Shallow-marine phreatomagmatic eruptions through a semi-solidified carbonate platform (ODP Leg 144, Site 878, Early Cretaceous, MIT Guyot, West Pacific)

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doi: 10.1016/S0025-3227(03)00358-X
Author(s): Martin, U.; Breitkreuz, C.; Egenhoff, S.; Enos, Paul; Jansa, L.
Author Affiliation(s): Primary:
TU Bergakadamie Freiberg, Geology Department, Freiberg, Federal Republic of Germany
University of Kansas, United States
Volume Title: Marine Geology
Source: Marine Geology, 204(3-4), p.251-272. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0025-3227 CODEN: MAGEA6
Note: In English. 64 refs.; illus., incl. sects., sketch map
Summary: Leg 144 (1995) of the Ocean Drilling Program recovered basalts and volcaniclastic material from the volcanic basement of several guyots in the northwest Pacific, including MIT Guyot in site 878. Tectonic reconstruction suggests that this seamount originated as an intraplate volcano on the Pacific Superswell in the Early Cretaceous. Tephra emplaced by mass flow within the sedimentary cap is the subject of this study. The tephra unit consists of palagonitized, moderately to strongly vesicular basaltic clasts of apparent phreatomagmatic origin, carbonate mud- to grainstone clasts, and armoured lapilli. Armoured lapilli are inferred to have been formed during eruption within a steam envelope that developed above the vent due to magma-water interaction and high gas content of the magma. Another distinctive feature of the tephra unit are abundant truncation surfaces that cut the lithotypes due to subsidence, and are juxtaposed to the same lithotypes. These truncation surfaces are inferred to represent intra-eruption slip surfaces, which formed during eruption of the volcano that generated the tephra pile. The resulting slumps initiated grainflows and dilute turbidity currents, whose deposits are interspersed with those of high-concentration density currents. A subaqueous setting of deposition and eruption is indicated by the abundance of sideromelane glass shards, cauliflower-chilled clasts, the underlying marine carbonates, the lack of tachylite within the deposits, and sedimentary structures within the breccia. Abstract Copyright (2004) Elsevier, B.V.
Year of Publication: 2004
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Basalts; Biostratigraphy; Carbonate platforms; Carbonate rocks; Cores; Cretaceous; Currents; Density currents; Depositional environment; Eruptions; Grain size; Grainstone; Hyaloclastite; Igneous rocks; Intraplate processes; Lagoonal environment; Lapilli; Leg 144; Lithostratigraphy; Lower Cretaceous; MIT Seamount; Magma-water interaction; Marine environment; Mass movements; Mesozoic; North Pacific; Northwest Pacific; ODP Site 878; Ocean Drilling Program; Ocean floors; Pacific Ocean; Pacific Superswell; Phreatomagmatism; Pyroclastics; Seamounts; Sedimentary rocks; Shallow-water environment; Slumping; Submarine volcanoes; Superswells; Turbidity currents; Volcanic rocks; Volcanism; Volcanoes; West Pacific
Coordinates: N271908 N271908 E1515302 E1515302
Record ID: 2004037412
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands