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Ocean plateau-seamount origin of basaltic rocks, Angayucham terrane, central Alaska

F. Barker·D. L. Jones·J. R. Budahn·P.J. Coney
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Abstract

The Angayucham terrane of north-central Alaska (immediately S of the Brooks Range) is a large (ca. 500 km E-W), allochthonous complex of Devonian to Lower Jurassic pillow basalt, diabase sills, gabbro plutons, and chert. The mafic rocks are transitional normal-to-enriched, mid-ocean-ridge (MORB) type tholeiites (TiO2 1.2-3.4%, Nb 7-23 ppm, Ta 0.24-1.08 ppm, Zr 69-214 ppm, and light REE's slightly depleted to moderately enriched). Geologic and geochemical constraints indicate that Angayucham terrane is the upper "skin' (ca. 3-4 km thick) of a long-lived (ca. 170-200 ma) oceanic plateau whose basaltic-gabbroic rocks are like those of seamounts of the East Pacific Rise. -Authors

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F. Barker, D. L. Jones, J. R. Budahn, P.J. Coney. 1988. Ocean plateau-seamount origin of basaltic rocks, Angayucham terrane, central Alaska. https://pubs.usgs.gov/publication/70014429

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