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The well‐known Baraboo Interval quartzites in the Laurentian midcontinent are a succession of mature red siliciclastic strata, locally more than 1.5 km thick, and covering an area >300,000 km2, much if not all of which was deposited after the Mazatzal orogeny (<1.63 Ga), and before the Baraboo Orogeny (~1.47 Ga). Ca. 1,300 new LA‐ICPMS detrital zircon ages from six Baraboo Interval inliers in Wisconsin and the Sioux Quartzite in South Dakota, USA attest to significant distal provenances not previously recognized. The principal ~1.8–1.9 Ga and >2.5 Ga age peaks represent local, southern Superior province sediment source areas. Yet more than 30% of our dataset includes ages between 1.9 and 2.5 Ga which are essentially absent from the region. We interpret these non‐locally derived zircons to have been transported ~2,500 km southeast to the Columbian supercontinental margin. The subsequent accretion of the Mazatzal terrane caused a major drainage reorganization, and transport of sediment for the uppermost Baraboo interval strata was north rather than south‐directed. [ABSTRACT FROM AUTHOR]

Here, we present the detrital zircon age spectra for five (n = 36, 68, 66, 41, 29) red quartzite gastroliths collected from the top of the Upper Jurassic Morrison Formation in the eastern Bighorn Basin, Wyoming, USA. The detrital zircon age spectra reveal geon 17 maximum depositional ages, and age peaks that are Yavapai (geon 17), Penokean (geon 18) and Archean (>geon 25). The colour, texture, composition and zircon age spectra of these exoliths are indistinguishable from those of geon 16 (i.e. Baraboo interval) quartzites present in the Laurentian midcontinent more than 1,000 km to the east. We interpret that these gastroliths were ingested by dinosaurs, most likely sauropods, in the Laurentian midcontinent and then transported in their digestive tracts to the site of deposition. These data support the hypothesis of long‐distance dinosaur migration, perhaps following low energy, continental‐scale drainage systems that flowed from the Appalachian highlands to the Morrison Formation depositional basin. [ABSTRACT FROM AUTHOR]

The Neoproterozoic Jacobsville Sandstone outcrops along the south and east shores of Lake Superior, USA. It records intraplate deformation, some during its deposition and some afterwards, after the c. 1,100 Ma Midcontinent Rift (MCR) failed. Here we analyse 549 new detrital zircon ages from five sites, combined with prior data. Initially, local palaeo‐topography controlled the source material, including the MCR‐adjacent Penokean and Archaean rocks. With time the percentage of distal sources increased, including the c. 1,300–980 Ma Grenville orogeny and 1,480–1,360 Ma Granite‐Rhyolite Province. Sites near the Keweenaw fault contain a significant number of MCR‐age zircons, presumably uplifted to the surface, indicating fault motion during deposition. Only a relatively small percentage of 1,090–980 Ma Grenville‐age zircons from collisions to the east are present, suggesting that they were not efficiently transported to the Lake Superior area. This work is innovative in that it is the first to use detrital zircon geochronology to understand the internal stratigraphy of the Jacobsville Sandstone, whose provenance provides new information about the Neoproterozoic tectonic and sedimentary history of Laurentia. [ABSTRACT FROM AUTHOR]

Paleozoic carbonates of cratonic eastern North America comprise the footwall of the Appalachian-Ouachita fold-and-thrust belt and contain a layer-parallel shortening (lps) fabric that is preserved by mechanically twinned calcite. Shortening directions are generally parallel to the Appalachian-Ouachita thrust-transport direction in carbonates of the thrust belt proper (restored width ∼400 km) and within carbonates up to 1700 km into the foreland, giving a pre-thrusting sedimentary prism ∼2100 km wide through which compressive orogenic stresses were transmitted. The shortening strain magnitudes (<6%) and the inferred calcite twinning differential stress magnitudes (<90 MPa) decrease exponentially away from the orogenic front. Calcite twinning strain patterns in other adjacent tectonic provinces, such as the Grenville, Laramide, Keweenawan Rift, and Newark Basin, are distinct from the twinning strains preserved in the cratonic Paleozoic carbonates. (Appalachian orogen, far-field stresses, calcite microstructures). [ABSTRACT FROM AUTHOR]