Conditions of rhodochrosite-nodule formation in Neogene-Pleistocene deep-sea sediments: evidence from O, C and Sr isotopes
✍ Scribed by S. Morad; I.S. Al-Aasm
- Book ID
- 104167253
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 810 KB
- Volume
- 114
- Category
- Article
- ISSN
- 0037-0738
No coin nor oath required. For personal study only.
✦ Synopsis
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 (6~3C = -4.3%0 to -1.3%o) at an estimated depth between ~30 and 70 cm beneath the seafloor. The rhodochrosites have 875r/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 ~80 isotopes (3tSOeDR up to +6.4%~) is attributed to the dissociation of gas hydrates.