China
Africa
Explore chapters and articles related to this topic
Outline of the stratigraphy of the Melbourne region
Published in W. A. Peck, J.L. Neilson, R.J. Olds, K.D. Seddon, Engineering Geology of Melbourne, 2018
Tertiary sediments are generally divided into three lithological associations - continental, paralic and marine (Abele, 1988). Continental and marine deposition was often comtemporaneous, with boundaries between rock units often diachronous or showing lateral facies changes owing to marine transgressions and regressions.
Middle Jurassic–Lower Cretaceous stratigraphy of the northern Great Australian Superbasin: insights from maximum depositional age constraints from the U–Pb detrital zircon record
Published in Australian Journal of Earth Sciences, 2022
E. K. Foley, E. M. Roberts, R. A. Henderson, C. N. Todd, E. M. Knutsen, C. Spandler
MDA estimates from some samples of stratigraphic units distributed across the basin raise questions of stratigraphic significance. Several examples arose in which samples from the same named lithostratigraphic unit yielded widely discrepant MDA estimates, indicating long-lived, diachronous facies systems, or that the sampled units are independent and have simply been miscorrelated. One such example relates to robust MDA estimates for samples of the Gilbert River Formation in the Carpentaria Basin that indicate a Late Jurassic (Oxfordian to Kimmeridgian) age in the north, but a considerably younger Early Cretaceous (Barremian) age in the south, an interpretation supported by palynostratigraphy (Foley, Roberts, et al., 2021, this study) (Figure 12b–d). In this case, we interpret the unit to be diachronous owing to progressive marine transgression from the northern Carpentaria Basin through its southern sector and into the northern Eromanga Basin (Foley et al., 2020; Foley, Roberts, et al., 2021). The Loth Formation, although no more than ∼120 m thick (Foley et al., 2020; Smart et al., 1971), yields MDA estimates that young progressively upwards, ranging from the Late Jurassic (Oxfordian) to Early Cretaceous (early Aptian) (Figures 6 and 11). As the Loth Formation is confined to the southeastern periphery of the Carpentaria Basin, we consider that this age pattern reflects episodic provision of basinal accommodation space, a circumstance that may prove significant in the subsidence history of the northern Great Australian Superbasin at large.
Paleoseismology of the Akatore Fault, Otago, New Zealand
Published in New Zealand Journal of Geology and Geophysics, 2020
Briar I. Taylor-Silva, Mark W. Stirling, Nicola J. Litchfield, Jonathan D. Griffin, Ella J. van den Berg, Ningsheng Wang
The Otago Range and Basin province has developed from displacements along an imbricate system of parallel northeast-striking reverse faults (Figure 1B; Beanland and Berryman 1989; Jackson et al. 1996; Norris 2004). The Otago Range and Basin province has been suggested to be a zone of back thrusting to the east of the Alpine Fault (Norris 2004). The faults of the province accommodate several mm/yr of oblique convergence (Jackson et al. 1996), and individual slip rates are in the range of 0.1–1 mm/yr (e.g. Stirling et al. 2012). The faults tend to have lengths of about 40–80 km, and are usually steeply dipping where observed. They have displaced Tertiary sediments and the underlying Waipounamu Erosion surface, also known as the Otago Peneplain (Landis et al. 2008). This erosion surface is a sub-horizontal regional unconformity between Mesozoic basement schist and is overlain by diachronous Cretaceous to Tertiary marine, fluvial and lacustrine sediments (Markley and Norris 1999; Landis et al. 2008).
Subaerial disconformities, microkarst and paleosols in Ordovician limestones at Bowan Park and Cliefden Caves, New South Wales, and their geoheritage significance
Published in Australian Journal of Earth Sciences, 2019
V. Semeniuk, I. G. Percival, M. Brocx
Microkarst and paleosols are important stratigraphic horizons in ancient rocks as they signal the occurrence of subaerial disconformities in marine successions. Paleosols and subaerial disconformities have been used in stratigraphic and paleogeography reconstructions as isochronous horizons for precise correlations within diachronous stratigraphy or within sequences where there are marked down-gradient facies changes in the stratigraphic units (Semeniuk, 1973a, 1975). For subaerially exposed marine materials and for rocks in the terrestrial environments they provide insights into the weathering/alteration of a variety of igneous, metamorphic, sedimentary rocks, particular minerals, hydrochemical and geochemical changes that occurred during pedogenesis, and into the climate of the time. While much has been written on pedogenesis and soils occurring in modern environments, and there has been extrapolation and applied interpretation of modern soil science into ancient rocks, in comparison there is little recording of pedogenesis and paleosols within older rocks. Nonetheless, paleosols have been recorded in rocks as far back as the Precambrian.