Detrital zircons in the Mesoproterozoic upper Belt Supergroup in the Pioneer, Beaverhead, and Lemhi Ranges, Montana and Idaho: The Big White arc

500–490 Ma detrital zircons in Upper Cambrian Worm Creek and correlative sandstones, Idaho, Montana, and Wyoming: Magmatism and tectonism within the passive margin

“…These detrital grains are interpreted as recycled from uppermost Belt Supergroup (Fig. 7A; Burmester et al, 2016), the country rock for the Beaverhead granitoids (Skipp, 1984;Link et al, 2007Link et al, , 2016.…”

Tectonic and sedimentary linkages between the Belt-Purcell basin and southwestern Laurentia during the Mesoproterozoic, ca. 1.60–1.40 Ga

“…The prevalence of unimodal 1.73 Ga populations throughout many kilometers of upper Belt strata over a vast area suggests a very large source region with a relatively consistent zircon age signature (Fig. 2B, panel A; e.g., Link et al, 2013). Winston (1986) noted a change to northwestward paleoflow directions in the Missoula Group consistent with a shift to southwestern Laurentia as a primary source region.…”

“…1.73 Ga age population (Fig. 2B, panel A; Stewart et al, 2010;Link et al, 2013). Limited Hf data from detrital zircons and Nd data from argillites within the upper Belt strata indicate isotopic heterogeneity in the Paleoproterozoic source region(s), leading Stewart et al (2010) to suggest East Antarctica as the primary sediment source for upper Belt strata.…”

Detrital Zircon Geochronology of Upper Cretaceous to Paleocene Sandstones From South‐Central Wyoming: Evidence for Middle Campanian Laramide Deformation

“…The Belt Supergroup ( n = 3,854), exposed today in western Montana, is characterized by a dominant 1800–1700 Ma age peak with minor populations at ~1500 and ~2500–2800 Ma (Ross & Villeneuve, ; Lewis et al, ; Stewart et al, ; Link et al, , and Mueller et al, ; Figure ). The Neoproterozoic to Cambrian Brigham Group and coeval strata ( n = 1,844) in Utah and southeastern Idaho is characterized by a prominent 1900–1600 Ma age peak, two smaller populations at ~1100 and ~1450 Ma, and minor population at ~2400‐2800 Ma (Yonkee et al, ; Link et al, ; Figure ).…”

“…The Belt Supergroup, with 58% Yavapai‐Mazatzal‐age grains (Lewis et al, ; Link et al, ; Mueller et al, ; Ross & Villeneuve, and Stewart et al, ), and Laramide Precambrian basement at 80% (Premo & Van Schmus, ) are the only two feasible sources. However, we argue that the Belt Supergroup is an unlikely primary source.…”