Article
Geography, Physical
Charles Breithaupt, Jason D. Gulley, Eric M. Bunge, Paul J. Moore, Charles Kerans, Fermin Fernandez-Ibanez, Shawn M. Fullmer
Summary: Banana holes are karst depressions primarily found in strandplains within the Bahamian archipelago. A new model suggests that these depressions may form in transient, perched aquifers on exposure zones, influenced by dissolution and organic carbon inputs.
EARTH SURFACE PROCESSES AND LANDFORMS
(2022)
Article
Engineering, Environmental
Brian Rippey, Julie Campbell, Yvonne McElarney, James Thompson, Mary Gallagher
Summary: A simplified model was established and applied to estimate the timescale of recovery from long-term P release from sediment after a reduction in the external load in four lakes. The study found that the rate of P release and recovery time varies in different lakes, but generally takes between one and three decades.
Article
Biodiversity Conservation
David F. Terrill, Emilia Jarochowska, Charles M. Henderson, Bryan Shirley, Oskar Bremer
Summary: Conodonts are a diverse and abundant vertebrate group found in marine Paleozoic and Triassic strata. This study tested the hypothesis that individual conodont taxa occupied different trophic niches, using Sr/Ca and Ba/Ca ratios preserved in dental elements.
Review
Geology
Adrian Immenhauser
Summary: This paper reviews the concepts, processes, and products that characterize the burial realm from the viewpoint of the carbonate geoscientist. It presents and discusses typical features of carbonate burial in different burial domains, from shallow to deep, and proposes improved conceptual delimitation and subdivision with intuitive terminology. The transition from shallow burial to deep-burial domains is described, including changes in fluid types, porosity evolution, and diagenetic fabrics.
DEPOSITIONAL RECORD
(2022)
Article
Paleontology
Daniel Vachard, Ioan I. Bucur, Axel Munnecke
Summary: A new genus of calcified codiacean alga (Vitinellopsis nov. gen.) is reported from the Silurian limestones of Gotland, Sweden. The well-preserved material provides insights into the calcareous wall and unique thallus structure of this taxon. The discovery suggests that Vitinellopsis nov. gen. may have potential applications in stratigraphy, facies, and paleobiogeographic studies.
Article
Geology
Tomasz Wrzolek, Michal Zaton
Summary: A rich collection of about 60 specimens of large rugose corals from the Silurian of Gotland, Sweden, was studied. The material, mostly fragmentary, provided reliable numerical data through the examination of growth lines. The analyzed parameters showed uniformity, indicating that all the material belonged to a single, variable species, Schlotheimophyllum patellatum.
ANNALES SOCIETATIS GEOLOGORUM POLONIAE
(2023)
Article
Geology
Johan Le Goff, Audrey Recouvreur, John J. G. Reijmer, Thierry Mulder, Emmanuelle Ducassou, Marie-Claire Perello, Vincent Hanquiez, Herve Gillet, Thibault Cavailhes, Natacha Fabregas
Summary: The depositional record of carbonate slopes provides insights into past environmental and climatic changes, with modern carbonate slopes revealing morphological variabilities shaped by slope collapses and turbidity currents. This study aims to link seafloor morphology and depositional processes in an active carbonate submarine channel in the Bahamas, showcasing the importance of knickpoints in sediment transport and accumulation. The research not only sheds light on the source-to-sink mechanisms in carbonate systems, but also provides new perspectives on understanding sea-level changes over the last 40 kyr.
Article
Geosciences, Multidisciplinary
Stephan C. Oborny, Bradley D. Cramer, Carlton E. Brett, Alyssa M. Bancroft
Summary: This study focuses on the Upper Silurian Salina Group in eastern North America and proposes a new chronostratigraphic correlation. By integrating geochemical and geophysical data, the research reveals significant changes in sedimentary environment and tectonic activity during the Silurian period, providing important insights into the geological history of the region.
Article
Multidisciplinary Sciences
Fowzia H. Abdullah
Summary: This study evaluated the impact of diagenetic processes on porosity and permeability in the paleokarst zone of the Middle Eocene Upper Dammam Formation in Kuwait. The results showed significant variations in porosity and permeability among different lithological units, with the chalky dolostone layer exhibiting the highest values and the karst carapace layer having the lowest values. The formation of pores in the rock framework was attributed to meteoric water dissolution, acidic gases from thermal maturation of kerogen, or a combination of both processes.
Article
Paleontology
Mike Reich, Manfred Kutscher
Summary: A new species and genus of stem-group 'soft corals' are described in detail and compared to other species in the fossil record. Sueciatractos leipnitzae gen. et sp. nov. was discovered in the Upper Silurian Hemse beds of Sweden. This new taxon is unique in its fused sclerites that form a nearly solid skeleton or supporting layers.
Article
Geochemistry & Geophysics
Aleksandra Kozlowska, Katarzyna Jarmolowicz-Szulc, Marta Kuberska, Krystyna Wolkowicz
Summary: This paper presents the latest state of knowledge on clastic sedimentary rocks from the Carboniferous complex in the SW part of the Polish Lowlands, studied to help determine their potential prospectivity for the occurrence of oil and/or gas deposits. The study involved analyses of the petrographic-mineralogical characteristics of the Carboniferous deposits, diagenesis, pressure-temperature conditions of mineral formation, and the presence of hydrocarbons, revealing potentially higher temperatures in local regions. Data on fluid inclusions in quartz and carbonates provided valuable information on homogenization temperatures for vein calcite in the samples.
Article
Geology
Olof Taromi Sandstrom, Peter Dahlqvist, Mikael Erlstrom, Lena Persson, Steve Kershaw, Mikael Calner
Summary: The Hemse Group in Gotland, Sweden, is one of the least understood stratigraphic units in the Silurian sequence. New insights from ATEM measurements, along with field studies and geophysical investigations, reveal the development of carbonate platforms during the early to mid-Ludlow Hemse Group, including a transgressive phase and extensive reef growth during a highstand period. The Kuppen-Snabben Unconformity Complex marks a key transition in the stratigraphy from rampiform settings with reef biostromes to a more rimmed setting with patch reefs.
Article
Geosciences, Multidisciplinary
J. Cochard, P. Leonide, J. Borgomano, Y. Guglielmi, G. Massonnat, J-P. Rolando, L. Marie, A. Pasquier
Summary: Integrated sedimentological, diagenetic, and structural analyses were conducted on microporous and tight Urgonian limestones in southeastern France to investigate the influence of diagenetic changes and structural deformation on the distribution of reservoir properties. The diagenetic history of the carbonates was divided into phases corresponding to regional geodynamic activity, with various calcite cement phases and micritic cement phases identified in relation to structural deformation. The results suggest that late diagenetic and microstructural processes were influenced by early diagenetic changes, leading to the development of different reservoir rock-types based on diagenetic characteristics and geochemical analyses.
JOURNAL OF PETROLEUM GEOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Hammad Tariq Janjuhah, Josep Sanjuan, Mohammad Alqudah, Mohamed K. Salah
Summary: Carbonate rocks with prolific hydrocarbon reserves, particularly in the Middle East, were studied in exposed marine sedimentary sequences in Southern Lebanon. The study analyzed the carbonate reservoir facies, diagenetic history, and reservoir quality, with Maghdoucheh dominated by limestone beds in a restricted marine platform environment, and Qennarit composed of mudstone/wackestone limestone beds with planktonic foraminifera related to open marine conditions. The porosity-permeability analysis revealed moderate to good porosity but very low permeability, mainly due to the presence of large isolated moldic pores. Diagenetic features were dominated by micritization and dissolution, with dissolution contributing to porosity enhancement but other factors negatively impacting permeability and overall reservoir quality.
ACTA GEOLOGICA SINICA-ENGLISH EDITION
(2021)
Article
Geology
Sascha Roest-Ellis, Justin Strauss, Nicholas J. Tosca
Summary: The study explores the mineralization pathways of synsedimentary calcite microspar cement through CaCO3 nucleation experiments in synthetic seawater. It demonstrates that dissolved PO4 levels above a certain threshold inhibit the nucleation of aragonite and calcite, leading to the formation of an amorphous Ca-Mg carbonate precursor that eventually recrystallizes into monohydrocalcite and/or calcite. This precipitation mechanism may suggest nontraditional pathways for the mineralization of CaCO3 in Proterozoic sediments.
