Nevitt, Johanna M.Warren, Jessica M.Kidder, StevenPollard, David D.2018-08-202018-08-20Copyright2017-03-30Nevitt, J. M., J. M. Warren, S. Kidder, and D. D. Pollard (2017), Comparison of thermal modeling, microstructural analysis, and Ti-in-quartz thermobarometry to constrain the thermal history of a cooling pluton during deformation in the Mount Abbot Quadrangle, CA, Geochem. Geophys. Geosyst., 18, 1270–1297, doi:10.1002/2016GC006655.1525-2027http://udspace.udel.edu/handle/19716/23680Granitic plutons commonly preserve evidence for jointing, faulting, and ductile fabric development during cooling. Constraining the spatial variation and temporal evolution of temperature during this deformation could facilitate an integrated analysis of heterogeneous deformation over multiple length-scales through time. Here, we constrain the evolving temperature of the Lake Edison granodiorite within the Mount Abbot Quadrangle (central Sierra Nevada, CA) during late Cretaceous deformation by combining microstructural analysis, titanium-in-quartz thermobarometry (TitaniQ), and thermal modeling. Microstructural and TitaniQ analyses were applied to 12 samples collected throughout the pluton, representative of either the penetrative ‘‘regional’’ fabric or the locally strong ‘‘fault-related’’ fabric. Overprinting textures and mineral assemblages indicate the temperature decreased from 400–5008C to <3508C during faulting. TitaniQ reveals consistently lower Ti concentrations for partially reset fault-related fabrics (average: 1264 ppm) than for regional fabrics (average: 31612 ppm), suggesting fault-related fabrics developed later, following a period of pluton cooling. Uncertainties, particularly in TiO2 activity, significantly limit further quantitative thermal estimates using TitaniQ. In addition, we present a 1-D heat conduction model that suggests average pluton temperature decreased from 5858C at 85 Ma to 3328C at 79 Ma, consistent with radiometric age data for the field. Integrated with the model results, microstructural temperature constraints suggest faulting initiated by 83 Ma, when the temperature was nearly uniform across the pluton. Thus, spatially heterogeneous deformation cannot be attributed to a persistent temperature gradient, but may be related to regional structures that develop in cooling plutons.en-USArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Article10.1002/2016GC006655