What’s on : Lectures

From Garnets to Gannets, exploring the Lonely Isles

Lectures
Date
20 Jul 2022
Start time
2:30 PM
Venue
Tempest Anderson Hall
Speaker
Dr Anna Bird, University of Hull
From Garnets to Gannets, exploring the Lonely Isles

Event Information

From Garnets to Gannets, exploring the Lonely Isles
Dr Anna Bird, University of Hull

Project Team: Anna Bird and Eddie Dempsey, Department of Geography, Geology and Environmental Sciences, University of Hull

Tim Armitage and Bob Holdsworth Department of Earth Sciences, Durham University

The Lonely Isles are series of well exposed, yet extremely remote islands that give a unique and previously unknown insight into the ancient geology of northern Scotland. These rocks are part of the Precambrian basement that underlies much of northern Scotland, including Orkney and Shetland, and parts of Greenland.

These Precambrian rocks also underlie the Clair Oil Field, which is situated to the west of Shetland, and represents the largest hydrocarbon resource in the UKCS and Europe. The hydrocarbons of the Clair field are found within Devonian-Carboniferous sandstones sitting on a ridge of this Precambrian metamorphic basement as well as within fractures in the basement rocks themselves. Despite the economic and scientific importance of these rocks, our understanding of the basement geology in these regions is extremely limited. Recent work that has been undertaken basement core samples retrieved from over several hundred km2 beneath the Atlantic Ocean suggest that the basement rocks here are Neoarchaen in age (ca 2-7-2.85 Ga) and that they lack the widespread Proterozoic “Laxfordian” event (ca. 1.6-1.75 Ga) seen in mainland Scotland and Outer Hebrides. This requires the presence of a northern “Laxford Front’ somewhere N of the Scottish mainland.

The Lonely Isles are the only place where these basement rocks outcrop above sea level providing a rare opportunity to examine and understand these enigmatic rocks. As such, understanding the geology of these islands is key to understanding the location and nature of this theorised terrane boundary between the Scottish Mainland and the basement rocks found under the Clare Oil Field.

In November 2018, a team of geologists from University of Hull and Durham University went to the Flannan Isles, North Rona and Sula Sgeir. The team, Dempsey, Bird and Armitage, (funded by Prof Holdsworth of Durham University) are the first geologists to examine the Flannan Isles since 1933 or North Rona since 1958. Many geological fundamental concepts have been developed or refined (including plate tectonics) in this time. This talk will show the highlights of the expedition and some of the initial findings of this study as well as future research and fieldwork plans.

This lecture will be held in the Tempest Anderson Lecture Theatre in the Yorkshire Museum, York at 2.30pm and will include the announcement/presentation of the 2022 John and Anne Phillips prize to a third year geologist from the University of Hull.