Interstitial water chemistry at DSDP Leg 67 Holes
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| Autores principales: | , , |
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| Formato: | Dataset Open Access |
| Lenguaje: | en |
| Publicado: |
PANGAEA
1982
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| _version_ | 1867168564088143872 |
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| author | Harrison, William E Hesse, Reinhard Gieskes, Joris M |
| author_facet | Harrison, William E Hesse, Reinhard Gieskes, Joris M |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Interstitial water chemistry has proved to be a sensitive indicator for early diagenetic reactions, particularly those related to organic matter oxidation. Downhole chemical variations in the pore waters from Deep Sea Drilling Project Holes 496 and 497 on the Middle America Trench slope off Guatemala are anomalous because both salinity and chlorinity show strong decreases to half the values of seawater, and d18O values become positive (maximum of about +2.5% at the bottom of the holes). These observations are explained in terms of dilution of pore waters after retrieval as a result of decomposition of the gas hydrates before removal of pore waters by shipboard squeezing techniques. In all holes, except Hole 495 (drilled in pelagic sediments), decomposition of organic matter leads to rapid sulfate depletion and subsequent methane generation. Associated with methane generation are large increases in alkalinity and dissolved ammonia. The latter component causes ion exchange reactions with clay minerals, which results in maxima in magnesium and perhaps potassium. At greater depths, as yet unidentified reactions cause the removal of magnesium. Especially in the deeper Trench Sites 499 and 500, rapid variations in calcium, magnesium, and alkalinity occur in turbidite sequences. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_817568 |
| institution | PANGAEA |
| language | en |
| publishDate | 1982 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Interstitial water chemistry at DSDP Leg 67 Holes Harrison, William E Hesse, Reinhard Gieskes, Joris M 67-494; 67-494A; 67-495; 67-496; 67-497; 67-498; 67-498A; 67-499; 67-500; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg67; North Pacific/SLOPE; North Pacific/TRENCH Interstitial water chemistry has proved to be a sensitive indicator for early diagenetic reactions, particularly those related to organic matter oxidation. Downhole chemical variations in the pore waters from Deep Sea Drilling Project Holes 496 and 497 on the Middle America Trench slope off Guatemala are anomalous because both salinity and chlorinity show strong decreases to half the values of seawater, and d18O values become positive (maximum of about +2.5% at the bottom of the holes). These observations are explained in terms of dilution of pore waters after retrieval as a result of decomposition of the gas hydrates before removal of pore waters by shipboard squeezing techniques. In all holes, except Hole 495 (drilled in pelagic sediments), decomposition of organic matter leads to rapid sulfate depletion and subsequent methane generation. Associated with methane generation are large increases in alkalinity and dissolved ammonia. The latter component causes ion exchange reactions with clay minerals, which results in maxima in magnesium and perhaps potassium. At greater depths, as yet unidentified reactions cause the removal of magnesium. Especially in the deeper Trench Sites 499 and 500, rapid variations in calcium, magnesium, and alkalinity occur in turbidite sequences. |
| title | Interstitial water chemistry at DSDP Leg 67 Holes |
| topic | 67-494; 67-494A; 67-495; 67-496; 67-497; 67-498; 67-498A; 67-499; 67-500; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg67; North Pacific/SLOPE; North Pacific/TRENCH |
| url | https://doi.org/10.1594/PANGAEA.817568 |