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Sedimentation gaps in cyclic sequences
Published in Wang Naiwen, J. Remane, Stratigraphy, 2020
Defining sedimentation gaps is best done in a negative way by defining a complete (gap free) stratigraphic section. A stratigraphic section is complete when each point on a time scale has a distinct corresponding point on the stratigraphic scale, which is represented by the thickness of the deposited sediment. Sections with gaps always have a lower number of corresponding points than complete sections and they are therefore shorter (see figure 1).
Site C Clean Energy Project, design overview
Published in Jean-Pierre Tournier, Tony Bennett, Johanne Bibeau, Sustainable and Safe Dams Around the World, 2019
A.D. Watson, G.W. Stevenson, A. Hanna
The stratigraphic section remains almost constant in thickness throughout the site, although rock units on the left (North) bank are often slightly coarser grained than their equivalent on the right (South) bank.
A review of the Gippsland Basin history based on comparison of 3D structural, stratigraphic and forward sedimentation models: recognition of source, reservoir, traps and canyons
Published in Australian Journal of Earth Sciences, 2023
The basin is a prolific petroleum and coal basin, which has led to acquisition of an abundant geological dataset including 3D and 2D seismic, gravity and aeromagnetic surveys, thousands of coal bores, deep onshore and offshore petroleum wells, with large petrophysical log, core, analytical and biostratigraphic datasets and excellent outcrops for part of the stratigraphic section. Consequently, the geology of the basin is well known from detailed industry, government and academic studies carried out over the past 100 years or more that include tectonic, structural, sedimentary, petrological, biostratigraphic and burial history studies (comprehensive compilations are provided in Birch, 2003). Most aspects of Gippsland Basin geology have had extensive publications by industry and research groups, including detailed sedimentary and facies interpretations of parts of the stratigraphy or parts of the basin. Yet, to date, no sedimentary modelling has been published that covers the entire basin sedimentary history from the Early Cretaceous to Holocene to better understand how the basin stratigraphy evolved.
Understanding present-day stress in the onshore Canning Basin of Western Australia
Published in Australian Journal of Earth Sciences, 2021
A. H. E. Bailey, A. J. M. Jarrett, E. Tenthorey, P. A. Henson
A detailed understanding of mechanical rock properties is essential for building 1 D MEMs, as they are a numerical representation of rock properties and stress states for a specific stratigraphic section (Figure 9) (Plumb et al., 2000). When fully developed, 1 D MEMs provide a full description of pore pressure, stress and mechanical properties. However, owing to data constraints, model complexity generally varies between wells, fields and basins (Plumb et al., 2000). In practice, construction of a 1 D MEM requires measurements of five properties: bulk rock density, static Young’s Modulus, static Poisson’s Ratio, uniaxial compressive stress and tensile strength (Brooke-Barnett et al., 2015; Plumb et al., 2000). Density is logged in almost all wells and sonic logs (both compressional and shear are commonly acquired), allowing for the calculation of dynamic velocity-based moduli from empirical relationships (e.g. Chang et al., 2006). However, conversion of these dynamic properties to static properties requires discrete measurements from laboratory tests that are undertaken far less frequently. In this study, dynamic to static transformations of Young’s Modulus and Poisson’s Ratio are derived from previously published mechanical rock testing data (Delle Piane et al., 2015; Schlumberger Reservoir Laboratories, 2017; Terratek, 2013).
Linking geoheritage sites: Geotourism and a prospective Geotrail in the Flinders Ranges World Heritage Nomination area, South Australia
Published in Australian Journal of Earth Sciences, 2020
Located in Enorama Creek—and effectively part of the Brachina Gorge Geological Trail, the Ediacaran Global Boundary Stratotype Sections and Points (GSSP) or ‘Ediacaran Golden Spike’ site is a special location (Preiss, 2005). Being the only GSSP site in the Southern Hemisphere, it represents an internationally agreed upon reference point on the Nuccaleena Formation, a stratigraphic section of rock that defines the lower boundary of stages on the geological time-scale, representing the beginning of the Ediacaran Period. Although the set of authorised drill holes in the Nuccaleena Formation, near where the ‘disc’ for the GSSP is set, were drilled before the GSSP site was formalised, souveniring that has occurred there indicates a need for caution, including from sampling. For this reason, this geotrail proposal is initial, and the map only shows general locations.