Supplemental Material: Neogene faulting, basin development, and relief generation in the southern Klamath Mountains (USA)

Abstract

<p>Figure 3 (interactive). Geologic and geophysical maps of southern Klamath Mountains province. Use the radio buttons to toggle between different maps. (A) Geologic map modified from Irwin (1994) showing interpretations of the La Grange fault (LGF) from Cashman and Elder (2002) with hachures on hanging wall, Browns Meadow fault (BMF) (Davis, 1968; this study), and fault-bounded grabens that preserve Weaverville Formation (Irwin 2009, 2010; this study). Faults are solid where known, dashed where inferred, and dotted where concealed. New bedrock apatite (U-Th)/He (AHe) mean age locations are shown by large circles; previously published AHe ages are shown by small circles, and apatite fission-track (AFT) ages from Batt et al. (2010b) and Piotraschke et al. (2015) are shown with triangles. Sample locations of new detrital zircon U-Pb age distributions are shown by gray squares. Geologic cross section lines A-A′ (Fig. 4A) and B-B′ (Fig. 4B) are indicated. (B) Isostatic gravity map. Contour interval = 4 mGal. Data are from Snyder et al. (1981), Smith (1984), Pan-American Center for Earth and Environmental Studies (2015), and Langenheim et al. (2023). (C) Isostatic gravity map with horizontal gravity gradient maxima. (D) Aeromagnetic map (North American Magnetic Anomaly Group, 2002).</p> <p>Figure 10 (interactive). Simplified geologic, gravity, and basin depth maps of the Hayfork graben using water well data. Use the radio buttons to toggle between different maps. (A) Simplified geologic map, modified slightly from Irwin (2010). Quaternary deposits are not shown. (B) Isostatic gravity map. (C) Basin depth map based on inversion of gravity data. </p>