Geological Quarterly最新文献

{"title":"Geological features of the Zn-Pb prospect in the Bou-Izourane district (Morocco)","authors":"Jamal Achmani, Ilham Chraibi, Said Courba, Soufiane Boudrif","doi":"10.7306/gq.1739","DOIUrl":"https://doi.org/10.7306/gq.1739","url":null,"abstract":"<p>The Zn-Pb mineralization in the Bou-Izourane district, located in the High Atlas Mountains of Morocco, contains estimated reserves of 40 200 tons of ore with an average grade of 20% Zn and 3.5% Pb. It is developed on N–S to NNW–SSE-trending faults that cut Liassic carbonate marl deposits. The paragenetic mineral sequence consists of galena, sphalerite and late-stage calcite. Oxidation phases of galena into cerussite and sphalerite into smithsonite are common in the Bou-Izourane ore, linked to the infiltration of meteoric waters and the oxidation of these sulphides. The Zn-Pb mineralization runs parallel to the fluorite veins associated with the igneous rocks of Tamazeght, but no petrographic or field relationship has been demonstrated between these two mineralizations (i.e., Zn-Pb and fluorite). The distribution of rare earth elements and yttrium (REY) in the Zn-Pb mineralization of Bou-Izourane shows a notable similarity with the Mississippi Valley Type (MVT) mineralization of the Central High Atlas of Morocco, although the concentrations more closely resemble those of REY in fluorite linked to the magmatic-hydrothermal activity of Tamazeght. However, the analysis of their distribution in post-fluorite calcite and post-Zn-Pb calcite reveals a strong concordance, suggesting that these two calcites are associated with the same phase and have a common origin. The classification of the Zn-Pb prospect in Bou-Izourane remains controversial, fluctuating between an MVT-type mineralization, similar to most Zn-Pb mineralizations in the Central High Atlas of Morocco, and a mineralization linked to the magmatic-hydrothermal activity of Tamazeght, which could provide heat and metallogenic material. Characterizing the Zn-Pb ore of Bou-Izourane is crucial for the future exploration of zinc and lead deposits in the High Atlas of Morocco and could advance the development of Zn-Pb mining in the region, from artisanal exploitation to professional mining</p>","PeriodicalId":12587,"journal":{"name":"Geological Quarterly","volume":"29 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140800431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Baltoscandian Ordovician and Silurian brachiopod carbon and oxygen stable isotope trends: implications for palaeoenvironmental and palaeotemperature changes","authors":"Bilal Gul, Leho Ainsaar, Tánu Meidla","doi":"10.7306/gq.1742","DOIUrl":"https://doi.org/10.7306/gq.1742","url":null,"abstract":"<p>Oxygen isotope palaeotemperature studies of Paleozoic limestones are based mainly on brachiopod shell material which is resistant to diagenesis and generally precipitated in oxygen isotopic equilibrium with ambient sea water. Here we present brachiopod C and O stable isotopic data from the Baltoscandian Ordovician-Silurian succession, and evaluate palaeotemperature and palaeoenvironmental variability during deposition of the Estonian Shelf facies. As the region has not been influenced significantly by tectonic events or deep burial diagenesis, the carbonate rocks and fossils are well-preserved in most of the locations studied. δ¹⁸O values for the Ordovician and Silurian carbonates and brachiopods range between ~–7 and 0‰. High δ¹⁸O values, locally accompanied by higher δ¹³O values, correspond to cooling if the isotope signal reflects the original oxygen isotopic composition in sea water and vice versa. Several Ordovician-Silurian δ¹³O_brac excursions identified on the Estonian Shelf reflect global palaeoenvironmental history and events, being synchronous with previously documented excursions in the bulk carbonate stable isotopic curves. Combining the published and new d13Cbrac and δ^13O_brac data allows us to address chemostratigraphic correlation of the interval from Lower Ordovician (Floian) up to the topmost Silurian (Přídolí). The δ^18O_brac data corroborate warmer temperatures during Early Ordovician (Floian-Dapingian) and a cooling trend into the Mid-Ordovician documented by previous studies in different palaeobasins. The Hirnatian isotopic carbon excursion (HICE) episode reveals the minimum temperature in this interval and the post-HICE data suggest a rising temperature trend. Another temperature minimum is evident in the strata reflecting the Ireviken Event (Sheinwoodian). Our study shows that brachiopod d18O values from the Ordovician-Silurian carbonates may tentatively be interpreted as reflecting major temperature trends</p><p> </p>","PeriodicalId":12587,"journal":{"name":"Geological Quarterly","volume":"90 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141947602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First evidence of vampyromorph cephalopod jaw structures from the Sinemurian, Lower Jurassic of Dorset","authors":"Gregory Price, Malcolm Hart, Chris Moore","doi":"10.7306/gq.1738","DOIUrl":"https://doi.org/10.7306/gq.1738","url":null,"abstract":"A new specimen of the Coleoidea from the Charmouth Mudstone Formation of the Dorset Coast has been identified as<em> Loligosepia bucklandi</em> (Voltz, 1840). The specimen includes the gladius and jaw fragments, which represent one of few records of its kind, but the head area, arms, hooks and suckers are not discernible. It can be favourably compared to other<em> L. bucklandi</em> fossils in the Natural History Museum in London and the J.F. Jackson Collection in the National Museum Wales in Cardiff. The range of<em> L. bucklandi</em> is determined to be from the Turneri Zone, Brooki Subzone to the Obtusum Zone, Stellare Subzone of the lower Sinemurian, with the new specimen stratigraphically a little older than the precisely located specimens in the J.F. Jackson Collection.","PeriodicalId":12587,"journal":{"name":"Geological Quarterly","volume":"63 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141947603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New data on the Sciuridae (Rodentia) from the Villafranchian site of Węże 2 in southern Poland","authors":"Michał Czernielewski","doi":"10.7306/gq.1714","DOIUrl":"https://doi.org/10.7306/gq.1714","url":null,"abstract":"<p>In addition to specimens attributable to <em>Pliopetaurista dehneli</em> (Pteromyini), already described by Sulimski (1964), the fossil tooth material collected at the Upper Pliocene (MN 16b) site of Węże 2 in southern Poland comprises specimens assignable to other representatives of the Sciuridae. These include Tamias orlovi (Marmotini), Blackia miocaenica (Pteromyini) and <em>Sciurus warthae</em> (Sciurini). All these species are otherwise relatively rare in the fossil record. Along with another MN 16b site, Frechen, as well as the MN 16 sites of Rębielice Królewskie 1A and Rębielice Królewskie 2, Węże 2 thus represents one of the youngest occurrences of <em>B. miocaenica</em> in the fossil record.<em> P. dehneli, B. miocaenica</em> and <em>S. warthae</em> are considered to have inhabited dense forests while <em>T. orlovi</em> probably also lived in more open wooded environments.<br /><br /></p>","PeriodicalId":12587,"journal":{"name":"Geological Quarterly","volume":"34 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The genesis of base and precious metals-bearing epithermal veins in the Gharehchay-Kurmolla area, south of Tikmehdash, NW Iran","authors":"Zahra Hassani Soughi, Ali Asghar Calagari, Ghahraman Sohrabi","doi":"10.7306/gq.1713","DOIUrl":"https://doi.org/10.7306/gq.1713","url":null,"abstract":"The Gharehchay-Kurmolla (Gh-Ku) base and precious metals occurrence is located in ~2 km south of Tikmehdash, 75 km south-east of Tabriz, and is a part of Bostanabad-Miyaneh gold-bearing district in the West Alborz-Azarbaidjan structural zone. Mineralization in the study area occurs in quartz veins and veinlets hosted by the Eocene volcanic-pyroclastic units as well as granite. Recognizable alteration zones around the quartz veins and veinlets include silicic, phyllic, intermediate argillic, and propylitic types. The mineralization was developed during three conspicuous stages. In stage 1, minerals such as quartz, pyrite, and chalcopyrite with slight amounts of gold were formed. During stage 2, minerals such as quartz, galena, sphalerite, and gold together with pyrite and chalcopyrite were developed. Stage 3 was concurrent with deposition of quartz accompanied by Mn-oxides and hydroxides (pyrolusite and psilomelane). The major gangue minerals are quartz, adularia, sericite, epidote, chlorite and calcite. Micro-thermometric investigations on primary 2-phase (LV) fluid inclusions in quartz crystals showed that the hydrothermal fluids responsible for mineralization had temperatures and salinities ranging from 215 to 325°C and from 2.6 to 10.4 wt.% NaCl eq., respectively. The oxygen isotopic composition of the fluid (+9.7 to +12.5‰) suggests that the ore-forming solutions had a largely magmatic component. The sulphur isotopic composition of the fluid (–1.5 to –3.4‰) is also indicative of magmatic origin. On the basis of data obtained from micro-thermometric and stable isotope analyses, boiling along with mixing were two important mechanisms involved in the precipitation of ore and gangue minerals in the study area. The geological and geochemical characteristics of the Gh-Ku area indicate that mineralization in this area is of epithermal type with a low-sulphidation style.","PeriodicalId":12587,"journal":{"name":"Geological Quarterly","volume":"115 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First evidence of seismically-induced deformations in fluvial deposits of the Lower Rotliegend in the Intra-Sudetic Basin, SW Poland","authors":"Izabela Ploch, A.J. (Tom) Van Loon, Marek Awdankiewicz, Sebastian Voigt, Paweł Raczyński","doi":"10.7306/gq.1722","DOIUrl":"https://doi.org/10.7306/gq.1722","url":null,"abstract":"The Lower Rotliegend in the Intra-Sudetic Basin, situated at the northern margin of the Bohemian Massif, is represented in the Polish part of the basin by the Krajanów and Słupiec formations. Both formations consist of fluvial and lacustrine deposits. The sedimentary processes during the deposition of the Słupiec Formation were influenced by volcanic activity that resulted in subvolcanic intrusions, lava flows and ignimbrites. Some slabs of fluvial sediments from the Słupiec Formation show a level consisting entirely of soft-sediment deformation structures, in particular load casts, sometimes representing successive phases of loading. These deformations are interpreted to record volcanism-related earthquakes. Also a level full of load casts in the fluvial part of the Słupiec Fm. can feasibly be explained only be earthquakes that must be ascribed to a volcanic eruption","PeriodicalId":12587,"journal":{"name":"Geological Quarterly","volume":"2020 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geomorphometric features and distribution of the loess covers in the Lublin Region","authors":"Leszek Gawrysiak, Renata Kołodyńska-Gawrysiak","doi":"10.7306/gq.1723","DOIUrl":"https://doi.org/10.7306/gq.1723","url":null,"abstract":"The study presents a new, accurate map of the distribution of loess patches in eastern Poland, developed on the basis of publications, geological maps and a high-resolution (1 m) digital terrain model (DTM). Seventy-two lobes were mapped, for the surfaces of which basic morphometric characteristics (mean height, local relief, slope, slope range) were calculated based on the DTM. The morphology of the patches was portrayed via geomorphons-geomorphometric features representing 10 basic landform elements. A map of the geomorphons and their morphometric features were used to analyse the similarity of the patches’ morphology using Kendall’s Tau correlation and hierarchical clustering, represented by a dendrogram and heat map. As a result, 3 groups of patches with different morphometric features were distinguished. The results obtained characterize in detail the morphological differentiation of loess covers of eastern Poland and will form the basis for further studies determining the evolution of loess cover relief.<br /><br />","PeriodicalId":12587,"journal":{"name":"Geological Quarterly","volume":"61 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The anisotropy of magnetic susceptibility as a method to study Quaternary deposits: theory and applications","authors":"Artur Teodorski","doi":"10.7306/gq.1720","DOIUrl":"https://doi.org/10.7306/gq.1720","url":null,"abstract":"The anisotropy of magnetic susceptibility is used as a geophysical method, based on the non-uniform magnetic properties of rocks, within which it exploits the individual types of minerals, their quantity, and distribution in the rocks. The anisotropy of minerals may be a result of their crystalline structure or the shape of mineral grains. If the anisotropy is connected to the shape of the minerals, as in the case of magnetite, the axis of maximum magnetic susceptibility is perpendicular to the grain long axis. This indirectly allows determination of grain orientation in the rocks studied. Therefore, this method can be used to reconstruct the directions of transport of rock components, such as in loess, fluvial or ice-dammed sediments, and to determine the directions of ice-sheet movement based on glacial till studies. The method is also used in tectonic stress reconstruction, complementing the results of palaeomagnetic dating or the logging of borehole cores. The rapid, inexpensive measurement of anisotropy of magnetic susceptibility along with low human error in measurement has made this method competitive with traditional research methods<br /><br />","PeriodicalId":12587,"journal":{"name":"Geological Quarterly","volume":"2020 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prehistoric human influence on soil dynamics and slope transformation on the Subcarpathian Loess Plateau, southeastern Poland","authors":"Piotr Gębica","doi":"10.7306/gq.1732","DOIUrl":"https://doi.org/10.7306/gq.1732","url":null,"abstract":"<p><br />This study examines the impact of prehistoric human activities on the landscape of the Subcarpathian Loess Plateau, focusing on areas such as the Kańczuga Plateau in southeastern Poland. Through a multidisciplinary approach that integrates archaeological excavation, soil profile analysis, and geomorphological survey techniques, environmental changes are traced from the Neolithic through the early Middle Ages. A key aspect comprises various soil types, particularly chernozems and brown soils, which have been influenced by early agricultural practices like deforestation and land cultivation. The use of radiocarbon and Optically Stimulated Luminescence (OSL) dating of soil profiles and archaeological sites provides insights into the timeline of human-induced erosional and depositional processes and deposits ranging in age from the Palaeolithic period to the early Middle Ages. The results highlight significant soil erosion and colluvial deposit formation, especially during periods of intensified agriculture. These changes in specific soil types underscore the substantial impact of human activities and climatic variations on land relief and soil cover in the Late Holocene. This study contributes to a deeper understanding of human-driven landscape alterations in loess areas, offering valuable insights for environmental management and conservation on the Kańczuga Plateau, in the Sandomierz Basin, and in other similar geomorphological settings.</p>","PeriodicalId":12587,"journal":{"name":"Geological Quarterly","volume":"96 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Pleistocene malacofauna of (MIS-2–MIS-4) loess-palaeosol sequence in Zalesie near Przemyśl (southern Poland)","authors":"Witold Paweł Alexandrowicz, Maria Grażyna Łanczont","doi":"10.7306/gq.1734","DOIUrl":"https://doi.org/10.7306/gq.1734","url":null,"abstract":"Lithological and malacological analysis was carried out at the loess site in Zalesie near Przemyśl. The profile exposed here comprises a loess-palaeosol sequence L-1 and is correlated with the Pleniglacial (MIS-2–MIS-4) of the Weichselian glaciation. Three loess layers separated by interstadial palaeosols are recognised here. Within the two younger parts of the cover, corresponding to the younger middle loess (LMs) and the younger upper loess (LMg), and in the soil horizon (Gi/LMs) separating them, numerous mollusc shells were found. The diversity of the malacofauna allowed five types of faunal assemblages to be distinguished. The main faunal components in the younger middle loess were open-country species typical of the dry subarctic steppe. The interstadial palaeosol horizon developed on this loess was dominated by hygrophilous taxa characteristic of the subarctic tundra environment. The malacofauna of the youngest part of the loess bed (LMg) contained mainly mesophilous snails, indicating the presence of open but relatively humid biotopes. The profile in Zalesie belongs to a tiny group of loess sites in Poland with a complete malacological sequence preserved, covering both the younger upper and middle loesses and the palaeosol horizon separating them.","PeriodicalId":12587,"journal":{"name":"Geological Quarterly","volume":"33 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}