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Evolution of a Highly Dilatant Fault Zone in the Grabens of Canyonlands
Solid Earth, 6, 839–855, 2015 www.solid-earth.net/6/839/2015/ doi:10.5194/se-6-839-2015 © Author(s) 2015. CC Attribution 3.0 License. Evolution of a highly dilatant fault zone in the grabens of Canyonlands National Park, Utah, USA – integrating fieldwork, ground-penetrating radar and airborne imagery analysis M. Kettermann1, C. Grützner2,a, H. W. van Gent1,b, J. L. Urai1, K. Reicherter2, and J. Mertens1,c 1Structural Geology, Tectonics and Geomechanics Energy and Mineral Resources Group, RWTH Aachen University, Lochnerstraße 4–20, 52056 Aachen, Germany 2Neotectonics and Natural Hazards, RWTH Aachen University, Lochnerstraße 4–20, 52056 Aachen, Germany anow at: COMET; Bullard Laboratories, Department of Earth Sciences, University of Cambridge, Cambridge, UK bnow at: Shell Global Solutions International, Rijswijk, the Netherlands cnow at: ETH Zürich, Zürich, Switzerland Correspondence to: M. Kettermann ([email protected]) Received: 20 February 2015 – Published in Solid Earth Discuss.: 17 March 2015 Revised: 18 June 2015 – Accepted: 22 June 2015 – Published: 21 July 2015 Abstract. The grabens of Canyonlands National Park are 1 Introduction a young and active system of sub-parallel, arcuate grabens, whose evolution is the result of salt movement in the sub- Understanding the structure of dilatant fractures in normal surface and a slight regional tilt of the faulted strata. We fault zones is important for many applications in geoscience. present results of ground-penetrating radar (GPR) surveys Reservoirs for hydrocarbons, geothermal energy and fresh- in combination with field observations and analysis of high- water often contain dilatant fractures (e.g., Ehrenberg and resolution airborne imagery. -
Faults and Joints
133 JOINTS Joints (also termed extensional fractures) are planes of separation on which no or undetectable shear displacement has taken place. The two walls of the resulting tiny opening typically remain in tight (matching) contact. Joints may result from regional tectonics (i.e. the compressive stresses in front of a mountain belt), folding (due to curvature of bedding), faulting, or internal stress release during uplift or cooling. They often form under high fluid pressure (i.e. low effective stress), perpendicular to the smallest principal stress. The aperture of a joint is the space between its two walls measured perpendicularly to the mean plane. Apertures can be open (resulting in permeability enhancement) or occluded by mineral cement (resulting in permeability reduction). A joint with a large aperture (> few mm) is a fissure. The mechanical layer thickness of the deforming rock controls joint growth. If present in sufficient number, open joints may provide adequate porosity and permeability such that an otherwise impermeable rock may become a productive fractured reservoir. In quarrying, the largest block size depends on joint frequency; abundant fractures are desirable for quarrying crushed rock and gravel. Joint sets and systems Joints are ubiquitous features of rock exposures and often form families of straight to curviplanar fractures typically perpendicular to the layer boundaries in sedimentary rocks. A set is a group of joints with similar orientation and morphology. Several sets usually occur at the same place with no apparent interaction, giving exposures a blocky or fragmented appearance. Two or more sets of joints present together in an exposure compose a joint system. -
Structural Geology
2 STRUCTURAL GEOLOGY Conventional Map A map is a proportionate representation of an area/structure. The study of maps is known as cartography and the experts are known as cartographers. The maps were first prepared by people of Sumerian civilization by using clay lens. The characteristic elements of a map are scale (ratio of map distance to field distance and can be represented in three ways—statement method, e.g., 1 cm = 0.5 km, representative fraction method, e.g., 1:50,000 and graphical method in the form of a figure), direction, symbol and colour. On the basis of scale, maps are of two types: large-scale map (map gives more information pertaining to a smaller area, e.g., village map: 1:3956) and small: scale map (map gives less information pertaining to a larger area, e.g., world atlas: 1:100 km). Topographic Maps / Toposheet A toposheet is a map representing topography of an area. It is prepared by the Survey of India, Dehradun. Here, a three-dimensional feature is represented on a two-dimensional map and the information is mainly represented by contours. The contours/isohypses are lines connecting points of same elevation with respect to mean sea level (msl). The index contours are the contours representing 100’s/multiples of 100’s drawn with thick lines. The contour interval is usually 20 m. The contours never intersect each other and are not parallel. The characteristic elements of a toposheet are scale, colour, symbol and direction. The various layers which can be prepared from a toposheet are structural elements like fault and lineaments, cropping pattern, land use/land cover, groundwater abstruction structures, drainage density, drainage divide, elongation ratio, circularity ratio, drainage frequency, natural vegetation, rock types, landform units, infrastructural facilities, drainage and waterbodies, drainage number, drainage pattern, drainage length, relief/slope, stream order, sinuosity index and infiltration number. -
Tectonic and Geological Structures of Gunung Kromong, West Java, Indonesia
International Journal of GEOMATE, Oct., 2020, Vol.19, Issue 74, pp.185–193 ISSN: 2186-2982 (P), 2186-2990 (O), Japan, DOI: https://doi.org/10.21660/2020.74.05449 Geotechnique, Construction Materials and Environment TECTONIC AND GEOLOGICAL STRUCTURES OF GUNUNG KROMONG, WEST JAVA, INDONESIA *Iyan Haryanto1, Nisa Nurul Ilmi2, Johanes Hutabarat3, Billy Gumelar Adhiperdana4, Lili Fauzielly5, Yoga Andriana Sendjaja6, and Edy Sunardi7 1-7Faculty of Geological Engineering, Universitas Padjadjaran, Indonesia *Corresponding Author, Received: 12 May 2020, Revised: 29 May 2020, Accepted: 15 June 2020 ABSTRACT: The Gunung Kromong complex is a solitary hill which physiographically located within the Jakarta Coastal Plain Zone. The research is mainly formed of primary data from observations and measurements of all geological elements especially morphological aspects and geological structures to reveal the tectonic background and its relation to the oil seepage. Sedimentary rocks outcrops appear in the western part around the cement plant surrounded by well exposed of igneous rocks. Oil seepage, gas and hot springs are found in limestone which has high fracture intensity and at low elevation. The distribution of sedimentary rocks is not only controlled by the folds and fault structures but also influenced by the igneous rock intrusion. The alignment of the structure in West Palimanan is formed by steep slopes on dacite igneous rock which is concluded as fault scarp. There are found abundance of fault indications in the form of slickenside, fault breccias, millonites, drag folds and have high intensity of shear joint. The KRG-7, KRG-8 and KRG-9 observation points, a slickenside with the same plane was found but has different slicken line, each shows a thrust fault and normal faults. -
Faulted Joints: Kinematics, Displacement±Length Scaling Relations and Criteria for Their Identi®Cation
Journal of Structural Geology 23 (2001) 315±327 www.elsevier.nl/locate/jstrugeo Faulted joints: kinematics, displacement±length scaling relations and criteria for their identi®cation Scott J. Wilkinsa,*, Michael R. Grossa, Michael Wackera, Yehuda Eyalb, Terry Engelderc aDepartment of Geology, Florida International University, Miami, FL 33199, USA bDepartment of Geology, Ben Gurion University, Beer Sheva 84105, Israel cDepartment of Geosciences, The Pennsylvania State University, University Park, PA 16802, USA Received 6 December 1999; accepted 6 June 2000 Abstract Structural geometries and kinematics based on two sets of joints, pinnate joints and fault striations, reveal that some mesoscale faults at Split Mountain, Utah, originated as joints. Unlike many other types of faults, displacements (D) across faulted joints do not scale with lengths (L) and therefore do not adhere to published fault scaling laws. Rather, fault size corresponds initially to original joint length, which in turn is controlled by bed thickness for bed-con®ned joints. Although faulted joints will grow in length with increasing slip, the total change in length is negligible compared to the original length, leading to an independence of D from L during early stages of joint reactivation. Therefore, attempts to predict fault length, gouge thickness, or hydrologic properties based solely upon D±L scaling laws could yield misleading results for faulted joints. Pinnate joints, distinguishable from wing cracks, developed within the dilational quadrants along faulted joints and help to constrain the kinematics of joint reactivation. q 2001 Elsevier Science Ltd. All rights reserved. 1. Introduction impact of these ªfaulted jointsº on displacement±length scaling relations and fault-slip kinematics. -
4. Deep-Tow Observations at the East Pacific Rise, 8°45N, and Some Interpretations
4. DEEP-TOW OBSERVATIONS AT THE EAST PACIFIC RISE, 8°45N, AND SOME INTERPRETATIONS Peter Lonsdale and F. N. Spiess, University of California, San Diego, Marine Physical Laboratory, Scripps Institution of Oceanography, La Jolla, California ABSTRACT A near-bottom survey of a 24-km length of the East Pacific Rise (EPR) crest near the Leg 54 drill sites has established that the axial ridge is a 12- to 15-km-wide lava plateau, bounded by steep 300-meter-high slopes that in places are large outward-facing fault scarps. The plateau is bisected asymmetrically by a 1- to 2-km-wide crestal rift zone, with summit grabens, pillow walls, and axial peaks, which is the locus of dike injection and fissure eruption. About 900 sets of bottom photos of this rift zone and adjacent parts of the plateau show that the upper oceanic crust is composed of several dif- ferent types of pillow and sheet lava. Sheet lava is more abundant at this rise crest than on slow-spreading ridges or on some other fast- spreading rises. Beyond 2 km from the axis, most of the plateau has a patchy veneer of sediment, and its surface is increasingly broken by extensional faults and fissures. At the plateau's margins, secondary volcanism builds subcircular peaks and partly buries the fault scarps formed on the plateau and at its boundaries. Another deep-tow survey of a patch of young abyssal hills 20 to 30 km east of the spreading axis mapped a highly lineated terrain of inactive horsts and grabens. They were created by extension on inward- and outward- facing normal faults, in a zone 12 to 20 km from the axis. -
PLANE DIP and STRIKE, LINEATION PLUNGE and TREND, STRUCTURAL MEASURMENT CONVENTIONS, the BRUNTON COMPASS, FIELD BOOK, and NJGS FMS
PLANE DIP and STRIKE, LINEATION PLUNGE and TREND, STRUCTURAL MEASURMENT CONVENTIONS, THE BRUNTON COMPASS, FIELD BOOK, and NJGS FMS The word azimuth stems from an Arabic word meaning "direction“, and means an angular measurement in a spherical coordinate system. In structural geology, we primarily deal with land navigation and directional readings on two-dimensional maps of the Earth surface, and azimuth commonly refers to incremental measures in a circular (0- 360 °) and horizontal reference frame relative to land surface. Sources: Lisle, R. J., 2004, Geological Structures and Maps, A Practical Guide, Third edition http://www.geo.utexas.edu/courses/420k/PDF_files/Brunton_Compass_09.pdf http://en.wikipedia.org/wiki/Azimuth http://en.wikipedia.org/wiki/Brunton_compass FLASH DRIVE/Rider/PDFs/Holcombe_conv_and_meas.pdf http://www.state.nj.us/dep/njgs/geodata/fmsdoc/fmsuser.htm Brunton Pocket Transit Rider Structural Geology 310 2012 GCHERMAN 1 PlanePlane DipDip andand LinearLinear PlungePlunge horizontal dddooo Dip = dddooo Bedding and other geological layers and planes that are not horizontal are said to dip. The dip is the slope of a geological surface. There are two aspects to the dip of a plane: (a) the direction of dip , which is the compass direction towards which the plane slopes; and (b) the angle of dip , which is the angle that the plane makes with a horizontal plane (Fig. 2.3). The direction of dip can be visualized as the direction in which water would flow if poured onto the plane. The angle of dip is an angle between 0 ° (for horizontal planes) and 90 ° (for vertical planes). To record the dip of a plane all that is needed are two numbers; the angle of dip followed by the direction (or azimuth) of dip, e.g. -
Stylolites: a Review
Stylolites: a review Toussaint R.1,2,3*, Aharonov E.4, Koehn, D.5, Gratier, J.-P.6, Ebner, M.7, Baud, P.1, Rolland, A.1, and Renard, F.6,8 1Institut de Physique du Globe de Strasbourg, CNRS, University of Strasbourg, 5 rue Descartes, F- 67084 Strasbourg Cedex, France. Phone : +33 673142994. email : [email protected] 2 International Associate Laboratory D-FFRACT, Deformation, Flow and Fracture of Disordered Materials, France-Norway. 3SFF PoreLab, The Njord Centre, Department of Physics, University of Oslo, Norway. 4Institute of Earth Sciences, The Hebrew University, Jerusalem, 91904, Israel 5School of Geographical and Earth Sciences, University of Glasgow, UK 6University Grenoble Alpes, ISTerre, Univ. Savoie Mont Blanc, CNRS, IRD, IFSTTAR, 38000 Grenoble, France 7OMV Exploration & Production GmbH Trabrennstrasse 6-8, 1020 Vienna, Austria 8 The Njord Centre,PGP, Department of Geosciences, University of Oslo, Norway *corresponding author Highlights: . Stylolite formation depends on rock composition and structure, stress and fluids. Stylolite geometry, fractal and self-affine properties, network structure, are investigated. The experiments and physics-based numerical models for their formation are reviewed. Stylolites can be used as markers of strain, paleostress orientation and magnitude. Stylolites impact transport properties, as function of maturity and flow direction. Abstract Stylolites are ubiquitous geo-patterns observed in rocks in the upper crust, from geological reservoirs in sedimentary rocks to deformation zones, in folds, faults, and shear zones. These rough surfaces play a major role in the dissolution of rocks around stressed contacts, the transport of dissolved material and the precipitation in surrounding pores. Consequently, they 1 play an active role in the evolution of rock microstructures and rheological properties in the Earth’s crust. -
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.____-_-___---__-_____-__-__-__..__. -
CANYONLANDS GEOLOGY INFORMATION Canyonlands
CANYONLANDS GEOLOGY INFORMATION Canyonlands National Park offers the visitor a grand spectacle of what earth forces can do to once flat and uniform rock layers. The different rock for mations here all have two things in common. One, they are all sedimentary rocks, and two, they have all been subjected to natural forces such as weath ering, erosion, and faulting. A major shaping force in Canyonlands has been a 3,000 foot thick deposit of salt and gypsum, known as the Paradox member of the Hermosa formation. The Paradox salts were left behind when the water evaporated from a large basin of sea water that once covered this area. The salt deposits provide an un stable platform for the countless millions of tons of rock that overly them. In the Needles district of Canyonlands is a series of parallel canyons known as the Grabens. Graben is a geological term for a canyon formed by a block of earth subsiding in relation to the rest of the area. The Grabens in Canyon lands formed as a result of the salt beneath the sandstone flowing away to areas of less pressure. The sandstone settled along pre-existing fault lines to create the Grabens. The Needles themselves result from weathering and erosion along joint and fault lines. The Needles area is crisscrossed with such fractures in the rocks. You can hike right through one such crack on the Joint Trail, which leaves from the four-wheel drive parking area near Chesler Park and ends up at the edge of Chesler Park. At the present time the joint through which the trail runs is only a couple of feet wide, but in the not too distant geologi cal future it will be many feet wide due to the constant work of weathering and erosion. -
Stylolites in Limestones: Barriers to Fluid Flow?
Stylolites in limestones: Barriers to fl uid fl ow? Michael J. Heap1, Patrick Baud1, Thierry Reuschlé1, and Philip G. Meredith2 1École et Observatoire des Sciences de la Terre, Université de Strasbourg (UMR 7516 Centre National de la Recherche Scientifi que), F-67084 Strasbourg cedex, France 2Department of Earth Sciences, University College London, London WC1E 6BT, UK ABSTRACT MATERIALS AND METHODS Stylolites—products of intergranular pressure-solution—are lat- The materials of this study were taken from vertical boreholes drilled erally extensive, planar features. They are a common strain localiza- around the ANDRA Underground Research Laboratory near Bure, France. tion feature in sedimentary rocks. Their potential impact on regional We selected four lithologies to sample (Fig. 1), three within the Oxford- fl uid fl ow has interested geoscientists for almost a century. Prevalent ian stage (Late Jurassic) and one within the Middle Jurassic “Dogger” views are that they act as permeability barriers, although laboratory series. We selected these lithologies based on their differences in porosity studies are extremely rare. Here we report on a systematic laboratory and texture. Macroscopically there is no systematic difference in stylolite study of the infl uence of stylolites on permeability in limestone. Our density or thickness (50–200 µm) between the limestone units, although data demonstrate that, contrary to conventional wisdom, the studied occasional thicker stylolites (1500–3000 µm) are observed in the Dogger stylolites do not act as barriers to fl uid fl ow. In detail, when a stylolite limestone. In this study we chose to focus on bedding-parallel sedimenta- occurs perpendicular to the direction of fl ow, the permeability simply ry stylolites; subvertical stylolites of tectonic origin are also present within follows the same power law permeability-porosity trend as the stylo- these formations (Rolland et al., 2013), but only occur rarely in borehole lite-free material. -
USBR Engineering Geology Field Manual Volume 1 Chapter 5
Chapter 5 TERMINOLOGY AND DESCRIPTIONS FOR DISCONTINUITIES General Structural breaks or discontinuities generally control the mechanical behavior of rock masses. In most rock masses the discontinuities form planes of weakness or surfaces of separation, including foliation and bedding joints, joints, fractures, and zones of crushing or shearing. These discontinuities usually control the strength, deformation, and permeability of rock masses. Most engineering problems relate to discontinuities rather than to rock type or intact rock strength. Discontinuities must be carefully and adequately described. This chapter describes terminology, indexes, qualitative and quantitative descriptive criteria, and format for describing discontinuities. Many of the criteria contained in this chapter are similar to criteria used in other established sources which are accepted as international standards (for example, International Journal of Rock Mechanics, 1978 [1]). Discontinuity Terminology The use of quantitative and qualitative descriptors requires that what is being described be clearly identified. Nomenclature associated with structural breaks in geologic materials is frequently misunderstood. For example, bedding, bedding planes, bedding plane partings, bedding separations, and bedding joints may have been used to identify similar or distinctly different geological features. The terminology for discontinuities which is presented in this chapter should be used uniformly for all geology programs. Additional definitions for various types of discontinuities are presented in the Glossary of Geology [2]; these may be used to further describe structural breaks. The following basic defi- nitions should not be modified unless clearly justified, and defined. FIELD MANUAL Discontinuity.—A collective term used for all structural breaks in geologic materials which usually have zero to low tensile strength.