Kemp, Alan E S; Pearce, Richard B; Koizumi, Itaru; Pike, Jennifer; Rance, Jae (1999): Diatoms and laminae of Mediterranean sapropels [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.769867, Supplement to: Kemp, AES et al. (1999): The role of mat-forming diatoms in the formation of Mediterranean sapropels. Nature, 398(6722), 57-61, https://doi.org/10.1038/18001
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Abstract:
The origins of sapropels (sedimentary layers rich in organic carbon) are unclear, yet they may be a key to understanding the influence of climate on ocean eutrophication, the mechanisms of sustaining biological production in stratified waters and the genesis of petroleum source rocks (Rohling, 1994, doi:10.1016/0025-3227(94)90202-X; Castradori, 1993, doi:10.1029/93PA00756; Calvert et al., 1992, doi:10.1038/359223a0). Recent microfossil studies of foraminifera (Rohling, 1994, doi:10.1016/0025-3227(94)90202-X) and calcareous nannofossils (Castradori, 1993, doi:10.1029/93PA00756) have focused attention on a deep chlorophyll maximum as a locus for the high production inferred (Calvert et al., 1992, doi:10.1038/359223a0) for sapropel formation, but have not identified the agent responsible. Here we report the results of a high-resolution, electron-microscope-based study of a late Quaternary laminated sapropel in which the annual flux cycle has been preserved. We find that much of the production was by diatoms, both mat-forming and other colonial forms, adapted to exploit a deep nutrient supply trapped below surface waters in a stratified water column. Reconstructed organic-carbon and opal fluxes to the sediments are comparable to those at high-productivity sites in today's oceans, and calculations based on diatom Si/C ratios suggest that the high organic-carbon content of sapropels may be entirely accounted for by sedimenting diatoms. We propose that this style of production may have been common in ancient Palaeogene and Cretaceous seas, environments for which conventional appeals to upwelling-driven production to account for the occurrence of diatomites, and some organic-carbon-rich sediments, have never seemed wholly appropriate.
Project(s):
Ocean Drilling Program (ODP)
Coverage:
Median Latitude: 33.800613 * Median Longitude: 26.579920 * South-bound Latitude: 33.713600 * West-bound Longitude: 24.701700 * North-bound Latitude: 34.068300 * East-bound Longitude: 32.725300
Date/Time Start: 1995-04-02T11:40:00 * Date/Time End: 1995-04-23T17:43:00
Event(s):
160-967B * Latitude: 34.068300 * Longitude: 32.725300 * Date/Time Start: 1995-04-02T11:40:00 * Date/Time End: 1995-04-03T00:40:00 * Elevation: -2555.0 m * Penetration: 121.5 m * Recovery: 126.61 m * Location: Eastern Basin * Campaign: Leg160 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 14 cores; 121.5 m cored; 0 m drilled; 104.2 % recovery
160-969E * Latitude: 33.841100 * Longitude: 24.883100 * Date/Time Start: 1995-04-16T17:55:00 * Date/Time End: 1995-04-16T15:20:00 * Elevation: -2201.0 m * Penetration: 97.9 m * Recovery: 100.23 m * Location: Eastern Basin * Campaign: Leg160 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 11 core; 97.9 m cored; 0 m drilled; 102.4 % recovery
160-971C * Latitude: 33.713600 * Longitude: 24.701700 * Date/Time Start: 1995-04-23T15:33:00 * Date/Time End: 1995-04-23T17:43:00 * Elevation: -2152.0 m * Penetration: 16.7 m * Recovery: 17.25 m * Location: Eastern Basin * Campaign: Leg160 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 2 cores; 16.7 m cored; 0 m drilled; 103.3 % recovery
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
2 datasets
Download Data
Datasets listed in this publication series
- Kemp, AES; Pearce, RB; Koizumi, I et al. (1999): (Table 1) Opal and carbon determinations of laminae in ODP Hole 160-971C. https://doi.org/10.1594/PANGAEA.769864
- Kemp, AES; Pearce, RB; Koizumi, I et al. (1999): (Table S1) Diatom abundances in laminae of ODP Leg 160 holes. https://doi.org/10.1594/PANGAEA.769866