Paleoenvironments, origin, and relative maturity of organic matter in Barremian-Aptian limestones of the eastern Prada Quarry, Organyà Basin, NE Spain Thesis

(2017). Paleoenvironments, origin, and relative maturity of organic matter in Barremian-Aptian limestones of the eastern Prada Quarry, Organyà Basin, NE Spain . 10.25148/etd.FIDC004053

thesis or dissertation chair

fiu authors

  • Llaguno, Jose R

abstract

  • This study is a multi-proxy analysis of a 30-m section of a Barremian-Aptian succession of interbedded, grayish black (N2) and black (N1) limestones from a quarry of the Sierra de Prada. Index taxa include planktic foraminifera Globigerinelloides blowi and Hedbergella sigali, which combined with δ13C data from Cresmina and Gorgo a Cerbara sections indicate a late Barremian to early Aptian age. The rocks are organic-rich with 0.67 - 3.10 wt% total organic carbon (TOC). A marlstone interval (~1m) at 2.24 m has a low bioturbation index (1), TOC ~6.66 wt%, framboidal pyrite, and enrichment spikes of major, biolimiting, and redox-sensitive trace elements (Al, Si, Ti, P, Fe, and Mo, Cr, Cu, V, Th), indicating an anoxic episode. Biomarker analyses show a predominance of n-alkanes (≤nC20) at this level, suggesting an in situ origin of organic matter from phytoplankton. Pr/Phy ratios below 2 imply that organic matter did not reach overmaturity.

publication date

  • November 16, 2017

keywords

  • Barremian-Aptian
  • Biomarker n-alkanes
  • Organic matter maturity
  • Organyà Basin
  • Oxygen-deficient conditions
  • Redox conditions

Digital Object Identifier (DOI)