Article
Geochemistry & Geophysics
E. S. Finzel, J. A. Rosenblume, D. M. Pearson, Pierre A. Zippi
Summary: The provenance and depositional age of the Upper Cretaceous Frontier Formation in southwestern Montana were determined using biostratigraphy, sandstone petrography, and detrital zircon geochronology. The results suggest that Laramide-style tectonism in Idaho-Montana may not be related to shallow-angle subduction, but rather controlled by factors such as inherited faults, basement highs, and sedimentary cover thickness.
Article
Geochemistry & Geophysics
Justin A. Rosenblume, Emily S. Finzel, David M. Pearson
Summary: The Lower Cretaceous Kootenai Formation in western Montana showed three discrete provenance signatures, indicating different sediment sources from adjacent regions in Early Cretaceous time. These findings provide insights into the sediment dispersal patterns and translational history of terranes in the hinterland of the orogen during this period.
Article
Geology
Matthew M. Jones, Sierra Petersen, Allison N. Curley
Summary: The mid-Cretaceous thermal maximum is considered one of the warmest periods in Earth's history, accompanied by significant paleoceanographic changes and the formation of epicontinental seaways. Analyzing Cenomanian oyster fossils revealed extreme mid-latitude warmth in North America, providing insights into Late Cretaceous temperature trends. The findings highlight the potential of clumped isotope paleotemperatures in resolving upper thermal limits of Phanerozoic greenhouse climates.
Review
Geosciences, Multidisciplinary
Lydian M. Boschman
Summary: The Andes, the longest continental mountain range on Earth, started forming in the Late Cretaceous with highly diachronous uplift in different regions. Reconstructing the timing of surface uplift is crucial for understanding continental-scale moisture transport, the origin and evolution of the Amazon River and Rainforest, and the coevolution of solid Earth, landscapes, climate, and life in South America.
EARTH-SCIENCE REVIEWS
(2021)
Article
Engineering, Civil
Kabir Rasouli, John W. Pomeroy, Paul H. Whitfield
Summary: This study investigates the sensitivity of mountain snow and runoff to warming and precipitation using a physically-based hydrological model. The results suggest that annual runoff is less sensitive to temperature compared to the snow regime, and that precipitation change is the primary factor affecting runoff. Additionally, the study finds that increased precipitation has a stronger compensating effect on snow and runoff regimes at higher elevations and latitudes.
JOURNAL OF HYDROLOGY
(2022)
Article
Geochemistry & Geophysics
Russell V. Di Fiori, Sean P. Long, Anne C. Fetrow, Kathryn E. Snell, Joshua W. Bonde, Jeff D. Vervoort
Summary: Documenting the deformation within fold-thrust belts is crucial for understanding orogen dynamics. Through geologic mapping and U-Pb zircon geochronology of the Cretaceous Newark Canyon Formation in central Nevada, this study revealed the spatio-temporal progression of deformation processes in the region, including thrusting/folding, east-vergent thrust fault motion, and post-dated east-vergent folding. These findings contribute to a better understanding of the long-duration strain partitioning between the foreland and hinterland in the Sevier hinterland during coupling above the basal decollement.
Editorial Material
Environmental Sciences
Isabel Cristina Hoyos Rincon
Summary: The reduction of mountain snowpack worldwide under climate change is causing concerns. Recent research warns of an anticipated transition to low-to-no snowpack in the American Cordillera, which will have consequences for freshwater availability.
NATURE CLIMATE CHANGE
(2022)
Article
Geosciences, Multidisciplinary
Andrew Zuza, Christopher D. Henry, Seth Dee, Charles H. Thorman, Matthew T. Heizler
Summary: The metamorphic core complex in northeastern Nevada reveals a multi-stage tectonic history of crustal thickening and thinning, with observations of polyphase cooling and reheating of Paleozoic-early Proterozoic rocks. Jurassic and Cretaceous contractional deformation, Eocene intrusions, and late Oligocene to middle Miocene extension activities were observed, indicating a dynamic pulsed evolution in the hinterland of the North American Cordillera.
Article
Environmental Sciences
Wouter R. Berghuijs, Louise J. Slater
Summary: The importance of soil moisture in triggering river floods is increasingly recognized. However, groundwater from the deeper, saturated zone plays a significant role in river flow and flooding, although its effects are not well understood. Analyzing hydroclimatic records of North American watersheds from 1981 to 2018, it is found that baseflow, which is groundwater-sustained river flow, influences the magnitude of annual flooding at different timescales. Floods are mainly caused by the combination of high precipitation and baseflow, with flood magnitudes more closely related to changes in baseflow than in soil moisture and short-term extreme precipitation. Additionally, long-term trends in flood magnitude and decadal variations align more with groundwater storage and baseflow trends rather than changing precipitation extremes and soil moisture, indicating the importance of groundwater in shaping North American river floods.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Zhiyang Li, Jennifer Aschoff
Summary: The stratigraphic record from the North American Cordilleran foreland basin provides valuable insights into the formation and filling of foreland basins by integrating various geological processes. This study summarizes the complex shoreline evolution in the central part of the basin through paleogeographic maps, showing high-resolution shoreline history and distribution of depositional environments during the Late Cretaceous. The study highlights the importance of subcrustal processes, such as mantle flow, in influencing subsidence/uplift and sediment dispersal patterns in the basin.
EARTH-SCIENCE REVIEWS
(2022)
Article
Multidisciplinary Sciences
Chase Doran Brownstein
Summary: During the Cretaceous period, terrestrial vertebrates experienced diversifications and turnovers due to global geographical change, although the poor fossil record from the early Late Cretaceous has concealed how dinosaurs and other terrestrial vertebrates responded to these events. This study describes two dinosaurs from the North American paleolandmass Appalachia, shedding light on the timing of important anatomical innovations in two widespread dinosaur lineages. The phylogenetic positions of the dinosaurs show similarities between Appalachian and Eurasian dinosaur faunas, indicating a degree of endemism in Appalachian dinosaur assemblages due to episodes of vicariance.
ROYAL SOCIETY OPEN SCIENCE
(2021)
Article
Geology
Steven L. Wick
Summary: The discovery of Late Cretaceous characiform fish fossils in the Lowerverse locality of the Aguja Formation in West Texas includes two different morphotypes. These findings support previous estimates on the timing of characiform fish entering North America from Europe or South America, and indicate a possible south-to-north radiation of Laramidian characiforms.
CRETACEOUS RESEARCH
(2021)
Article
Geography, Physical
Seung Choi, Noe-Heon Kim, Hyo-Im Kim, Jin Jung Kweon, Sung Keun Lee, Shukang Zhang, David J. Varricchio
Summary: Turtles are the only amniotes that lay aragonitic eggs. A discovery in Montana, USA, confirmed the existence of aragonite in turtle eggs dating back to at least the Campanian period, around 76 million years ago. This finding supports the hypothesis that aragonitic eggshell is a unique feature of all turtles and suggests high-quality, unaltered paleoenvironmental information can be obtained from localities with aragonitic turtle eggs.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Geochemistry & Geophysics
Roy D. Hyndman, Dante Canil
Summary: Recent volcanic rocks across the Cordillera landward of the volcanic arc are mainly produced by partial melt in the upper asthenosphere, where two conditions are met: thin lithosphere and shallow hot asthenosphere, with a wet upper asthenosphere. Integrated geochemical analyses, seismic velocities, and receiver functions help to constrain the source temperature and depth of partial melt, as well as define the lithosphere-asthenosphere boundary. The spatial distribution of these recent volcanics is discussed in terms of mechanisms such as small-scale convection and phase transitions at specific depths.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Multidisciplinary Sciences
Case Youngflesh, Graham A. Montgomery, James F. Saracco, David A. W. Miller, Robert P. Guralnick, Allen H. Hurlbert, Rodney B. Siegel, Raphael LaFrance, Morgan W. Tingley
Summary: Changes in phenology have been observed globally, with concerns that ecological interactions may become decoupled. However, evidence for the demographic consequences of phenological asynchrony remains elusive.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Geochemistry & Geophysics
Lingyu Zhang, Kristoffer Szilas
Summary: This study presents new petrological and geochemical data for the Narssaq Ultramafic Body (NUB) in the Itsaq Gneiss Complex of SW Greenland. The results indicate that the ultramafic rocks of NUB are not mantle residues, but instead represent crustal cumulates derived from high-Mg magmas.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Rong Xu, Sarah Lambart, Oliver Nebel, Ming Li, Zhongjie Bai, Junbo Zhang, Ganglan Zhang, Jianfeng Gao, Hong Zhong, Yongsheng Liu
Summary: This study investigated the iron isotope compositions of Cenozoic basalts in Southeast China, finding significant variations related to different types of basalts and their respective sources.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
C. J. Ebinger, Miriam C. Reiss, Ian Bastow, Mary M. Karanja
Summary: The East African rift system is formed above mantle upwellings and the formation of rifts is related to lithospheric thinning and magmatic activity. The amount of splitting varies spatially and the fast axes are predominantly parallel to the orientation of the rifts. Thick lithospheric modules have less splitting and different orientations, which may indicate mantle plume flow. Splitting rotates and increases in strength as it enters the rift zones, suggesting that the anisotropy is mainly present at shallow depths.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Correction
Geochemistry & Geophysics
Ekaterina Rojas-Kolomiets, Owen Jensen, Michael Bizimis, Gene Yogodzinski, Lukas Ackerman
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Robert W. Nicklas, Igor S. Puchtel, Ethan F. Baxter
Summary: Oxygen fugacity is a fundamental parameter for understanding redox processes in igneous systems. This study compares the Fe-XANES oxybarometry method with the V-in-olivine method for evaluating fO(2) in MORB lavas. The results show that the V-in-olivine method is not applicable to samples with low MgO content, and that the majority of Archean komatiite sources have lower fO(2) than modern MORB.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Chunfei Chen, Stephen F. Foley, Sebastian Tappe, Huange Ren, Lanping Feng, Yongsheng Liu
Summary: The volatile components CO2 and H2O play a major role in mantle melting and heterogeneity. In this study, Ca isotopes were used to trace the lithological heterogeneity in alkaline magmatic rocks. The results revealed the presence of K-richterite and carbonate components as the source of alkaline magmas with low delta 44/40Ca values. These findings highlight the importance of Ca isotopes as a robust tracer of lithological variation caused by volatiles in the Earth's upper mantle.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Timothee Jautzy, Gilles Rixhon, Regis Braucher, Romain Delunel, Pierre G. Valla, Laurent Schmitt, Aster Team
Summary: Although the current approach to estimate catchment-wide denudation rates using only 10Be concentrations has made significant progress in geomorphology, this study argues for the inclusion of 26Al measurements and testing of steady-state assumptions in slow eroding, formerly glaciated landscapes. The study conducted measurements of both 10Be and 26Al in stream sediments from the Vosges Massif in France and found that elevation, slope, channel steepness, and precipitation were the primary factors controlling denudation rates. The study also revealed a significant relationship between the extent of past glaciation and the cosmogenic (un-)steadiness in the stream sediments.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Erik van der Wiel, Douwe J. J. van Hinsbergen, Cedric Thieulot, Wim Spakman
Summary: Numerical models of Earth's mantle dynamics can predict the vigour and mixing of mantle flow, and the average slab sinking rates are an unexplored parameter that can provide intrinsic information on these characteristics. Through numerical experiments, it has been found that slab sinking rates are strongly correlated with mantle convection and mixing, and may explain geochemical observations from hotspot volcanoes.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)