Facies and petrophysical signature of the Tournaisian/Viséan (Lower Carboniferous) sea-level cycle in carbonate ramp to basinal settings of the Wales-Brabant massif, British Isles

摘要: We studied the relationships between stratigraphic distribution of outcrop spectral gamma-ray, magnetic susceptibility and carbonate facies stacking patterns across regionally significant transgressive–regressive cycle at Tournaisian/Visean boundary (Tn/V, early Carboniferous) in southern Great Britain Ireland (South Wales, North Staffordshire Dublin Basin). The Tn/V coincides with a prominent climatic pulse connected Late Paleozoic glaciation Gondwana. aim was to correlate gamma-ray log ramp- basin settings discuss global/regional nature magnitude this cycle. A robust ramp-to-basin correlation produced based on patterns, foraminifer biostratigraphy. concentrations K Th, “clay” values and, partly, are dependent show systematic changes along inferred bathymetric profile from inner ramp outer basin. model productivity-driven dilution fine-grained siliciclastics CaCO3 as major control petrophysical is discussed. cleaning-up cleaning-down trends related down-dip up-dip shifts factory changing relative sea level. In middle-to-outer settings, generates just opposite shelves where peaks known be associated peak regressions. distinct, late Tournaisian Visean regressive-to-transgressive sequence located close stage can seen sections. Glacioeustatic origin its sections Europe, carbon isotope data South China glacial deposits hemisphere mentioned by previous authors.