Morphological and sedimentological characteristics of the Neogene submarine coherent lavas and hyaloclastites in Southwest Hokkaido, Japan

Yamagishi, Hisakazu

doi:10.1016/0037-0738(91)90032-9

Cited by 78 publications

(50 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar deep submarine deposits have been described for Pacific Ocean seamounts (Batiza et al, 1984), for the Mid-Atlantic Ridge (Schmincke et al, 1979), and for fossil seamounts in Hokkaido, Japan (Yamagishi, 1991). Batiza et al (1984) described crudely bedded hyaloclastite deposits accumulating in depressions present at the crests of seamounts.…”

Section: Geological Settingsupporting

confidence: 62%

Evolution of fluid–rock interaction in the Reykjanes geothermal system, Iceland: Evidence from Iceland Deep Drilling Project core RN-17B

Fowler

Zierenberg

Schiffman

et al. 2015

Journal of Volcanology and Geothermal Research

View full text Add to dashboard Cite

We describe the lithology and present spatially resolved geochemical analyses of samples from the hydrothermally altered Iceland Deep Drilling Project (IDDP) drill core RN-17B. The 9.3 m long RN-17B core was collected from the seawater-dominated Reykjanes geothermal system, located on the Reykjanes Peninsula, Iceland. The nature of fluids and the location of the Reykjanes geothermal system make it a useful analog for seafloor hydrothermal processes, although there are important differences. The recovery of drill core from the Reykjanes geothermal system, as opposed to drill cuttings, has provided the opportunity to investigate evolving geothermal conditions by utilizing in-situ geochemical techniques in the context of observed paragenetic and spatial relationships of alteration minerals. The RN-17B core was returned from a vertical depth of~2560 m and an in-situ temperature of~345°C. The primary lithologies are basaltic in composition and include hyaloclastite breccia, fine-grained volcanic sandstone, lithic breccia, and crystalline basalt. Primary igneous phases have been entirely pseudomorphed by calcic plagioclase + magnesium hornblende + chlorite + titanite + albitized plagioclase + vein epidote and sulfides. Despite the extensive hydrothermal metasomatism, original textures including hyaloclastite glass shards, lithic clasts, chilled margins, and shell-fragment molds are superbly preserved. Multi-collector LA-ICP-MS strontium isotope ratio ( 87 Sr/ 86 Sr) measurements of vein epidote from the core are consistent with seawater as the dominant recharge fluid. Epidote-hosted fluid inclusion homogenization temperature and freezing point depression measurements suggest that the RN-17B core records cooling through the two-phase boundary for seawater over time to current in-situ measured temperatures. Electron microprobe analyses of hydrothermal hornblende and hydrothermal plagioclase confirm that while alteration is of amphibolite-grade, it is in disequilibrium and the extent of alteration is dependent upon protolith type and water/rock ratio. Alteration in the RN-17B core bares many similarities to that of Type II basalts observed in Mid-Atlantic Ridge samples.

show abstract

Section: Geological Settingsupporting

confidence: 62%

Evolution of fluid–rock interaction in the Reykjanes geothermal system, Iceland: Evidence from Iceland Deep Drilling Project core RN-17B

Fowler

Zierenberg

Schiffman

et al. 2015

Journal of Volcanology and Geothermal Research

View full text Add to dashboard Cite

show abstract

“…A few sparsely porphyritic basalt clasts are ovoid with internal concentric fractures (cf. 'concentric pillow breccia', Yamagishi, 1991). The well-rounded porphyritic basalt clasts vary from non-vesicular to highly vesicular and range in size up to 20 cm.…”

Section: The Ba Volcanic Group At Yaqaramentioning

confidence: 99%

Characteristics and origin of peperite involving coarse-grained host sediment

Squire

McPhie

2002

Journal of Volcanology and Geothermal Research

View full text Add to dashboard Cite

Peperite involving basalt and polymictic volcanic conglomerate occurs in the Pliocene Ba Volcanic Group at Yaqara in northern Viti Levu, Fiji. Because the host sediment is coarse-grained and dominated by basalt clasts, the peperite could be easily overlooked and mistaken for another coarse volcaniclastic facies. However, the presence of groups of basalt clasts that show jigsaw-fit texture, fluidally shaped basalt clasts with complete glassy margins, gradational contacts with adjacent sedimentary facies and the absence of stratification indicate that molten basalt mingled with unconsolidated gravel. Using these criteria, we show that other superficially similar, coarse, polymictic facies with fluidal basalt clasts are not peperite. Both blocky and fluidal basalt clasts occur together in the peperite. The amoeboid basalt clasts in the fluidal peperite result from dismembering of ductile, low-viscosity, relatively hot magma. At this stage, propagating magma lobes were probably insulated from direct contact with the wet sediment by a vapour film. The angular, polyhedral basalt clasts in the blocky peperite indicate brittle disintegration of somewhat cooler, higher-viscosity magma. The presence of jigsaw-fit texture and polyhedral clasts with glassy margins suggest that quench fragmentation of the basalt was important in the formation of the blocky peperite. Although there is no positive evidence for steam explosivity, the presence of steam could be recorded by small quartz-filled cavities that occur within the host sediment. The co-existence of fluidal and blocky basalt clasts is interpreted to reflect successive ductile then brittle fragmentation of intruding magma. The change from fluidal to blocky peperite might have resulted from progressive cooling of the magma during intrusion, and also from the breakdown of fluidisation when the limited supply of fine sediment in the host gravel was exhausted. ß

show abstract

“…(i.e. Lydon 1968;Yamagishi 1991;Hanson and Hargrove 1999). These studies make clear that phenomena of magma/wet sediment interactions are common in geologic settings where thick sediment sequences accumulate during active volcanism.…”

Section: Introductionmentioning

confidence: 92%

Interaction between a Late Miocene andesitic dyke swarm and wet sediment in the Szoros Valley, Eastern Borsod Basin, Northeast Hungary

Csámer¹

2015

Central European Geology

View full text Add to dashboard Cite

Magma/wet sediment interaction (e.g. autobrecciation, magma-sediment mingling, hyaloclastite and peperite-forming, etc.) is a common phenomenon, where hot magma intrudes into unconsolidated or poorly consolidated water saturated sediment. In the Eastern Borsod Basin (NE-Hungary) relatively small (2-30 m) subvolcanic bodies, sills and dykes with contact lithofacies zones were found generated by mechanical stress and quenching of the magma, and interacting with unconsolidated wet andesitic lapilli-tuff and tuff-breccia. Close to the contact between sediment and intrusions, thermal and mechanical effects may occur in the host sediment. Hydrothermal alteration and stratification of the host sediment were developed only locally along the contact zone, probably due to the paleo-hydrogeologic and paleo-rheological inhomogeneities of the lapilli-tuff-tuff-breccia deposits. Processes of magma/wet sediment interaction may be difficult to recognize because of limited exposure and/or certain similarities of the brecciated intrusions to the characteristics of the host sediment; hence detailed field work (geologic mapping or profiling) was required to demonstrate the subvolcanic origin of the brecciated andesite bodies.

show abstract

Morphological and sedimentological characteristics of the Neogene submarine coherent lavas and hyaloclastites in Southwest Hokkaido, Japan

Cited by 78 publications

References 23 publications

Evolution of fluid–rock interaction in the Reykjanes geothermal system, Iceland: Evidence from Iceland Deep Drilling Project core RN-17B

Evolution of fluid–rock interaction in the Reykjanes geothermal system, Iceland: Evidence from Iceland Deep Drilling Project core RN-17B

Characteristics and origin of peperite involving coarse-grained host sediment

Interaction between a Late Miocene andesitic dyke swarm and wet sediment in the Szoros Valley, Eastern Borsod Basin, Northeast Hungary

Contact Info

Product

Resources

About