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Rare-earth elements and uranium in high-temperature solutions from an East Pacific Rise hydrothermal vent field (13°N)
OLR (1983)30 (12)
D. SubmarineGeologyand Geophysics
The volcanic detritus was primarily plagioclase; magnetite and minor amounts of pyroxene and volcanic quartz were present also. The morphology, distribution, origin and alteration of the minerals were discussed. Inst. fur Meeresforsch., Am Handelshafen 12, D-2850 Bremerhaven, FRG. (msg) 83:6727 Williams, A.O. Jr., 1983. Normal-mode propagation in deep-ocean sediment channels: a sequel. J. acoust. Soc. Am., 73(6):1985-1988. A former simplifying assumption was that %, the speed of sound in water, is constant everywhere; here, it is more realistically assumed that cw decreases slowly and linearly with height above the water-sediment interface. Consequently an acoustic barrier exists from the interface to, typically, 100-200 m above it. Acoustic energy in a signal traveling along the sediment channel can tunnel upward through the barrier, causing a 'leakage' attenuation along the channel. The amplitude attenuation factor caused by leakage in this example is negligible, justifying the approximation of constant cw; for a normal mode nearer cutoff, the leakage would increase considerably. Dept. of Phys., Naval Postgrad. Sch., Monterey, Calif. 93940, USA.
D140. Submarine hydrology (springs, hyd r o t h e r m a l deposits, etc.) 83:6728 Michard, A., F. Albar~de, G. Michard, J.F. Minster and J.L. Charlou, 1983. Rare-earth elements and uranium in high-temperature solutions from an East Pacific Rise hydrothermai vent field (13°N). Nature, Lond., 303(5920):795-797. Sampling of hydrothermal vent waters from the EPR at 13°N provides the first direct evidence of REE-enriched solutions (leaving the budget of these elements in the crust and ocean rather unmodified). In contrast, uranium, like magnesium, is quantitatively taken up from seawater during the hydrothermal process. Centre de Rech. Petrograph. et Geochim. et ENS Geol., BP 20, 54501 Vandoeuvre Cedex, France. 83:6729 Shearme, S., D.S. Cronan and P.A. Rona, 1983. Geochemistry of sediments from the TAG Hydrothermal Field, MAR at latitude 26°N. Mar. Geol., 51(3/4):269-291. The sediments show evidence of hydrothermal inputs in the form of Fe, Cu and Zn enrichments,
921
thought to have been introduced as finely divided sulphides precipitated from suspension and since oxidized; Mn enrichment is believed to be primary oxide precipitate. The elements can be distributed between various phases in the different types of sediments studied; diagenetic transfer from one phase to another occurs on burial. The general lack of metal enrichments of the intensity sometimes found on the EPR is thought largely the result of major metal precipitation subsurface. Inst. of Oceanogr. Sci., Wormley, Surrey, UK.
D170. Historical geology, stratigraphy 83:6730 Bartsch-Winkler, Susan, A.T. Ovenshine and Reuben Kachadoorian, 1983. Hoiocene history of the estuarine area surrounding Portage, Alaska as recorded in a 93 m core. Can. J. Earth Sci., 20(5):802-820. Includes a fold-out geological map. USGS, Anchorage, Alaska 99504, USA. 83:6731 Behairy, A.K.A., 1983. Marine transgressions on the west coast of Saudi Arabia (Red Sea) between the Mid-Pleistocene and Present. Mar. Geol., 52(I/2):M25-M31. Fac. of Mar. Sci., King Abdulaziz Univ., Jeddah, Saudi Arabia. 83:6732 Corliss, B.H. and R.C. Thunell, 1983. Carbonate sedimentation beneath the Antarctic Circumpolar Current during the Late Quaternary. Mar. Geol., 51 (3/4) :293 -326. CaCO 3 content and planktonic foraminiferal fragmentation were analyzed in 4 Southeast Indian Ridge cores. The CaCO 3 record in the 2 southernmost cores revealed distinct glacial-interglacial cycles with low carbonate associated with glacial intervals; carbonate records of the more northerly cores were independent of the paleoclimatic record. WHOI, Woods Hole, Mass. 02543, USA. (msg) 83:6733 Faugeres, J.C., E. Gonthier and J. Poutiers, 1983. Facies and sediment dynamics in the CharlieGibbs Fracture Zone during the Late Quaternary. Mar. Geol., 52(1/2):101-119. Analyses of 5 cores from 4 types of environments revealed that sedimentary processes in the fracture zone are dominated by gravity flows, which rework material supplied both by 'ubiquiste' sedimentation and bottom currents and which mask the effects of those two depositional processes. Inst. de Geol. du
D. SubmarineGeologyand Geophysics
The volcanic detritus was primarily plagioclase; magnetite and minor amounts of pyroxene and volcanic quartz were present also. The morphology, distribution, origin and alteration of the minerals were discussed. Inst. fur Meeresforsch., Am Handelshafen 12, D-2850 Bremerhaven, FRG. (msg) 83:6727 Williams, A.O. Jr., 1983. Normal-mode propagation in deep-ocean sediment channels: a sequel. J. acoust. Soc. Am., 73(6):1985-1988. A former simplifying assumption was that %, the speed of sound in water, is constant everywhere; here, it is more realistically assumed that cw decreases slowly and linearly with height above the water-sediment interface. Consequently an acoustic barrier exists from the interface to, typically, 100-200 m above it. Acoustic energy in a signal traveling along the sediment channel can tunnel upward through the barrier, causing a 'leakage' attenuation along the channel. The amplitude attenuation factor caused by leakage in this example is negligible, justifying the approximation of constant cw; for a normal mode nearer cutoff, the leakage would increase considerably. Dept. of Phys., Naval Postgrad. Sch., Monterey, Calif. 93940, USA.
D140. Submarine hydrology (springs, hyd r o t h e r m a l deposits, etc.) 83:6728 Michard, A., F. Albar~de, G. Michard, J.F. Minster and J.L. Charlou, 1983. Rare-earth elements and uranium in high-temperature solutions from an East Pacific Rise hydrothermai vent field (13°N). Nature, Lond., 303(5920):795-797. Sampling of hydrothermal vent waters from the EPR at 13°N provides the first direct evidence of REE-enriched solutions (leaving the budget of these elements in the crust and ocean rather unmodified). In contrast, uranium, like magnesium, is quantitatively taken up from seawater during the hydrothermal process. Centre de Rech. Petrograph. et Geochim. et ENS Geol., BP 20, 54501 Vandoeuvre Cedex, France. 83:6729 Shearme, S., D.S. Cronan and P.A. Rona, 1983. Geochemistry of sediments from the TAG Hydrothermal Field, MAR at latitude 26°N. Mar. Geol., 51(3/4):269-291. The sediments show evidence of hydrothermal inputs in the form of Fe, Cu and Zn enrichments,
921
thought to have been introduced as finely divided sulphides precipitated from suspension and since oxidized; Mn enrichment is believed to be primary oxide precipitate. The elements can be distributed between various phases in the different types of sediments studied; diagenetic transfer from one phase to another occurs on burial. The general lack of metal enrichments of the intensity sometimes found on the EPR is thought largely the result of major metal precipitation subsurface. Inst. of Oceanogr. Sci., Wormley, Surrey, UK.
D170. Historical geology, stratigraphy 83:6730 Bartsch-Winkler, Susan, A.T. Ovenshine and Reuben Kachadoorian, 1983. Hoiocene history of the estuarine area surrounding Portage, Alaska as recorded in a 93 m core. Can. J. Earth Sci., 20(5):802-820. Includes a fold-out geological map. USGS, Anchorage, Alaska 99504, USA. 83:6731 Behairy, A.K.A., 1983. Marine transgressions on the west coast of Saudi Arabia (Red Sea) between the Mid-Pleistocene and Present. Mar. Geol., 52(I/2):M25-M31. Fac. of Mar. Sci., King Abdulaziz Univ., Jeddah, Saudi Arabia. 83:6732 Corliss, B.H. and R.C. Thunell, 1983. Carbonate sedimentation beneath the Antarctic Circumpolar Current during the Late Quaternary. Mar. Geol., 51 (3/4) :293 -326. CaCO 3 content and planktonic foraminiferal fragmentation were analyzed in 4 Southeast Indian Ridge cores. The CaCO 3 record in the 2 southernmost cores revealed distinct glacial-interglacial cycles with low carbonate associated with glacial intervals; carbonate records of the more northerly cores were independent of the paleoclimatic record. WHOI, Woods Hole, Mass. 02543, USA. (msg) 83:6733 Faugeres, J.C., E. Gonthier and J. Poutiers, 1983. Facies and sediment dynamics in the CharlieGibbs Fracture Zone during the Late Quaternary. Mar. Geol., 52(1/2):101-119. Analyses of 5 cores from 4 types of environments revealed that sedimentary processes in the fracture zone are dominated by gravity flows, which rework material supplied both by 'ubiquiste' sedimentation and bottom currents and which mask the effects of those two depositional processes. Inst. de Geol. du