Name
The role of subduction in the formation of Pangean oceanic large igneous provinces
Date & Time
Wednesday, May 10, 2023, 2:00 PM - 2:15 PM
Description
During the formation, tenure, and breakup of the supercontinent Pangea, there is an increase in emplacement events of large igneous provinces (LIPs). There is currently no clear consensus on the origin of LIPs, but a hypothesis relates their formation to hot plume material originating in the deep mantle. The interaction of subducted slabs with the lowermost mantle thermal boundary and subsequent return-flow is a key control on such plume generation. This mechanism has been explored for LIPs below the interior of a supercontinent (i.e., continental LIPs). However, a number of LIPs formed exterior to Pangea in the Pacific Ocean (e.g., Ontong Java Plateau), with no consensus on their formation mechanism. Here, we consider the dynamics of supercontinent processes as predicted by numerical models of mantle convection, and analyse whether circum-supercontinent subduction could generate both interior (continental) and exterior (oceanic) deep-mantle plumes. Our numerical models show that subduction related to the supercontinent cycle can reproduce the location and timing of the Ontong Java Plateau, Caribbean LIP, and potentially the Shatsky Rise, by linking the origin of these LIPs to the return-flow that generated deep mantle exterior plumes.
Location Name
Aspen
Full Address
Banff Park Lodge Resort Hotel & Conference Centre
201 Lynx St
Banff AB T1L 1K5
Canada
Abstract
During the formation, tenure, and breakup of the supercontinent Pangea, there is an increase in emplacement events of large igneous provinces (LIPs). There is currently no clear consensus on the origin of LIPs, but a hypothesis relates their formation to hot plume material originating in the deep mantle. The interaction of subducted slabs with the lowermost mantle thermal boundary and subsequent return-flow is a key control on such plume generation. This mechanism has been explored for LIPs below the interior of a supercontinent (i.e., continental LIPs). However, a number of LIPs formed exterior to Pangea in the Pacific Ocean (e.g., Ontong Java Plateau), with no consensus on their formation mechanism. Here, we consider the dynamics of supercontinent processes as predicted by numerical models of mantle convection, and analyse whether circum-supercontinent subduction could generate both interior (continental) and exterior (oceanic) deep-mantle plumes. Our numerical models show that subduction related to the supercontinent cycle can reproduce the location and timing of the Ontong Java Plateau, Caribbean LIP, and potentially the Shatsky Rise, by linking the origin of these LIPs to the return-flow that generated deep mantle exterior plumes.
Session Type
Breakout Session