Abstract
Calcic rhodochrosite occurs as nodules around burrows in late Neogene - early Pleistocene pelagic sediments of the Galapagos Ridge in the Guatemala Basin, eastern equatorial Pacific (DSDP Leg 68; Site 503). Growth was accomplished in the suboxic zone (δ13C = -4.3‰ to -1.3‰) at an estimated depth between ≈30 and 70 cm beneath the seafloor. The rhodochrosites have 87Sr/86Sr ratios (0.708945-0.709073) that largely record the small-scale changes in seawater Sr-isotopic composition. The anomalous enrichment of the rhodochrosite in 18O isotopes (δ18OPDB up to +6.4‰) is attributed to the dissociation of gas hydrates.
Original language | British English |
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Pages (from-to) | 295-304 |
Number of pages | 10 |
Journal | Sedimentary Geology |
Volume | 114 |
Issue number | 1-4 |
DOIs | |
State | Published - Dec 1997 |
Keywords
- Diagenesis
- Gas hydrates
- Isotopes
- Rhodocrosite