Lower–Middle Pennsylvanian strata in the North American midcontinent record the interplay between erosional unroofing of the Appalachians and eustatic sea-level rise

Abstract

Morrowan, Atokan, and Desmoinesian (Lower-Middle Pennsylvanian) clastic strata in the Forest City (Iowa, northwest Missouri, eastern Nebraska, and Kansas) and Illinois Basins on the North American midcontinent record the interaction between fluctuations in eustatic sea-level and major tectonic events. One of three major Paleozoic eustatic sea-level lows occurred near the Mississippian/Pennsylvanian boundary and was followed by a eustatic rise that continued into Late Pennsylvanian time. Alleghenian mountain building that is linked to the creation of the Pangean supercontinent also began during latest Mississippian time and continued until latest Pennsylvanian or earliest Permian time. Detrital-zircon geochronology and stratigraphic descriptions allow reconstruction of sediment dispersal patterns associated with these events. Our detrital-zircon signatures from Morrowan-lower Desmoinesian strata in the Illinois Basin are interpreted to reflect a change from regional drainages that reworked underlying Mississippian strata to extensive extrabasinal fluvial systems that supplied detritus shed from southeastern New England. By middle Desmoinesian time, detrital-zircon signatures in the Illinois Basin are more similar to those from coeval units in the central Appalachian Basin, indicating a southward shift in the provenance of the fluvial systems. In the Forest City Basin, Morrowan strata are absent and our detrital-zircon data indicate that Atokan-early Desmoinesian sedimentation was dominated by regional fluvial systems that recycled underlying strata. The introduction of extrabasinal fluvial systems with New England headwaters in the middle Desmoinesian coincided with the overtopping of the Mississippi River Arch and depositional linking of the Forest City and Illinois Basins. The Forest City and Illinois Basins collectively contain an Early-Middle Pennsylvanian sedimentary record in the backbulge depozone of the Alleghenian foreland basin system that reflects overtopping of the forebulge located along the Cincinnati Arch and the effects of eustatic sea-level rise. These results lend credence to the previously proposed transcontinental fluvial systems during late Paleozoic time and help to better constrain their courses.

Provenance of Pennsylvanian–Permian sedimentary rocks associated with the Ancestral Rocky Mountains orogeny in southwestern Laurentia: Implications for continental-scale Laurentian sediment transport systems

“…Source B's age distribution is similar to the commonly invoked Appalachian detrital zircon age signature observed in the central Appalachian Basin (Fig. 13) from Mississippian through early Permian (Eriksson et al, 2004;Thomas et al, 2004;Becker et al, 2005Becker et al, , 2006Gehrels et al, 2011;Kissock et al, 2018;Thomas et al, 2017). Source C's age distribution closely resembles early Paleozoic rocks along North America's western margin exhumed during the Antler orogeny (Beranek et al, 2016).…”

“…Source A's age distribution is similar to the northern Appalachian detrital zircon source invoked for Pennsylvanian sandstone in the Illinois and Forest City Basins (Kissock et al, 2018). In this interpretation, exhumation of Pan-African metasedimentary terranes (presently in the subsurface) within the northern Appalachian Mountains, containing Neoproterozoic zircons (Zartman et al, 1988;Heatherington et al, 1999;Wortman et al, 2000;Hibbard et al, 2002;Pollock et al, 2007;Fyffe et al, 2009), mixed with early Paleozoic (490-270 Ma) and Grenville (1.3-0.9 Ga) detrital zircons while en route to the midcontinent (Kissock et al, 2018) and possibly North American western margin. Source B's age distribution is similar to the commonly invoked Appalachian detrital zircon age signature observed in the central Appalachian Basin (Fig.…”

“…At the continental scale, Morrowan-Atokan Arizona shelf samples from this time interval are statistically distinct from samples proximal to nascent ARM uplifts as well as from samples within the Ouachita-Marathon foreland (Buratowski, 2014), the Illinois and Forest City Basins (Kissock et al, 2018), and the Appalachian Basin (Becker et al, 2005;Park et al, 2010) (Fig. 9).…”

LA-ICPMS U-Pb geochronology of detrital zircon grains from the Coconino, Moenkopi, and Chinle Formations in the Petrified Forest National Park (Arizona)

“…1; Dickinson, 2018). The age distributions for these regions include data from: (1) upper Paleozoic strata of the Appalachian foreland basin (Thomas et al, 2017) and Illinois and Forest City basins (Kissock et al, 2018), (2) upper Paleozoic strata of the Delaware (Xie et al, 2018), Fort Worth (Absalem et al, 2018, and Marathon (Thomas et al, 2019) basins, (3) lower Paleozoic strata of the Grand Canyon (Gehrels et al, 2011) and…”

Detrital Zircon Geochronologic Constraints on Patterns and Drivers of Continental‐Scale Sediment Dispersal in the Late Mississippian

“…An increasing number of studies have focused their efforts on testing various aspects of the Gehrels et al () model (e.g., Finzel, ; Benyon et al, ; Lawton et al, ; Xie, O'Connor, et al, ; Xie, Cains, et al, ; Xie, Buratowski, et al, , Xie, Anthony, & Busbey, ; Xu et al, ; Thomas et al, ; Alsalem et al, ; Kissock et al, ). However, most of these published investigations have focused on Pennsylvanian and younger strata.…”