Miocene lithological, foraminiferal and palynological data from the Belverde borehole (Portugal)

P. Legoinha, L. Sousa, J. Pais, J. Ferreira, A. Rita Amado

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Preliminary data on litho stratigraphy and biostratigraphy of the Belverde borehole (http://www. dct.Jct.unl.pt/ SondagemISondagem/colunalindex_col.html) is presented. The borehole attained 619,77 m of depth, crossing 130 m of Plio-Pleistocene and 460 m of Miocene dep osits. Main lithologies are fine sands , marl s and biocalcarenites. A coral reef was recognized in the lower part of the borehole (530-585 m). Gamma ray, neutrons and sonic diagraphies were obtained. Eight 87Sr/86Sr isotopic ages (H. Elderfield, Cambridge University)and the presence of some of the main planktonic foraminifera markers were used to establish the chronostratigraphic framework. Plankt onic spikes are related to the major transgression s of the Lower Tagus Basin (LTB): M. Burdigalian (sample Belv 459 ; 446 m), L. Serravallian (Belv 76; 244 m) and L. Tortonian (Belv 51, 202 m). Benthi c assemblages are dominated by Ammonia, Elphidium and Nonion. Spores suggest a mild and humid climate during the uppermost Burdigalian to the Tortonian. Pollen is scarce. Thirty dinoflagellates taxa (26 Gonyaulacoids and 4 Peridinioids) have been identi fied, indicating coastal to shallow marine environments. In the uppermost Burdigalian to the Tortonian the presence of peridinioids and scarce acritarchs suggest influence of inshore to brackish environments. Several 87Sr /86Sr ages obtained by H. Elderfield (Cambridge University) fit well with the biostratigraphy for the Lower an Middle Miocene, but values given by Howarth and Mcarthur (1997) are closer to the Upper Miocene bio stratigraphic data.
Original languageEnglish
Title of host publicationXVIII Jornadas de Paleontología y II Congreso lbérico de Paleontologia. Livro de resúmenes
PublisherEdiciones Universidad de Salamanca
Pages196-197
ISBN (Print)84-699-9351-8
Publication statusPublished - 2002
EventXVIII Jornadas de Paleontolog{a y II Congreso lbérico de Paleontologia - Universidad de Salamanca, Salamanca, Spain
Duration: 24 Sep 200229 Sep 2002

Conference

ConferenceXVIII Jornadas de Paleontolog{a y II Congreso lbérico de Paleontologia
CountrySpain
CitySalamanca
Period24/09/0229/09/02

Fingerprint Dive into the research topics of 'Miocene lithological, foraminiferal and palynological data from the Belverde borehole (Portugal)'. Together they form a unique fingerprint.

  • Cite this

    Legoinha, P., Sousa, L., Pais, J., Ferreira, J., & Amado, A. R. (2002). Miocene lithological, foraminiferal and palynological data from the Belverde borehole (Portugal). In XVIII Jornadas de Paleontología y II Congreso lbérico de Paleontologia. Livro de resúmenes (pp. 196-197). Ediciones Universidad de Salamanca.