Article
Geosciences, Multidisciplinary
B. S. Tober, J. W. Holt, M. S. Christoffersen, M. Truffer, C. F. Larsen, D. J. Brinkerhoff, S. A. Mooneyham
Summary: The Malaspina Glacier is the largest piedmont glacier in the world, located on the coast of southern Alaska. It is experiencing rapid thermokarst erosion in the ice-cored foreland zone, which separates it from the warm waters of the Gulf of Alaska. The glacier is thinning at a rate of over 1 m/yr, and its bed elevation is below sea level in some places. The mapping of the glacier's subglacial topography using airborne radar sounding data shows that previous models overestimated the glacier's volume and that it mainly occupies a basin grounded below sea level, with potential implications for global sea-level rise.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2023)
Article
Geosciences, Multidisciplinary
Maureen A. L. Walton, Sean P. S. Gulick, Peter J. Haeussler
Summary: This study presents an improved tectonic framework for the Yakutat area in southeastern Alaska, based on marine geophysical data collected in 2012. By combining various data sources, the researchers were able to update the fault map, develop a structural model of Yakutat Bay, and assess the uncertainties of previous geologic coseismic uplift measurements. The results provide valuable insights into earthquake hazards in the region.
Review
Geosciences, Multidisciplinary
John W. F. Waldron, Phil J. A. McCausland, Sandra M. Barr, David I. Schofield, Doug Reusch, Lei Wu
Summary: The study of the Iapetus Ocean's history is important for understanding the relationship between orogeny and plate motion. Research shows that the Iapetus Ocean consisted of several terranes that moved and rotated over time due to plate tectonics. Studying these terranes can provide insights into the origin, motion, and evolution of the crust.
EARTH-SCIENCE REVIEWS
(2022)
Article
Geosciences, Multidisciplinary
Trevor S. Waldien, Sarah M. Roeske, Jeffrey A. Benowitz, Evan Twelker, Meghan S. Miller
Summary: Terrane accretion leads to complex slip histories in lithospheric-scale fault systems. This study in the Alaska Range suture zone documents the geological evolution of reactivated shortening structures and metamorphic rocks, revealing the linkage between different upper crustal structures through the lithosphere. Detrital zircon U-Pb age spectra highlight distinct metasedimentary belts and a connection to the Wrangellia composite terrane, with the Valdez Creek fault playing a key role in reactivating structures within the suture zone.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2021)
Article
Geosciences, Multidisciplinary
Sarah N. Heinlein, Terry L. Pavlis, Ronald L. Bruhn
Summary: The study evaluates the kinematics of the Ragged Mountain fault in Alaska, USA, using high-resolution three-dimensional terrain models. It suggests that the uphill-facing normal fault scarps along the fault may represent extension above a buried thrust ramp. Through detailed geomorphic mapping and theoretical modeling, the study analyzes the relationship between thrust displacement, upper-plate extension, and ramp dip, providing insights into the active tectonics of the region.
Article
Geosciences, Multidisciplinary
Bruno Ribeiro, Leonardo B. L. Lopes, Christopher L. Kirkland, Peter A. Cawood, Frederico M. Faleiros, Michael I. H. Hartnady, Wilson Teixeira, Jacob A. Mulder, Nick M. W. Roberts, Colombo C. G. Tassinari
Summary: This study verifies the petrogenetic link between the SW Amazonian Craton, Rio Apa, and Paragua terranes through the comparison of zircon isotopic data. The findings also suggest a similar pattern of advancing and retreating episodes in these terranes, resembling modern accretionary orogens such as the Andes.
PRECAMBRIAN RESEARCH
(2022)
Article
Geochemistry & Geophysics
Sarah E. Petersen, Thomas D. Hoisch, Ryan C. Porter
Summary: This study investigates the role of hydration in influencing slab buoyancy and the geometry of the downgoing oceanic plate in low-angle subduction settings, finding that a moderate amount of hydration can reduce slab density and maintain slab buoyancy, which is important for altering the subduction geometry in Alaska.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geology
Alexandra B. Nagurney, Mark J. Caddick, Chris E. White
Summary: This study presents data on the pressure and temperature conditions experienced by metamorphic rocks in the Meguma Terrane of Nova Scotia, Canada. The results suggest that amphibolite facies metamorphism occurred during the Devonian Neoacadian orogeny, and the diffusion of aluminum was likely the rate-limiting step for garnet crystallization. The study also indicates that the nature of the orogeny is still not well understood and further research is needed to better understand it.
JOURNAL OF METAMORPHIC GEOLOGY
(2022)
Article
Multidisciplinary Sciences
Alexander Koptev, Matthias Nettesheim, Sarah Falkowski, Todd A. Ehlers
Summary: This article presents a geomorphic model of the studied area in southern Alaska. The results show that the interaction between tectonic deformation and surface erosion processes controls the rock uplift patterns in the region.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Andrew J. Calvert, Michael P. Doublier, Samantha E. Sellars
Summary: Reprocessed seismic reflection profiles from the northwest Archaean Yilgarn Craton and the Palaeoproterozoic Capricorn Orogen of western Australia reveal the existence of a similar to 4 km thick south-dipping band of seismic reflectors, interpreted as a relict suture zone within the lithosphere. These reflectors could have been created by subduction of an oceanic plate or underthrusting of continental crust deep into the lithosphere during different geological periods.
NATURE COMMUNICATIONS
(2021)
Article
Geosciences, Multidisciplinary
Zakaria Hamimi, Mohamed Abdelkareem, Abdel-Rahman Fowler, Mohammed H. Younis, Mohammed Matsah, Fathy Abdalla
Summary: The Central Asir Shear Zone (CASZ) in southern Saudi Arabia is a N- to NNE-oriented inhomogeneous strain zone parallel to the Nabitah shear belt. It has a complex deformation history involving arc-collision, dextral transpression and sinistral strike-slip faulting. Remote-sensing analysis and field investigations reveal geological and structural features along the CASZ, showing evidence of polyphase deformation with distinctive lineaments indicating different strain orientations.
JOURNAL OF ASIAN EARTH SCIENCES
(2021)
Article
Geochemistry & Geophysics
T. S. Waldien, R. O. Lease, S. M. Roeske, J. A. Benowitz, P. B. O'Sullivan
Summary: Our study shows that the dextral Denali fault system in the eastern Alaska Range has facilitated bedrock exhumation and topographic growth during oblique flat slab subduction. The data suggest that most high topography regions in southern Alaska have undergone rapid bedrock cooling and exhumation since 30 Ma, with active strike-slip fault systems playing a key role.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geology
Xiao-Hui Sun, Yan Luan, Tian-Yun Zhang, Matthew J. Brzozowski, Hui Ye, Chang-Zhi Wu
Summary: In this study, an integrated approach was used to investigate the Yudongzi banded iron formations in the Bikou Terrane, Central China. The results suggest that the iron deposits were formed in the early Neoarchean and underwent metamorphism at around 2480 and 1818 million years ago. The formation of the iron deposits may be related to submarine hydrothermal fluid.
ORE GEOLOGY REVIEWS
(2023)
Article
Geosciences, Multidisciplinary
Yvette D. Kuiper, Andre Michard, Etienne Ruellan, Christopher S. Holm-Denoma, James L. Crowley
Summary: The study suggests that the rocks of the Mazagan Escarpment likely have a Northwest African origin, rather than being part of an exotic Avalonian terrane.
JOURNAL OF AFRICAN EARTH SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
T. R. K. Chetty
Summary: The geological and structural complexities of the Southern Granulite Terrane (SGT) of India are increasingly recognized, with the reconstruction of structural cross sections revealing multiple thrust systems, indicating the large-scale collision resulting from the south directed subduction of ancient plates.
JOURNAL OF ASIAN EARTH SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Catherine H. Ross, Daniel F. Stockli, Cornelia Rasmussen, Sean P. S. Gulick, Sietze J. de Graaff, Philippe Claeys, Jiawei Zhao, Long Xiao, Annemarie E. Pickersgill, Martin Schmieder, David A. Kring, Axel Wittmann, Joanna Morgan
Summary: Determining the nature and age of the Chicxulub impact target rock is crucial for understanding the evolution of the Maya Block basement. The data from Expedition 364 shed light on the pre-impact tectonic evolution of the Chicxulub target rocks, suggesting the existence of a continental volcanic arc in the Maya Block.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2022)
Article
Geosciences, Multidisciplinary
Sietze J. de Graaff, Pim Kaskes, Thomas Dehais, Steven Goderis, Vinciane Debaille, Catherine H. Ross, Sean P. S. Gulick, Jean-Guillaume Feignon, Ludovic Ferriere, Christian Koeberl, Jan Smit, Nadine Mattielli, Philippe Claeys
Summary: This study characterizes the petrography and geochemistry of rocks and impactites from the Chicxulub impact structure in Mexico, aiming to investigate the components involved in impact melt formation and the emplacement processes at Chicxulub. The different impactite units are interpreted as different stages of impact melt rock injection and surface deposition during crater formation. The geochemical characterization of pre-impact lithologies provides insights into the composition of the impact melt rock units.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2022)
Article
Geosciences, Multidisciplinary
Pim Kaskes, Sietze J. de Graaff, Jean-Guillaume Feignon, Thomas Dehais, Steven Goderis, Ludovic Ferriere, Christian Koeberl, Jan Smit, Axel Wittmann, Sean P. S. Gulick, Vinciane Debaille, Nadine Mattielli, Philippe Claeys
Summary: This study presents a new classification of a similar to 100-m-thick crater suevite sequence, providing valuable insights into the formation and sedimentary processes of suevite on top of the Chicxulub peak ring. The data set obtained from this study sheds light on the dynamics and timing of proximal marine cratering processes following a large impact event.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2022)
Article
Geochemistry & Geophysics
L. Hernandez-Terrones, L. Martinez, J. Szamotulski, E. Gonzalez-Partida, J. V. Morgan, C. M. Lowery, S. P. S. Gulick, M. Rebolledo-Vieyra, D. Kring
Summary: The aim of this study is to evaluate fluid circulation and determine the composition of hydrothermal fluids in the Chicxulub crater after the impact. The results show that the temperature and composition of the fluids changed as they migrated through the crater rocks, and post-impact fluid circulation modified the temperature distribution.
APPLIED GEOCHEMISTRY
(2022)
Article
Geochemistry & Geophysics
C. G. Nixon, D. R. Schmitt, R. Kofman, J. Lofi, S. P. S. Gulick, S. Saustrup, G. L. Christeson, D. A. Kring
Summary: This study conducted a vertical seismic profile in a borehole to better understand the seismic reflectivity and in situ seismic properties of the Chicxulub impact structure peak ring. The results showed that the strong seismic reflection event observed in the seismic reflection data was caused by discontinuities in the elastic impedance. The seismic wavefield below the reflection event was chaotic, indicating high levels of scattering. Shear wave speeds and damage parameters were also determined, which can aid in calibrating impact models and assessing levels of fracturing.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geology
Cole M. Speed, John M. Swartz, Sean P. S. Gulick, John A. Goff
Summary: This study reveals the preservation and stratigraphic expression of coastal geomorphic features through the analysis of seismic reflection data. It also proposes recognition criteria for the seismic stratigraphic expression of coastal floodplain channels.
Article
Geochemistry & Geophysics
Sietze J. de Graaff, Catherine H. Ross, Jean-Guillaume Feignon, Pim Kaskes, Sean P. S. Gulick, Steven Goderis, Thomas Dehais, Vinciane Debaille, Ludovic Ferriere, Christian Koeberl, Nadine Mattielli, Daniel F. Stockli, Philippe Claeys
Summary: The study presents the first ages of pre-impact magmatic dikes preserved in Chicxulub's peak ring, providing insights into the subsurface composition and evolutionary history of the Yucatan Peninsula. The dating results reveal two age groups, Carboniferous dacites (328-318 Ma) and Jurassic dolerites (169-159 Ma), suggesting the presence of previously unsampled magmatic phases. The investigation of isotopic compositions further indicates that the dolerites contributed significantly to the Chicxulub impact melt rock, representing a pervasive Jurassic magmatic phase associated with the opening of the Gulf of Mexico.
Article
Geosciences, Multidisciplinary
Jacob T. Burstein, John A. Goff, Sean P. S. Gulick, Christopher Lowery, Patricia Standring, John Swartz
Summary: Understanding the role of antecedent topography in the evolution of barrier islands is valuable for preparing coastal communities for future impacts of climate change. This study investigates the stratigraphic framework of the Trinity River incised valley offshore Galveston, Texas to examine the influence of antecedent topography on the evolution of an early Holocene barrier island system. The findings highlight the central role of the geometry and elevation of the underlying antecedent topography in promoting both initiation and stabilization of the barrier island system.
Article
Geochemistry & Geophysics
Gail L. Christeson, Sean P. S. Gulick, Maureen A. L. Walton, Ginger A. Barth
Summary: This study investigates the crustal structure of the Gulf of Alaska Seamount Province and reveals that variations in crustal thickness and lithospheric thickness play a significant role in the magmatic underplating at seamounts and seamount provinces.
Article
Geochemistry & Geophysics
Christina M. Verhagen, Ji-In Jung, Sonia M. Tikoo, Axel Wittmann, David A. Kring, Stefanie Brachfeld, Laying Wu, Dale H. Burns, Sean P. S. Gulick
Summary: Using advanced microscopy techniques, this study investigated the nature and occurrence of primary and secondary Fe-oxide and Fe-sulfide minerals in the suevite of the Chicxulub impact crater. The results showed decomposition and dissolution patterns of large primary Fe-oxides and the presence of sub-micrometer Fe-oxide crystals concentrated within clay. Secondary Fe-sulfide minerals, associated with Ni- and Co-rich phases, were also found. These findings provide insights into hydrothermal trends and the remobilization of Fe and associated elements in suevites.
Article
Astronomy & Astrophysics
Cyril Grima, Nathaniel E. Putzig, Bruce A. Campbell, Matthew Perry, Sean P. S. Gulick, Russell C. Miller, Aaron T. Russell, Kirk M. Scanlan, Gregor Steinbrugge, Duncan A. Young, Scott D. Kempf, Gregory Ng, Dillon Buhl, Donald D. Blankenship
Summary: Building on previous research, this study investigates the response of the Martian surface to orbital radar using a reflectometry technique known as radar statistical reconnaissance. The results provide statistical parameters describing the surface and near-surface structure of the test region, allowing for the identification of smooth and level terrains. The findings also highlight the complementarity of different data sets and advocate for the use of self-affine radar backscattering models to account for roughness variations at different scales.
PLANETARY SCIENCE JOURNAL
(2022)
Meeting Abstract
Geochemistry & Geophysics
S. P. S. Gulick, J. V. Morgan
METEORITICS & PLANETARY SCIENCE
(2022)
Meeting Abstract
Geochemistry & Geophysics
S. P. S. Gulick, N. McCall, C. Ross, D. Stockli, C. Rasmussen, G. L. Christeson, M. Hesse, M. Malenda, E. L. Lopes, T. M. Chaffee, S. M. Tikoo-Schantz, T. Vanorio, J. V. Morgan
METEORITICS & PLANETARY SCIENCE
(2022)