Gravity inversion helps solve pluton emplacement debate
A longstanding debate about whether granitic magmas in England ascended through the crust as diapirs or along networks of dykes to form tabular structures has taken a step closer to resolution.
A gravity inversion performed to model the 3D structure of the St Austell pluton, one of six major plutons associated with the Cornubian batholith of Southwest England, suggests the pluton is comprised of at least two separately intruded sheets of granite.
Adam Goddard, a recent geophysics graduate from the University of Durham, performed the inversion using data from 2,702 gravity stations from the British Geological Survey (BGS)’s gravity databank and a separate gravity survey designed to supplement the BGS data. Goddard used Geosoft Oasis montaj to grid the gravity data and GM-SYS 3D to make the 3D models.