Supplemental Material: Hydrogeochemical evolution of formation waters responsible for sandstone bleaching and ore mineralization in the Paradox Basin, Colorado Plateau, USA

Table S1: (ST1). PHREEQC inverse mixing modeling for the Mississippian Leadville Ls brine (Solution 3) assumed to be evolved from a mixture of the meteoric water endmember (Solution 1) and evaporated paleo-seawater endmember (Solution 2); Table S2: (ST2). PHREEQC inverse mixing modeling for the salt anticline brine (Solution 3) assumed to be evolved from a mixture of the meteoric water endmember (Solution 1) and evaporated paleo-seawater endmember (Solution 2).

Supplemental Material: Hydrogeochemical evolution of formation waters responsible for sandstone bleaching and ore mineralization in the Paradox Basin, Colorado Plateau, USA

Table S1: (ST1). PHREEQC inverse mixing modeling for the Mississippian Leadville Ls brine (Solution 3) assumed to be evolved from a mixture of the meteoric water endmember (Solution 1) and evaporated paleo-seawater endmember (Solution 2); Table S2: (ST2). PHREEQC inverse mixing modeling for the salt anticline brine (Solution 3) assumed to be evolved from a mixture of the meteoric water endmember (Solution 1) and evaporated paleo-seawater endmember (Solution 2).

Grand Canyon-Parashant National Monument: Paleontological resource inventory (public version)

Grand Canyon-Parashant National Monument (PARA) in northwestern Arizona has significant paleontological resources, which are recognized in the establishing presidential proclamation. Because of the challenges of working in this remote area, there has been little documentation of these resources over the years. PARA also has an unusual management situation which complicates resource management. The majority of PARA is administered by the Bureau of Land Management (BLM; this land is described here as PARA-BLM), while about 20% of the monument is administered by the National Park Service (NPS; this land is described here as PARA-NPS) in conjunction with Lake Mead National Recreation Area (LAKE). Parcels of state and private land are scattered throughout the monument. Reports of fossils within what is now PARA go back to at least 1914. Geologic and paleontologic reports have been sporadic over the past century. Much of what was known of the paleontology before the 2020 field inventory was documented by geologists focused on nearby Grand Canyon National Park (GRCA) and LAKE, or by students working on graduate projects; in either case, paleontology was a secondary topic of interest. The historical record of fossil discoveries in PARA is dominated by Edwin McKee, who reported fossils from localities in PARA-NPS and PARA-BLM as part of larger regional projects published from the 1930s to the 1980s. The U.S. Geological Survey (USGS) has mapped the geology of PARA in a series of publications since the early 1980s. Unpublished reports by researchers from regional institutions have documented paleontological resources in Quaternary caves and rock shelters. From September to December 2020, a field inventory was conducted to better understand the scope and distribution of paleontological resources at PARA. Thirty-eight localities distributed across the monument and throughout its numerous geologic units were documented extensively, including more than 420 GPS points and 1,300 photos, and a small number of fossil specimens were collected and catalogued under 38 numbers. In addition, interviews were conducted with staff to document the status of paleontology at PARA, and potential directions for future management, research, protection, and interpretation. In geologic terms, PARA is located on the boundary of the Colorado Plateau and the Basin and Range provinces. Before the uplift of the Colorado Plateau near the end of the Cretaceous 66 million years ago, this area was much lower in elevation and subject to flooding by shallow continental seas. This led to prolonged episodes of marine deposition as well as complex stratigraphic intervals of alternating terrestrial and marine strata. Most of the rock formations that are exposed in the monument belong to the Paleozoic part of the Grand Canyon section, deposited between approximately 510 and 270 million years ago in mostly shallow marine settings. These rocks have abundant fossils of marine invertebrates such as sponges, corals, bryozoans, brachiopods, bivalves, gastropods, crinoids, and echinoids. The Cambrian–Devonian portion of the Grand Canyon Paleozoic section is represented in only a few areas of PARA. The bulk of the Paleozoic rocks at PARA are Mississippian to Permian in age, approximately 360 to 270 million years old, and belong to the Redwall Limestone through the Kaibab Formation. While the Grand Canyon section has only small remnants of younger Mesozoic rocks, several Mesozoic formations are exposed within PARA, mostly ranging in age from the Early Triassic to the Early Jurassic (approximately 252 to 175 million years ago), as well as some middle Cretaceous rocks deposited approximately 100 million years ago. Mesozoic fossils in PARA include marine fossils in the Moenkopi Formation and petrified wood and invertebrate trace fossils in the Chinle Formation and undivided Moenave and Kayenta Formations.

Climate-Driven Dietary Change on the Colorado Plateau, USA, and Implications for Gender-Specific Foraging Patterns

Complementary archaeological and paleoenvironmental datasets from North Creek Shelter (Colorado Plateau, Utah, USA) are analyzed using the diet breadth model, revealing human dietary patterns during the early and middle Holocene. Abundance indices are derived from botanical and faunal datasets and, along with stone tools, are used to test the prediction that increasing aridity caused the decline of high-return resources. This prediction appears valid with respect to botanical resources, given that high-ranked plants drop out of the diet after 9800 cal BP and are replaced with low-ranked, small seeds. The prediction is not met, however, with respect to faunal resources: high-ranked artiodactyls are consistently abundant in the diet. The effects of climate change on dietary choices are also examined. Findings show that increased aridity coincides with greater use of small seeds and ground stone tools but not with increases in low-ranked fauna, such as leporids. The patterns observed from the North Creek Shelter botanical and faunal datasets may reflect different foraging strategies between men and women. This would explain why low-ranked plant resources became increasingly abundant in the diet without a corresponding decrease in abundance of high-ranked artiodactyls. If so, then archaeological records with similar datasets should be reexamined with this perspective.

Identification of seasonal varves in the lower Pliocene Bouse Formation, lower Colorado River Valley, and implications for Colorado Plateau uplift

The cause of Cenozoic uplift of the Colorado Plateau is one of the largest remaining problems of Cordilleran tectonics. Difficulty in discriminating between two major classes of uplift mechanisms, one related to lithosphere modification by low-angle subduction and the other related to active mantle processes following termination of subduction, is hampered by lack of evidence for the timing of uplift. The carbonate member of the Pliocene Bouse Formation in the lower Colorado River Valley southwest of the Colorado Plateau has been interpreted as estuarine, in which case its modern elevation of up to 330 m above sea level would be important evidence for late Cenozoic uplift. The carbonate member includes laminated marl and claystone interpreted previously in at least one locality as tidal, which is therefore of marine origin. We analyzed lamination mineralogy, oxygen and carbon isotopes, and thickness variations to discriminate between a tidal versus seasonal origin. Oxygen and carbon isotopic analysis of two laminated carbonate samples shows an alternating pattern of lower δ18O and δ13C associated with micrite and slightly higher δ18O and δ13C associated with siltstone, which is consistent with seasonal variation. Covariation of alternating δ18O and δ13C also indicates that post-depositional chemical alteration did not affect these samples. Furthermore, we did not identify any periodic thickness variations suggestive of tidal influence. We conclude that lamination characteristics indicate seasonal genesis in a lake rather than tidal genesis in an estuary and that the laminated Bouse Formation strata provide no constraints on the timing of Colorado Plateau uplift.

A constraint on post–6 Ma timing of western Grand Canyon (Arizona, USA) incision removed: Local derivation indicated by ca. 5.4 Ma fluvial deposits below Shivwits Plateau basalts north of Grand Canyon

The timing of integration of the Colorado River system is central to understanding the landscape evolution of much of the southwestern United States. However, the time at which the Colorado River started incising the westernmost Grand Canyon (Arizona) is still an unsettled question, with conflicting interpretations of both geologic and thermochronologic data from western Grand Canyon. Fluvial gravels on the Shivwits Plateau, north of the canyon, have been reported to contain clasts derived from south of the modern canyon, suggesting the absence of western Grand Canyon at the time of their deposition. In this study, we reassess these deposits using modern geochronologic measurements to determine the age of the deposits and the presence or absence of clasts from south of the Grand Canyon. We could not identify southerly derived clasts, so cannot rule out the existence of a major topographic barrier such as Grand Canyon prior to the age of deposition of the gravels. 40Ar/39Ar analysis of a basalt clast entrained in the upper deposit (in combination with prior data) supports a maximum age of deposition of ca. 5.4 Ma, limiting deposition to post-Miocene, a period from which very few diagnostic and dated fluvial deposits remain in the western Colorado Plateau. Analysis of detrital zircon composition of the sand matrix supports interpretation of the deposit as being locally derived and not part of a major throughgoing river. We suggest that the published constraint of <6 Ma timing of Grand Canyon incision may be removed, given that no clasts that must be sourced from south of Grand Canyon were found in the only known outcrop of gravels under the Shivwits Plateau basalts at Grassy Mountain north of Grand Canyon.

Uranium and Vanadium Resources of Utah: An Update in the Era of Critical Minerals and Carbon Neutrality

Utah is the second largest vanadium producing state and the third largest uranium producing state in the United States. Carnotite, a primary ore mineral for both vanadium and uranium, was first discovered and used by Native Americans as a source of pigment in the Colorado Plateau hysiographic province of eastern Utah. Radioactive deposits have been ommercially mined in Utah since about 1900, starting with radium, followed by vanadium, and thenuranium. In 1952, the discovery of the Mi Vida mine in Utah’s Lisbon Valley mining district in San Juan County kicked off a uranium exploration rush across the Colorado Plateau. As a result, the United States dominated the global uranium market from the early 1950s to late 1970s. In the modern mining era, Utah is an important contributor to the domestic uranium and vanadium markets with the only operating conventional uranium-vanadium mill in the country, multiple uranium-vanadium mines on standby, and active uranium-vanadium exploration. Overall, Utah has produced an estimated 122 million lbs U3O8 and 136 million lbs V2O5 since 1904. Most of this production has been from the sandstone-hosted deposits of the Paradox Basin, with minor production from volcanogenic deposits and as byproducts from other operations across the state