and fringe volcanic clasts. The 2–3 m thick formation contains abundant fossiliferous material in the uppermost 20 cm which has been previously correlated with fossiliferous marine deposits on Black Island, White Island, and Cape Bird. A well-developed aragonite cement encloses both fossils and volcanic material. Stratigraphic relationships and physical and petrographic characteristics of the formation suggest eruption of volcanics into a shallow marine environment during the middle to late Pliocene. The formation has subsequently been raised by glacioisostatic and/or tectonic movements to its present position, 150–200 m above the lev...