Search

Abstract: The sedimentology and cyclic stratigraphy of palaeokarst structures in Aptian peritidal carbonate successions are interpreted using field and laboratory microfacies analyses of closely spaced samples from measured outcrop stratigraphic sections in southwest Turkey. Cycles displaying shallowing-upward metre-scale cyclicity are generally composed of lime mudstones/wackestones/packestones at the bottom and stromatolites or lime mudstones with charophytes and ostracods at the top. Subaerial exposure structures such as in situ karst breccias, dissolution vugs/pipes, mud cracks and sheet cracks are encountered at the top of the cycles. The presence of limestone layers between the successive karst breccia levels indicates that they are in situ palaeokarst structures, not recent karstifications or deep penetration from the upper palaeokarst surface down to the older strata. Palaeokarst breccia deposits are interpreted as mantling breccia formed as a result of epikarstification. Three main palaeokarst levels are recorded in nearly all sections. The sedimentology of the palaeokarst breccias, their position in cyclic peritidal carbonates and the biostratigraphic framework are used to trace the record of the global mid-Aptian sea-level fall in the southwest Taurides. The successive occurrences of three karst breccia levels close to the mid-Aptian sea-level fall correspond to falling periods of high-amplitude sea-level fluctuation within a late high-stand or early fall condition of a third-order sea level. [Copyright &y& Elsevier]

We carried out combined micropaleontological, microfacies and multivariate statistical analyses of benthic foraminiferal assemblages on a previously undocumented lowermost Cretaceous carbonate succession from the western part of the Getic Carbonate Platform (Pui-Bănița zone, Southern Carpathians). The microfacies analysis and interpretations suggest that these limestones were developed under peritidal settings within different zones of a shallow-water inner platform paleoenvironment (bioclastic grainy bars, subtidal–intertidal flats and intertidal–supratidal ponds), where benthic foraminifera, microbial microstructures and calcareous algae were the main carbonate producers. The well-preserved micropaleontological content (mostly benthic foraminiferal assemblages) is important for lowermost Cretaceous Neotethyan biostratigraphy and allows the recognition of the Valanginian stage within this part of the Getic Carbonate Platform. The multivariate data processing (diversity indices, cluster analyses and principal components analyses) performed on the benthic foraminifera assemblages provide valuable information about their compositional patterns, diversity trends and spatial distribution with respect to the main facies zones. The results obtained through these analyses are extremely useful for the recognition of common/different paleoecological features and for a more precise interpretation of depositional paleoenvironments. • Combined micropaleontological, microfacies and multivariate statistical analyses. • Important biostratigraphic arguments for the Berriasian–lower Valanginian. • Diversity indices reflect strong facies control over species richness and the spatial distribution of species. • A more accurate interpretation of the paleoenvironmental/paleoecological conditions. [ABSTRACT FROM AUTHOR]