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
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
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
Geochemistry & Geophysics
Zijian Zhang, Yabo Tong, Shuchen Jin, Xinxin Sun, Lifu Hou, Junling Pei, Zhenyu Yang
Summary: This study conducted a paleomagnetic and geochronologic study of the late Eocene trachyte intrusive mass in the Mangkang area of Tibet. The results indicate that the Eastern Himalayan Syntaxis was formed after 35 Ma when Eurasia was penetrated by northward-moving India. The study links the tectonic activity of the Eastern Himalayan Syntaxis to the lateral extrusion of the southeastern margin of the Tibetan Plateau, providing a new perspective on the evolution of this region since the late Eocene.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geography, Physical
Zhen Wei, Xianghui Li, Andrew K. Laskowski, Aislin N. Reynolds, Xiaolong Fan
Summary: This study investigates the Lilong succession in southeastern Tibet, China, confirming its provenance from the central-northern and southern Lhasa Terrane based on observations from petrography, stratigraphy, sedimentology, detrital-zircon geochronology, and bulkrock Sr-Nd isotope analysis. The Lilong succession is proposed to correlate with the Ngamring Formation in the Xigaze forearc basin, suggesting it as a counterpart remnant of the eastern Xigaze forearc basin system, different from the forearc basin systems in the western Himalaya.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Ling Zhang, Shiming Liang, Xiaoping Yang, Weijun Gan, Chenglong Dai
Summary: The KJFZ is considered the southernmost major fault in the Tibetan plateau's strike-slip fault system, but the strike-slip rates are still debated. New GPS measurements show different dextral strike-slip rates for different parts of the Jiali fault.
JOURNAL OF ASIAN EARTH SCIENCES
(2021)
Article
Geochemistry & Geophysics
Devajit Hazarika, Abhishek Kundu, Parthapratim Ghosh
Summary: The seismicity in the north-eastern fringe of the Indian Plate in the Eastern Himalayan Syntaxis has been analyzed and it is found that the region is seismically active up to about 40 km depth. In contrast, the seismicity in the Indo-Burma Ranges is observed up to a depth of about 200 km, indicating the active subduction process of the Indian plate beneath the IBR. The indentation process of the rigid Indian plate into south-east Asia predominantly controls the seismicity north of the IBR.
Article
Geochemistry & Geophysics
Daniel Kwayisi, Marlina Elburg, Jeremie Lehmann
Summary: This study presents new geochemical and isotopic data for the mafic suite of the Buem structural unit in Ghana, providing insights into its origin, geodynamic setting, relationship to the Pharusian suture zone, and significance in the Dahomeyide belt. The results suggest that the Buem structural unit represents the remnant of the Pharusian oceanic crust, formed during the breakup of Rodinia, and corresponds to a continental margin-type ophiolite.
Article
Geosciences, Multidisciplinary
Christopher D. Connors, David W. Houseknecht
Summary: The interpretation of seismic data from the U.S. Chukchi shelf reveals the occurrence of four tectonic events in the last 400 million years, resulting in distinct inherited structures. These events include the formation of a fold-and-thrust belt, the development of the Hanna Trough, deep thrusting in the North Chukchi high, and Cenozoic extension and strike-slip faulting in the Hanna Trough.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Geology
Philip J. Heron, A. L. Peace, K. J. W. McCaffrey, A. J. Yu, R. N. Pysklywec
Summary: Earth's continental crust has gone through supercontinent cycles, leaving behind ancient cores and younger crustal additions. However, the mechanism of continental fragment dispersal during breakup is not well understood. Inherited structures from previous tectonic activity may play a role in the generation of continental terranes. By studying the Torngat orogen and the Nain Province continental fragment in Eastern Canada, researchers have shown that deep lithospheric scarring can separate and strand narrow continental terranes, with a width limited by tectonic conditions during continental suturing. This finding has important implications for understanding terrane generation and continent breakup.
Article
Geography, Physical
Gaia Siravo, Paola Molin, Andrea Sembroni, Maria Giuditta Fellin, Claudio Faccenna
Summary: Through the study of high-elevation plateaus in the South American continent, it is found that these landforms are gradually formed under different environmental conditions, influenced by both crustal deformation and sub-crustal processes. By analyzing various aspects such as river systems and topography, researchers have revealed the evolutionary processes and discussed the reorganization pattern of the drainage network in different periods.
Article
Multidisciplinary Sciences
Abdelmonem Eldougdoug, Maha Abdelazeem, Mohamed Gobashy, Mohamed Abdelwahed, Yasser Abd El-Rahman, Ahmed Abdelhalim, Said Said
Summary: Gold mining is a strategic sector that relies on geophysical techniques for uncovering potential metal deposits. A recent geological field investigation in the South Abu Marawat area suggests that gold mineralization is associated with altered ultramafic zones characterized by low magnetic susceptibility anomalies.
SCIENTIFIC REPORTS
(2023)
Article
Geochemistry & Geophysics
Huang ChenYu, Chang LiJun, Ding ZhiFeng
Summary: This study is based on teleseismic waveform data from 48 broadband seismic stations in the eastern Himalayan syntaxis and adjacent areas. The results show that the crustal anisotropy in these regions is mainly attributed to the middle and lower crust, with the Pms wave splitting reflecting the anisotropy of the middle and lower crust. The anisotropy of the upper mantle is believed to be responsible for SKS wave splitting.
CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
(2021)
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.
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
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
Geosciences, Multidisciplinary
Brandon Shuck, Sean P. S. Gulick, Harm J. A. Van Avendonk, Michael Gurnis, Rupert Sutherland, Joann Stock, Erin Hightower
Summary: This study reveals the spatial-temporal evolution of stress during subduction initiation and suggests an accelerated transition to self-sustaining subduction. In contrast to previous hypotheses, the study proposes a four-dimensional evolution where horizontal forces initially dominate but vertical forces accelerate over time and facilitate the development of self-sustaining subduction.
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.
Article
Multidisciplinary Sciences
Francisco J. Rodriguez-Tovar, Pim Kaskes, Jens Ormo, Sean P. S. Gulick, Michael T. Whalen, Heather L. Jones, Christopher M. Lowery, Timothy J. Bralower, Jan Smit, David T. King, Steven Goderis, Philippe Claeys
Summary: Researchers have reconstructed the macrobenthic tracemaker community and marine paleoenvironment in the Chicxulub impact area prior to the large impact event using paleoichnology and micropaleontology. The study shows that the K-Pg impact event did not have significant effects on the composition of the macroinvertebrate tracemaker community in the Chicxulub region.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Uisdean Nicholson, Veronica J. Bray, Sean P. S. Gulick, Benedict Aduomahor
Summary: Evidence of marine target impacts is rare on Earth. Seismic reflection data from the Guinea Plateau suggest the presence of a complex impact crater that formed approximately 66 million years ago, similar to the age of the Chicxulub impact crater. The crater may have formed as part of a closely timed impact cluster or through the breakup of a common parent asteroid.
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)