10Be in island-arc volcanoes and implications for subduction

This chapter contains sections titled: Introduction Physical Description of Continental Flood Basalt Lava Flows Early Model of Flood Basalt Emplacement A New Model for the Emplacement of Flood Basalt Lava Flows Potential for Atmospheric Effects from Flood Basalt Eruptions Conclusions

Flood basalt

Deccan Traps

10.1029/gm100p0381

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Citations (283)

Plate Consumption: Some Comments from an Island Arc

Nature (1971)

T. Hatherton

Corollary

Island arc

Consumption

10.1038/234294a0

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Citations (3)

Are flood basalt eruptions monogenetic or polygenetic?

International Journal of Earth Sciences (2014)

Hetu Sheth Edgardo Cañón‐Tapia

Flood basalt

Lava field

Stratovolcano

10.1007/s00531-014-1048-z

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Citations (28)

Thickness Characteristics of Pāhoehoe Lavas in the Deccan Province, Western Ghats, India, and in Continental Flood Basalt Provinces Elsewhere

Frontiers in Earth Science (2021)

Stephen Self Tushar Mittal A. E. Jay

Constraining the eruption rates of flood basalt lava flows remains a significant challenge despite decades of work. One potential observable proxy for eruption rates is flood basalt lava-flow lobe thicknesses, a topic that we tackle here quantitatively. In this study, we provide the first global compilation of pāhoehoe lava-lobe thicknesses from various continental flood basalt provinces (∼ 3,800 measurements) to compare characteristic thicknesses within and between provinces. We refer to thin lobes (∼ ≤5 m), characteristic of “compound” lavas, as hummocky pāhoehoe lava flows or flow-fields. Conversely, we term thicker lobes, characteristic of “simple” flows, as coming from sheet-lobe-dominated flows. Data from the Deccan Traps and Columbia River flood-basalt provinces are archetypal since they have the most consistent datasets as well as established chemo- and litho-stratigraphies. Examining Deccan lobe thicknesses, we find that previously suggested (and disputed) distinct temporal and regional distributions of hummocky pāhoehoe and sheet-lobe-dominated flow fields are not strongly supported by the data and that each geochemically defined formation displays both lobe types in varying amounts. Thin flow-lobes do not appear to indicate proximity to source. The modal lobe thickness of Deccan formations with abundant “thin” lava-lobes is 8 m, while the mode for sheet-lobe-dominated formations is only 17 m. Sheet-lobes up to 75–80 m are rare in the Deccan and Columbia River Provinces, and ones >100 m are exceptional globally. For other flood basalt provinces, modal thickness plots show a prevalence toward similar lobe thicknesses to Deccan, with many provinces having some or most lobes in the 5–8 m modal range. However, median values are generally thicker, in the 8–12 m range, suggesting that sheet-lobes dominate. By contrast, lobes from non-flood basalt flow-fields (e.g., Hawai’i, Snake River Plain) show distinctly thinner modes, sub-5 m. Our results provide a quantitative basis to ascertain variations in gross lava morphology and, perhaps, this will in future be related to emplacement dynamics of different flood basalt provinces, or parts thereof. We can also systematically distinguish outlier lobes (or regions) from typical lobes in a province, e.g., North American Central Atlantic Magmatic Province lava-lobes are anomalously thick and are closely related to feeder-intrusions, thus enabling a better understanding of conditions required to produce large-volume, thick, flood basalt lava-lobes and flows.

Flood basalt

Deccan Traps

Lobe

10.3389/feart.2020.630604

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Citations (21)

Origin of north Queensland Cenozoic volcanism: Relationships to long lava flow basaltic fields, Australia

Journal of Geophysical Research Atmospheres (1998)

F L Sutherland

A plume model proposed for north Queensland late Cenozoic volcanism and long lava flow distribution combines basalt ages with recent seismic studies of Australia's mantle, regional stress fields, and plate motion. Several basalt fields overlie mantle “thermal” anomalies, and other fields outside these anomalies can be traced to them through past lithospheric motion. Elsewhere, anomalies close to Australia's eastern rift margin show little volcanism, probably due to gravity‐enhanced compression. Since final collision of north Queensland with New Guinea, areas of basaltic volcanism have developed over 10 Myr, and episodes appear to migrate southward from 15° to 20°S. Long lava flows increase southward as area/volume of fields increases, but topography, vent distributions, and uplifts play a role. This is attributed to magmatic plume activation within a tensional zone, as lithosphere moves over mantle thermal anomalies. The plume model predicts peak magmatism under the McBride field, coincident with the Undara long lava flow and that long lava flow fields will erupt for another 5–10 Myr. Queensland's movement over a major N‐S thermal system imparts a consistent isotopic signature to its northern younger basalts, distinct to basalts from older or more southern thermal systems. Australia's motion toward this northern thermal system will give north Queensland fields continued vigorous volcanism, in contrast to the Victorian field which is leaving its southern thermal system.

Mantle plume

Rift zone

Lava field

Asthenosphere

10.1029/97jb03578

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Citations (24)

Subduction zones and back arc basins — A review

Geologische Rundschau (1981)

Seiya Uyeda

Back-arc basin

Eclogitization