ABSTRACT: The presence of microtektites, indicative of a single short-lived event, may be a useful tool for constraining the timing of barren and monotonous beds thereby enabling more accurate long-distance correlation. While the Paleozoic Laurentian epeiric seas have been studied for more than a century, their geologically complex histories, large areal expanse, and seeming monotony of contained barren stratigraphic units precludes simple extrabasinal correlation. Recent investigations of the Upper Devonian succession in western New York have yielded evidence of extraterrestrial impact events in the form of microtektites. Geothermal well spoils from the coeval Antrim Shale (Norwood Member) of the Michigan Basinwere collected and completely digested. Sediments retrieved from these spoils (shale, clay, and limestone) contain four genera of benthic foraminifera, algal cysts, and other microfossils confirming a Devonian age. The sediments also contain microspherules inferred to be microtektites similar to those recovered from western New York and are potentially evidence of a large impact event. The microspherules may be a useful inter-basin marker event within the Late Devonian beds in North America that has gone previously unreported.