DOI: 10.17632/9z92cj7vx6
title: Microfacies, Larger Benthic Foraminiferal Assemblages, and Age Determinations of Eocene and Oligocene Limestone Samples from the Fila de Cal and Térraba Formations, Southern Costa Rican Forearc – Data Reports

description: The dataset consists of six individual data files, including Data Summary and Methods, sampling location map, and four data reports written in 2017 and 2019 in collaboration with the Centro de Investigación en Ciencias Geológicas of the University of Costa Rica (CICG-UCR); ongoing research projects: (1) Strengthening research in Stratigraphy and Tectonics of southern Costa Rica (research grant UCR 830-B0-242) and (2) Cenozoic Calcareous Depositional System of the Fila de Cal Formation, Costa Rica (research grant UCR 830-B7-277) in charge of Percy Denyer, Teresita Aguilar, Aristides Alfaro, Valentin Chesnel, and Erick Rodríguez. During these research projects, a total of 29 thin sections made of nineteen selected limestone rocks collected from the Fila de Cal and Térraba Formations have been prepared until yet for further laboratory sample analysis and age determination. The reports contain the limestone microfacies descriptions and detailed micropaleontological results, including sample age determinations based on their larger foraminiferal assemblages. The summary of the data reports contains in addition the research methods. The selected limestone samples were collected during field research campaigns in the Fila Costeña thrust belt area of southern Costa Rica by the CICG researchers and later examined and dated by Angela Bolz and Claudio Calvo in Stuttgart, Germany where part of the studied materials (thin sections and high-resolution image copies) are actually stored. The original hard rock samples as well as the thin sections of sample series VC remain with the CICG collectors at the University of Costa Rica. Sampling localities and their precise coordinates are depicted on Google site map file of the dataset: Sampling site map.kmz, with location of sample series CH, Te, Co, and VC. All laboratory sample analysis and data reports were carried out in scientific collaboration with the researchers at the Centro de Investigación en Ciencias Geológicas of the Universidad de Costa Rica mentioned above. In sedimentological terms, the sampled limestone succession records a large and stable carbonate platform. The microfacies and limestone age determinations show that both shallow and deeper marine platform environments were concomitant in the Eocene as well as in the Oligocene. The Rupelian upper part of the carbonate succession and the few Henningsen (1966) limestone beds record the drowning carbonate platform episode in this area. This development has likely to do with the carbonate platform declining caused by the siliciclastic sedimentation of the Térraba Formation, which finished the carbonate domain of the Fila de Cal. The larger foraminifers determined in these limestone samples also reveal two successive assemblages. That means the carbonate factory of the Fila de Cal platform didn’t stop its sediment production in the late Eocene (Priabonian) to continue into the early Oligocene (Rupelian). Stuttgart and San José in October 2019