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Study on characteristics of the conglomerate reservoir in Shahezi Formation of XJWZ
Published in Ahmad Safuan Bin A Rashid, Junwen Zhang, Advances in Mineral Resources, Geotechnology and Geological Exploration, 2023
The amplitude, continuity, and internal reflection structure were selected as the main parameters for seismic phase analysis, and the geometric appearance was used as auxiliary parameters. According to the principle of seismic stratigraphy and the previous research results on the deep seismic reflection characteristics in the northern Songliao Basin, there are mainly six seismic phases of Shahezi Formation in this area: Strong amplitude-continuous-mat-like parallel reflectionMedium and strong amplitude-continuous-mat parallel reflectionMedium and weak amplitudes-more continuous-wedge-divergent reflectionMedium and strong amplitude-intermittent-mound anterior product reflectionMedium and weak amplitudes-intermittent-hillock reflectionMoundy blank reflex
Devonian-Carboniferous Boundary in the Neritic Facies Areas of South China from the Viewpoint of Integrative Stratigraphy
Published in Wang Naiwen, J. Remane, Stratigraphy, 2020
Wang Xunlian, Zhang Shihong, Xue Xiaofeng
In regard to isochroneity of stratigraphical unit boundaries, the present stratigraphical methods may be divided into two types. One includes event stratigraphy, sequence stratigraphy, ecostratigraphy, magnetostratigraphy, seismic stratigraphy, and stable isotope stratigraphy, in which the unit boundaries are by definition isochronous and correlatable over wide extent. However, these units lack unique signals and are recurrent in geological history. Their age can not be decided without biostratigraphy or isotope geochronology. The other is biostratigraphy based on the principle of irreversible evolution of life, and therefore not recurrent in geological history. Thus biostratigraphy is basic in stratigraphy, and pay a key role in establishing stratigraphical framework, although its unit boundaries are in most cases diachronous. In general, only within a stratigraphical framework established on biostratigraphy, can other methods be validly applied to more precise division and correlation.
Geological evolution of the Ischia volcanic complex (Naples Bay, Tyrrhenian sea) based on submarine seismic reflection profiles
Published in Tatiana Rotonda, Manuela Cecconi, Francesco Silvestri, Paolo Tommasi, Volcanic Rocks and Soils, 2016
Marine geophysics around the Ischia island has shown a great improvement during the last ten years, due to the bathymetric surveys acquired by the GNV and CARG Projects. These bathymetric surveys resulted in a Multibeam coverage all around the Ischia island (Aiello et al., 2010). Swath bathymetry was acquired in a wide depth range, with various echosounders, each characterized by its own frequency (from 60 to 300 kHz) and spatial resolution (from 0.3 to 10 m the footprint). The merging of these surveys with the island subaerial topography has allowed the construction of a DTM in which the elementary cell size has been averaged to 20 m obtaining a good compromise among coverage depth and resolution in shallow waters. The sea floor structure has been determined through the analysis of the DTM. The study grid is composed of dip lines perpendicular to the shoreline and tie lines parallel to the shoreline, interpreted accordingly to criteria of seismic stratigraphy and volcanic geomorphology. The classification of volcanic landforms has been recently improved taking into account the complexity in the generation of volcanic structures and their control factors, such as the magmatic systems, the styles of eruption and the erupted materials. The DEM datasets are often available, making possible the morphometric characterization of large composite volcanoes at a global scale.
The potential for palaeoseismic and palaeoclimatic reconstructions from Lake Tennyson, North Canterbury, New Zealand
Published in New Zealand Journal of Geology and Geophysics, 2023
John-Mark Woolley, Andrew Lorrey, Paul Augustinus, Patricia S. Gadd
In addition, the landscape around Lake Tennyson has been examined provisionally for palaeoecology (McLea 1996), glacial history and palaeoseismic evidence (R. McCalpin 1992; Mcginty et al. 1997; Langridge et al. 2016), but no studies to date have exploited the Lake Tennyson basin as a source of evidence for palaeoenvironmental change. In this study, we fill several knowledge gaps focused on understanding how the Lake Tennyson stratigraphy can be used to refine the palaeoenvironmental change history of the northern South Island region, with specific emphasis on climatic and seismic events. Our preliminary investigation focuses on lake bathymetry and seismic stratigraphy validated with detailed analysis of short sediment cores. We provide provisional interpretations of these sequences based on a limited number of radiocarbon ages, and make recommendations for future work at this site.
Marine Geology and Sand Resources of the Southern North Carolina Inner Shelf
Published in Marine Georesources & Geotechnology, 2022
Ian Conery, John P. Walsh, David Mallinson, David R. Corbett
The deeper QT reflector is visible in the eastern third of this region (20% of the mapped linear distance) and the overlying unit contains thicker sands up to 4.7 m (mean = 2.5 m)(e.g., Figure 5). Paleochannels and hardbottom are frequently observed in the central region (Figure 4), and are present in 31% and 23%, respectively, of the total mapped distance. When ASAP interpretations are overlain on Hine and Snyder (1985), numerous areas of mapped paleochannels align that are interpreted as relict tidal inlets/lower coastal plain streams that can be identified by truncation in the Tertiary seismic stratigraphy (Figure 6). Radiocarbon ages from four cores within channels show two channels contain surficial Holocene sand and variable Pleistocene fill below (VC31 and VC33; Table 2; Figures 4 and 7), whereas the other two channels are filled with Pleistocene or reworked sediments (0.3 − 1.5 m depth) (VC32 and VC34; Table 2; Figures 4 and 7). The infilling of the paleochannels is variable and complex, and mostly appears to be representative of estuarine and fluvial fill (i.e., sands interbedded with muds and clay and gravel base) (Hine and Snyder 1985). While some buried channels may contain sands suitable for nourishment as shown by core and seismic appearance, more core validation is needed. Hine and Snyder (1985) show areas of especially thick (10 − 20 m) Quaternary sediments within channels that are corroborated by ASAP data (see black box focus area in Figure 7).
Scientific ocean drilling in the Australasian region: a review
Published in Australian Journal of Earth Sciences, 2022
The general conclusions from the expedition were that well-preserved calcareous microfossil assemblages from different paleodepths will generate paleotemperature and biotic records from the very warm Cretaceous climatic conditions. Paleotemperature proxies and other data will reveal the waxing and waning of peak hothouse temperatures. The sites also record the mid-Eocene to early Oligocene opening of the Tasman Gateway and the Miocene–Pliocene restriction of the Indonesian Gateway, both important for global oceanography and climate. Understanding the paleoceanographic changes will provide a global test of models of Cenomanian–Turonian oceanographic and climatic conditions, including extreme Turonian warmth and the evolution of oceanic anoxic event (OAE) 2. The Lower Cretaceous volcanic rocks and underlying Jurassic sediments constrain the timing of different stages of the Gondwana breakup. One result will be a re-evaluation of the basin-wide seismic stratigraphy and tectonic models for the region. Erosional hiatuses and faults in the sedimentary succession can now be dated and linked with episodes of uplift, erosion and subsidence, which in turn can be linked to the wider tectonic and thermal histories of this margin.