Deformation and fluid flow during fault zone development in granitic rocks

Conference · Wed Jan 01 04:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5879821

Pollard, D D; Buergmann, R; Christiansen, P P ^[1]; Martel, S J ^[2]

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1. Stanford Univ., CA (United States). Geology Dept.
2. Lawrence Berkeley Lab., CA (United States)

Fault zone development in crystalline rock of the Lake Edison granodiorite, Sierra Nevada, California, is characterized by five stages with distinct physical mechanisms, each identified by outcrop mapping, and understood through mechanical analysis. Because fluid flow through the developing fault system can influence the rock properties and loading, and because rock fracturing can influence the fluid pathways, the phenomena of deformation and fluid flow are closely coupled. Both the faulting mechanisms and the evolution of permeability in crystalline rocks are demonstrably different from fault zones in porous sedimentary rocks. The paper describes the five stages of fault development. Deformation of the adjacent granodiorite at each stage of growth for a particular fault zone depended on the distribution of slip. This distribution is a function of the remote stress state, the constitutive rock properties, the geometry of the fault surfaces, and their frictional properties. Simple forward models, using elasticity theory, illustrate how the displacement distributions can vary with remote loading, friction, and geometry. Inverse methods provide the analytical tools to deduce these variables from outcrop data, but their implementation awaits a credible model that couples the fluid flow and rock deformation.

• OSTI ID: 5879821
• Report Number(s): CONF-921058--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 24:7
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CALIFORNIA
CRACK PROPAGATION
DEFORMATION
DEVELOPED COUNTRIES
FLUID FLOW
GEOLOGIC FAULTS
GEOLOGIC FORMATIONS
GEOLOGIC FRACTURES
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GRANITES
IGNEOUS ROCKS
MECHANICS
NORTH AMERICA
PERMEABILITY
PLUTONIC ROCKS
ROCK MECHANICS
ROCKS
SEDIMENTARY ROCKS
USA