| _version_ | 1867171817186131968 |
|---|---|
| author | Meyers, Philip A Yum, Jong-Gwon Wise, Sherwood W |
| author_facet | Meyers, Philip A Yum, Jong-Gwon Wise, Sherwood W |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | We have conducted elemental, isotopic, and Rock-Eval analyses of Cenomanian-Santonian sediment samples from ODP Site 1138 in the southern Indian Ocean to assess the origin and thermal maturity of organic matter in mid-Cretaceous black shales found at this high-latitude location. Total organic carbon (TOC) concentrations range between 1 and 20 wt% in black to medium-gray sediments deposited around the Cenomanian-Turonian boundary. Results of Rock-Eval pyrolysis indicate that the organic matter is algal Type II material that has experienced modest alteration. Important contributions of nitrogen-fixing bacteria to the amplified production of organic matter implied by the high TOC concentrations is recorded in d15N values between -5 and 1 per mil , and the existence of a near-surface intensified oxygen minimum zone that favored organic carbon preservation is implied by TOC/TN ratios between 20 and 40. In contrast to the marine nature of the organic matter in the Cenomanian-Turonian boundary section, deeper sediments at Site 1138 contain evidence of contributions land-derived organic matter that implies the former presence of forests on the Kerguelen Plateau until the earliest Cenomanian. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_817646 |
| institution | PANGAEA |
| language | en |
| publishDate | 2009 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | (Table 1) Carbon and nitrogen chemistry of ODP Hole 183-1138A Meyers, Philip A Yum, Jong-Gwon Wise, Sherwood W 183-1138A; Calcium carbonate; Carbon, organic, total; Carbon, organic/Nitrogen, total ratio; Carbonate bomb (Müller & Gastner, 1971); DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Element analyser CHNS-O, Carlo Erba EA1108; Hydrogen index, mass HC, per unit mass total organic carbon; Indian Ocean; Joides Resolution; Leg183; Lithologic unit/sequence; Lithology/composition/facies; Mass spectrometer Finnigan Delta Plus XL; Ocean Drilling Program; ODP; Oxygen index, mass CO2, per unit mass total organic carbon; Pyrolysis temperature maximum; Rock eval pyrolysis (Behar et al., 2001); Sample code/label; Stage; δ13C, organic carbon; δ15N We have conducted elemental, isotopic, and Rock-Eval analyses of Cenomanian-Santonian sediment samples from ODP Site 1138 in the southern Indian Ocean to assess the origin and thermal maturity of organic matter in mid-Cretaceous black shales found at this high-latitude location. Total organic carbon (TOC) concentrations range between 1 and 20 wt% in black to medium-gray sediments deposited around the Cenomanian-Turonian boundary. Results of Rock-Eval pyrolysis indicate that the organic matter is algal Type II material that has experienced modest alteration. Important contributions of nitrogen-fixing bacteria to the amplified production of organic matter implied by the high TOC concentrations is recorded in d15N values between -5 and 1 per mil , and the existence of a near-surface intensified oxygen minimum zone that favored organic carbon preservation is implied by TOC/TN ratios between 20 and 40. In contrast to the marine nature of the organic matter in the Cenomanian-Turonian boundary section, deeper sediments at Site 1138 contain evidence of contributions land-derived organic matter that implies the former presence of forests on the Kerguelen Plateau until the earliest Cenomanian. |
| title | (Table 1) Carbon and nitrogen chemistry of ODP Hole 183-1138A |
| topic | 183-1138A; Calcium carbonate; Carbon, organic, total; Carbon, organic/Nitrogen, total ratio; Carbonate bomb (Müller & Gastner, 1971); DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Element analyser CHNS-O, Carlo Erba EA1108; Hydrogen index, mass HC, per unit mass total organic carbon; Indian Ocean; Joides Resolution; Leg183; Lithologic unit/sequence; Lithology/composition/facies; Mass spectrometer Finnigan Delta Plus XL; Ocean Drilling Program; ODP; Oxygen index, mass CO2, per unit mass total organic carbon; Pyrolysis temperature maximum; Rock eval pyrolysis (Behar et al., 2001); Sample code/label; Stage; δ13C, organic carbon; δ15N |
| url | https://doi.org/10.1594/PANGAEA.817646 |