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Sea stack example11/8/2023 ![]() Yet Tom and I knew that the majority of the stacks and the surrounding Brassfield had been blasted away and crushed (for agricultural lime). Brett and Kleffner indicated an interest in obtaining additional sea stack samples to study. Picture of some of the many types of microscopic conodont tooth-like structures. Kleffner was studying the Brassfield, we showed him the sea stacks, which he sampled for conodont analysis – this could help with dating the structures. Conodonts are known to have changed in a predictable pattern over time, permitting their use as comparative index fossils. Their primary interest is analysis of conodonts (tooth-like microfossils from eel-like creatures) to determine age of the Brassfield Limestone of Indiana relative to other similar formations in the region. Mark Kleffner and his colleagues (OSU) have also joined us at the quarry. And from his examination of the strata at the base of the stacks, it grades uniformly from the underlying Ordovician Whitewater Formation into the stacks (no sharp boundary like there is between the Whitewater and the Brassfield above).ĭr. That conclusion is based primarily on the presence of Rafinesquina brachiopods and Isotelus trilobites, neither of which are known to have survived the mass extinction event at the end of the Ordovician period. One was to study these stacks, which he suspects are Ordovician in age. Carl Brett (UC) has joined us at the quarry several times to discuss various projects. Over the past few years, Tom Bantel and I have examined these many times, and discussed them with local professionals.ĭr. ![]() ![]() And the quarry manager (who has worked there for decades) stated he and his father before him had never previously seen them either (the quarry has been in operation since at least the 1960s). I’ve been collecting this quarry for over 35 years – never saw sea stacks in the past. Sea stack protruding into the Silurian “Golden” Brassfield Limestone in Ripley County, Indiana. ![]()
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