The Sgurr Beag nappe: A reassessment of the stratigraphy and structure of the Northern Highland Moine

Research Article| May 01, 1987 The Sgurr Beag nappe: A reassessment of the stratigraphy and structure of the Northern Highland Moine ALAN M. ROBERTS; ALAN M. ROBERTS 1Jane Herdman Laboratories, Department of Geological Sciences, University of Liverpool Liverpool L69 3BX, England Search for other works by this author on: GSW Google Scholar ROBIN A. STRACHAN; ROBIN A. STRACHAN 2Department of Geology and Physical Sciences, Oxford Polytechnic, Headington, Oxford, OX3 OPB, England Search for other works by this author on: GSW Google Scholar ANTHONY L. HARRIS; ANTHONY L. HARRIS 3Jane Herdman Laboratories, Department of Geological Sciences, University of Liverpool Liverpool L69 3BX, England Search for other works by this author on: GSW Google Scholar DAVID BARR; DAVID BARR 4British Geological Survey, "Southpark," 19 Grange Terrace, Edinburgh, EH9 2LF, Scotland Search for other works by this author on: GSW Google Scholar ROBERT E. HOLDSWORTH ROBERT E. HOLDSWORTH 5Jane Herdman Laboratories, Department of Geological Sciences, University of Liverpool Liverpool L69 3BX, England Search for other works by this author on: GSW Google Scholar GSA Bulletin (1987) 98 (5): 497–506. https://doi.org/10.1130/0016-7606(1987)98<497:TSBNAR>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation ALAN M. ROBERTS, ROBIN A. STRACHAN, ANTHONY L. HARRIS, DAVID BARR, ROBERT E. HOLDSWORTH; The Sgurr Beag nappe: A reassessment of the stratigraphy and structure of the Northern Highland Moine. GSA Bulletin 1987;; 98 (5): 497–506. doi: https://doi.org/10.1130/0016-7606(1987)98<497:TSBNAR>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The rocks of the Northern Highland Moine have suffered two phases of intense, mid-crustal orogenesis. Elucidation of original stratigraphic relationships within these rocks requires the application of techniques that can be applied to other terranes of this type, in which the regional lithostratigraphy has, on first inspection, been obscured by a complex deformation history.Mapping along the boundary between the Glenfinnan and Loch Eil divisions of the Moine has shown that the rocks of both divisions have a common structural, metamorphic, and igneous history. The Glenfinnan division passes upward by stratigraphic passage into the Loch Eil division. The usefulness of assigning rocks rigorously to one division or the other is therefore called into question. It is suggested that the Moine rocks in the Northern Highlands which lie above the Sgurr Beag thrust, that is, those previously assigned to the Glenfinnan or Loch Eil divisions, should be referred to a single tectonostratigraphic unit, the Sgurr Beag nappe. The Glenfinnan and Loch Eil divisions have the status of lithostratigraphic groups within the nappe. It is further possible to subdivide the stratigraphy of the nappe into a number of mappable formations, some of which are laterally continuous, and some of which die out laterally. The base of the Loch Eil Group may be diachronous. Stratigraphic considerations suggest that the Sgurr Beag thrust cuts down-section northward, exposing deeper levels of the nappe from Loch Quoich northward than those present above the slide farther south.The Morar division is also thought to have the status of a lithostratigraphic group, but its original relationship to the Glenfinnan and Loch Eil groups is normally obscured by the Sgurr Beag thrust. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.