Calcareous nannofossils from the Upper Cretaceous of northern James Ross Island, Antarctica: a pilot study

• Main Authors: Švábenická, Lilian, Vodrážka, Radek, Nývlt, Daniel
• Format: Article in Journal/Newspaper
• Language: English
• Published: Polish Geological Institute-National Research Institute 2012
• Subjects: Antarctica; James Ross Island; Upper Cretaceous; calcareous nannofossils; biostratigraphy; Lachman; Lachman Crags; Ross Island; Antarc*; Antarctica; James Ross Island
• Online Access: https://gq.pgi.gov.pl/article/view/7847; https://doi.org/10.7306/gq.v56i4.7847

The Czech scientific expedition to northern James Ross Island, Antarctica has tested the use of calcareous nannofossils as a possible tool for stratigraphic correlation of Cretaceous and Neogene strata. Only a few samples with poor nannofossil content gave useful information for biostratigraphy. The Lower Campanian Chiastozygus garrisonii Zone and Gephyrobiscutum diabolum Subzone, respectively, was established in the lower part of the Santa Marta Formation, Lachman Crags Member, from the common occurrence of Gephyrobiscutum diabolum associated with Broinsonia parca parca and Acuturris scotus. Deposits of the Late Miocene Mendel Formation yielded exclusively reworked nannofossils from the older Upper Cretaceous deposits. Nannofossils indicate at least two distinct stratigraphic levels: Middle Coniacian and Santonianbasal Campanian, and these must have been sourced from the immediate area. The majority of the marine deposit samples studied were barren of nannofossils, probably due to late diagenetic secondary decalcification.