• journal_title：Journal of the Geological Society
• Contributor：M. F. THIRLWALL
• Publisher：Geological Society of London
• Date：1989-
• Format：text/html
• Language：en
• Identifier：10.1144/gsjgs.146.3.0373
• journal_abbrev：Journal of the Geological Society
• issn：0016-7649
• volume：146
• issue：3
• firstpage：373
• section：Article

Regional chemical and isotopic differences seen in Ordovician–Devonian igneous rocks of northern Britain are thought to be due to subduction-related and collision magmatism tapping a variety of mantle and crustal sources. Matching of spatial chemical variation across major fault zones restricts post-magmatic transcurrent movement north of the Southern Upland Fault (SUF) to a few tens of kilometres on each fault. A unique mantle isotopic signature present in the same area may restrict post-1.5 Ga movement to less than a few hundred kilometres. No such restrictions exist on displacement across the SUF, to the south of which all magmas show a Pb isotopic component derived from southern sources.