Cinder Cone Age Estimation Using Two-Dimensional Nonlinear Diffusive Numerical Modeling Based on Maximum External Slope Angle, Buffalo Valley, Nevada, USA

Buffalo Valley Volcanic Field (North-Central Nevada, USA; BVVF) is composed of several Quaternary cinder cones with breaching basalt flows that line the western flank of the Fish Creek Mountains. These cinder cones and flows have been previously dated to 0.95-1.40 Ma using Ar40/Ar39 methods. In the case of Lunar Volcanic Field (Central Nevada), argon dating is believed to have overestimated the age of basalts, additionally the morphology of several BVVF cinder cones suggest that BVVF is younger than the geochemically derived dates. Cinder cones form with exterior angles near the angle of repose ( 30o) that subsequently shallow with age and erosion. Based on this assumption, we use two-dimensional nonlinear diffusive numerical modeling to estimate the morphological age of the four most prominent BVVF cinder cones. We generate topographic profiles, perpendicular to the direction of breakout using ArcMap, and calculate maximum external slope angle (MESA) for each cone. Using the published diffusion constant for Lathrop Wells Cinder Cone (k=3.9 m/kyr), we utilize the Matlab code written by Mattia Vitturi (2013), designed to assess nonlinear slope evolution of cinder cones, to estimate the age of each cone based on MESA. The steepest MESA (24o) belongs to the southern-most cone. The MESA of the remaining three cones shallow progressively northward (23o, 21o, and 20o). Age curves generated in Matlab, using the diffusion constant k=3.9 m/kyr yield morphological ages of 550 ka to 1.1 Ma based on the MESAs of the four BVVF cinder cones and indicate progressive younging of the Buffalo Valley Volcanic Field from North to South.