The Dinantian West Lothian Oil-Shale Formation of the Midland Valley, Scotland, is a laterally variable lacustrine sequence, deposited in an overall humid climatic period. The sequence comprises non-marine limestones, dolostones, oil-shales, mudrocks and deltaic sandstones. Thin marine bands and the thick freshwater Burdiehouse Limestone are the most reliable stratigraphic markers. Eight individual outcrops of microbial carbonatesa, ll stratigraphically close to the Burdiehouse Limestone, are correlatable, and therefore important in helping to clarify the Asbian stratigraphy of the eastern Midland Valley of Scotland. The microbial carbonates were deposited in varied shallow lake settings. Lake waters had a long residence time, suggested by fairly positive stable carbon and oxygen isotope ratios. Petrography and geochemistry suggest the primary carbonate was high-Mg calcite. Isotopic variations are mainly controlled by depositional water depth, diagenetic fluid temperaturesl,o calised magmatica ctivity and in-situ organicm atterd ecay. A regional dolornitisation event affected the lithologies, with high Fe" and Mg2+ concentrations suggesting early diagenetic dolomitisation under phreatic conditions. High Sr dolomite suggestst hat the lake and / or regional groundwaters were Sr enriched. Both the Sr ions and the Mg ions for dolomitisation were probably derived from chemically-enriched, seaward flowing groundwaters, that originated on a westerly situated volcanic plateau. The microbial carbonates represent regional and localised regressive sequences, lake, and in volcanically-isolated depositional sub-basins. The carbonates probably correspond to a regionally-significant period of aridity within the Asbian of south-east Scotland, similar to fluctuating seasonal semi-arid and humid conditions identified in the Dinantian of England and Wales.

Although karst processes in south central Kentucky have been studied extensively, the Haney Limestone Member of the Golconda Formation has not been studied in detail in contrast to limestones stratigraphically below it that are thicker. In addition, the relationship between petrographic features of the Haney Limestone and the formation of caves and karst features has not been studied extensively compared to lithographic, petrographic, or structural variables Petrographic data were collected using core and surface exposures across the study area of south central Kentucky from northern Logan and Warren counties up toward the Rough Creek Graben region, and stratigraphic columns were constructed. Twenty-three petrographic thin-sections were made from samples collected at these sites, described, and photo documented. These studies have revealed that grain size and silica content play a role in how the Haney weathers both in surface exposure and in a cave setting. Petrographic thin-section analysis suggests that the Haney possesses a complex diagenetic history that involves several generations of calcite cementation, dolomitization, silicification, and pressure-dissolution features in the form of microstylolites and stylolites. A basal shale in the Big Clifty occurs commonly at the Big Clifty/Haney contact and acts as a confining hydrogeologic unit, which is favorable for the development of springs and caves. Studying the Haney Limestone petrographically provides an opportunity not only to study a lesser known unit, but also in the context of relating petrographic influences or controls on the morphology of Haney cave-passage development under both vadose and phreatic hydrologic regimens. Heretofore, the vast majority of cave morphological studies have only linked the hydrologic regimen to formation of cave passages, but such studies have not considered petrographic variance. This study not only relates karst features to petrographic variance, but also provides a petrographical description of the Haney across south central Kentucky, whereas many previous studies focused on Illinois and Indiana. Understanding Haney petrographic characteristics also provides context for potential carbonate hydrocarbon reservoirs and groundwater resources in the Illinois Basin region.