New Tyennan structural synthesis
The aim of this study (GSP14) was to re-examine the structure of the Tyennan Proterozoic rocks in the context of Cambrian continental margin subduction-obduction. Deformation of this former Cambrian continental margin beneath the advancing ophiolite sheet has involved crustal-scale stacking of sheets of different metamorphic grade, isoclinal folding and internal sheet deformation, with sheets welded along their contacts by shear zones and/or brittle faulting. Subsequent erosional removal of the ophiolite sheet has provided an exposed 50-100 km window into these underlying rocks.
This paper represents a synthesis of the regional structure of the Eastern Tyennan subdomain with companion Geological Survey Papers 7 and 13 defining the structures and structural relationships in the adjoining Central Tyennan subdomain and Southern Tyennan subdomain respectively.