Heat flow variation with depth in Poland: evidence from equilibrium temperature logs in 2.9-km-deep well Torun-1     

Jacek?Majorowicz  Jan??afanda  Torun- Working Group 《International Journal of Earth Sciences》2008,97(2):307-315

High-precision temperature measurements were carried out up to a depth of 2,930 m in the 5.5-km-deep well Torun-1, 26 years after completion of drilling. The temperature log provides equilibrium thermal state information for the Polish Lowland at the western margin of the Precambrian craton. Geothermal gradient calculated from the equilibrium temperature log, together with estimates of thermal conductivity from ‘net rock’ geophysical well logging analysis and available core measurements, yields heat flow in the range 50–60 mW/m² below 2-km depth. Heat flow of 50 mW/m² plus ∼10 mW/m² generated within thick sediments and highly metamorphosed sedimentary wedge is typical for the western margin of the Precambrian East European craton. Heat-flow variations with depth can be explained by a model of surface-temperature changes >10°C (glaciation to Holocene). Torun-1 Working Group: Marta Wróblewska, Jacek Majorowicz, Jan Szewczyk, Jan Šafanda, Vladimír Cermák  相似文献   

Study on reliable GNSS positioning with intense TEC fluctuations at high latitudes     

Sieradzki  Rafał  Paziewski  Jacek 《GPS Solutions》2016,20(3):553-563

GPS Solutions - The study presents the influence of strong total electron content (TEC) fluctuations occurring at high latitudes on rapid static positioning. The authors propose an algorithm...  相似文献   

FE-studies on the influence of initial void ratio,pressure level and mean grain diameter on shear localization     

Jacek Tejchman  Ivo Herle  Jimmy Wehr 《国际地质力学数值与分析法杂志》1999,23(15):2045-2074

The paper is concerned with shear localization in the form of a spontaneous shear zone inside a granular material during a plane strain compression test. The influence of an initial void ratio, pressure and a mean grain diameter on the thickness of a shear zone is investigated. A plane strain compression test with dry sand is numerically modelled with a finite element method taking into account a polar hypoplastic constitutive relation which was laid down within a polar (Cosserat) continuum. The relation was obtained through an extension of a non-polar hypoplastic constitutive law according to Gudehus and Bauer by polar quantities: rotations, curvatures, couple stresses and a characteristic length. It can reproduce the essential features of granular bodies during shear localization. The material constants can be easily calibrated. The FE-calculations demonstrate an increase in the thickness of the shear zone with increasing initial void ratio, pressure level and mean grain diameter. Polar effects manifested by the appearance of grain rotations and couple stresses are only significant in the shear zone. A comparison between numerical calculations and experimental results shows a satisfying agreement. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

Jurassic Progonocimicidae (Hemiptera) from China and phylogenetic evolution of Coleorrhyncha     

Bo Wang  Jacek Szwedo  HaiChun Zhang 《中国科学D辑(英文版)》2009,52(12):1953-1961

The fossil record of Progonocimicidae of Hemiptera suborder Coleorrhyncha from China is reviewed. Ovicimex laiyangensis Hong et Wang, 1990, from the Lower Cretaceous of Laiyang, is excluded from Coleorrhyncha. The available generic name Mesocimex Hong, 1983 is resurrected from synonymy and proposed for replacement of the preoccupied name and junior homonym Mesoscytina Hong, 1983, non Mesoscytina Tillyard, 1919. It resulted in following new combinations: Mesocimex abditus (Yu. Popov, 1982) comb. n., Mesocimex ambiguus (Yu. Popov, 1985) comb. n., Mesocimex brunneus (Hong, 1983), comb. n., Mesocimex fidus (Yu. Popov, 1982) comb. n., Mesocimex intermedius (Yu. Popov, 1985) comb. n., Mesocimex kuzbasicus (Yu. Popov, 1985) comb. n., Mesocimex liliputus (Yu. Popov, 1988) comb. n., Mesocimex minutus (Yu. Popov, 1982) comb. n., Mesocimex modestus (Yu. Popov, 1985) comb. n., Mesocimex paulinus (Yu. Popov, 1982) comb. n., Mesocimex cognatus (Yu. Popov, 1982) comb. n. An annotated list of species of Mesocimex is given. In addition, a new species, Mesocimex lini sp. nov., is described based on well-preserved specimens with wings and bodies from the Middle Jurassic of Daohugou, China. This discovery supports the Middle Jurassic age of Daohugou Lagerstatte, since all species of Mesocimex are confined to the Lower-Middle Jurassic. The phylogenetic evolution of Coleorrhyncha is discussed: Cicadocorinae, Karabasiinae, Hoploridiinae, and Peloridiidae are monophyletic clades whereas Progonocimicinae and Karabasidae are clearly paraphyletic groups.  相似文献   

Integrating X‐ray mapping and microtomography of garnet with thermobarometry to define the P–T evolution of the (near) UHP Międzygórze eclogite,Sudetes, SW Poland     

Jaros&#x;aw Majka  Stanis&#x;aw Mazur  Maria M&#x;ynarska  Iwona Klonowska  Lorraine Tual  Karolina Komi&#x;ska  Jacek Tarasiuk  Sebastian Wro&#x;ski 《Journal of Metamorphic Geology》2019,37(1):97-112

Detailed X‐ray compositional mapping and microtomography have revealed the complex zoning and growth history of garnet in a kyanite‐bearing eclogite. The garnet occurs as clusters of coalesced grains with cores revealing slightly higher Ca and lower Mg than the rims forming the coalescence zones between the grains. Core regions of the garnet host inclusions of omphacite with the highest jadeite, and phengite with the highest Si, similar to values in the cores of omphacite and phengite located in the matrix. Therefore, the core compositions of garnet, omphacite, and phengite have been chosen for the peak pressure estimate. Coupled conventional thermobarometry, average P–T, and phase equilibrium modelling in the NCKFMMnASHT system yields P–T conditions of 26–30 kbar at 800–930°C. Although coesite is not preserved, these P–T conditions partially overlap the coesite stability field, suggesting near ultra‐high–pressure (UHP) conditions during the formation of this eclogite. Therefore, the peak pressure assemblage is suggested to have been garnet–omphacite–kyanite–phengite–coesite/quartz–rutile. Additional lines of evidence for the possible UHP origin of the Mi?dzygórze eclogite are the presence of rod‐shaped inclusions of quartz parallel to the c‐axis in omphacite as well as relatively high values of Ca‐Tschermak and Ca‐Eskola components. Late zoisite, rare diopside–plagioclase symplectites rimming omphacite, and minor phlogopite–plagioclase symplectites replacing phengite formed during retrogression together with later amphibole. These retrograde assemblages lack minerals typical of granulite facies, which suggests simultaneous decompression and cooling during exhumation before the crustal‐scale folding that was responsible for final exhumation of the eclogite.  相似文献   

Fen ecosystem responses to water‐level fluctuations during the early and middle Holocene in central Europe: a case study from Wilczków,Poland          下载免费PDF全文

Mateusz Płóciennik  Andrzej Kruk  Jacek Forysiak  Dominik Pawłowski  Kamila Mianowicz  Scott Elias  Ryszard K. Borówka  Marek Kloss  Milena Obremska  Marek Krąpiec  Piotr Kittel  Sławomir Żurek 《Boreas: An International Journal of Quaternary Research》2015,44(4):721-740

This paper presents a palaeoenvironmental reconstruction of the Wilczków fen (central Poland). The fen developed in an inactive valley at the onset of the Holocene (~11 ka BP) and peat accumulation lasted until 5.7 ka BP. Multi‐proxy reconstructions were made on the basis of palaeobotanical, cladoceran, chironomid, beetle and geochemical analyses. A Kohonen self‐organizing map (SOM, unsupervised artificial neural network) of the biotic sequence distinguished four stages of fen history. Stage X₁ (11.0–10.7 ka BP) was relatively wet and cool. Organic matter started to accumulate but the habitat conditions remained unstable. Moss, sedge and fern communities then developed. Sedimentary changes reveal an intensive groundwater supply at that time. Numerous and diverse chironomid and cladoceran subfossils indicate nearly permanent aquatic conditions. During stage Y₁ (10.6–9.2 ka BP) conditions were dry and the upper peat layer desiccated. Cladocera nearly disappeared whereas chironomids were represented by semi‐terrestrial and predatory (Tanypodinae) species. Conditions started to be more reducing. All the remaining samples belonged to the interweaving stages X₂ and Y₂. Stage Y₂ (mostly 9.1–7.3 and 6.0–5.7 ka BP) was also dry but humidity increased towards the top. Oxidizing conditions occurred and the pH became more alkaline, favouring Cladium mariscus. The basin received mostly allochthonous matter input at that time. Stage X₂ (mostly 6.8–6.1 ka BP) was humid and warm. The groundwater supply remained low but there was an increase in precipitation, changing local conditions to ombrotrophic. Species‐rich chironomid and cladoceran communities were associated with temporary pools. Finally, conditions returned to those characteristic of stage Y₂. The presented reconstruction documents long‐term abiotic and biotic changes determined by water supply, including groundwater outflow, which have rarely been detected at a multi‐proxy scale. We show that inactivated valley fens are sensitive to climate‐driven hydrological fluctuations. Kohonen neural networks appear to be a promising method for analysing variability in multi‐proxy data.  相似文献   

Depleted subcontinental lithospheric mantle and its tholeiitic melt metasomatism beneath NE termination of the Eger Rift (Europe): the case study of the Steinberg (Upper Lusatia,SE Germany) xenoliths     

Anna Kukuła  Jacek Puziewicz  Magdalena Matusiak-Małek  Theodoros Ntaflos  Jörg Büchner  Olaf Tietz 《Mineralogy and Petrology》2015,109(6):761-787

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From mantle roots to surface eruptions: Cenozoic and Mesozoic continental basaltic magmatism     

Horst Kämpf  Karoly Németh Dr.  Jacek Puziewicz  Jan Mrlina  Wolfram H. Geissler 《International Journal of Earth Sciences》2015,104(8):1909-1912

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Bacterial ancient DNA as an indicator of human presence in the past: its correlation with palynological and archaeological data     

Jacek Madeja  Agnieszka Wacnik  Agata Zyga  Elzbieta Stankiewicz  Ewa Wypasek  Witold Guminski  Krystyna Harmata 《第四纪科学杂志》2009,24(4):317-321

Palynological investigation is one of the most important tools for reconstructing past vegetation. Some plants have proved to be relatively sensitive indicators of human activity, but most of them are not specific. In this paper we propose a method which can be used for the verification of phases of anthropogenic impact on vegetation distinguished in pollen diagrams. In this work we adopted the existing molecular methods for tracking bacterial ancient DNA of Bifidobacterium and Bacteroides‐Prevotella (known as human‐ and cow‐specific genetic markers) in palynologically and archaeologically associated sediments. This method can be helpful in determining local human presence, especially in those time periods when pollen analysis has not always been very discriminating (Palaeolithic, Mesolithic) and at sites without archaeological evidence. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Semipermeable membrane devices link site-specific contaminants to effects: Part 1 - Induction of CYP1A in rainbow trout from contaminants in Prince William Sound, Alaska   总被引：1，自引：1，他引：0  

Springman KR  Short JW  Lindeberg MR  Maselko JM  Khan C  Hodson PV  Rice SD 《Marine environmental research》2008,66(5):477-486

Extracts from semi-permeable membrane devices (SPMDs) deployed on beaches in Prince William Sound (PWS), Alaska, were used to evaluate if complex contaminant mixtures from different sources can be distinguished by the resulting cytochrome P450 1A (CYP1A) activity in exposed test animals. Deployment sites included canneries, salmon hatcheries, and beaches where lingering oil remains from discharges during the 1964 earthquake or the 1989 Exxon Valdez oil spill. Other sites were selected at random to evaluate region-wide contaminant inputs or were located in salmon streams to evaluate contaminants carried and released by migrating salmon carcasses following reproduction. Following standard deployments of approximately 28 d, an aliquot of the accumulated contaminants was intraperitoneally injected without cleanup into juvenile rainbow trout (Oncorhynchus mykiss). After 2 d and 7 d, the activity of CYP1A was measured by the ethoxyresorufin-o-deethylase (EROD) assay. Exposure to extracts from the oiled sites and one hatchery site with numerous creosote pilings elicited strong EROD responses, whereas fish exposed to salmon stream extracts elicited weak but significant responses during late summer compared to late spring. Responses from the other sites were not significant, indicating contaminants from these sources are unlikely to cause CYP1A induction in resident biota. Rather than simply assessing extant contaminants, this method evaluates the potency of the different sites for bringing about aryl hydrocarbon receptor responses in resident biota.  相似文献