Exhumation of the High‐Pressure Tsäkkok Lens, Swedish Caledonides: Insights From the Structural and White Mica 40Ar/39Ar Geochronological Record
Integrated structural, geochemical, and geochronological investigations were conducted on metasedimentary rocks in the eclogite-bearing Tsäkkok Lens of the Seve Nappe Complex (Scandinavian Caledonides) to resolve its exhumation history. Three deformation events are defined. D1 is likely related to the prograde to peak-metamorphic stages, represented by a locally preserved S1. D2 resulted in vertical shortening and is defined by a pervasive S2 and cm-/m-scale F2 closed folds. D2 terminated with Scandian thrusting, which emplaced the overlying Köli Nappe Complex. D3 records NE-SW shortening and constitutes m-/km-scale F3 open folds that deformed the Tsäkkok Lens and Köli Nappe Complex togethe…
Tectono-metamorphic evolution of the pre-Athabasca basement within the Wollaston-Mudjatik Transition zone, Saskatchewan
The Paleoproterozoic tectono-metamorphic evolution of the pre-Athabasca basement (∼1.7 Ga) within the Wollaston–Mudjatik Transition Zone (WMTZ) (Saskatchewan, Canada) has been characterized using both exposed basement and drill cores from the Wolly–McClean exploration drilling project. The finite ductile strain pattern of the WMTZ results from the superposition of two tectono-metamorphic events M1–D1 and M2–D2. M1–D1 is associated with the development of a gently dipping foliation striking N90°–N100° and a southward decrease in peak pressures from up to 10 kbar (1 kbar = 100 MPa) in the Cochrane River area down to 6 kbar in the Wolly–McClean exploration drilling project. The M2–D2 event is…