Kaskaskia Sequence

Contents

Kaskaskia Sequence The Kaskaskia Sequence marks a major transgressive–regressive marine episode spanning parts of the Devonian, Mississippian, Carboniferous, and regional chronostratigraphic frameworks across North America, tied to shifts recorded in strata exposed in the Illinois Basin, Appalachian Basin, Michigan Basin, Williston Basin, and Western Canada Sedimentary Basin.

Overview

The sequence concept was developed by stratigraphers studying siliciclastic and carbonate cycles in the context of sea‑level changes observed in the Midcontinent Rift System, Laurentia, Canadian Shield, Appalachian Mountains, Ouachita Orogeny, and the broadly correlated frameworks used by the United States Geological Survey, Geological Society of America, Paleontological Society, International Commission on Stratigraphy, and key regional surveys.

Stratigraphic architecture of the interval includes carbonate platforms, shale basins, and clastic wedges documented in cores and outcrops from the Cincinnati Arch, Indiana Limestone exposures, Niagaran Reef Complex, and sections described in the literature by workers associated with the University of Illinois, Ohio State University, Purdue University, University of Michigan, and the Royal Ontario Museum; lithologies range from bioclastic limestone, oolitic grainstone, argillaceous marl, black shale, and sandstone linked to deposits in the Chautauqua Arch, Sauk Sequence contact zones and unconformities recognized by researchers at the Smithsonian Institution and the American Association of Petroleum Geologists.

Deposits attributed to the episode are mapped across the Illinois Basin, Arkoma Basin, Michigan Basin, Sacosky Shelf, and portions of the Ancestral Rocky Mountains per paleogeographic reconstructions used by the Paleomap Project, National Oceanic and Atmospheric Administration, British Geological Survey, and university research groups, recording shallow epicontinental seas, ramp carbonates, tidal flats, lagoonal facies, and deeper basinal shales equivalent to facies seen in the Bakken Formation, Monterey Formation, Chattanooga Shale, and shelf margins analogous to the Permian Basin rim settings.

Fossil assemblages include corals, brachiopods, trilobites, conodonts, crinoids, gastropods, and foraminifera documented in museum collections at the Field Museum, American Museum of Natural History, Yale Peabody Museum, Natural History Museum, London, and in regional faunal lists prepared by the Paleobiology Database and the International Paleontological Association; biostratigraphic zonations use conodont biostratigraphy, ammonoid markers, and brachiopod provincialism correlated with biostratigraphic schemes developed by the United States Geological Survey, Canadian Geological Survey, European Geosciences Union, and stratigraphers working on the Devonian Reef Complexes and Mississippian Carbonate Platforms.

Tectonic drivers include flexural responses to the Alleghenian Orogeny, subsidence related to the Acadian Orogeny, basin development tied to the Ouachita-Marathon orogen, and far-field stresses from plate interactions involving Laurentia, Gondwana, and terranes examined in studies hosted by the Geological Society of London, Society for Sedimentary Geology, Texas Bureau of Economic Geology, and the Colorado School of Mines; eustatic signals are interpreted against global sea-level curves synthesized by the International Commission on Stratigraphy, Haq et al. frameworks, and isotope records curated by researchers at the Scripps Institution of Oceanography and the Lamont–Doherty Earth Observatory.

Reservoir and source-rock intervals within the sequence host hydrocarbons in fields explored by companies such as ExxonMobil, Shell plc, Chevron Corporation, ConocoPhillips, and national agencies including the Bureau of Land Management and Natural Resources Canada; mineral resources include carbonate-hosted lead‑zinc mineralization studied by the United States Bureau of Mines, aggregate and dimension stone quarried for projects in Chicago, Indianapolis, and Cleveland, and groundwater aquifers managed by state water resources departments and engineers at the Army Corps of Engineers and the Environmental Protection Agency.

Category:Stratigraphy Category:Devonian geology Category:Mississippian geology