NDLI: Permeability of a fault zone crosscutting a sequence of sandstones and shales and its influence on hydraulic head distribution in the Chatsworth Formation, California, USA

Content Provider	Springer Nature Link
Author	Cilona, Antoni Aydin, Atilla Johnson, Nicholas M.
Copyright Year	2014
Abstract	Faults influence groundwater flow paths. The transport of groundwater contaminants within the faulted sandstones and shales of Chatsworth Formation exposed in southern California, USA, have been investigated. Structural and hydrogeological data are combined to interpret the hydraulic-head drop measured across a fault with tens of meters of oblique-slip. The fault zone architecture was delineated at two locations: an outcrop and a borehole intersecting the fault at depth. At the first station, the fault juxtaposes sandstones against shales with a fault core mostly consisting of deformed shale. A series of shale beds striking parallel to the fault zone and dipping ∼50° toward the fault zone provides evidence that the shale was incorporated into the fault zone. At the second station, borehole images show a plane juxtaposing fractured sandstone against shale-rich fault rock. Hydraulic heads measured at 30 wells show a drop of 75 m across the fault, which is interpreted to be a result of the low-permeability shaley fault rock. It is proposed that the shale was incorporated into the fault zone by shale smearing. These results are consistent with numerical modeling, which requires a low-permeability fault core to simulate the observed hydraulic head differences. Understanding the hydraulic nature of this fault provides a critical constraint for evaluating the future migration of contaminants in the groundwater system.Les failles influencent le cheminement des eaux souterraines. Le transport de contaminants des eaux souterraines au sein des grès et schistes faillés de la formation de Chatsworth qui affleure en Californie du Sud, USA, ont été étudiés. Des données structurales et hydrogéologiques sont combinées pour interpréter la baisse de charge hydraulique mesurée à travers une faille de plusieurs dizaines de mètres de déplacement oblique. L’architecture de la zone de faille a été caractérisée en deux endroits : un affleurement et un forage recoupant la faille en profondeur. Au premier emplacement, la faille juxtapose les grès et les schistes avec un cœur de faille consistant principalement de schistes déformés. Une série d’horizons de schistes parallèles à la zone de faille et d’un pendage de ∼50° vers la zone de faille montrent que les schistes ont été incorporés à la zone de faille. Au second emplacement, l’imagerie de forage montre un plan mettant en contact le grès fracturé et une roche faillée riche en schistes. Les charges hydrauliques mesurées au niveau de30 puits montrent une baisse de 75 m à travers la faille qui est interprétée comme résultant de la faible perméabilité de la roche schisteuse faillée. Il est proposé que le schiste ait été incorporé à la zone de faille par beurrage schisteux. Ces résultats sont cohérents avec la modélisation numérique qui requiert un cœur de faille de faible conductivité hydraulique pour simuler les différences de charges hydrauliques observées. La compréhension de la nature hydrodynamique de cette faille fournit des éléments de contraintes déterminants pour évaluer la migration future des contaminants dans le système hydrogéologique.Las fallas influyen en las trayectorias de flujo de agua subterránea. Se investigó el transporte de contaminantes del agua subterránea dentro de areniscas y esquistos fallados de la Formación Chatsworth expuestas en el sur de California, EEUU. Se combinaron los datos hidrogeológicos y estructurales para interpretar la caída de la carga hidráulica a través de una falla con decenas de metros de desplazamiento oblicuo. Se delineó la arquitectura de la zona de falla en dos ubicaciones: un afloramiento y una perforación que intersecta la falla en profundidad. En la primera estación, la falla yuxtapone las areniscas contra los esquistos con un núcleo de falla consistente en su mayor parte en un esquisto deformado. Una serie de bancos de esquistos de rumbo paralelo a la zona de falla y buzamiento de ∼50° hacia la zona de falla proporciona evidencia que el esquisto fue incorporado dentro de la zona de falla. En la segunda estación, las imágenes de la perforación muestran una plano que yuxtapone la arenisca fracturada contra la falla en la roca rica en esquisto. Las cargas hidráulicas medidas en 30 pozos muestran una caída de 75 m a través de la falla que es interpretada como un resultado de la baja permeabilidad de la una roca esquistosa fallada. Se propone que el esquisto fue incorporado dentro de la zona de falla por la impregnación del esquisto.. Estos resultados son consistentes con el modelado numérico, que requiere un núcleo de baja permeabilidad en la falla para simular las diferencias observadas de carga hidráulica. La comprensión de la naturaleza hidráulica de esta falla proporciona una limitante crítica para evaluar la migración futura de los contaminantes en el sistema de agua subterránea.断层影响地下水流路径。调查了出露于美国加利福尼亚州南部的查特斯沃地层中断裂的砂岩和页岩内地下水污染物的运移。结合构造资料和水文地质资料解译了通过横贯数十米侧向滑动测量的断层水头下降。在两个地方描述了断层带构造:出露区及交汇于深部断层的钻孔。在第一个地方,断层使砂岩和页岩并置, 断层岩芯主要由变形的页岩组成。一系列页岩层平行于断层带并以∼50°向断层带下倾,这证明页岩被并入断层带。在第二个地方,钻孔图像显示出了一个与富含页岩的断层岩石并置的断裂砂岩。30口井的测量结果显示,水头穿过断层下降了75米,通过解译,发现这是由渗透性低的页岩质断层岩石造成的。认为页岩通过页岩拖尾效应并入到了断层带。这些结果与需要渗透性低的断层岩芯模拟观测的水头差的数值模拟一致。了解这个断层的水力特性为评估未来地下水系统中污染物的迁移提供了关键的约束条件。As falhas influenciam os caminhos de fluxo da água subterrânea. O transporte de contaminantes na água subterrânea foi investigado em arenitos e xistos expostos da Formação Chatsworth, no sul da Califórnia, EUA. Dados hidrogeológicos e estruturais são combinados para interpretar o decréscimo piezométrico medido ao cruzar uma falha com dezenas de metros de superfície de inclinação. A arquitetura da zona de falha foi delineada em dois locais: um afloramento e um furo intercetando a falha em profundidade. No primeiro local, a falha justapõe arenitos a xistos, com um núcleo de falha que consiste principalmente em xisto deformado. Uma série de camadas de xistos contactando paralelamente a zona de falha e inclinando ∼50° para a zona de falha fornece evidências de que o xisto foi incorporado na zona de falha. No segundo local, imagens de sondagem mostram um plano justapondo arenito fraturado a uma rocha de falha rica em xisto. Níveis piezométricos medidos em 30 furos mostram um declínio de 75 m de um lado para o outro da falha, o que é interpretado como resultado da baixa permeabilidade da zona de falha xistosa. Pensa-se que o xisto foi incorporado na zona de falha por esmagamento do xisto. Estes resultados são consistentes com a modelação numérica, que requere a introdução de uma zona de falha de baixa permeabilidade para simular as diferenças piezométricas observadas. A interpretação da natureza hidráulica desta falha proporciona a restrição crítica para avaliar a migração futura dos poluentes no sistema hidrogeológico.
Starting Page	405
Ending Page	419
Page Count	15
File Format	PDF
ISSN	14312174
Journal	Hydrogeology Journal
Volume Number	23
Issue Number	2
e-ISSN	14350157
Language	Portuguese
Publisher	Springer Berlin Heidelberg
Publisher Date	2014-11-20
Publisher Institution	International Association of Hydrogeologists
Publisher Place	Berlin, Heidelberg
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Fault permeability Shale smearing Hydraulic head Contamination USA Hydrogeology Hydrology/Water Resources Geology Waste Water Technology Water Pollution Control Water Management Aquatic Pollution
Content Type	Text
Resource Type	Article
Subject	Earth and Planetary Sciences Water Science and Technology

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Permeability of a fault zone crosscutting a sequence of sandstones and shales and its influence on hydraulic head distribution in the Chatsworth Formation, California, USA

The relationship between methane migration and shale-gas well operations near Dimock, Pennsylvania, USA

Groundwater movement, recharge, and perchlorate occurrence in a faulted alluvial aquifer in California (USA)

Indicator geostatistics for reconstructing Baton Rouge aquifer-fault hydrostratigraphy, Louisiana, USA

Review: Hydraulic head measurements—new technologies, classic pitfalls

Analysis of fault leakage from Leroy underground natural gas storage facility, Wyoming, USA

Evidence and mechanisms for Appalachian Basin brine migration into shallow aquifers in NE Pennsylvania, USA

Remediation scenarios for selenium contamination, Blackfoot watershed, southeast Idaho, USA

Hydraulic conductivity explored by factor analysis of borehole geophysical data

Permeability of a fault zone crosscutting a sequence of sandstones and shales and its influence on hydraulic head distribution in the Chatsworth Formation, California, USA

Similar Documents

Permeability of a fault zone crosscutting a sequence of sandstones and shales and its influence on hydraulic head distribution in the Chatsworth Formation, California, USA

The relationship between methane migration and shale-gas well operations near Dimock, Pennsylvania, USA

Groundwater movement, recharge, and perchlorate occurrence in a faulted alluvial aquifer in California (USA)

Indicator geostatistics for reconstructing Baton Rouge aquifer-fault hydrostratigraphy, Louisiana, USA

Review: Hydraulic head measurements—new technologies, classic pitfalls

Analysis of fault leakage from Leroy underground natural gas storage facility, Wyoming, USA

Evidence and mechanisms for Appalachian Basin brine migration into shallow aquifers in NE Pennsylvania, USA

Remediation scenarios for selenium contamination, Blackfoot watershed, southeast Idaho, USA

Hydraulic conductivity explored by factor analysis of borehole geophysical data

Permeability of a fault zone crosscutting a sequence of sandstones and shales and its influence on hydraulic head distribution in the Chatsworth Formation, California, USA