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Endogenous growth of a Miocene submarine dacite cryptodome, Rebun Island, Hokkaido, Japan

Citation

Goto, Y and McPhie, J, Endogenous growth of a Miocene submarine dacite cryptodome, Rebun Island, Hokkaido, Japan, Journal of Volcanology and Geothermal Research, 84, (3-4) pp. 273-286. ISSN 0377-0273 (1998) [Refereed Article]

DOI: doi:10.1016/S0377-0273(98)00040-7

Abstract

Momo-iwa, Rebun Island, Hokkaido, Japan, is a dacite cryptodome 200-300 m across and 190 m high. The dome is inferred to have intruded wet, poorly consolidated sediment in a shallow marine environment. The internal structure of the dome is concentric, with a massive core, banded rim, and narrow brecciated border, all of which are composed of compositionally uniform feldspar-phyric dacite. Boundaries between each of the zones are distinct but gradational. The massive core consists of homogeneous coherent (unfractured) dacite and is characterized by radial columnar joints 60-200 cm across. The banded rim encircles the massive core and is 40 m wide. It is characterized by large-scale flow banding parallel to the dome surface. The flow banding comprises alternating partly crystalline and more glassy bands 80-150 cm thick. The outermost brecciated border is up to 80 cm thick, and consists of in situ breccia and blocky peperite. The in situ breccia comprises polyhedral dacite clasts 5-20 cm across and a cogenetic granular matrix. The blocky peperite consists of polyhedral dacite clasts 0.5-2 cm across separated by the host sediment (mudstone). The internal structures of the dome suggest endogenous growth involving a continuous magma supply during a single intrusive phase and simple expansion from the interior. Although much larger, the internal structures of Momo-iwa closely resemble those of lobes in subaqueous felsic lobe-hyaloclastite lavas.

Item Details

Item Type:Refereed Article
Research Division:Earth Sciences
Research Group:Geology
Research Field:Volcanology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
Author:McPhie, J (Professor Jocelyn McPhie)
ID Code:15402
Year Published:1998
Web of Science® Times Cited:40
Deposited By:Centre for Ore Deposit Research - CODES CoE
Deposited On:1998-08-01
Last Modified:2011-08-10
Downloads:0

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