Leicester geologist features in international research publication
The work of Leicester geologist Richard Walker features in a new online publication by The Geological Society of America.
Dr Walker, lecturer in structural geology, is among a number of academics whose research is featured here.
Dr Walker’s research focuses on Controls on transgressive sill growth. This article is online here and will appear in the February edition of Geology.
He will also be presenting this work, and the basis of a second paper on the topic of intrusions, this week during the annual Tectonic Studies Group meeting (details of the meeting here). Dr Walker also have two students presenting related work at the meeting, as posters
Igneous horizontal intrusions (sills) represent an important contribution to magma transport and storage systems in the subsurface. The mechanisms of sill emplacement are critically important to models for thermal effects on the host rock, including hydrocarbon maturation, and greenhouse gas generation. Current models suggest that sill emplacement is controlled by layering within the hosting stratigraphy.
The purpose of this study is to use detailed field observations from an exemplary sill in the Faroe Islands, on the European Atlantic Margin, to constrain the controls on sill emplacement in layered sequences. The sill climbs through the host stratigraphy at a low angle, parallel to thrust faults that accommodate minor regional shortening. The preserved early stages of sill emplacement -- minor segments, and steps in the sill margin -- show that it was emplaced during a phase of regional shortening, in an otherwise extensional (rift) setting. The sill locally exploits some layer interfaces, but overall, layering does not control sill geometry.
This study presents the first identification of regional horizontal shortening as a major control on sill emplacement. The study also emphasizes the importance of the scale of observation when considering controls of sill emplacement.