Present address: Institute of Seismology, University of Helsinki PL 68 (Gustaf Hällströmin katu 2b), 00014 Helsinki, Finland.
Kilometre-scale sand injectites in the intracratonic Murzuq Basin (South-west Libya): an igneous trigger?
Article first published online: 19 DEC 2011
© 2011 The Authors. Journal compilation © 2011 International Association of Sedimentologists
Volume 59, Issue 4, pages 1321–1344, June 2012
How to Cite
MOREAU, J., GHIENNE, J. F. and HURST, A. (2012), Kilometre-scale sand injectites in the intracratonic Murzuq Basin (South-west Libya): an igneous trigger?. Sedimentology, 59: 1321–1344. doi: 10.1111/j.1365-3091.2011.01308.x
- Issue published online: 16 MAY 2012
- Article first published online: 19 DEC 2011
- Accepted manuscript online: 31 OCT 2011 01:29PM EST
- Manuscript received 3 December 2010; revision accepted 26 October 2011
- Circular structures;
- igneous intrusion;
- intracratonic basin;
- North Africa;
- sand injection;
- tectonic uplift;
Mount Telout, situated at the edge of the Murzuq Basin, is a 325 m high conical hill within a circular collapse structure that records 0·5 km3 of sand intrusion into Silurian shales. Based on a comparison with other similar circular collapse structures around the Murzuq Basin, it is argued that sand injection in the form of pipes occurred during the Devonian. The overpressures triggering the process are inferred to result from a combination of: (i) tectonic uplift at a basin scale that initially focused regional ground water flows; and (ii) igneous intrusion within the sand-rich Cambrian–Ordovician strata. The palaeorelief buried under the regionally extensive Silurian shales may have locally focused overpressures and localized sand injection at the 1 to 10 km scale. The Mount Telout injected sandbody and related features offer exceptional, seismic-scale outcrop analogues for sand injections that are often identified in seismic reflection data. Large-scale sand injections might be essential in petroleum exploration of the North African Lower Palaeozoic basins as they form seal-bypass systems.