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

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