Geology, Earth & Marine Sciences最新文献

{"title":"Generation of Hydrogen along the Mid-Atlantic Ridge: Onshore and Offshore","authors":"Valentine Combaudon, I. Moretti","doi":"10.31038/gems.2021343","DOIUrl":"https://doi.org/10.31038/gems.2021343","url":null,"abstract":"Since the 1980s, oceanic ridges have been proven to be sites at which diagenetic processes (such as serpentinization) result in the generation of natural hydrogen, which escapes through oceanic vents. The water depths in this setting and the location of ocean ridges far offshore would seem to preclude exploitation of this resource, but similar geological contexts are found onshore. Iceland is located along the axis of the Mid-Atlantic Ridge (MAR) and is also a hot spot. As a result, the emerging ridge allows for the study of hydrogen generation within this specific oceanic extensional context. Geothermal energy is well developed in Iceland; accordingly, the presence of natural hydrogen is known based on data from numerous geothermal wells which allowed us to constrain the hydrogen occurrences and compare them with MAR emissions. The results show that H 2 contents are high only in the neo-volcanic zone and very low outside the immediate vicinity of this active axis. Values reaching 198 mmol H 2 /kg fluid have been recorded in Landmannalaugar. Farther north, the gas mixture in the Námafjall area reaches up to 57 vol% hydrogen. These well data are in the same range as those along the MAR. The oxidation of ferrous minerals, combined with the reduction of water, allows for the formation of hydrogen. In Iceland, H 2 concentrations in steam seem to be enhanced by both the low concentrations of NaCl in hydrothermal fluids and the strong fracturing of the upper crust, which provides a rapid and constant supply of meteoric fluids for oxidation reactions.","PeriodicalId":328860,"journal":{"name":"Geology, Earth & Marine Sciences","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115585640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"About Climate, Flooding and Underwater Technologies","authors":"","doi":"10.31038/gems.2021335","DOIUrl":"https://doi.org/10.31038/gems.2021335","url":null,"abstract":"","PeriodicalId":328860,"journal":{"name":"Geology, Earth & Marine Sciences","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125190346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Earth Science Needs Thorough Introspective Analysis and Renovation","authors":"S. Sen","doi":"10.31038/gems.2021334","DOIUrl":"https://doi.org/10.31038/gems.2021334","url":null,"abstract":"Despite several breakthrough discoveries, earth science needs modification especially related to its deeper parts of the planet where temperature and pressure have been presumed to be high. Based on the concept of earth’s expansion, the author considers that the mantle of the unexpanded ocean-less earth was considerably fluid owing to incorporation of ocean-forming water. In such a globe gravitational pull from an extraterrestrial planetary body would cause expansion triggered by swelling up of the semi-fluid mantle and consequent formation of a number of expansion cracks on the crust. Through these cracks or mid-oceanic ridges extensive molten magma would expel out and deposit on both sides of the crack to form ocean basins. Matching thickness of the earth’s fluid outer core with the extent of expansion points out that owing to massive expansion original core-mantle conjunction of the planet was ruptured along which a void zone, identified as outer core of the prevalent concept, was gradually opened up. Such disposition of occurrence of two discrete geospheres separated by a virtually void zone would give rise to the phenomenon of reverse gravity in the deep interior of the planet thereby sustaining a low pressure and low temperature zone at depth.","PeriodicalId":328860,"journal":{"name":"Geology, Earth & Marine Sciences","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127666602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reconstructing the Early Exposure Regime of the Middle Russian Sea (Jurassic, Russian Platform)","authors":"","doi":"10.31038/gems.2021333","DOIUrl":"https://doi.org/10.31038/gems.2021333","url":null,"abstract":"","PeriodicalId":328860,"journal":{"name":"Geology, Earth & Marine Sciences","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128592337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Caddisflies as an Underwater Architectures and Indicator for Water Quality and Classification of Water Habits","authors":"H. Vatandoost","doi":"10.31038/gems.2021321","DOIUrl":"https://doi.org/10.31038/gems.2021321","url":null,"abstract":"Trichoptera (Caddisflies) insects has long, silky hairs that cover most of the body and wings. This order of insect is included: 21 families, 145 Genera and 1200 species. This order is closely related to Lepidoptera. The Immature stage is aquatic and respiration at the larval stage by respiratory gills. Adults are active and winged insects and they have broad diversity of habitats. Larvae are worm-like, soft bodies, head contains a hard covering, color vary from yellow or brown, but usually green, larvae are known for their construction of hollow cases that they either carry with them or attach to rock, cases are built from sand, twigs, small stones, crushed shells, rolled leaves, and bark pieces, cases used for protection and pupation, length up to 1 inch. Larvae are Eruciform (caterpillar-like) body, abdomen usually enclosed in a case made of stones, leaves, twigs, or other natural materials.Head capsule well-developed with chewing mouthparts . Thread-like abdominal gills usually present in case-makers . They have one pair of hooked prolegs often present at tip of abdomen (Figure 1). larvae feed on algae,small bits of plant material . Some species build nets where they catch drifting food, fed upon by several species of fish. They are sensitive to water pollution and are used as important indicators in studies of water quality. The larval habitats are; lotic, lentic, erosional,warm rivers, headwater stream, cool streams, rock face streams, seeps, large rivers, small spring, marshland, small rapid stream, pond, pool, lake, temporary streams, depositional","PeriodicalId":328860,"journal":{"name":"Geology, Earth & Marine Sciences","volume":"47 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115943718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detailed Hydrogeological and Hydrochemical Reassessment of Coastal Basins of Southwestern Nigeria","authors":"S. Wali, I. M. Dankani, S. D. Abubakar, M. A. Gada, Kabiru Jega Uma","doi":"10.31038/gems.2021312","DOIUrl":"https://doi.org/10.31038/gems.2021312","url":null,"abstract":"Water is an indispensable prerequisite of life deemed an economic resource rather than a social good [1-4]. Even though freshwater storage in the ecosystem remains steady, freshwater pressure such as subsurface water has experience expansion due to population increase, development, dry season farming, and household activities [1,5]. Though, the quality and quantity of this economic resource are likewise critical factors in the perspective of modern water quality management, especially in coastal areas [1,6,7]. Factors such as quality of recharge, rock weathering and mineralogical composition of the underlying rock types, land use, and climate change usually play a vital role in groundwater chemistry, affecting groundwater quality [1,8].Understanding groundwater evolution involves the hydrochemical analyses of major dissolved ions of groundwater, discovering the principal geochemical processes, and evaluating the impacts of land-use types on groundwater quality in various regions of the world [1,9,10]. Many factors such as rock-water interactions, climate changes, precipitation or dissolution of mineral species, the intensity of chemical weathering of the different rock types, groundwater resources, exchange reactions, and human activities, Research Article","PeriodicalId":328860,"journal":{"name":"Geology, Earth & Marine Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124354802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distinction between Natural and Anthropogenic Contaminants of Atmospheric Precipitates from Northeastern Kansas Based on Their Elemental Contents and Strontium Isotopic Signatures","authors":"N. Clauer, S. Chaudhuri, I. Techer, R. Boutin","doi":"10.31038/gems.2021311","DOIUrl":"https://doi.org/10.31038/gems.2021311","url":null,"abstract":"This study was designed to identify and possibly evaluate the changing occurrence of major pollutants in different atmospheric precipitates (rain, snow and hail) that were collected in northeastern Kansas next to the Konza Prairie Preservation site by analyzing their elemental and Sr isotope compositions. Potential pollutants like the local soils and their clay material, as well as the fly ash of a nearby coal-burning power plant were also analyzed. Positively correlated with K in the analyzed precipitates, the Na contents of the precipitates suggest a supply of fertilizers and/or natural plant organics. Combining the four identified pollutants of the precipitates that is to say the soils, the fly ash, the fertilizers and the plants allows evaluation of their changing contribution during a single precipitation event. The duration of the rain events monitors also the changing contribution of the identified pollutants. Variations of the 87Sr/86Sr ratio from precipitates during lasting events are confirmed by changing distribution patterns of the REEs. In fact, soil minerals contribute mostly at the beginning of the precipitation events and are replaced progressively by the industrial fly ash that becomes dominant towards the end of the precipitation events, depending on the duration and wind directions. At last not least, the different contaminants are recognizable by changing elemental contributions, REE distribution patterns and 87Sr/86Sr ratios. Their variable occurrence can be followed in the wet solutes, but a strict quantification cannot be provided due to elemental and isotopic interconnections between the natural and the anthropogenic contributors.","PeriodicalId":328860,"journal":{"name":"Geology, Earth & Marine Sciences","volume":"141 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126074763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differentiation of Sediment Source Regions in the Southern Benue Trough and Anambra Basin, Nigeria: Insights from Geochemistry of Upper Cretaceous Strata","authors":"Edegbai Aitalokhai Joel, Schwark Lorenz","doi":"10.31038/gems.2020224","DOIUrl":"https://doi.org/10.31038/gems.2020224","url":null,"abstract":"It is widely accepted that the lithic fill of the Anambra Basin, Southern Nigeria was sourced from the reworked pre-Santonian rocks of the Benue Trough. However, this hypothesis cannot account for the large sand volumes within the basin especially as the lithic fill of the Southern Benue Trough comprises mudstones, carbonates and subordinate sandstone units. In this study, we set out to investigate the provenance of the Mamu Formation as well as pre-Santonian Awgu and Eze-Aku groups by undertaking geochemical evaluation of cuttings from 5-wells spread across the Anambra Basin. The results of the well data, which was integrated with our previously generated data on the western margin of the Anambra basin as well as published data on the eastern margin reveal that the pre-Santonian units are characterized by a lower degree of chemical alteration and were sourced from basement complex rocks. By contrast, the more chemically altered Mamu Formation is sourced from recycled Southern Benue Trough strata, basement complex rocks as well as, anorogenic granites. In addition, the pre-Santonian units show spatio-temporal compositional variability, which is due to a large proportion of detrital contribution accruing from mafic rocks in the latest Cenomanian to early Turonian, whereas from middle Turonian to Coniacian the detrital contribution was more from felsic sources. Furthermore, the observed spatial geochemical variability of the Mamu Formation is adduced to be a consequence of detrital contribution from three source regions: the eastern, western and northern provenance regions. The eastern provenance region is characterized by a stronger mafic signature, low levels of Nb, Ta, Sn and Ti, high levels of W, Pb and Zn, strong Pb-Zn covariation as well as enrichment of Zn over Pb (Pb/Zn < 1), whereas the western and northern regions show higher levels of Nb, Ta, Sn and Ti. In addition, the western provenance is characterized by higher Pb over Zn (Pb/Zn >1) and lower W concentration, which is distinct from the northern provenance with Pb/Zn <1 and higher W concentration. Discriminant plots show clear evidence of mixing of provenance regions especially in the Idah-1 and Amansiodo-1 well whose sediments show secondary Pb, Sn and W mineral enrichment respectively.","PeriodicalId":328860,"journal":{"name":"Geology, Earth & Marine Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130325432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-Term Conductivity Measurements as a Source of Knowledge about Tree Life Cycles","authors":"P. Rutkowski, Monika Konatowska, Tomasz S. Wajsowicz","doi":"10.31038/gems.2020223","DOIUrl":"https://doi.org/10.31038/gems.2020223","url":null,"abstract":"The underlying physiological processes for tree activities in winter are still unclear, and changes occurring the growing season have been observed mainly on the basis of tedious phenological research. Devices, constructed and tested in a 3-year cycle by the Department of Forest Sites and Ecology, allows for tracking the activity of a tree throughout the year by using integrated measurements of conductivity, temperature and air humidity. That can be tracked online (see web site https://thingspeak.com/channels/698713). Observations on the impacts to four tree species ( Acer pseudoplatanus , Alnus glutinosa , Carpinus betulus , Fagus sylvatica ), were made for when temperatures fall below 0°C, during the spring activity phase, during the maximum of summer activity and during the autumn decline in activity. Thanks to the conductivity measurement method, tracking the activity of the trees year-round is easy. The sensors showed that the trees were active (although at a low level) during the winter; the real dormancy period was noted when the air temperature dropped below – 5.7 C o . For some temperature values, the conductivity is inhibited both in winter and in summer. The described method in this paper of measuring the conductivity of a tree may be very useful for future research related to trees, phenology, climate change and other ecological research. It can also be used as a utility tool that may, for example, be of interest to producers of maple syrup, as it indicates the moment when trees enter the phase of its most intensive production.","PeriodicalId":328860,"journal":{"name":"Geology, Earth & Marine Sciences","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115034969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Survey on Entomopathogens from the Arasbaran Biosphere Reserve (Iran) with a Modified Bait Insect Technique","authors":"E. Tarasco, Naser Eyvasian Kary, E. Fanelli, D. Mohammadi, A. Mehrvar, F. Luca, Alberto, Troccoli","doi":"10.31038/gems.2020221","DOIUrl":"https://doi.org/10.31038/gems.2020221","url":null,"abstract":"A survey on entomopathogens was carried out in Arasbaran Biosphere Reserve soils during June 2018 using Galleria mellonella L. (Lepidoptera, Pyralidae) larvae as bait insect with a modified bait insect technique. Three entomopathogen’s categories were recorded in 34 out of 36 soil samples (94.4%) collected from different natural habitat; the entomopathogens were identified as nematodes (23.5%), fungi (61%) and bacteria (15.5%) using molecular and morphological techniques.","PeriodicalId":328860,"journal":{"name":"Geology, Earth & Marine Sciences","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129939580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}