The Gondwanian orogeny within the Antarctic Peninsula: a discussion

• Main Authors: Storey, B.C., Thomson, M.R.A., Meneilly, A.W.
• Other Authors: McKenzie, Garry D.
• Format: Book Part
• Language: unknown
• Published: American Geophysical Union 1987
• Subjects: Earth Sciences; Antarctic; The Antarctic; Antarctic Peninsula; Antarc*
• Online Access: http://nora.nerc.ac.uk/id/eprint/523002/; https://agupubs.onlinelibrary.wiley.com/doi/10.1029/GM040p0191

The relevance of the term “Gondwanian orogeny” to deformation within upper Paleozoic to Mesozoic rocks of the Antarctic Peninsula is reviewed, and the tectogenesis of deformation within this time frame is discussed. The term, originally applied by du Toit to deformation of middle Paleozoic to lower Mesozoic rocks in the Samfrau geosyncline, has been used extensively in Antarctic literature . However, the Gondwanian fold belt includes deformed regions of significantly different ages. For example, in southern Africa the Gondwanide Cape folding is a singlephase multiple‐event period of deformation which spanned the beginning of the Permian to the Middle Triassic, a period of approximately 50 m.y. In the Antarctic Peninsula, although data are insufficient to reconstruct a full tectonic history, the Gondwanian orogen is now known to include rocks and structures of a younger age. The only ages which presently fall within the above time frame are some estimates of a period of metamorphism whose tectonic significance is uncertain. The authors favor the use of the term “Peninsula orogeny” for deformation of Triassic and Early Jurassic rocks below the “Peninsula unconformity” in preference to the term Gondwanian orogeny.