Abstract
The Iceland Plume has significantly impacted the North Atlantic region. Igneous edifices and large seamounts in the Rockall region were linked to Iceland plume pulsations during the Late Cretaceous to Mid-Eocene. In the south of the Rockall Basin a chain of northwest-southeast trending volcanic ridges known as the Barra Volcanic Ridge System (BVRS) have been identified on seismic and magnetic datasets. However, the timing, morphology, extent, and emplacement mechanism of the BVRS are not well understood. To investigate the volcanic ridge system, we analyze a 360-km-long pre-stack time migrated seismic section along the margin, which covers the southern extent of BVRS. The high velocity (4.5-4.8 km/s) obtained by using first arrival travel time tomography of downward continued data set, high magnetic anomaly and the typical morphology of the ridges suggest that they could be volcanoes of basaltic compositions. The integration of gravity and seismic data constrain the crustal structure and thickness, which indicates that the crust could be as thin as 4 km beneath the BVRS, requiring a maximum stretching factor > 6. Folded compressional structures and lava flows within the Early Paleocene to Mid-Eocene sediments draping the volcanic ridges, suggest that these volcanic intrusions possibly have occurred post Early Paleocene age, which is
approximately the same time-period when Iceland mantle plume arrived in the Rockall region. These results suggest that the BVRS developed because of pre-existing lithospheric configuration in the Rockall Basin and could be one of the southernmost volcanic provinces of the North Atlantic Igneous Province (NAIP).
approximately the same time-period when Iceland mantle plume arrived in the Rockall region. These results suggest that the BVRS developed because of pre-existing lithospheric configuration in the Rockall Basin and could be one of the southernmost volcanic provinces of the North Atlantic Igneous Province (NAIP).
| Original language | English |
|---|---|
| Article number | 106237 |
| Number of pages | 14 |
| Journal | Marine and Petroleum Geology |
| Volume | 152 |
| Early online date | 11 Apr 2023 |
| DOIs | |
| Publication status | Published - Jun 2023 |
Bibliographical note
AcknowledgementsThis project was funded by the Irish Centre for Research in Applied Geosciences (iCRAG), Science Foundation Ireland (SFI), Irish Shelf and Petroleum Studies Group (ISPSG) of the Petroleum Infrastructure Programme (PiP) and Dublin Institute for Advanced Studies (DIAS). This publication uses data and survey results acquired during a project undertaken on behalf of the Irish Shelf Petroleum Studies Group (ISPSG) of the Irish Petroleum Infrastructure programme Group 4. The ISPSG comprises: AzEire Petroleum Ltd, Cairn Energy Plc, BP Exploration Operating Company Ltd, CNOOC Petroleum Europe Limited, ENI Ireland BV, Equinor Energy Ireland Limited, Europa Oil & Gas Plc, ExxonMobil E&P Ireland (Offshore) Ltd, Husky Energy, Petroleum Affairs Division of the Department of Communications, Climate Action and Environment, Providence Resources plc, Repsol Exploración SA, Sosina Exploration Ltd, Total EP, Tullow Oil Plc and Woodside Energy (Ireland) Pty Ltd. processing is done by using ECHOS software from Paradigm. We are very thankful to Dr. J. Kim Welford for providing us with the 3D Moho map of Irelands offshore. We acknowledge the Geological Survey Ireland and the Marine Institute (INFOMAR), for providing the data for this work. We also acknowledge Schlumberger for providing an academic license of Petrel software for this study. SR further acknowledges research funding from Science Foundation Ireland (SFI) and PIP. This publication derives from research supported in part by a research grant from SFI under Grant Number 13/RC/2092 and co-funded under the European Regional Development Fund and by iCRAG industry partners. Sincere thanks to Tim Minshul, Laurent Gernigon and a third reviewer for providing helpful reviews and insightful comments on the paper, which greatly improved the quality of the manuscript.