A brief comparison of lava flows from the Deccan Volcanic Province and the Columbia-Oregon Plateau Flood Basalts: Implications for models of flood basalt emplacement

Bondre, Ninad; Duraiswami, Raymond A.; Dole, Gauri

doi:10.1007/bf02704039

Cited by 32 publications

(14 citation statements)

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“…Gunn and Watkins (1970) and Johnson et al (1998) have briefly described flow characters and textures of flows from sections along the main eastern scarp of Steens Mountain. and Bondre et al (2004b) have commented on the commonly compound nature of Steens flows. The former authors suggest that many flows might consist of inflated pahoehoe lobes and they also identify several flows capped by breccias or rubble.…”

Section: Previous Workmentioning

confidence: 98%

Morphological and textural diversity of the Steens Basalt lava flows, Southeastern Oregon, USA: implications for emplacement style and nature of eruptive episodes

Bondre

2007

Bull Volcanol

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This study focuses on Middle Miocene tholeiitic flood basalt lava flows from the Oregon Plateau, northwestern USA (Steens Basalt), and is the first to comprehensively document and evaluate their morphology. Field observations of flows from several sections within and proximal to the main exposures at Steens Mountain have been supplemented with textural and geochemical data, and are used to offer preliminary insights into their emplacement. Compound pahoehoe flows of variable thickness appear to be common throughout the study area, laterally and vertically. These tend to be plagioclase phyric and the morphology and disposition of constituent flow lobes are quite similar to those from other provinces such as Hawaii and the Snake River Plain. Classic a'a flows with brecciated upper and basal crusts are not abundant, but by no means uncommon. Flows with characters different from typical pahoehoe and a'a are also common. Such flows display a range in morphology; flows with preserved upper crusts but brecciated basal crusts, as well as those displaying well-developed flow-top breccias and preserved basal crusts (rubbly pahoehoe) are observed. The Steens Basalt appears to display greater morphological and textural diversity at the outcrop scale than that described for some other flood basalt provinces. The abundant compound pahoehoe flows (often rich in plagioclase phenocrysts) were likely emplaced during slow but sustained eruptive episodes; their constituent lobes show clear evidence for endogenous growth. The relatively aphyric flows with brecciated surfaces (including a'a) hint at higher strain rates and/or higher viscosity, probably caused by higher effusion rates. A couple of sections are characterized by compositionally similar, but morphologically different flows that were possibly part of the same eruption. While differences in pre-eruptive topography could explain this, it is also possible that certain physical parameters changed substantially and abruptly during eruption and that such changes were accompanied by differentiation processes within the plumbing system. It is possible that such observations indicate temporal fluctuations within complex magmatic and eruptive systems, and deserve closer scrutiny.

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Section: Previous Workmentioning

confidence: 98%

Morphological and textural diversity of the Steens Basalt lava flows, Southeastern Oregon, USA: implications for emplacement style and nature of eruptive episodes

Bondre

2007

Bull Volcanol

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“…Each flow temporarily blocked the Owyhee River forming lakes before being subsequently incised by the river [e.g., Orem , ; Ely et al ., ]. The three best‐preserved lava dams and associated lakes are the West Crater (∼70 ka), the Saddle Butte 2 (∼144 ka), and the Bogus Rim lava flows (∼1.9 Ma) [ Bondre , ; Bondre et al ., ; Brossy , ; Orem , ; Ely et al ., ].…”

Section: Inflated Flows Emplaced In Subaqueous Environmentsmentioning

confidence: 99%

Morphology and dynamics of inflated subaqueous basaltic lava flows

Deschamps

Grigné

Saout

et al. 2014

Geochem Geophys Geosyst

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During eruptions onto low slopes, basaltic Pahoehoe lava can form thin lobes that progressively coalesce and inflate to many times their original thickness, due to a steady injection of magma beneath brittle and viscoelastic layers of cooled lava that develop sufficient strength to retain the flow. Inflated lava flows forming tumuli and pressure ridges have been reported in different kinds of environments, such as at contemporary subaerial Hawaiian-type volcanoes in Hawaii, La R eunion and Iceland, in continental environments (states of Oregon, Idaho, Washington), and in the deep sea at Juan de Fuca Ridge, the Galapagos spreading center, and at the East Pacific Rise (this study). These lava have all undergone inflation processes, yet they display highly contrasting morphologies that correlate with their depositional environment, the most striking difference being the presence of water. Lava that have inflated in subaerial environments display inflation structures with morphologies that significantly differ from subaqueous lava emplaced in the deep sea, lakes, and rivers. Their height is 2-3 times smaller and their length being 10-15 times shorter. Based on heat diffusion equation, we demonstrate that more efficient cooling of a lava flow in water leads to the rapid development of thicker (by 25%) cooled layer at the flow surface, which has greater yield strength to counteract its internal hydrostatic pressure than in subaerial environments, thus limiting lava breakouts to form new lobes, hence promoting inflation. Buoyancy also increases the ability of a lava to inflate by 60%. Together, these differences can account for the observed variations in the thickness and extent of subaerial and subaqueous inflated lava flows.

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“…These emplacement mechanisms do not require abundant surface water; their potential alteration to sulfates could be enhanced by the circulation of volcanic hydrothermal fluids (e.g., Kaasalainen & Stefánsson, 2011). Lava and ash deposits are typically thick and internally jointed (Bondre et al, 2004), and lavas are usually erosionally resistant.…”

Section: Conceptual Approach: Formation Mechanisms For the Layered Sumentioning

confidence: 99%

The Deposition and Alteration History of the Northeast Syrtis Major Layered Sulfates

Quinn

Ehlmann

2019

JGR Planets

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Ancient stratigraphy on Isidis Basin's western margin records the history of water on early Mars. Noachian units are overlain by layered, basaltic composition sedimentary rocks that are enriched in polyhydrated sulfates and capped by more resistant units. The layered sulfates—uniquely exposed at northeast Syrtis Major—comprise a sedimentary sequence up to 600 m thick that has undergone a multistage history of deposition, alteration, and erosion. Siliciclastic sediments enriched in polyhydrated sulfates are bedded at meter scale and were deposited on slopes up to 10°, embaying and thinning against preexisting Noachian highlands around the Isidis Basin rim. The layered sulfates were modified by volume loss fracturing during diagenesis. Resultant fractures hosted channelized flow and jarosite mineral precipitation to form resistant ridges upon erosion. The structural form of the layered sulfates is consistent with packages of sediment fallen from either atmospheric or aqueous suspension; coupling with substantial diagenetic volume loss may favor deepwater basin sedimentation. After formation, the layered sulfates were capped by a “smooth capping unit” and then eroded to form paleovalleys. Hesperian Syrtis Major lavas were channelized by this paleotopography, capping it in some places and filling it in others. Later fluvial features and phyllosilicate‐bearing lacustrine deposits, sharing a regional base level of ∼−2,300 m, were superimposed on the sulfate‐lava stratigraphy. The layered sulfates suggest surface bodies of water and active groundwater upwelling during the Noachian‐Hesperian transition. The northeast Syrtis Major stratigraphy records at least four distinct phases of surface and subsurface aqueous activity spanning from late Noachian to early Amazonian time.

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A brief comparison of lava flows from the Deccan Volcanic Province and the Columbia-Oregon Plateau Flood Basalts: Implications for models of flood basalt emplacement

Cited by 32 publications

References 25 publications

Morphological and textural diversity of the Steens Basalt lava flows, Southeastern Oregon, USA: implications for emplacement style and nature of eruptive episodes

Morphological and textural diversity of the Steens Basalt lava flows, Southeastern Oregon, USA: implications for emplacement style and nature of eruptive episodes

Morphology and dynamics of inflated subaqueous basaltic lava flows

The Deposition and Alteration History of the Northeast Syrtis Major Layered Sulfates

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