Article
Engineering, Chemical
Tongyang Lou, Congjun Feng, Mengsi Sun, Zhiqiang Chen
Summary: This study identifies the sedimentary microfacies types and reservoir characteristics of braided river thin-bedded sandstones in the Chang 81 Member at Daijiaping, Ordos Basin through the integration of data from core samples, drilling, and seismic information. A method of constrained correlation between seismic waveform and seismic facies was employed to accurately determine the sand body stacking patterns and spatial distribution of thin-bedded tight sandstones. The findings provide valuable guidance for well deployment and enhancing oil and gas recovery.
Article
Geosciences, Multidisciplinary
Kevin J. Toth, James O. Puckette
Summary: Valley filling sandstone in parts of Noble, Pawnee, and Osage Counties in Oklahoma exhibit linear distribution patterns and have produced significant oil and gas reserves since their discovery in the early twentieth century. The highly elongated and narrow sandstone-bearing channels contain thick accumulations of sandstone and unexpectedly stacked reservoirs, leading to the hypothesis that accommodation was generated along the same trend across multiple high-frequency cycles. The distribution of these narrow sandstones can be challenging to map using wire-line log control, but seismic data can provide additional exploration tools to locate potentially lucrative Pennsylvanian shoestring sandstone reservoirs.
Article
Geochemistry & Geophysics
George E. Mustoe, Thomas A. Dillhoff
Summary: Silicified wood is abundant in the Middle Miocene flows and sedimentary interbeds of the Columbia River Basalt Group in central Washington State. The fossil wood's mineralogy is diverse, including opal-A, opal-CT, chalcedony, and macrocrystalline quartz. Silicification occurred as a sequential process influenced by changes in the geochemical environment or anatomical structures.
Article
Geography, Physical
Emese M. Bordy, T'Nielle Haupt, Howard Head
Summary: This study focuses on the uppermost Karoo Supergroup in southern Africa, documenting evidence of a humid phase and climatic changes during the Early Jurassic period. Facies changes in the studied interval provide insight into shifts in the ancient landscape and associated conditions. The findings suggest a transition from a dry desert setting to a wetter desert ecosystem, supporting a diverse biota during the Late Pliensbachian period.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geochemistry & Geophysics
George E. Mustoe
Summary: Wood silicification is not a simple process of permineralization as previously believed, as evidence from worldwide localities suggests. There are multiple pathways for wood silicification and permineralization is relatively rare. Silica precipitation occurs in successive episodes and changes in the geochemical environment cause different silica polymorphs to coexist in the same specimen.
Article
Geosciences, Multidisciplinary
John M. Holbrook, Sarah D. Allen
Summary: The study investigates the unique mechanism of meandering in a braided river like the Missouri River, characterized by the development of point assemblages instead of point bars for bends. Unlike traditional meandering rivers, this braided system utilizes repeated accretions to form compound bar elements, forcing the river to meander over successive bends. Contrary to single-thread rivers, the braided meandering Missouri River exhibits different deposition patterns with fusiform bar elements and cutbank scars associated with contraction.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2021)
Article
Engineering, Civil
Shih-Yen Hsu, Shaohua Marko Hsu
Summary: This study used a numerical model to simulate the processes and morphological changes of the downstream of Shigang Dam in the Da-jia River, Taiwan. The results can serve as an important reference for future research on river morphology evolution, river engineering, and river space planning.
JOURNAL OF HYDROLOGY
(2022)
Article
Engineering, Civil
Eddie W. Banks, Leanne K. Morgan, Alice J. Sai Louie, David Dempsey, Scott R. Wilson
Summary: Braided river systems are dynamic environments where the leakage process and recharge rates are not well understood. Using heat as a tracer can help map these processes and is important for river management. Research shows that groundwater recharge pathways vary spatially beneath the Waikirikiri Selwyn River.
JOURNAL OF HYDROLOGY
(2022)
Article
Geology
Xiao-Ju Yang, Jian-Guo Li
Summary: A new species of conifer wood, Brachyoxylon lalongense sp. nov., was discovered from the Duoni Formation of Bangoin County in Southwest China. The absence of growth rings indicates that this conifer was evergreen and the area was dominated by a hot climate during the Early Cretaceous, which is consistent with other paleobotanical and palynological evidence found in Tibet.
CRETACEOUS RESEARCH
(2022)
Article
Environmental Sciences
Cheston T. Peterson, David A. Gandy, Sandra D. Brooke
Summary: River flow plays a crucial role in the estuarine ecology by delivering freshwater and nutrients that influence the physical characteristics and productivity of the ecosystem. This study examined the long-term patterns in nekton community structure in Apalachicola Bay and investigated the effects of Apalachicola River flow rate on these patterns. The results indicated episodic shifts in species abundances and seasonal variations in species assemblages, with the most significant changes occurring during drought years. River flow rates affected community structure at different time lags and varied among gear types and spatial zones within the system.
ESTUARIES AND COASTS
(2023)
Article
Mathematics, Applied
Ankit Agarwal, Ravi Kumar Guntu, Abhirup Banerjee, Mayuri Ashokrao Gadhawe, Norbert Marwan
Summary: This study investigates the spatiotemporal relationship of extreme precipitation events in the Ganga river basin and reveals that the network degree decreases in a southwest to northwest direction. The timing of 50th percentile precipitation within a year influences the spatial distribution of the network degree, and the timing is inversely related to elevation. Lower elevation greatly influences the connectivity of the sites.
Article
Environmental Sciences
Guillaume Brousse, Frederic Liebault, Gilles Arnaud-Fassetta, Bertrand Breilh, Sandrine Tacon
Summary: This study investigates the effectiveness of using gravel replenishment and channel widening for restoring altered river morphologies. The results show that, in a context of low hydrological forcing, the restored reach gradually adjusts to local braiding characteristics, but still faces local scouring and sustainability issues.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Geology
Zaki A. Abdel-Fattah, Haytham Sehsah
Summary: The paper presents new data and results that improve the depositional models of lacustrine and alluvial fan deposits in the Precambrian. Siliciclastic profiles in the Kareim Basin provide evidence of Late Neoproterozoic lacustrine/fan delta and alluvial fan settings. Thirteen depositional facies belonging to six facies associations are defined based on detailed sedimentologic data. The incorporation of facies architectures, sedimentary structures, stratigraphic relations, and depositional patterns suggests three inter-related depositional phases.
SEDIMENTARY GEOLOGY
(2023)
Article
Plant Sciences
Ronny Roessler, Steffen Truemper, Robert Noll, Alexandra Hellwig, Sandra Niemirowska
Summary: Silicified wood is a common and insightful record of ancient life, with cellular anatomy often well preserved but organic matter alterations occurring during fossilization. Volume reduction is widespread in fossilized wood, with tissue contraction varying considerably and being affected by factors like microbial degradation.
REVIEW OF PALAEOBOTANY AND PALYNOLOGY
(2021)
Article
Geosciences, Multidisciplinary
John T. Kemper, Sara L. Rathburn, Erich R. Mueller, Ellen Wohl, Julianne Scamardo
Summary: Alterations to sediment supply can cause morphological adjustment in fluvial channels, but understanding the specific changes that occur in response to sediment supply modifications has been challenging. This review focuses on the geomorphic response of low-gradient, braided and meandering alluvial river channels to increases in sediment supply. The synthesis of existing literature suggests that channel adjustment occurs at different scales, determined by thresholds defined by the characteristics of the sediment influx, and future research should aim to quantify these thresholds and investigate other controlling factors.
EARTH-SCIENCE REVIEWS
(2023)
Article
Geosciences, Multidisciplinary
Frank Loecse, Ulf Linnemann, Gitta Schneider, Mathias Merbitz, Ronny Roessler
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2019)
Article
Geography, Physical
Steffen Truemper, Joerg W. Schneider, Tamara Nemyrovska, Dieter Korn, Ulf Linnemann, Dong Ren, Olivier Bethoux
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2020)
Article
Geosciences, Multidisciplinary
Steffen Truemper, Sebastian Germann, Jorg W. Schneider, Dorothee Mertmann, Jens Goetze, Ronny Roessler
ZEITSCHRIFT DER DEUTSCHEN GESELLSCHAFT FUR GEOWISSENSCHAFTEN
(2020)
Article
Plant Sciences
Ronny Roessler, Steffen Truemper, Robert Noll, Alexandra Hellwig, Sandra Niemirowska
Summary: Silicified wood is a common and insightful record of ancient life, with cellular anatomy often well preserved but organic matter alterations occurring during fossilization. Volume reduction is widespread in fossilized wood, with tissue contraction varying considerably and being affected by factors like microbial degradation.
REVIEW OF PALAEOBOTANY AND PALYNOLOGY
(2021)
Article
Plant Sciences
Rodrigo Neregato, Ronny Roessler, Robert Noll, Rosemarie Rohn
Summary: A new petrified calamitalean, Arthropitys buritiranensis sp. nov., has been described from the Permian Motuca Formation in the Parnaiba Basin of central-north Brazil. This semi-self-supporting woody plant is characterized by a unique branch system and cellular anatomy, with irregular growth interruptions indicating a seasonally dry climate. The new species was part of riparian vegetation in a setting with tree ferns, calamitaleans, and gymnosperms.
REVIEW OF PALAEOBOTANY AND PALYNOLOGY
(2021)
Article
Paleontology
Ralf Werneburg, Florian Witzmann, Joerg W. Schneider, Ronny Roessler
Summary: A new temnospondyl fossil was discovered in the Chemnitz Fossil Lagerstatte, adding to the richness of the fossil assemblage in the area. This fossil, named Chemnitzion richteri gen. nov. et sp. nov., is almost complete and provides valuable insights into the morphology and phylogenetic relationships within the group.
Article
Geosciences, Multidisciplinary
Sebastian Voigt, Thomas Schindler, Marion Tichomirowa, Alexandra Kaessner, Joerg W. Schneider, Ulf Linnemann
Summary: The Saar-Nahe Basin is one of the largest intra-continental basins of the European Variscides, filled with up to 6500 m thick volcano-sedimentary rocks representing 40 million years of basin evolution. The first high-precision U-Pb CA-ID-TIMS age of a previously undated ash tuff layer of the Altenglan Formation yielded a result of 298.7 +/- 0.4 Ma. Comparative analyses of zircons from the same layer confirmed this age, supporting a Pennsylvanian-Permian boundary within the Altenglan Formation and suggesting an earliest Asselian age for a globally important fossil tetrapod lagerstaette.
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2022)
Article
Plant Sciences
Hans Kerp, Hendrik Bodigea, Benjamin Bomfleur, Jorg W. Schneider
Summary: Two previously unrecorded conifer genera were discovered in the late Permian Zechsteinmergel of Gera-Trebnitz in Germany, which were only known from northern Italy before. The type species of one conifer genus was found to be a synonym of the type species of another conifer genus. All species attributed to the first genus after 1964 are transferred to a new genus.
Article
Paleontology
Steffen Truemper, Bjoern Vogel, Sebastian Germann, Ralf Werneburg, Joerg W. Schneider, Alexandra Hellwig, Ulf Linnemann, Mandy Hofmann, Ronny Roessler
Summary: Wetlands play a crucial role in continental evolution by providing habitats for emerging and declining species. The fossiliferous deposits found in wetlands are essential for understanding past and future biodiversity. In this study, the trophic structure and age of the Manebach Lake ecosystem in Germany were reconstructed. The lake, which existed during a time of significant climate change, was home to a diverse range of organisms. The findings highlight the importance of studying past limnic biotas to reconstruct ancient continental ecosystems.
Article
Biodiversity Conservation
Joerg W. Schneider, Ronny Roessler
Summary: Large-winged blattoids of the Middle to Late Pennsylvanian exhibit diversification, colonization, and decline. The families Necymylacridae and Gyroblattidae, as well as the mylacrid genus Opsiomylacris, were the largest blattoids before the Cenozoic era. These giant insects spread during the Bashkirian-Moscovian transition, diversified during late Moscovian and Kasimovian times, and disappeared in the middle Gzhelian. Gyroblattids followed meso- to xerophilous plants and colonized areas with a broader range of soil conditions.