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Recent research has shown that Archaean lode-gold deposits occur in environments that range in their metamorphic grade from prehnite-pumpellyite to lower granulite facies. Based on this data a new classification is proposed for these deposits. In this classification, shallow-level gold deposits are classed as epizonal, the so-called mesothermal deposits are mesozonal, and the deeper deposits, commonly in mid-amphibolite or lower-granulite terrains, are hypozonal. 相似文献
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Mathematical Geosciences - One of the main problems associated with applying data assimilation methods for facies models is the lack of geological plausibility in updates. This issue is even more... 相似文献
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Matthias Fleischer Ayobami Abegunrin Daniel A. Hepp Stefan Kreiter Mark Coughlan Tobias Mörz 《Boreas: An International Journal of Quaternary Research》2023,52(1):78-98
A detailed stratigraphic and geotechnical investigation of the uppermost 50 m below the sea floor was carried out for parts of the German North Sea sector using combined information from shallow seismic reflection surveys, 50-m-long sediment cores and cone penetration tests covering an area of ~150 km2. While most recent studies concentrate on unusual features such as buried tunnel- or river-valleys, this study focused on the less well understood, regionally dominant sand units deposited after the retreat of the last glaciers in this region. We identified two sandy units which dominate the late- to post-Saalian geology: (i) the Upper Fluvial Member, believed to be derived from deposition of the Weser, Ems and Elbe palaeorivers as well as other tributaries of the Elbe Palaeovalley in the NE during the Saalian; and (ii) the Aeolian Member, which correlates with periglacial deposits of Weichselian age. Additionally, a Saalian Buried Valley Member believed to comprise fluvial deposit was also identified. Key stratigraphic units within the uppermost 50 m below the sea floor were also identified and mapped. Detailed geotechnical properties were obtained for each of the individual stratigraphic units. The regional extent of the Aeolian and Upper Fluvial Members was documented in the region west of the Elbe Palaeovalley and south of the Dogger Bank, where their geotechnical properties are important for foundation design. In conclusion, the study complements the established regional geotechno-stratigraphy and offers new and detailed publically accessible information beneficial for offshore wind farm development within the region. 相似文献