| one publication added to basket [61982] | Petrology of submarine volcanics and sediments in the vicinity of the Mendocino fracture zone
Nayudu, Y.R. (1965). Petrology of submarine volcanics and sediments in the vicinity of the Mendocino fracture zone, in: Prog. Oceanogr. 3. Progress in Oceanography, 3: pp. 207-220
In: (1965). Prog. Oceanogr. 3. Progress in Oceanography, 3. Pergamon Press: Oxford. 407 pp., more
In: Progress in Oceanography. Pergamon: Oxford,New York,. ISSN 0079-6611; e-ISSN 1873-4472, more
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| Abstract |
Pyroxene-rich basalts, glassy basalts, olivine basalts and paloganite tuff breccias of various sizes were dredged from the top and in the vicinity of the Mendocino Fracture Zone. Some of these rocks have encrustations of ferromanganese oxide minerals. In addition, manganese nodules of different sizes were recovered which contain a nucleus of palagonite tuff.Several sediment cores collected to the north and south of the Mendocino Fracture Zone contain mostly medium yellowish brown clay, commonly known as red clay. Study of the cores revealed two areally restricted bio-lithologic units: (1) Radiolaria-Foraminifera-rich silty clay, and (2) Radiolaria-rich silty clay. The above units grade down into Foraminifera-rich silty clay and silty clay barren of Radiolaria respectively. Red clay is characteristically confined to Radiolaria-rich silty clay, silty clay barren of Radiolaria and contains abundant ferromanganese micronodules. Greater concentrations of ferromanganese micronodules occur below the sediment surface and are associated with palagonite grains. The sediments to the north of the Mendocino Fracture Zone are rich in zircon, rutile? and zeolites.The petrography and petrology of the dredged basalts, manganese nodules and sediments are discussed. It is suggested that the sediments, especially in the Radiolaria-rich clay, are dominantly volcanic in origin and locally derived. It is concluded that manganese nodules and red clay containing manganese micronodules (manganese grains) are genetically associated with palagonite complexes formed by submarine volcanism which was related to the development of the Mendocino Fracture Zone. |
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