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The Influence Of Flaws On Joint Spacing And Saturation: Results Of One-Dimensional Mechanical Modeling, Mark P. Fischer, A. Polansky
The Influence Of Flaws On Joint Spacing And Saturation: Results Of One-Dimensional Mechanical Modeling, Mark P. Fischer, A. Polansky
Faculty Peer-Reviewed Publications
In bedded sedimentary or mechanically anisotropic rocks, joints often occur in laterally persistent, parallel sets with distinctive spacing attributes. Three of those attributes include a positively skewed distribution of joint spacings, a positive correlation between median spacing and mechanical layer thickness, and the tendency for rocks to appear saturated with joints and to show a ratio of layer thickness to median joint spacing near one. We identify total applied strain, mechanical interaction, joint propagation velocity, and flaws as key variables in the progressive jointing process, and we use a one-dimensional model of mechanically interacting joints to characterize the specific influence …
Tracing Nitrogen In Volcanic And Geothermal Volatiles From The Nicaraguan Volcanic Front, James A. Walker, L.J. Elkins, T.P. Fischer, D.R. Hilton, Z.D. Sharp, S. Mcknight
Tracing Nitrogen In Volcanic And Geothermal Volatiles From The Nicaraguan Volcanic Front, James A. Walker, L.J. Elkins, T.P. Fischer, D.R. Hilton, Z.D. Sharp, S. Mcknight
Faculty Peer-Reviewed Publications
We report new chemical and isotopic data from 26 volcanic and geothermal gases, vapor condensates, and thermal water samples, collected along the Nicaraguan volcanic front. The samples were analyzed for chemical abundances and stable isotope compositions, with a focus on nitrogen abundances and isotope ratios. These data are used to evaluate samples for volatile contributions from magma, air, air-saturated water, and the crust. Samples devoid of crustal contamination (based upon He isotope composition) but slightly contaminated by air or air-saturated water are corrected using N2/Ar ratios in order to obtain primary magmatic values, composed of contributions from upper mantle and …