Models for coupled fluid flow, mineral reaction, and isotopic alteration during contact metamorphism: The Notch Peak aureole, Utah

Journal Article · · American Mineralogist; (United States)

OSTI ID:7201858

Ferry, J M; Dipple, G M ^[1]

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1. Johns Hopkins Univ., Baltimore, MD (United States)

Three different models were developed to simulate the effect of contact metamorphism and fluid-rock interaction on the prograde mineralogical and O isotopic evolution of calcareous argillites from the Notch Peak aureole, Utah. All models assume local mineral-fluid equilibrium, a steady-state temperature profile corresponding to peak metamorphic values, and the thermodynamic data for minerals and fluid of Berman (1988). The preferred model, metamorphism with flow of a time-integrated fluid flux of 2 {plus minus} 0.5 {center dot} 10{sup 4} mol/cm{sup 2} in the direction of increasing temperature, successfully reproduces the principal petrologic and isotopic features of the aureole: (1) occurrence and positions (in map view) of diopside-in, tremolite-out, grossular-in, wollastonite-in, and quartz-out isograds; (2) stable coexistence of tremolite + calcite + quartz + diopside over an {approx}1 km distance between the diopside-in and tremolite-out isograds; (3) variable whole-rock {sup 18}O depletions of {approx}6-9{per thousand} adjacent to the contact; and (4) a gradual and irregular increase in {delta}{sup 18}O with increasing distance from the pluton. Results demonstrate how isotopic and petrologic data for contact aureoles can be integrated to provide quantitative constraints on the magnitude and geometry of metamorphic fluid flow.

• OSTI ID: 7201858
• Journal Information: American Mineralogist; (United States), Vol. 77:5-6; ISSN 0003-004X
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
ARGILLITE
GEOCHEMISTRY
HYDROTHERMAL ALTERATION
UTAH
GEOLOGIC FORMATIONS
CHEMICAL REACTIONS
DIAGENESIS
FLUID FLOW
GEOLOGIC MODELS
METAMORPHISM
MINERALOGY
REACTION KINETICS
ROCK-FLUID INTERACTIONS
CHEMISTRY
DEVELOPED COUNTRIES
FEDERAL REGION VIII
KINETICS
NORTH AMERICA
ROCKS
SEDIMENTARY ROCKS
SHALES
USA
580000* - Geosciences