Submarine environments

During Miocene age most of this province was in a submarine environment. Violent submarine volcanism (bimodal and basic type) took place at Miocene age in this province. This geologic environment may be related to an extensional stress regime (Uyeda and Kanamori, 1979). The Kuroko deposits have been formed related to this tectonic situation. 

It is generally accepted that Kuroko deposits formed under the submarine environment, while polymetallic vein-type deposits in central and Northwest Japan (Ashio, Tsugu, Kishu, Obira, etc.) under the subaerial environment. 

As noted already, the formation of polymetallic vein-type deposits and Kuroko deposits occurred under the subaerial and submarine environments, respectively, at nearly the same time (middle Miocene). 

Life evolved soon after Earth s formation, befiare any continents were present, during a time when the oceans were chemically and thermally controlled by tectonic processes. Thus, it has been proposed that the life evolved in hot anaerobic submarine environments similar to present-day hydrothermal vent systems. This hypothesis is supported by the observation of structures, thought to be the remains of protocells, in rocks formed by hydrothermal processes 3.5 to 3.8 billion years ago. Thus, the first organisms on Earth were probably anaerobic hyperthermophiles. Hydrothermal vent habitats probably offered an additional benefit by providing a stable environment relatively isolated from the catastrophic effects of bolide impacts. In other words, submarine hydrothermal vents coifld have acted as refugia enabling survival of early life forms. 

The isotopic composition of present day ocean water is more or less constant with 5-values close to 0%c. The isotopic composition of ancient ocean water is less well constrained, but stiU should not be removed from 0 by more than 1 or 2%c. Many volcanogenic massive sulfide deposits are formed in submarine environments from heated oceanic waters. This concept gains support from the recently observed hydrothermal systems at ocean ridges, where measured isotopic compositions of fluids are only slightly modified relative to 0%c. 8 0 and 5D-values of vent fluids are best understood in terms of sea water interaction with the ocean crust (Shanks 2001). 

Leveille, R.J., Williams-Jones, A., Cousens, B.L., Gillis, K., Channing, C., Chadwick, W.W. Jr., Embley, R.W., Butterfield, D.A. and Juniper, K. (2002) The Nature of Sulfide Weathering in the Submarine Environment Evidence From the Southern Explorer Ridge, American Geophysical Union, Fall Meeting, Abstract T11C-1269. 

In this contribution, we focus on the noble gas systematics of subduction zones. First, we review the various methodologies of sampling noble gases (and other volatiles) using fluids and rocks in both the subaerial and submarine environments. The aim is to... 

Nissenbaum, A. 1974. Deuterium content of humic acids from marine and submarine environments. Mar. Chem. 2 59-63. 

This approach is useful if the environment is well characterized and a few weeks or months have been allocated for the test examples include exposure to salt spray to simulate sea coastal areas, exposure to 3.5 wt% NaCl solution for submarine environment, Kesternich chamber test (humid SO2 and CO2 mixture) for industrial environment [6], and mixed flowing gas tests for a range of environments. 

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