A large-scale detachment system in the central Eastern Alps (Upper Austroalpine Unit, Austria)

2020 ◽  
Author(s):  
Manuel Werdenich ◽  
Christoph Iglseder ◽  
Bernhard Grasemann ◽  
Gerd Rantitsch ◽  
Benjamin Huet
Keyword(s):  
Large Scale ◽  
Hanging Wall ◽  
Shear Bands ◽  
Carbonaceous Material ◽  
Eastern Alps ◽  
Low Grade ◽  
Fold Axis ◽  
Wall Unit ◽  
Detachment Zone ◽  
Austroalpine Unit

<p>Based on new structural field data and Raman micro-spectroscopy on carbonaceous material a major detachment juxtaposing Drauzug-Gurktal Nappe System (DGN) against the transgressive Permo-Mesozoic cover sequence of the Ötztal-Bundschuh Nappe System (BN, Stangalm Mesozoic s. str.) in the area SE of Flattnitz (Carinthia, Austria). An Eo-alpine top-SE kinematic has been identified.</p><p>The hanging wall unit comprise lithologies of the DGN phyllites, conglomerates and graphite schists (Stolzalpe nappe), which have experienced only low grade greenschist deformation. Raman constrains 350°C±40°C.</p><p>The footwall unit consists of dolomitic ultra-mylonites, calcitic marble mylonites, meta-conglomerates and quarzites (Stangalm Mesozoic and Kuster nappe), which have experienced at least four main deformation phases. The oldest structures (D1) corresponding to Eo-Alpine nappe stacking are overprinted by (D2) isoclinal recumbent folds with E-W oriented shallow dipping fold axis and an axial plane schistosity, dipping shallowly to WSW. Ductile to brittle-ductile top to the E shearing (D3) is indicated by ESE-trending stretching lineation, C-type shear bands, stylolites, crystal- and shape preferred orientations of mineral grains. Late brittle deformation (D4) is recorded in steep joint sets with dip-directions to NW. Raman constrains 480°C±40°C.</p><p>The detachment zone comprises a complicate zone of high strain including units from DGN folded together within the Stangalm Mesozoic, which have experienced the same deformation as the BN.</p>

Bulk inclusion dating: a geochronological tool to date low-grade metamorphism

2020 ◽  
Author(s):  
Marianne Sophie Hollinetz ◽  
David A. Schneider ◽  
Christopher R. M. McFarlane ◽  
Benjamin Huet ◽  
Bernhard Grasemann
Keyword(s):  
Ostwald Ripening ◽  
Carbonaceous Material ◽  
Spot Size ◽  
Eastern Alps ◽  
Low Grade ◽  
Chemical Zoning ◽  
Icp Ms ◽  
The Matrix ◽  
Suitable Target ◽  
The Stability

<p>The petrologic evolution of low-grade metamorphic rocks is essential for a coherent understanding of subduction- and exhumation-related processes during collisional orogeny. Retrieving useful P-T-t-d data from low-grade metamorphic units however is challenging as these rocks commonly lack suitable target minerals for geothermobarometry and/or geochronology. Herein we introduce a new geochronological method termed ‘bulk inclusion dating’ and present an example of a rock sampled at the base of the Stauffen-Höllengebirge Nappe (Austroalpine Unit, Eastern Alps, Austria) that witnessed an Eo-Alpine tectono-metamorphic event in the Late Cretaceous.</p><p>The investigated schist contains mm-scale chloritoid porphyroblasts in a foliated matrix consisting of chlorite, muscovite and quartz. Accessory minerals include ilmenite, hematite, rutile, zoned epidote with REE-rich cores, euhedral apatite and zircon. Thermodynamic modeling in the MnCNKFMASHTO system predicts the stability of the equilibrium assemblage in a narrow P-T field between 450–490°C and 5–7 kbar. Ilmenite, rutile and hematite inclusions in chloritoid cores indicate porphyroblast growth within this field, which is consistent with the observed chemical zoning of the chloritoid. The interpreted peak P-T conditions agree with the observation of garnet in a sample from the same outcrop and independent peak temperature constraints around 490°C derived from Raman spectroscopy of carbonaceous material.</p><p>Detailed petrographic investigations using high-resolution SEM imaging combined with EDX analysis revealed abundant minute (100 nm – 3 µm), idiomorphic zircons both included in chloritoid porphyroblasts and in the matrix. In the chloritoid rim, zircon comprises >95% of the inclusionary phases.  Based on grain size distribution, we interpret zircon growth during prograde metamorphism via dissolution-precipitation mechanism and progressive coarsening due to Ostwald ripening. In situ laser ablation ICP-MS analysis of the bulk zircon population included in the chloritoid rim using a 120 µm spot size yields a U-Pb age of 116.7 ± 6.4 Ma (MSWD: 1.5; n: 79). Combined with the results of thermodynamic forward modeling, we link the age to the late prograde part of the P-T evolution. The latest synorogenic sediments on top of the Stauffen-Höllengebirge Nappe were deposited at ca. 120 Ma, giving a consistent upper bound the late prograde age. An apatite U-Pb age from the same sample yields 429.3 ± 14.6 Ma (MSWD: 1.2; n: 60). Considering the protolith is an altered tuff and the apatite is likely magmatic, a Devonian protolith age is inferred. That the apatite age was not reset during Eo-Alpine metamorphism is in agreement with the inferred metamorphic conditions. We emphasize that the strength of the bulk inclusion dating approach lies in the improved link of P-T and age data and its relative ease of application compared to other geochronological methods.</p>

Meso- and micro-structural analysis of the Briançonnais Front in the Grand Saint Bernard area (Aosta Valley - Italy, and Valais - Switzerland)

2020 ◽  
Author(s):  
Daniele Pini ◽  
Gloria Arienti ◽  
Matteo Pozzi ◽  
Bruno Monopoli ◽  
Andrea Bistacchi
Keyword(s):  
Large Scale ◽  
Shear Bands ◽  
Structural Evolution ◽  
Shear Zones ◽  
Pressure Solution ◽  
Low Grade ◽  
Fine Grained ◽  
Ductile Shear Zones ◽  
Type 3 ◽  
Saint Bernard

<p>We present preliminary results on the meso- and micro-structural evolution of high-strain rocks of the Houillère Zone and Pierre-Avoi Unit outcropping along the Swiss-Italy boundary ridge, to the west of the Grand Saint Bernard Pass.</p><p>The stack of Middle and External Pennidic units is folded by polyphasic folds, developed at least partly under low-grade metamorphic conditions. Different generations of folds show isoclinal to open geometries. Fold axes are subhorizontal, trending NE-SW, and the overall fold interference pattern can be generally classified as a type 3 (Ramsay). At the microscale, an important deformation mechanism is pressure solution cleavage, consistent with relatively low-temperature conditions.</p><p>Brittle-ductile shear zones, characterized by anastomosing bands of very fine-grained fault rocks, with pressure solution seams and SCC’ shear bands, exploit the weak and strongly anisotropic phyllosilicate-rich layers, particularly in the black schists of the Houillère Zone.</p><p>Brittle high-angle faults crosscut ductile and semi-brittle features and show an oblique-normal kinematics. These faults are particularly well developed in the more competent rocks of the Pierre-Avoi Unit (e.g. massive carbonates, metaconglomerates and metasandstones).</p><p>A continuous horizon, a few metres thick, with a high density of quartz veins, can be followed in the internal and upper part of the Houillère Zone. This horizon is folded, at least by the younger open folds, and constitutes a major marker to study the large-scale structure of this unit.</p>

Direct Observation of Crystalline Ordering In Naturally Graphitized Carbon Produced by Low Grade Metamorphism

1977 ◽  
Vol 35 ◽  
pp. 162-163
Author(s):  
Thomas R. McKee ◽  
Peter R. Buseck
Keyword(s):  
Crystallite Size ◽  
Sedimentary Rocks ◽  
Carbonaceous Material ◽  
Low Grade ◽  
X Ray ◽  
Graphitized Carbon ◽  
Transmission Electron ◽  
Heat Treated ◽  
Commercial Carbon ◽  
Metamorphic Zone

Sediments commonly contain organic material which appears as refractory carbonaceous material in metamorphosed sedimentary rocks. Grew and others have shown that relative carbon content, crystallite size, X-ray crystallinity and development of well-ordered graphite crystal structure of the carbonaceous material increases with increasing metamorphic grade. The graphitization process is irreversible and appears to be continous from the amorphous to the completely graphitized stage. The most dramatic chemical and crystallographic changes take place within the chlorite metamorphic zone.The detailed X-ray investigation of crystallite size and crystalline ordering is complex and can best be investigated by other means such as high resolution transmission electron microscopy (HRTEM). The natural graphitization series is similar to that for heat-treated commercial carbon blacks, which have been successfully studied by HRTEM (Ban and others).

scholarly journals Late oligocene–early miocene shortening in the Thrace Basin, northern Aegean

2021 ◽  
Author(s):  
Ümitcan Erbil ◽  
Aral I. Okay ◽  
Aynur Hakyemez
Keyword(s):  
Large Scale ◽  
Middle Eocene ◽  
Early Miocene ◽  
Fold Axis ◽  
Late Oligocene ◽  
The Balkans ◽  
Sedimentary Sequences ◽  
The North ◽  
Early Oligocene ◽  
Thrace Basin

AbstractLate Cenozoic was a period of large-scale extension in the Aegean. The extension is mainly recorded in the metamorphic core complexes with little data from the sedimentary sequences. The exception is the Thrace Basin in the northern Aegean, which has a continuous record of Middle Eocene to Oligocene marine sedimentation. In the Thrace Basin, the Late Oligocene–Early Miocene was characterized by north-northwest (N25°W) shortening leading to the termination of sedimentation and formation of large-scale folds. We studied the stratigraphy and structure of one of these folds, the Korudağ anticline. The Korudağ anticline has formed in the uppermost Eocene–Lower Oligocene siliciclastic turbidites with Early Oligocene (31.6 Ma zircon U–Pb age) acidic tuff beds. The turbidites are underlain by a thin sequence of Upper Eocene pelagic limestone. The Korudağ anticline is an east-northeast (N65°E) trending fault-propagation fold, 9 km wide and 22 km long and with a subhorizontal fold axis. It is asymmetric with shallowly-dipping northern and steeply-dipping southern limbs. Its geometry indicates about 1 km of shortening in a N25°W direction. The folded strata are unconformably overlain by Middle Miocene continental sandstones, which constrain the age of folding. The Korudağ anticline and other large folds in the Thrace Basin predate the inception of the North Anatolian Fault (NAF) by at least 12 myr. The Late Oligocene–Early Miocene (28–17 Ma) shortening in the Thrace Basin and elsewhere in the Balkans forms an interlude between two extensional periods, and is probably linked to changes in the subduction dynamics along the Hellenic trench.

1-D Model Analysis of Tesla Turbine for Small Scale Organic Rankine Cycle (ORC) System

2017 ◽  
Author(s):  
Jian Song ◽  
Chun-wei Gu
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Organic Rankine Cycle ◽  
Axial Flow ◽  
Rankine Cycle ◽  
Expansion Ratio ◽  
Working Fluid ◽  
Small Scale ◽  
Low Grade ◽  
D Model

Energy shortage and environmental deterioration are two crucial issues that the developing world has to face. In order to solve these problems, conversion of low grade energy is attracting broad attention. Among all of the existing technologies, Organic Rankine Cycle (ORC) has been proven to be one of the most effective methods for the utilization of low grade heat sources. Turbine is a key component in ORC system and it plays an important role in system performance. Traditional turbine expanders, the axial flow turbine and the radial inflow turbine are typically selected in large scale ORC systems. However, in small and micro scale systems, traditional turbine expanders are not suitable due to large flow loss and high rotation speed. In this case, Tesla turbine allows a low-cost and reliable design for the organic expander that could be an attractive option for small scale ORC systems. A 1-D model of Tesla turbine is presented in this paper, which mainly focuses on the flow characteristics and the momentum transfer. This study improves the 1-D model, taking the nozzle limit expansion ratio into consideration, which is related to the installation angle of the nozzle and the specific heat ratio of the working fluid. The improved model is used to analyze Tesla turbine performance and predict turbine efficiency. Thermodynamic analysis is conducted for a small scale ORC system. The simulation results reveal that the ORC system can generate a considerable net power output. Therefore, Tesla turbine can be regarded as a potential choice to be applied in small scale ORC systems.

scholarly journals Case Report: Efficacy of Pyrotinib in ERBB2 Amplification Pulmonary Adenoid Cystic Carcinoma

2021 ◽  
Vol 11 ◽  
Author(s):  
Zhongben Tang ◽  
Feng Lin ◽  
Jiarong Xiao ◽  
Xiaojun Du ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Adenoid Cystic Carcinoma ◽  
Large Scale ◽  
Case Reports ◽  
Growth Factor Receptor ◽  
Low Grade ◽  
Adenoid Cystic ◽  
Epidermal Growth ◽  
Low Incidence ◽  
Current Report

Primary pulmonary adenoid cystic carcinomas are salivary tumors that are low-grade malignant and prone to recurrence and metastasis. Surgery is currently the main treatment, but there is no standard with regard to postoperative adjuvant therapy. Adenoid cystic carcinoma is more sensitive to radiotherapy and patients benefit less from chemotherapy, but few studies have focused on targeted therapy, and their conclusions are inconsistent. With respect to primary pulmonary adenoid cystic carcinoma, large-scale studies cannot be conducted due to its low incidence, and studies on the targeted therapy of it are very scarce. A few case reports indicate that targeted therapy can be effective however, suggesting that it may be a good option. The current report is the first on the occurrence of human epidermal growth factor receptor 2 amplification in pulmonary adenoid cystic carcinoma. The patient was treated with pyrotinib for 6 months and achieved stable disease.

The Analysis and Application of Energy-Internet in the Low-Carbon Community

2010 ◽  
Author(s):  
Hao Liang ◽  
Weiding Long ◽  
Yingqian Song ◽  
Fang Liu
Keyword(s):  
Renewable Energy ◽  
Large Scale ◽  
Energy Use ◽  
Optimal Path ◽  
Energy Generation ◽  
Hot Water ◽  
Low Grade ◽  
Low Carbon ◽  
Urban District ◽  
Energy Internet

The energy-Internet is a new energy supply method based on urban compact and densely populated community in a low-carbon city. The principle is to connect small energy generation stations and combined heat and power system (CHP) based on distributed energy technology and renewable energy into a network in the urban district. In this way, the cooling, heating and electricity could all back each other up. Each building of the community could collect the energy and then put that energy into the energy-internet to supply the heating and power to buildings. The power in the energy-internet could also be used for charging electric vehicles. So the energy use in the urban community would be basically self-sufficient. The energy generation stations in the energy-internet could be solar power, wind power, biomass cogeneration (including refuse power generation), household fuel cell, low-grade heat in rivers, lakes, urban sewage and soil. In this way, large-scale renewable energy and unused energy could be fully used and applied in a compact and dense community. If the energy-internet is suitable designed, the equipment capacity, energy consumption and CO2 emission of the community could be greatly reduced, energy efficiency could be optimized and improved and the heat island effect could also be alleviated. This article explores three major problems of the construction of energy internet and their solutions: namely, the location and layout of the energy station, the environmental economic dispatch model of the energy internet with power dispatching as an example, the optimal path design of hot water pipe network combined with graph theory and genetic algorithms.

scholarly journals Hydrodynamic and Flotation Kinetic Analysis of a Large Scale Mechanical Agitated Flotation Cell with the Typical Impeller and the Arc Impeller

Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 79 ◽  
Author(s):  
Zhengchang Shen ◽  
Ming Zhang ◽  
Xuesai Fan ◽  
Shuaixing Shi ◽  
Dengfeng Han
Keyword(s):  
Large Scale ◽  
Hydrodynamic Performance ◽  
Collision Probability ◽  
Collision Kernel ◽  
Low Grade ◽  
Performance Parameters ◽  
Effective Volume ◽  
Mineral Particles ◽  
Flotation Cells ◽  
Flotation Cell

The processing of low grade mineral ores using large scale flotation cells is obviously more advantageous than smaller-scale processing. Large-scale flotation cells have become increasingly important for effective volume scale-up. In this study, the latest and largest flotation cell in China, with an effective volume of 680 m3, is considered. Hydrodynamics and flotation kinetics analyses are conducted using computational fluid dynamics (CFD) simulation. It is demonstrated that the flotation cell with a typical impeller produces suitable hydrodynamics for mineral particles based on analysis of the flow pattern, gas dispersion and solid suspension. The performance of the large-scale flotation cell is studied using hydrodynamic performance parameters. The variation of the performance parameters, such as the power number (Np), the Froude number (Fr), the air flow number (Na), and so on, with the flotation cell volumes, followed trends similar to that of previous cells of a different size, which were proven to be effective for engineering applications. To decrease the detachment of mineral particles, a new type of impeller, for which the impeller plate is a hyperbolic curve, viz. an arc impeller, was developed. Compared with the typical impeller, the arc impeller expands and lifts the low circulating flow, thereby shortening the transportation distance of the mineral particles. The data indicates that kinetic eddy dissipation plays a key role in determining the collision kernel and collision probability profile. The newly designed arc impeller leads to a higher collision probability than the typical impeller, resulting in better flotation performance. This research should aid in the optimization of the structure of the 680 m3 flotation cell.

Practical Experience in Large-Scale Development of Zijinshan Low-Grade Gold-Copper Mine

2020 ◽  
Vol 37 (4) ◽  
pp. 1339-1347 ◽  
Author(s):  
Jinghe Chen ◽  
Shuiping Zhong ◽  
Ding Tang ◽  
Chen Kuang
Keyword(s):  
Scale Development ◽  
Large Scale ◽  
Practical Experience ◽  
Low Grade ◽  
Copper Mine
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