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Social and Behavioral Sciences Commons

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Early

2007

Physical Sciences and Mathematics

Articles 1 - 2 of 2

Full-Text Articles in Social and Behavioral Sciences

Structural, Metamorphic, And Geochronological Constraints On Alternating Compression And Extension In The Early Paleozoic Gondwanan Pacific Margin, Northeastern Australia, Christopher L. Fergusson, R A Henderson, I. W. Withnall, C M Fanning, D. Phillips, K. J. Lewthwaite Jan 2007

Structural, Metamorphic, And Geochronological Constraints On Alternating Compression And Extension In The Early Paleozoic Gondwanan Pacific Margin, Northeastern Australia, Christopher L. Fergusson, R A Henderson, I. W. Withnall, C M Fanning, D. Phillips, K. J. Lewthwaite

Faculty of Science - Papers (Archive)

The Ross-Delamerian orogenic belt formed along the early Paleozoic active Pacific margin of the newly merged Gondwana supercontinent. In its northern-most segment in the Townsville region of northeastern Australia, we have identified a short contractional phase of the Delamerian orogeny in the Argentine Metamorphics postdating formation of a mafic breccia with a U-Pb zircon age of 500 ± 4 Ma. Contraction was followed by widespread inferred extensional deformation with formation of flat-lying foliation, domal features, and amphibolite grade and greenschist retrograde metamorphism all synchronous with latest Cambrian to Early Ordovician extensional backarc volcanism, sedimentation and intrusions. One of these intrusions …


Structural History Of The Greenvale Province, North Queensland: Early Palaeozoic Extension And Convergence On The Pacific Margin Of Gondwana, Christopher L. Fergusson, R A Henderson, I. W. Withnall, C M Fanning Jan 2007

Structural History Of The Greenvale Province, North Queensland: Early Palaeozoic Extension And Convergence On The Pacific Margin Of Gondwana, Christopher L. Fergusson, R A Henderson, I. W. Withnall, C M Fanning

Faculty of Science - Papers (Archive)

The southeastern Georgetown Inlier (Greenvale Province) consists of Early Palaeozoic metamorphic rocks in fault contact along the Lynd Mylonite Zone with the Palaeoproterozoic to Mesoproterozoic craton of northeastern Australia. It has a central assemblage of metamorphosed silicic volcanic and sedimentary rocks considered equivalent to the Late Cambrian to Early Ordovician Seventy Mile Range Group that developed in an extensional backarc in the Charters Towers Province to the southeast. In the western part of the Greenvale Province the Oasis Metamorphics has a U-Pb zircon SHRIMP metamorphic age of 476 ± 5 Ma and is intruded by the granodioritic Lynwater Complex with …