New Evidence for Carboniferous Age of the Taungnyo Group Exposed in the Loikaw Area, Kayah State
New Carboniferous faunas from the Taungnyo Group, Loikaw area are reported. These include two new Late Tournaisian/early Visean (Lower Carboniferous/Mississippian) trilobite species, 'Liobole loikawensis', 'Crassibole karenniensis' and conodont faunas representative of the late Tournaisian 'Scaliognathous anchoralis' and 'Gnathodus typicus-Protognathodus' cordiformis conodonts zone. The age of the Taungnyo Group, Loikaw area is confirmed as Lower Carboniferous (Mississippian) for the sampled part of this stratigraphic unit. The presence of Carboniferous in the Shan Plateau Region of Myanmar is confirmed. The trilobites are most closely related to species from deep water facies of late Tournaisian and Visean age from central and Western Europe. Biogeographic links between upper Tournaisian and early Visean conodonts on the Sibumasu Terrane and Laurentia and Eastern Australian Gondwana support a NW Australian Gondwana margin position for Sibumasu in the Late Paleozoic.
Conodont Colour Alteration pattern in the Carboniferous of the Craven Basin and adjacent areas, northern England
Conodont Colour Alteration Indices (CAI) values in the Craven area show a general range of 2.5–3.5, the majority being a value of 3. The higher values generally occur in the south and south-west and low values are found on the Ashnott High (Ashnott Anticline and eastern closure of the Whitewell Anticline) and in Waulsortian limestones. These values are consistent with the limited vitrinite reflectance data and are a result of the Carboniferous sedimentary and tectonic history of the region. There is no evidence of significant modification by subsequent burial, igneous events, reheating or mineralization. Low values of CAI 2–2.5 on the Ashnott High are interpreted to be due to the thinner sedimentary cover in that area and possible insulation derived from underlying Waulsortian limestones. Relatively high values of CAI 4 for Dinantian strata in the Holme Chapel Borehole and 3.5 in the Silesian sediments to the south of the Craven Basin probably reflect a thicker Westphalian cover than further north.
Phanerozoic Tectonic and Palaeogeographical Evolution of East and Southeast Asia: Myanmar in Context
Present-day East and Southeast Asia comprises a heterogeneous collage of continental blocks derived from the Indian-west Australian margin of eastern Gondwana, and subduction related volcanic arcs assembled by the closure of multiple Tethyan and back-arc ocean basins. Now destroyed ocean basins are represented by suture zones containing ophiolites, accretionary complexes and remnants of ocean islands complex.
The Permian-Triassic Boundary in Western Australia: evidence from the Bonaparte and Northern Perth basins - exploration implications
Several sedimentary basins in west Australia contain petroleum reservoirs of Late Permian or older age that are overlain by thick shaly sequences (400–2,000 m) that have been assigned an Early Triassic age. The age of the base of the Triassic shales has been, and continues to be, contentious with strata being variously ascribed to the latest Permian (Changhsingian Stage) or wholly within the earliest Triassic (Induan Stage). In the Perth Basin the Permian‑Triassic boundary appears to be located somewhere in the Hovea Member of the Kockatea Shale. In the Bonaparte Basin, the boundary would appear to be either in the uppermost Penguin Formation or at the boundary between the Penguin and Mairmull formations. The uncertainty of the boundary placement relates to the interpretation of the sedimentological, biostratigraphic and geochemical record in individual sections and basins. Major problems relate to the recognition, or even the presence of unconformities, complications related to the presence of reworked sediments and paleontological material (both conodonts and spore-pollen) and to the significance of geochemical shifts. The age of the basal Kockatea Shale (northern Perth Basin) and the basal Mt Goodwin Sub-group (Bonaparte Basin) is reassessed using palaeontological data, augmented by carbon isotopic measurements and geochemical analyses, supported by wireline log correlations and seismic profiles. The stratigraphy of the latest Permian to Early Triassic succession in the Bonaparte Basin is also revised, as is the nomenclature for the Early Triassic Arranoo Member of the Kockatea Shale in the northern Perth Basin. The Mt Goodwin Sub-group (new rank) is composed of the latest Permian Penguin Formation overlain by the Early Triassic Mairmull, Ascalon and Fishburn formations (all new).