Abstract
The Levantine high productivity sequence is a product of an extensive upwelling system that operated in the Late Cretaceous along the SE Tethyan margin. This system resulted in the deposition of a unique sequence of carbonate, chert, porcellanite, phosphorite and organic-rich (oil shale) sediments in a series of basins located proximally and marginally to the upwelling center. This study presents a detailed and updated chronostratigraphic framework for the high productivity sequence in Israel based on eight sections covering a N-S cross section of ~90km. The Shefela Basin (central Israel) represents the thickest and the most complete penetrated stratigraphic interval of the oil shale deposits in Israel. The newly drilled Aderet borehole in the Shefela Basin provided a continuous core record coupled with high quality geophysical well logs and was used in this study as a 'type-section' for the detailed chronostratigraphic scheme of the high productivity sequence. A total of 23 datum levels were recognized using planktic and benthic foraminiferal biostratigraphy, lithostratigraphy and gamma ray well log markers. The varying lithostratigraphic units (containing chert, phosphate, porcellanite and organic-rich carbonates) of the more proximal basins of southern Israel (Negev) were individually correlated to specific horizons within the monotonous organic-rich carbonates of the distal setting of the Shefela Basin. The first occurrence of the Late Cretaceous organic-rich carbonates in Israel is documented in the Negev during the late Coniacian, within the upper Dicarinella concavata Zone, and corresponds chronologically to the upper part of the lower Menuha Formation. The regional unconformity around the Santonian/Campanian boundary was found to be less substantial at the distal localities in comparison to the proximal ones. The distinct appearance of the 'Mishash Tongue' chert in the Shefela was correlated to the massive Chert Member (Mishash Formation) in the Negev, and assigned to the middle Campanian. Deposition of the overlying phosphate series spans from the lower Contusotruncana plummerae to the base of the Pseudoguembelina palpebra Zones (78.3-71.7Ma) and co-occurs in both proximal and deeper distal areas, although in a much lesser magnitude in the latter. The top of the phosphatic unit is marked by a regional unconformity. The oil shale deposits in southern Israel coincide with the 100m richest TOC interval (average of 15.2wt.% TOC) in the Shefela. The diminishing phase of organic-rich deposition occurred in a diachronous step-wise manner across Israel, from the top of the P.palpebra Zone to the upper part of the Abathomphalus mayaroensis Zone in southern and central Israel, respectively. Thisindicates that the full duration of the high productivity sequence in Israel spans approximately 19myr.Arabian Plate-wide maximum flooding surfaces (MFS) recorded during the Tectonic Mega-Sequence (TMS) AP9 timeframe (92-63Ma) are identified here in the local sedimentary system of the Levant: K160 signifying the onset of organic-rich carbonates; K170 at the upper part of the massive and brecciated Chert Member; and K180 marking the diminishing phase of the high productivity sequence in Israel.
Original language | English |
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Pages (from-to) | 187-213 |
Number of pages | 27 |
Journal | Cretaceous Research |
Volume | 50 |
DOIs | |
State | Published - Jul 2014 |
Externally published | Yes |
Bibliographical note
Funding Information:We wish to express our gratitude to IEI Ltd. for the use of the Aderet core material, gamma ray log and laboratory equipment. We would like to specifically thank H. Vinegar and Y. Bartov for the helpful insights and discussions, greatly contributing to this paper. We would also like to thank M. Kitin and F. Gelman from the Geological Survey of Israel and E. Danon from IEI Ltd. for their assistance in the laboratory procedures, T. Minster from the Geological Survey of Israel and the Soreq Nuclear Research Center for the invaluable data set of gamma ray logs. We would like to include a special appreciation to O. Bialik for his contribution and advice in the regional stratigraphic correlation. We thank two anonymous reviewers for suggestions resulting in a significantly improved manuscript. The research was supported by GIF – The German-Israeli Foundation for Scientific Research and Development – grant no. 956-38.8/2007 and by the Israeli Ministry of Infrastructure grant no. 277-17-018 .
Keywords
- Chronostratigraphy
- Foraminifera
- Gamma ray
- High productivity
- Late Cretaceous
- Southern Tethys
ASJC Scopus subject areas
- Paleontology