M. S. Schulz — Page 2

USGS1990

Mineralogy and geochemistry of Co-rich ferromanganese crusts and substrate rocks from Karin Ridge and Johnston Island, Farnella Cruise F7-86-HW

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Open-File Report↗

USGS1990

Geological, geochemical, geophysical, and oceanographic data and interpretations of seamounts and co-rich ferromanganese crusts from the Marshall Islands, KORDI-USGS R.V. Farnella cruise F10-89-CP

No abstract available.

Open-File Report↗

USGS1990

Insular and submarine ferromanganese mineralization of the Tonga-Lau region

Ferromanganese oxides in the Tonga-Lau region are divided into crusts and stratabound deposits. Crusts were collected from the Tonga and Lau Ridges and have Fe/Mn ratios greater than 1, and an average Co content of 0.25%. The crusts average less than 10 mm thick with a maximum of 50 mm, and growth rates of tens of millimeters per million years. The thickest crust is probably less than a million years old. Crusts formed by both hydrogenetic and hydrothermal precipitation, with the hydrothermal input averaging 76%. Stratabound deposits are divided into three types. The source rocks through which the circulating fluids passed controlled the dominant minor element compositions of the stratabound deposits from each area: Valu Fa Ridge, Mo; Tonga Ridge Ti; Tonumea, Sr and Eua, V. -from Authors

Marine Mining↗