Palaeoenvironments and palaeoclimate records in lacustrine deposits at the Eocene-Oligocene Transition. New insight from de CDB1 borehole (Rennes Basin, France)
type: Dataset
description: On behalf the CINERGY project, a 675m-long borehole was cored through the sedimentary column (405 m) and the basement (270 m). The studied interval encompasses 3 lithostratigraphic units, from 66m to 405m depth. The chronostratigraphic framework of the sedimentary series relies on benthic foraminifera and palynology. Palaeoenvironmental reconstruction is based on sedimentology, pollen analysis and clay mineralogy. 95% of the series deposited continuously from the Early-Middle Bartonian to the Rupelian, including 290 m-thick lacustrine shaly organic deposits, alternating open and closed system depending on the floatting vegetal mats extension. Climate evolution is illustrated by palynological content. The Eocene climate evolves from a from warm and humid condition to a more contrasted seasons. the EOT is marked by a short drier and fresher period, the Rupelian is characterized by disappearance of megathermic taxa but back to more humid condition. Clay mineralogy changes more abruptly at the E/O boundary (~200 m depth), from an almost pure kaolinitic content to a kaolinite-smectite dominated assemblage. Whether the sudden mineralogical change across de E/O boundary is related to a change in source material or to a change in the hydrolysis in soil clay production, a climatic origin is very likely.
landing page: ISC 2014
keyword: borehole
keyword: cinergy
keyword: conference-papers
keyword: core
keyword: eocene-oligocene-transition
keyword: eot
keyword: infoeu-reposemanticsconferenceobject
keyword: lacustrine
keyword: palynology
keyword: rennes-basin
keyword: sdustustsciences-of-the-universe-physicsearth-sciencesstratigraphy
issued: 2026-05-05T10:28:18.957677
modified: 2026-05-05T10:28:18.957681
language: en
contact point: Organization
  fn: CCSD

test_moissonnage_selune
type: Agent

Palaeoenvironments and palaeoclimate records in lacustrine deposits at the Eocene-Oligocene Transition. New insight from de CDB1 borehole (Rennes Basin, France)
type: Distribution
format: HTML
access URL: https://brgm.hal.science/hal-00995163
issued: 2026-05-05T10:28:18.959084
modified: 2026-05-05T10:28:18.943468