Publication Date:
2023-08-28
Description:
Fifty-five rock fragments and pebbles were dredged at 2,550-2,800 fathoms (4,650-5,100 metres) near Jimmu Seamount, 700 miles southeast of Kamchatka. Tuffaceous shale, andesitic and dacitic tuff, pyroxene-hornblende dacite-pumice, and augite-hypersthene andesite are the most abundant rock types. Minor constituents in the haul include augite-pigeonite basalt, augite-olivine basalt, olivine dolerite, quartz syenite porphyry, metabasalt, sandstone, and chert. Petrographic and chemical analyses indicate closer affinities with Kuril Islands and Kamchatka volcanic rocks than with Cenozoic Japanese or Pacific Basin types. Probably these rocks were dropped by Pleistocene icebergs carried south and east by ocean currents.
Keywords:
Date/Time of event; Deposit type; DEPTH, sediment/rock; Description; Dredge; DRG; Elevation of event; Latitude of event; Longitude of event; NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS; Position; Quantity of deposit; Sample ID; Sediment type; Size; Spencer F. Baird; Substrate type; TRAN_JG; TRANSPAC; Trans-Pacific; Uniform resource locator/link to image; Western Pacific
Type:
Dataset
Format:
text/tab-separated-values, 9 data points
