Danish University Colleges Developing Reasoning Competence
Total Page：16
File Type：pdf, Size：1020Kb
Load more
Recommended publications
-
Mechanical Stratigraphic Controls on Natural Fracture Spacing and Penetration
Journal of Structural Geology 95 (2017) 160e170 Contents lists available at ScienceDirect Journal of Structural Geology journal homepage: www.elsevier.com/locate/jsg Mechanical stratigraphic controls on natural fracture spacing and penetration * Ronald N. McGinnis a, , David A. Ferrill a, Alan P. Morris a, Kevin J. Smart a, Daniel Lehrmann b a Department of Earth, Material, and Planetary Sciences, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238-5166, USA b Geoscience Department, Trinity University, One Trinity Place, San Antonio, TX 78212, USA article info abstract Article history: Fine-grained low permeability sedimentary rocks, such as shale and mudrock, have drawn attention as Received 20 July 2016 unconventional hydrocarbon reservoirs. Fracturing e both natural and induced e is extremely important Received in revised form for increasing permeability in otherwise low-permeability rock. We analyze natural extension fracture 21 December 2016 networks within a complete measured outcrop section of the Ernst Member of the Boquillas Formation Accepted 7 January 2017 in Big Bend National Park, west Texas. Results of bed-center, dip-parallel scanline surveys demonstrate Available online 8 January 2017 nearly identical fracture strikes and slight variation in dip between mudrock, chalk, and limestone beds. Fracture spacing tends to increase proportional to bed thickness in limestone and chalk beds; however, Keywords: Mechanical stratigraphy dramatic differences in fracture spacing are observed in mudrock. A direct relationship is observed be- Natural fractures tween fracture spacing/thickness ratio and rock competence. Vertical fracture penetrations measured Fracture spacing from the middle of chalk and limestone beds generally extend to and often beyond bed boundaries into Fracture penetration the vertically adjacent mudrock beds. -
The Central Zagros Fold-Thrust Bemt (Iran) : New Insights from Seismic Data Field Observation and Sandbox Modelling S
The Central Zagros fold-thrust bemt (Iran) : New insights from seismic data field observation and sandbox modelling S. Sherkati, J. Letouzey, Dominique Frizon de Lamotte To cite this version: S. Sherkati, J. Letouzey, Dominique Frizon de Lamotte. The Central Zagros fold-thrust bemt (Iran) : New insights from seismic data field observation and sandbox modelling. Tectonics, American Geo- physical Union (AGU), 2006, 25 (4), pp.TC4007. 10.1029/2004TC001766. hal-00069591 HAL Id: hal-00069591 https://hal.archives-ouvertes.fr/hal-00069591 Submitted on 29 May 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Copyright TECTONICS, VOL. 25, TC4007, doi:10.1029/2004TC001766, 2006 Central Zagros fold-thrust belt (Iran): New insights from seismic data, field observation, and sandbox modeling S. Sherkati,1 J. Letouzey,2 and D. Frizon de Lamotte3 Received 10 November 2004; revised 27 January 2006; accepted 29 March 2006; published 20 July 2006. [1] We present five generalized cross sections across levels are activated sequentially from deeper horizons the central Zagros fold-and-thrust belt (Iran). These to shallower ones. However, in one case (Gachsaran sections show that the fold geometry varies de´collement) a shallow de´collement is activated during significantly both horizontally and vertically. -
Shear Zone-Related Folds
Journal of Structural Geology 27 (2005) 1229–1251 www.elsevier.com/locate/jsg Shear zone-related folds Jordi Carreras, Elena Druguet*, Albert Griera Departament de Geologia, Universitat Auto`noma de Barcelona, 08193 Bellaterra, Spain Received 18 April 2003; received in revised form 27 February 2004; accepted 14 June 2004 Available online 30 November 2004 Abstract Folds in ductile shear zones are common structures that have a variety of origins. These can be pre-existing folds that become modified or folds developed during the shearing event. Among the syn-shearing folds, a second subdivision is based on the relative age of the folded surface, which can be pre-existing or newly formed during the shearing event. In each of the three categories final fold geometry and orientation show complex relationships with the kinematic frame. The final fold geometry depends on the vorticity within the shear zone, the rheology and the initial orientation of the folded surface relative to the kinematic framework. It follows that folds are complex structures, difficult to use as kinematic indicators. However, in shear zones where undeformed wall rocks with pre-shear structures are accessible and where kinematics can be well established, folds can provide a valuable natural means to understand the initiation and evolution of structures under non-coaxial regimes. We point to the need of discriminating among different plausible categories, based on the nature of the folded surface and on the inherent structural features of each category. q 2004 Elsevier Ltd. All rights reserved. Keywords: Fold; Shear zone; Geometry; Kinematics; Cap de Creus 1. Introduction final geometry, symmetry and orientation of a shear-related fold are influenced by many variables other than the shear Folds are common structures in many ductile shear sense. -
Stress and Fluid Control on De Collement Within Competent Limestone
Journal of Structural Geology 22 (2000) 349±371 www.elsevier.nl/locate/jstrugeo Stress and ¯uid control on de collement within competent limestone Antonio Teixell a,*, David W. Durney b, Maria-Luisa Arboleya a aDepartament de Geologia, Universitat AutoÁnoma de Barcelona, 08193 Bellaterra, Spain bDepartment of Earth and Planetary Sciences, Macquarie University, Sydney, NSW 2109, Australia Received 5 October 1998; accepted 23 September 1999 Abstract The Larra thrust of the Pyrenees is a bedding-parallel de collement located within a competent limestone unit. It forms the ¯oor of a thrust system of hectometric-scale imbrications developed beneath a synorogenic basin. The fault rock at the de collement is a dense stack of mainly bedding-parallel calcite veins with variable internal deformation by twinning and recrystallization. Veins developed as extension fractures parallel to a horizontal maximum compressive stress, cemented by cavity-type crystals. Conditions during vein formation are interpreted in terms of a compressional model where crack-arrays develop at applied stresses approaching the shear strength of the rock and at ¯uid pressures equal to or less than the overburden pressure. The cracks developed in response to high dierential stress, which was channelled in the strong limestone, and high ¯uid pressure in or below the thrust plane. Ductile deformation, although conspicuous, cannot account for the kilometric displacement of the thrust, which was mostly accommodated by slip on water sills constituted by open cracks. A model of cyclic dierential brittle contraction, stress reorientation, slip and ductile relaxation at a rheological step in the limestone is proposed as a mechanism for episodic de collement movement. -
GSA on the Web
Vol. 6, No. 4 April 1996 1996 Annual GSA TODAY Meeting Call for A Publication of the Geological Society of America Papers Page 17 Electronic Dipping Reflectors Beneath Abstracts Submission Old Orogens: A Perspective from page 18 the British Caledonides Registration Issue June GSA Today John H. McBride,* David B. Snyder, Richard W. England, Richard W. Hobbs British Institutions Reflection Profiling Syndicate, Bullard Laboratories, Department of Earth Sciences, University of Cambridge, Madingley Road, Cambridge CB3 0EZ, United Kingdom A B Figure 1. A: Generalized location map of the British Isles showing principal structural elements (red and black) and location of selected deep seismic reflection profiles discussed here. Major normal faults are shown between mainland Scotland and Shetland. Structural contours (green) are in kilome- ters below sea level for all known mantle reflectors north of Ireland, north of mainland Scotland, and west of Shetland (e.g., Figs. 2A and 5); contours (black) are in seconds (two-way traveltime) on the reflector I-I’ (Fig. 2B) pro- jecting up to the Iapetus suture (from Soper et al., 1992). The contour inter- val is variable. B: A Silurian-Devonian (410 Ma) reconstruction of the Caledo- nian-Appalachian orogen shows the three-way closure of Laurentia and Baltica with the leading edge of Eastern Avalonia thrust under the Laurentian margin (from Soper, 1988). Long-dash line indicates approximate outer limit of Caledonian-Appalachian orogen and/or accreted terranes. GGF is Great Glen fault; NFLD. is Newfoundland. reflectors in the upper-to-middle crust, suggesting a “thick- skinned” structural style. These reflectors project downward into a pervasive zone of diffuse reflectivity in the lower crust. -
Estimation of Spatiotemporal Isotropic and Anisotropic Myocardial Stiffness Using
Estimation of Spatiotemporal Isotropic and Anisotropic Myocardial Stiffness using Magnetic Resonance Elastography: A Study in Heart Failure DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Ria Mazumder, M.S. Graduate Program in Electrical and Computer Engineering The Ohio State University 2016 Dissertation Committee: Dr. Bradley Dean Clymer, Advisor Dr. Arunark Kolipaka, Co-Advisor Dr. Patrick Roblin Dr. Richard D. White © Copyright by Ria Mazumder 2016 Abstract Heart failure (HF), a complex clinical syndrome that is characterized by abnormal cardiac structure and function; and has been identified as the new epidemic of the 21st century [1]. Based on the left ventricular (LV) ejection fraction (EF), HF can be classified into two broad categories: HF with reduced EF (HFrEF) and HF with preserved EF (HFpEF). Both HFrEF and HFpEF are associated with alteration in myocardial stiffness (MS), and there is an extensively rich literature to support this relation. However, t0 date, MS is not widely used in the clinics for the diagnosis of HF precisely because of the absence of a clinically efficient tool to estimate MS. Current clinical techniques used to measure MS are invasive in nature, provide global stiffness measurements and cannot assess the true intrinsic properties of the myocardium. Therefore, there is a need to non-invasively quantify MS for accurate diagnosis and prognosis of HF. In recent years, a non-invasive technique known as cardiac magnetic resonance elastography (cMRE) has been developed to estimate MS. However, most of the reported studies using cMRE have been performed on phantoms, animals and healthy volunteers and minimal literature recognizing the importance of cMRE in diagnosing disease conditions, especially with respect to HF is available. -
Fabric Foliation
2/14/15 Fabric • The characteristics of the geometry and spacing of the elements that make up a rock. – Linear – Planar – Random Foliation • Any fabric-forming planar or curvi-planar structure. • May be primary or tectonic • Many rocks have more than one foliation • Approximate as planes and/or surfaces 1 2/14/15 Cleavage • Describes the tendency of a rock to split along foliation planes • Not the same as cleavage of a single crystal/mineral ! Where well-developed, synonym for foliation. Lineation • Linear elements in a rock • One axis >> other two • Penetrative, surface or geometric Image from your friend Wikipedia 2 2/14/15 Keep thinking about strain ellipse • Foliations form perpendicular to shortening (e3 axis is pole to foliation plane) • Lineations – Elongation – mineral stretching = e1 – Shear lineations – oblique to strain ellipse axes, gives asymmetry/rotation 3 2/14/15 Tectonites • Fabrics in deformed metamorphic rocks are referred to as tectonites L-tectonite 4 2/14/15 S-tectonite Gneissic banding • Gneiss – Early layering is folded – Flattened limbs are parallel • Transposed foliation 5 2/14/15 Mylonites • Contain a “mylonitic foliation” formed by crystal plastic deformation in a shear zone (pure or simple) • Transposed layering • Shear zone fault rocks Describing cleavage 6 2/14/15 Metamorphosis of a pelite • Slaty cleavage – Preferential dissolution of some minerals – Perpendicular to shortening • Minerals line up • Becomes more continuous as it 1mm develops Crenulation = 2nd foliation folds first 7 2/14/15 Crenulation Cleavage -
Grand Teton National Park Geologic Resource Evaluation Scoping Report
Grand Teton National Park Geologic Resource Evaluation Scoping Report Sid Covington and Melanie V. Ransmeier Geologic Resources Division Denver, Colorado August 22, 2005 Table of Contents Executive Summary........................................................................................................ ii Introduction..................................................................................................................... 1 Geologic Setting.............................................................................................................. 2 Geologic History............................................................................................................. 4 Significant Geologic Resource Management Issues....................................................... 7 Earthquake Hazard Assessment and Planning............................................................ 7 Fluvial Geomorphology.............................................................................................. 8 Glacial and Peri-glacial Monitoring............................................................................ 9 Cave and Karst Resources ........................................................................................ 10 Hydrothermal Features.............................................................................................. 10 Wetlands ................................................................................................................... 11 Oil and Gas Development........................................................................................ -
Virtual Strike And
https://doi.org/10.5194/gc-2021-16 Preprint. Discussion started: 28 June 2021 c Author(s) 2021. CC BY 4.0 License. 1 Virtual strike and dip - Advancing inclusive and accessible field geology 2 3 Natalie Bursztyn1, Pejman Sajjadi2,3, Hannah Riegel4, Jiawei Huang2,3, Jan Oliver Wallgrün3, 4 Jiayan Zhao2,3, Bart Masters3, Alexander Klippel2,3 5 6 1Department of Geosciences, University of Montana, Charles H Clapp Building 126, Missoula, 7 MT 59812, USA 8 9 2Department of Geography, The Pennsylvania State University, Walker Building, 302 N Burrowes 10 Street, University Park, PA 16802, USA 11 12 3Center for Immersive Experiences, The Pennsylvania State University 13 University Park, PA 16802, USA 14 15 4Department of Geological and Environmental Sciences, Appalachian State University, 033 16 Rankin Science West, Boone, NC 28608, USA 17 18 19 1 https://doi.org/10.5194/gc-2021-16 Preprint. Discussion started: 28 June 2021 c Author(s) 2021. CC BY 4.0 License. 20 ABSTRACT 21 Accessibility and inclusivity in field geology have become increasingly important issues to address 22 in geoscience education and have long been set aside due to the tradition of field geology and the 23 laborious task of making it inclusive to all. Although a popular saying among geologists is “the 24 best geologists see the most rocks”, field trips cost money, time, and are only accessible for those 25 who are physically able to stay outside long hours. With the availability of 3D block diagrams, an 26 onslaught of virtual learning environments is becoming increasingly viable. Strike and dip is at the 27 core of any field geologist’s education and career; learning and practicing these skills is 28 fundamental to making geologic maps and understanding the regional geology of an area. -
Essays on Georg Rasch and His Contribution to Statistics
Essays on Georg Rasch and his contributions to statistics PhD thesis Lina Wøhlk Olsen Institute Of Economics University of Copenhagen ii Summary This PhD thesis consists of six self-contained articles. All of them are connected to Georg Rasch and his contributions to statistics. Chapter 1 is a biography of Georg Rasch covering the years 1901 to the late 1940s. Special attention is paid Rasch’s road from being a mathematician to becoming a statistician. His life in the late 1940s is also described at some length. He was a statistical consultant, but he also lectured on mathematics and statistics at the Uni- versity of Copenhagen. This way, and especially by influencing his young assistants, Rasch was a prominent figure in the progress of statistics in Denmark. Chapter 2 rediscovers Rasch’s work on Growth. We shall see the theory that Rasch developed and explore the events that inspired him to analyse growth. The Growth Model had it’s origin in an empirical analysis of calves, but afterwards Rasch used it to model the growth of other animals. By time, Rasch became intrigued by developing a theoretical frame for the Growth Model. Chapter 2 also includes an empirical example of using the Growth Model on recent data. Chapter 3 is an account of how Rasch developed the Rasch models. Rasch was triggered by an empirical analysis and in the course of some ten years he gained the insight that the idea underlying this particular analysis was a special case of something much more general, namely specific objectivity. Chapter 3 also supplies background information on Rasch prior to his development of the Rasch model, but the main focus stays at the late 1940s and the 1950s. -
Anticline and Adjacent Areas Grand County, Utah
Please do not destroy or throw away this publication. If you have no further use for it write to the Geological Survey at Washington and ask for a frank to return it UNITED STATES DEPARTMENT OF THE INTERIOR Harold L. Ickes, Secretary GEOLOGICAL, SURVEY W. C. Mendenhall, Director Bulletin 863 GEOLOGY OF THE SALT VALLEY ANTICLINE AND ADJACENT AREAS GRAND COUNTY, UTAH BY C. H. DANE UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1935 For sale by the Superintendent of Documents, Washington, D. C. - - Price $1.00 (Paper cover) CONTENTS Abstract.____________________________________________________ 1 .Introduction____________________________________________ 2 Purpose and scope of the work_____________________________ 2 Field work.____________________________________________________ 4 Acknowledgments....-___--____-___-_--_-______.__________ 5 Topography, drainage, and water supply. ______ 5 Climate_._.__..-.-_--_-______- _ ____ 11 Vegetation. ____________________________ 14 Fuel.._____________________________________ 15 Population, accessibility, routes of travel___--______..________ 15 Previous publications......--.-.-.---.-...__---_-__-___._______ 17 Stratigraphy __ ____.____-__-_---_--____---______--___________.__ 18 Pre-Cambrian complex___---_-_-_-_-_-_-_--__ __--______ 20 Carboniferous system..______--__--_____-_-_-_-_-___-___.______ 24 Pennsylvanian (?) series.__________________________________ 24 Unnamed conglomerate--_______-._____________________ 24 Pennsylvanian series..--____-_-_-_-_-_-______--___.________ 25 Paradox formation.____-_-___---__-_____-__-__-__..__. -
Meng and Hodgetts 2019
The University of Manchester Research Structural styles and decoupling in stratigraphic sequences with double décollements during thin-skinned contractional tectonics: Insights from numerical modelling DOI: 10.1016/j.jsg.2019.103862 Document Version Accepted author manuscript Link to publication record in Manchester Research Explorer Citation for published version (APA): Meng, Q., & Hodgetts, D. (2019). Structural styles and decoupling in stratigraphic sequences with double décollements during thin-skinned contractional tectonics: Insights from numerical modelling. Journal of Structural Geology, 127, 103862. https://doi.org/10.1016/j.jsg.2019.103862 Published in: Journal of Structural Geology Citing this paper Please note that where the full-text provided on Manchester Research Explorer is the Author Accepted Manuscript or Proof version this may differ from the final Published version. If citing, it is advised that you check and use the publisher's definitive version. General rights Copyright and moral rights for the publications made accessible in the Research Explorer are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Takedown policy If you believe that this document breaches copyright please refer to the University of Manchester’s Takedown Procedures [http://man.ac.uk/04Y6Bo] or contact [email protected] providing relevant details, so we can investigate your claim. Download date:11. Oct. 2021 1 Structural styles and decoupling in stratigraphic sequences with double 2 décollements during thin-skinned contractional tectonics: insights from 3 numerical modelling 4 Qingfeng Meng*1, David Hodgetts 5 School of Earth and Environmental Sciences, University of Manchester, M13 9PL, UK 6 Abstract 7 Six series of particle-based numerical experiments were performed to simulate thin-skinned 8 contractional tectonics in stratigraphic sequences with double décollements during horizontal 9 shortening.