Flood Basalts and Hot-Spot Tracks: Plume Heads and Tails

Abstract

Continental flood basalt eruptions have resulted in sudden and massive accumulations of basaltic lavas in excess of any contemporary volcanic processes. The largest flood basalt events mark the earliest volcanic activity of many major hot spots, which are thought to result from deep mantle plumes. The relative volumes of melt and eruption rates of flood basalts and hot spots as well as their temporal and spatial relations can be explained by a model of mantle plume initiation: Flood basalts represent plume "heads" and hot spots represent continuing magmatism associated with the remaining plume conduit or "tail." Continental rifting is not required, although it commonly follows flood basalt volcanism, and flood basalt provinces may occur as a natural consequence of the initiation of hot-spot activity in ocean basins as well as on continents.

The Early Permian Tarim Large Igneous Province: Main characteristics and a plume incubation model

“…Melts generated in this way depend on the origin and evolution of the lithospheric mantle, and correspond to a long time span and a relatively low eruption rate (Gibson et al, 2006;Kent et al, 1992). In contrast, flood basalts generated by decompression melting of plume mantle, either in response to lithospheric extension (White and McKenzie, 1989), or to sudden arrival of a large head of plume material during the initiation of a mantle plume (Campbell and Griffiths, 1990;Richards et al, 1989) commonly have a very high eruption rate (~1 km 3 /year) and have compositions similar to OIB.…”

“…One attributes the formation of LIPs to the arrival of a plume head at the base of the lithosphere, and subsequent decompression melting of a deflated plume head with a diameter reaching up to 2000 km (Campbell and Griffiths, 1990;Richards et al, 1989). The other proposes that a plume head grows more slowly (incubates) especially underneath thick continental lithosphere (N 120 km) which inhibits melting of mantle plumes Saunders et al, 1992).…”

Basalts and picrites from a plume-type ophiolite in the South Qilian Accretionary Belt, Qilian Orogen: Accretion of a Cambrian Oceanic Plateau?

“…Their origin has a close affinity with the activity of mantle plumes (Herzberg and Hara, 2002;Herzberg et al, 2007;Herzberg and Asimow, 2015). Picrites and komatiites (e.g., Le Bas, 2000;Kerr and Arndt, 2001), are relatively rare in Earth history and generally are associated with LIPs caused by the melting of large hot plumes from the deep mantle (e.g., Campbell and Griffiths, 1990;Richards et al, 1989;Kerr et al, 1996b).…”

New insights into the origin and evolution of the Hikurangi oceanic plateau

“…Large igneous provinces are commonly believed to have formed over relatively short time scales (several million years) through massive, mushroom-shaped mantle upwellings associated with the initial stages of mantle plumes [Richards et al, 1989] .Alternative hypotheses include formation through plumeridge interaction [e.g., Mahoney and Spencer, 1991],large-scale melting triggered by meteoritic impacts [e.g., Rogers, 1982],and accu mulation and amalgamation of multiple intra-plate volcanic structures into a LIP through the subduction process [e.g., Hoernle et a/., 2004].…”