Deformationsprozesse und hydrogeologische Eigenschaften von Störungszonen in Karbonatgesteinen

Im Rahmen der vorliegenden Diplomarbeit wurde eine vergleichende Studie an Störungszonen in obertriassischen Kalk- und Dolomitgesteinen der Wettersteinformation durchgeführt. Untersucht und verglichen wurden der interne Aufbau von Störungskern und damage zones der Störungszonen, die auftretenden Störungsgesteine sowie hydrogeologische Eigenschaften unterschiedlicher Bereiche. Die Störungszonen befinden sich im nördlichen Hochschwabmassiv. Es handelt sich um sinistrale Blattverschiebungen, die in geringen Krustentiefen während der lateralen Extrusion der Ostalpen im Oligozän und Unteren Miozän entstanden. Störungszonen in Kalkgesteinen sind relativ eng begrenzte Zonen mit deutlich abgrenzbarem Störungskern und damage zones. Störungskerne, die die Hauptstörung der Störungszone beinhalten, werden durch kataklastische Störungsgesteine charakterisiert. Mit dem Störungskern assoziierte Harnischflächen separieren Kataklasite unterschiedlichen Typs voneinander oder grenzen Kataklasite vom Nebengestein ab. Kataklasite unterscheiden sich hinsichtlich Komponentengröße, Matrixgehalt und der Rundung der Komponenten. Kataklasit –Mikrostrukturen deuten progressive Kataklasis und beträchtlichen Versatz entlang der Störungsgesteine an. Die Heterogenität des Störungskerns ist in höher entwickelten Störungszonen (Störungszonen mit großem Versatz) generell geringer als in kleineren Störungszonen mit geringem Versatz. In allen Störungszonen treten Kataklasite in Bändern auf, die sich zu geometrisch komplexen, anastomosierenden Gesteinsvolumen verbinden. Es ist schwierig, die 3D-Geometrie komplexer Störungskerne im Aufschlussmaßstab aufzulösen. Neben kataklastischem Fließen konnten Drucklösungsprozesse, die Kataklasite überprägen, dokumentiert werden. Die damage zones von Störungszonen in Kalkgesteinen werden durch intensiv geklüftetes Ausgangsgestein und dilatation breccias charakterisiert, die Dilatationsprozesse und peripheral wall rock weakening belegen. Diese Prozesse begleiten die (Fort-) Entwicklung der Störungszonen. Große Volumen von Karbonatzementen in den dilatation breccias deuten an, dass solche Prozesse mit hohen Fluiddrucken und mit der Perkolation großer Fluidvolumen einhergehen. Auf der Basis unterschiedlicher Kluftdichten wurden in den damage zones verschiedene Bereiche unterschieden. Kluftdichten (P32, in m² Kluftfläche pro m³ Gestein) variieren entlang aller untersuchten Störungszonen. In höher entwickelten Störungszonen mit größerem Versatz wurden die größten Kluftdichten gefunden, die hier vor allem mit großflächigen Riedelscherflächen in den damage zones assoziiert sind. Auch in unmittelbarem Kontakt zum Störungskern sind hohe Kluftdichten anzutreffen. Auf der Grundlage eines Klassifikationsschemas wurden im Gelände fracture facies definiert, um eine semi-quantitative Abschätzung der Dichte und räumlichen Verteilung von kleinmaßstäblichen Klüften zu erhalten. Unterschiedliche Bereiche wurden mit fracture facies 1 bis 4 charakterisiert, wobei fracture facies 4 für die höchsten Kluftdichten steht. Störungszonen in Dolomitgesteinen weisen, auch bei geringem strain, mehrere Störungskerne auf, die in breiteren Zonen von geklüftetem Ausgangsgestein liegen. Verglichen mit Störungszonen mit ähnlichem Versatz in Kalkgesteinen, sind die damage zones in Dolomiten breiter und sie weisen höher Kluftdichten. Dilatation breccias treten häufiger auf, die klare Unterscheidung/Abgrenzung von Störungskern und damage zone ist schwieriger. Damage zones, die an lateralen (mode III) tips der untersuchten Blattverschiebungen gefunden wurden, belegen, dass hydraulic fracturing und Fluidfluss durch die propagierende Störung einen bedeutenden Faktor in der Entwicklung der Störungszone darstellen. Ein typischer Übergang von Ausgangsgestein, dass sich vor der propagierenden Störung befindet, zum Störungskern der bewegten Störung beinhaltet dicht geklüftetes Ausgangsgestein, Ausgangsgestein mit häufigen Zement-verfüllten Zerrspalten, dilatation breccias und Kataklasite, in denen dilatation breccias und Ausgangsgesteinen aufgearbeitet werden. Die detaillierte Dokumentation von verschiedenen Einheiten in Störungszonen wurde durch Porositätsmessungen ergänzt, um so Aussagen über die hydrogeologischen Eigenschaften von Störungszonen treffen zu können. In allen untersuchten Störungszonen finden sich höher permeable Einheiten vor allem in den damage zones. Charakterisiert werden sie durch hohe Kluftdichten. Die Porositätsmessungen ergaben für dilatation breccias (bis zu 6%) und geklüftetes Ausgangsgestein (fracture facies 4) die höchsten Werte (die Porosität von undeformiertem Ausgangsgestein liegt bei durchschnittlich 1,5%, mit dem Maximum bei 2%). Dünnschliffe belegen, dass der größte Anteil der Porosität durch unzementierte Klüfte entsteht. Daraus lässt sich ableiten, dass die Kluftporosität der kontrollierende Faktor hinsichtlich der Permeabilität der Störungszonen ist. Die unterschiedlichen Typen von Kataklasiten in den Störungskernen haben geringe intra-granulare Porosität (durchschnittlich bei 2,5%) und sehr geringe Kluftdichten. Sie können als gering-permeable Einheiten der Störungszonen eingestuft werden.The topic of this diploma thesis is a comparative analysis of fault zones in limestone and dolomite rocks comparing the architecture of fault core and damage zones, fault rocks, and the hydrodynamic properties of faults exposed in the Upper Triassic Wetterstein Fm. of the Hochschwab Massif (Austria). All analysed faults are sinistral strike-slip faults, which formed at shallow crustal depth during the process of eastward lateral extrusion of the Eastern Alps in the Oligocene and Lower Miocene. Fault zones in limestone tend to be relatively narrow zones with distinct fault core and damage zones. Fault cores, which include the principle slip surface of the fault, are characterized by cataclastic fault rock associated with slickensides separating strands of catalasite from surrounding host rock or occurring between different types of cataclasite. Cataclasites differ in terms of fragment size, matrix content and the angularity of fragments. Cataclasite fabrics indicate progressive cataclasis and substantial displacement across the fault rock. Fault core heterogeneity tends to decrease within more evolved (higher displacement) faults. In all fault cores cataclasites are localized within strands, which connect to geometrically complex anastomosing volumes of fault rock. The 3D geometry of such fault cores is difficult to resolve on the outcrop scale. Beside cataclastic flow pressure solution, overprinting cataclastic fabrics, could be documented within fault zones. Damage zones in limestone fault zones are characterized by intensively fractured (jointed) host rock and dilatation breccias, indicating dilatation processes and peripheral wall rock weakening accompanying the growth of the fault zone. Dilatation breccias with high volumes of carbonate cement indicate these processes are related to high fluid pressure and the percolation of large volumes of fluid. Different parts of the damage zones were differentiated on the base of variable fracture densities. Fracture densities (P32 in m² joint surfaces per m³ rock) generally vary along all investigated faults. They are especially high in more evolved (higher displacement) fault zones where they are associated with large-scale Riedel shears and in parts of the damage zones, that are next to the fault cores. The assessment of the abundance of small-scale fractures uses fracture facies as an empirical classification providing semi-quantitative estimates of fracture density and abundance. Different units were assigned to fracture facies 1 to 4, with fracture facies 4 indicating highest fracture density. Fault zones in dolomite tend to have several fault cores localized within wider zones of fractured wall rock (damage zones), even at low strain. Compared to fault zones with similar displacement in limestone, damage zones in dolomite tend to be wider and have higher fracture densities. Dilatation breccias are more abundant. A clear separation of fault core and damage zone is more difficult. Damage zones observed at the lateral (mode III) tips of the analysed strike-slip faults show that hydraulic fracturing and fluid flow through the propagating fault are of major importance for its evolution. A typical transition from the wall rock ahead of the propagating fault to the core of the slipped fault includes: densely jointed wall rock, wall rock with abundant cement-filled tension gashes, dilatation breccia and cataclasite reworking both dilatation breccia and wall rock. The detailed documentation of different fault zone units is supplemented by porosity measurements in order to assess the hydrogeological properties of the fault zones. High permeability units are first of all located in the damage zones, characterized by high fracture densities. Porosity measurements on fault rocks showed highest porosity (up to 6%) for fractured wall rocks (fracture facies 4) and dilatation breccias (porosity of undeformed wall rock: 1,5 % average, 2 % maximum). Thin sections prove that most of the porosity is carried by uncemented fractures. Fracture porosity therefore is the controlling factor of fault zone permeability. The different types of cataclasite in fault cores show low intra-granular porosities (average 2,5 %) and very low fracture density. They therefore are classified as low-permeability units

Using Wikis to Promote Reflective Teaching and Collaboration among Higher Education Institutions

The purpose of this article is to describe how teacher educators from different higher education institutions used Web 2.0 technology to facilitate collaboration in a small pedagogy group. Faculty from three different institutions participated in monthly face-to-face group meetings. They used technology to facilitate reflection on practice and scholarship. In addition, they were engaged in interactive journaling and collaborative writing activities. Wikis provided useful supports, and enhanced their learning. The group used a hybrid format that allowed increased opportunities to meet group and individual goals and extend benefits to students. Some themes emerged from the qualitative analysis of reflections in response to prompts regarding the impact of using Wikis. These included co-ownership, communication, organization, sharing resources, accessibility, and community. The authors offered some suggestions for facilitating the successful use of this technology in collaborative efforts. Each member of a Wiki must clearly understand the purpose of his or her involvement. Wiki communities participate in social negotiation. This means that each individual should have a clear role, and a sense of belonging. The group used Wikis as extensions and supports that assist group members to reach shared goals. Wiki selfefficacy, or how capable members feel while using wikis, depend on perceived ease of use and decreased sense of user anxiety

Complete genome sequence of Lutibacter profoundi LP1T isolatet from an Arctic deep-sea hydrothermal vent system

Lutibacter profundi LP1T within the family Flavobacteriaceae was isolated from a biofilm growing on the surface of a black smoker chimney at the Loki’s Castle vent field, located on the Arctic Mid-Ocean Ridge. The complete genome of L. profundi LP1T is the first genome to be published within the genus Lutibacter. L. profundi LP1T consists of a single 2,966,978 bp circular chromosome with a GC content of 29.8%. The genome comprises 2,537 protein-coding genes, 40 tRNA species and 2 rRNA operons. The microaerophilic, organotrophic isolate contains genes for all central carbohydrate metabolic pathways. However, genes for the oxidative branch of the pentose-phosphate-pathway, the glyoxylate shunt of the tricarboxylic acid cycle and the ATP citrate lyase for reverse TCA are not present. L. profundi LP1T utilizes starch, sucrose and diverse proteinous carbon sources. In accordance, the genome harbours 130 proteases and 104 carbohydrate-active enzymes, indicating a specialization in degrading organic matter. Among a small arsenal of 24 glycosyl hydrolases, which offer the possibility to hydrolyse diverse poly- and oligosaccharides, a starch utilization cluster was identified. Furthermore, a variety of enzymes may be secreted via T9SS and contribute to the hydrolytic variety of the microorganism. Genes for gliding motility are present, which may enable the bacteria to move within the biofilm. A substantial number of genes encoding for extracellular polysaccharide synthesis pathways, curli fibres and attachment to surfaces could mediate adhesion in the biofilm and may contribute to the biofilm formation. In addition to aerobic respiration, the complete denitrification pathway and genes for sulphide oxidation e.g. sulphide:quinone reductase are present in the genome. sulphide:quinone reductase and denitrification may serve as detoxification systems allowing L. profundi LP1T to thrive in a sulphide and nitrate enriched environment. The information gained from the genome gives a greater insight in the functional role of L. profundi LP1T in the biofilm and its adaption strategy in an extreme environment.publishedVersio

Late Miocene-Quaternary fault evolution and interaction in the southern California Inner Continental Borderland

Changing conditions along plate boundaries are thought to result in the reactivation of preexisting structures. The offshore southern California Borderland has undergone dramatic adjustments as conditions changed from subduction tectonics to transform tectonics, including major Miocene oblique extension, followed by transpressional fault reactivation. However, consensus is still lacking about stratigraphic age models, fault geometry, and slip history for the near-offshore area between southern Los Angeles and San Diego (California, USA). We interpret an extensive data set of seismic reflection, bathymetric, and stratigraphic data from that area to determine the three-dimensional geometry and kinematic evolution of the faults and folds and document how preexisting structures have changed their activity and type of slip through time. The resulting structural representation reveals a moderately landward-dipping San Mateo–Carlsbad fault that converges downward with the steeper, right-lateral Newport-Inglewood fault, forming a fault wedge affected by Quaternary contractional folding. This fault wedge deformed in transtension during late Miocene through Pliocene time. Subsequently, the San Mateo–Carlsbad fault underwent 0.6–1.0 km displacement, spatially varying between reverse right lateral and transtensional right lateral. In contrast, shallow parts of the previously identified gently dipping Oceanside detachment and the faults above it appear to have been inactive since the early Pliocene. These observations, together with new and revised geometric representations of additional steeper faults, and the evidence for a pervasive strike-slip component on these nearshore faults, suggest a need to revise the earthquake hazard estimates for the coastal region

Photon drag effect in (Bi1−xSbx)2Te3 three-dimensional topological insulators

We report on the observation of a terahertz radiation-induced photon drag effect in epitaxially grown nand p-type (Bi1-xSbx)(2)Te-3 three-dimensional topological insulators with different antimony concentrations x varying from 0 to 1. We demonstrate that the excitation with polarized terahertz radiation results in a dc electric photocurrent. While at normal incidence a current arises due to the photogalvanic effect in the surface states, at oblique incidence it is outweighed by the trigonal photon drag effect. The developed microscopic model and theory show that the photon drag photocurrent can be generated in surface states. It arises due to the dynamical momentum alignment by time-and space-dependent radiation electric field and implies the radiation-induced asymmetric scattering in the electron momentum space. We show that the photon drag current may also be generated in the bulk. Both surface states and bulk photon drag currents behave identically upon variation of such macroscopic parameters as radiation polarization and photocurrent direction with respect to the radiation propagation. This fact complicates the assignment of the trigonal photon drag effect to a specific electronic system

A cross-cultural study on odor-elicited life stage-associations

Associative conceptualization plays an important role in how we perceive and interact with our environment. Particularly odor associations can be highly vivid and often long-lasting due to their close connection with our episodic memory and emotions. Based on the findings of a study conducted in Austria in 2017, this work was carried out to investigate odor-elicited life stage-associations (OELSA) in seven nations and to identify potential similarities and differences in conceptualizing odor impressions across these nations. A total of 1144 adults (aged 21–60) from Austria, Australia, Germany, Switzerland, Thailand, USA, and Vietnam participated in this study. Nine odors (vanilla, orange, lemon, mint, coconut, basil, rose, anise, and hay) were presented to the participants, and they were asked to answer questions about their spontaneous associations with life stages. The results indicate the existence of OELSA in all investigated nations. For example, vanilla was predominantly assigned to children in all nations, while hay was primarily assigned to elder people. While most of the investigated odors were most frequently associated with adults, some significant differences in OELSA were observed between the different nationalities. For instance, mint was more frequently associated with children by Australian participants compared to participants from all other nations, while coconut was more strongly associated with children by the Vietnamese participants compared to all other participants. The results of this study demonstrate the existence of consistent life stage-related associations elicited by certain odors across different nations and cultures and, at the same time points to differences in life stage-related association with certain odors between the nations. Since this work was not designed to identify the reasons for these differences, we can only make assumptions about the potential underlying causes for these behaviors

Studies of Metabolic Phenotypic Correlates of 15 Obesity Associated Gene Variants

Genome-wide association studies have identified novel BMI/obesity associated susceptibility loci. The purpose of this study is to determine associations with overweight, obesity, morbid obesity and/or general adiposity in a Danish population. Moreover, we want to investigate if these loci associate with type 2 diabetes and to elucidate potential underlying metabolic mechanisms.15 gene variants in 14 loci including TMEM18 (rs7561317), SH2B1 (rs7498665), KCTD15 (rs29941), NEGR1 (rs2568958), ETV5 (rs7647305), BDNF (rs4923461, rs925946), SEC16B (rs10913469), FAIM2 (rs7138803), GNPDA2 (rs10938397), MTCH2 (rs10838738), BAT2 (rs2260000), NPC1 (rs1805081), MAF (rs1424233), and PTER (rs10508503) were genotyped in 18,014 middle-aged Danes.Five of the 15 gene variants associated with overweight, obesity and/or morbid obesity. Per allele ORs ranged from 1.15-1.20 for overweight, 1.10-1.25 for obesity, and 1.41-1.46 for morbid obesity. Five of the 15 variants moreover associated with increased measures of adiposity. BDNF rs4923461 displayed a borderline BMI-dependent protective effect on type 2 diabetes (0.87 (0.78-0.96, p = 0.008)), whereas SH2B1 rs7498665 associated with nominally BMI-independent increased risk of type 2 diabetes (1.16 (1.07-1.27, p = 7.8×10(-4))).Associations with overweight and/or obesity and measures of obesity were confirmed for seven out of the 15 gene variants. The obesity risk allele of BDNF rs4923461 protected against type 2 diabetes, which could suggest neuronal and peripheral distinctive ways of actions for the protein. SH2B1 rs7498665 associated with type 2 diabetes independently of BMI

Human macrophage foam cells degrade atherosclerotic plaques through cathepsin K mediated processes

<p>Abstract</p> <p>Background</p> <p>Proteolytic degradation of Type I Collagen by proteases may play an important role in remodeling of atherosclerotic plaques, contributing to increased risk of plaque rupture.</p> <p>The aim of the current study was to investigate whether human macrophage foam cells degrade the extracellular matrix (ECM) of atherosclerotic plaques by cathepsin K mediated processes.</p> <p>Methods</p> <p>We 1) cultured human macrophages on ECM and measured cathepsin K generated fragments of type I collagen (C-terminal fragments of Type I collagen (CTX-I) 2) investigated the presence of CTX-I in human coronary arteries and 3) finally investigated the clinical potential by measuring circulating CTX-I in women with and without radiographic evidence of aortic calcified atherosclerosis.</p> <p>Results</p> <p>Immune-histochemistry of early and advanced lesions of coronary arteries demonstrated co-localization of Cathepsin-K and CTX-I in areas of intimal hyperplasia and in shoulder regions of advanced plaques. Treatment of human monocytes with M-CSF or M-CSF+LDL generated macrophages and foam cells producing CTX-I when cultured on type I collagen enriched matrix. Circulating levels of CTX-I were not significantly different in women with aortic calcifications compared to those without.</p> <p>Conclusions</p> <p>Human macrophage foam cells degrade the atherosclerotic plaques though cathepsin K mediated processes, resulting in increase in levels of CTX-I. Serum CTX-I was not elevated in women with aortic calcification, likely due to the contribution of CTX-I from osteoclastic bone resorption which involves Cathepsin-K. The human macrophage model system may be used to identify important pathway leading to excessive proteolytic plaque remodeling and plaque rupture.</p