Dallas H. Abbott, William Menke and Roger Morin

Constraints upon water advection in sediments of the Mariana Trough

Journal of Geophysical Research(February 1983), 88(B2):1075-1093

Index Terms/Descriptors: advection; carbonates; consolidation; crust; diagenesis; geochemistry; geothermal gradient; heat flow; hydrothermal conditions; Mariana Trough; marine sediments; materials; measurement; North Pacific; Northwest Pacific; oceanic crust; Pacific Ocean; physical properties; pore water; sea-floor spreading; sediments; silica; solution; tectonophysics; theoretical studies; thermal effects; thermal properties; West Pacific

Latitude & LongitudeN17°30'00'' - N18°30'00'' and E143°30'00'' - E145°30'00''

Abstract:

Thermal gradient measurements, consolidation tests, and pore water compositions. Maximum advection rates may be as high as 10 (super -5) cm s (super -1) but are most commonly in the range of 1 to 5X10 (super -6) cm s (super -1) . Dissolution may be impeded or enhanced (depending upon the direction of flow) by a factor of 2 to 5 times the rate for diffusion alone. If dissolution of silica occurs within the sediment column, then the advection velocities needed to affect chemical gradients are at least 3X10 (super -8) cm s (super -1) and may be as high as 3X10 (super -6) cm s (super -1) . This order of magnitude increase is probably applicable to other cations in addition to silica. If so, then the advection velocities needed to affect heat flow (>10 (super -8) cm s (super -1) ) and pore water chemical gradients are much nearer in magnitude than previously assumed.--Modified journal abstract.