Multistage magmatic intrusion in Narmada–Tapti region, India: Insights from geopotential modelling

Prasad, K. Rajendra; Singh, Aneesha; Rao, P. Rama; Prakash, Om; Begum, S. Kareemunnisa

doi:10.1007/s12040-021-01721-z

Cited by 9 publications

(1 citation statement)

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“…In Figure 4, we show model calculations for a range of magma reservoir radii. The depth of all the reservoirs is 5 km, representative of an upper crustal magma body (e.g., Narmada‐Tapi region of Deccan Traps Prasad et al., 2021, Dufek‐Forrestal intrusions Ferris et al., 1998). We note that for most of the reservoir sizes, a 5 km depth is not realistic since the top of the magma body would be above the ground.…”

Section: Model Results—magma Reservoir Modelmentioning

confidence: 99%

The Magmatic Architecture of Continental Flood Basalts: 2. A New Conceptual Model

Mittal

Richards

2021

JGR Solid Earth

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Continental flood basalts intruded and erupted millions of km3 of magma over ∼1–5 Ma. Previous work proposed the presence of large (>105 $ > {\mathrm{10}}^{5}$–106 km3) crustal magma reservoirs to feed these eruptions. However, in Paper I, we illustrated that this model is inconsistent with observations, by combining eruptive rate constraints with geochemical and geophysical observations from the Deccan Traps and other Continental flood basalt provinces (CFBs). Here, we use a new mechanical magma reservoir model to calculate the variation of eruptive fluxes (km3/year) and volumes for different magmatic architectures. We find that a single magma reservoir cannot explain the eruptive rate and duration constraints for CFBs. Using a 1D thermal model and characteristic timescales for magma reservoirs, we conclude that CFB eruptions were likely fed by a number of interconnected small‐medium (∼102–103 km3) magma reservoirs. It is unlikely that each individual magma reservoir participated in every eruption, thus permitting the occasional formation of large xenocrysts (e.g., megacrystic plagioclase). This magmatic architecture permits (a) large volume eruptive episodes with 10–100s of years duration, and (b) relatively short time‐periods separating eruptive episodes (1000s of years) since multiple mechanisms can trigger eruptions (via magma recharge or volatile exsolution, as opposed to long term (105–106 year) accumulation of buoyancy overpressure), and (c) lack of large upper‐crustal intrusive bodies in various geophysical datasets. Our new proposed magmatic architecture has significant implications for the tempo of CFB volatile release (CO2 and SO2), potentially helping explain the pre‐K‐Pg warming associated with Deccan Traps.

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Section: Model Results—magma Reservoir Modelmentioning

confidence: 99%