Hydrothermal processes influence the along-strike morphologic variability of fault scarp profiles: applying supervised machine learning to Holocene scarps in the Stillwater Seismic Gap, Dixie Valley, Nevada, USA
DOI:
https://doi.org/10.59236/geomorphica.v2i2.58Keywords:
fault scarp, machine learning, hydrothermal alteration, sinter, support vector machinesAbstract
Fault scarp morphology can yield information about the age and slip distribution of surface-rupturing earthquakes. However, bedrock characteristics and geomorphic modification also contribute to scarp form. Additional complications arise in settings where hydrothermal processes modify the material properties of the faulted surface material. We present a case study where a single Holocene scarp offsets three adjacent units: alluvial and colluvial gravels; quartz-rich sinter and silicified gravels; and clay-rich, acid-sulfate altered gravels and bedrock.
We examined scarp-normal topographic profiles in each unit and employed supervised machine learning to describe the variations in scarp form and quantify changes in morphologic variability. In the alluvial and colluvial deposits, scarp profiles have a mean height of 6.2 (±0.9) m and exhibit low morphologic variability. The section of the scarp through hot spring sinter and cemented gravels has a mean height of 5.8 (±0.8) m and exhibits a high degree of along-strike variability. In the altered region, the individual Holocene scarp is difficult to discern and has low morphologic variability. Our study emphasizes the need to consider fault scarp composition during paleoseismic interpretation, and illustrates the potential utility of along-strike fault scarp morphologic variability in identifying lithologic and paleohydraulic boundaries.
References
Adam, R. N., Scott, C., Arrowsmith, J. R., & others. (2025). A systematic approach to mapping tectonic faults and documenting supporting geomorphology. Geosphere, 21(2), 227–244. https://doi.org/10.1130/GES02767.1
Andrews, D. J., & Bucknam, R. C. (1987). Fitting degradation of shoreline scarps by a nonlinear diffusion model. Journal of Geophysical Research: Solid Earth, 92(B12), 12857–12867. https://doi.org/10.1029/JB092iB12p12857
Andrews, D. J., & Hanks, T. C. (1985). Scarp degraded by linear diffusion: Inverse solution for age. Journal of Geophysical Research: Solid Earth, 90(B12), 10193–10208. https://doi.org/10.1029/JB090iB12p10193
Avouac, J. P. (1993). Analysis of scarp profiles: Evaluation of errors in morphologic dating. Journal of Geophysical Research: Solid Earth, 98(B4), 6745–6754. https://doi.org/10.1029/92JB01962
Backeberg, N. R., Rowe, C. D., & Barshi, N. (2016). Alteration-weakening leading to localized deformation in a damage aureole adjacent to a dormant shear zone. Journal of Structural Geology, 90, 144–156. https://doi.org/10.1016/j.jsg.2016.07.008
Bell, J. W. (1981). Quaternary Fault Map of the Reno 1circ x 2circ Quadrangle (p. 63) [Techreport]. U.S. Geological Survey. https://doi.org/10.3133/ofr81982
Bell, J. W., Caskey, S. J., Ramelli, A. R., & Guerrieri, L. (2004). Pattern and Rates of Faulting in the Central Nevada Seismic Belt, and Paleoseismic Evidence for Prior Beltlike Behavior. Bulletin of the Seismological Society of America, 94(4), 1229–1254. https://doi.org/10.1785/012003226
Bell, J. W., & Katzer, T. (1990). Timing of late Quaternary faulting in the 1954 Dixie Valley earthquake area, central Nevada. Geology, 18(7), 622–625. https://doi.org/10.1130/0091-7613(1990)018<0622:TOLQFI>2.3.CO;2
Brigham, C. A. P., & Crider, J. G. (2022). A new metric for morphologic variability using landform shape classification via supervised machine learning. Geomorphology, 399, 108065. https://doi.org/10.1016/j.geomorph.2021.108065
Browne, P. R. L., & Lawless, J. V. (2001). Characteristics of hydrothermal eruptions, with examples from New Zealand and elsewhere. Earth-Science Reviews, 52(4), 299–331. https://doi.org/10.1016/S0012-8252(00)00030-1
Bucknam, R. C., & Anderson, R. E. (1979). Estimation of fault-scarp ages from a scarp-height–slope-angle relationship. Geology, 7(1), 11–14. https://doi.org/10.1130/0091-7613(1979)7<11:EOFAFA>2.0.CO;2
Caine, J. S., Bruhn, R. L., & Forster, C. B. (2010). Internal structure, fault rocks, and inferences regarding deformation, fluid flow, and mineralization in the seismogenic Stillwater normal fault, Dixie Valley, Nevada. Journal of Structural Geology, 32(11), 1576–1589. https://doi.org/10.1016/j.jsg.2010.03.004
Callahan, O. A., Eichhubl, P., & Davatzes, N. C. (2020). Mineral precipitation as a mechanism of fault core growth. Journal of Structural Geology, 140, 104156. https://doi.org/10.1016/j.jsg.2020.104156
Callahan, O. A., Eichhubl, P., Olson, J. E., & Davatzes, N. C. (2019). Fracture Mechanical Properties of Damaged and Hydrothermally Altered Rocks, Dixie Valley-Stillwater Fault Zone, Nevada, USA. Journal of Geophysical Research: Solid Earth, 124(4), 4069–4090. https://doi.org/10.1029/2018JB016708
Callahan, O., Brigham, C., Heitmann, E., & others. (2023). High-resolution structure-from-motion models of hydrothermal sites in the Central Nevada Seismic Belt: applications in tectonic, climate, and hydrothermal investigations. Proceedings.
Caskey, J. (2002). Historic Faulting, Chronostratigraphy, and Paleoseismicity of the Central Nevada Seismic Belt: Field Guide (p. 122).
Chen, Z., Scott, C., Keating, D., Clarke, A., Das, J., & Arrowsmith, R. (2023). Quantifying and analysing rock trait distributions of rocky fault scarps using deep learning. Earth Surface Processes and Landforms, 48(6), 1234–1250. https://doi.org/10.1002/esp.5545
Cheng, R. L., Michalski, J. R., & Campbell, K. A. (2024). Compositional Remote Sensing and Hyperspectral Laboratory Analyses of Sinters in Hydrothermal Fields in Chile, With Relevance to Astrobiological Targets on Mars. Journal of Geophysical Research: Planets, 129(5), e2023JE007999. https://doi.org/10.1029/2023JE007999
Clarke, B. A., & Burbank, D. W. (2010). Evaluating hillslope diffusion and terrace riser degradation in New Zealand and Idaho. Journal of Geophysical Research: Earth Surface, 115(F2). https://doi.org/10.1029/2009JF001279
Coolbaugh, M. F. (2023). Mapping of hydrothermal eruption features.
Culling, W. E. H. (1960). Analytical Theory of Erosion. The Journal of Geology, 68(3), 336–344.
Culling, W. E. H. (1963). Soil Creep and the Development of Hillside Slopes. The Journal of Geology, 71(2), 127–161.
Freski, Y. R., Hecker, C., van der Meijde, M., & Setianto, A. (2021). The effects of alteration degree, moisture and temperature on laser return intensity for mapping geothermal manifestations. Geothermics, 97, 102250. https://doi.org/10.1016/j.geothermics.2021.102250
Gao, B., Chen, N., Blaschke, T., & others. (2021). Automated Characterization of Yardangs Using Deep Convolutional Neural Networks. Remote Sensing, 13(4), 4. https://doi.org/10.3390/rs13040733
Hanks, T. C. (2000). The age of scarplike landforms from diffusion-equation analysis. In Quaternary Geochronology: Methods and Applications (Vol. 4, pp. 313–338). American Geophysical Union. https://doi.org/10.1029/RF004p0313
Hanks, T. C., Bucknam, R. C., Lajoie, K. R., & Wallace, RE. (1984). Modification of wave-cut and faulting-controlled landforms. Journal of Geophysical Research: Solid Earth, 89(B7), 5771–5790. https://doi.org/10.1029/JB089iB07p05771
Heap, M. J., Kennedy, B. M., Pernin, N., & others. (2015). Mechanical behaviour and failure modes in the Whakaari (White Island volcano) hydrothermal system, New Zealand. Journal of Volcanology and Geothermal Research, 295, 26–42. https://doi.org/10.1016/j.jvolgeores.2015.02.012
Hermant, B., Kiersnowski, L., & Bellanger, M. (2025). Using Deep Learning to Map Quaternary Faults in Western USA. Proceedings.
Hodge, M., Biggs, J., Fagereng, AA., Elliott, A., Mdala, H., & Mphepo, F. (2019). A semi-automated algorithm to quantify scarp morphology (SPARTA): application to normal faults in southern Malawi. Solid Earth, 10(1), 27–57. https://doi.org/10.5194/se-10-27-2019
Jiang, D., Li, S., Hajnsek, I., Siddique, M. A., Hong, W., & Wu, Y. (2025). Glacial lake mapping using remote sensing Geo-Foundation Model. International Journal of Applied Earth Observation and Geoinformation, 136, 104371. https://doi.org/10.1016/j.jag.2025.104371
Juliani, C. (2019). Automated discrimination of fault scarps along an Arctic mid-ocean ridge using neural networks. Computers & Geosciences, 124, 27–36. https://doi.org/10.1016/j.cageo.2018.12.010
Kennedy-Bowdoin, T., Martini, B. A., Silver, E. A., & Pickles, W. L. (2003). Hydrothermal Alteration Mineral Mapping Using Hyperspectral Imagery in Dixie Valley, Nevada. GRC Transactions, 27, 649–651.
Kokkalas, S., & Koukouvelas, I. K. (2005). Fault-scarp degradation modeling in central Greece: The Kaparelli and Eliki faults (Gulf of Corinth) as a case study. Journal of Geodynamics, 40(2–3), 200–215. https://doi.org/10.1016/j.jog.2005.07.006
Kraal, K. O., & Schwering, P. C. (2024). Remote Sensing Case Studies for Detection and Interpretation of Geothermal Surface Materials for Geothermal Exploration in the Basin and Range, Nevada, USA. GRC Transactions, 48.
Li, J., Zhang, J., & Fu, Y. (2025). CTHNet: A CNN–Transformer Hybrid Network for Landslide Identification in Loess Plateau Regions Using High-Resolution Remote Sensing Images. Sensors, 25(1), 1. https://doi.org/10.3390/s25010273
Lutz, S. J., Caskey, S. J., & Johnson, S. D. (2003). Geyserite, Faulted Sinter Terraces, and Other Fossil Hot Spring Deposits, Northern Dixie Valley Fault System, Nevada. In Geothermal Resources Council Transactions (pp. 75–89).
Lutz, S. S., Caskey, S. J., Mildenhall, D. D., Browne, P. R. L., & Johnson, S. D. (2002). Dating sinter deposits in northern Dixie Valley, Nevada - the paleoseismic record and implications for the Dixie Valley geothermal system. Proceedings, 10.
Martini, B. A., Silver, E. A., Pickles, W. L., & Cocks, P. A. (2004). Hyperspectral mineral mapping in support of geothermal exploration: examples from Long Valley Caldera, CA and Dixie Valley, NV, USA. Proceedings, 7.
Nash, D. B. (1980). Morphologic Dating of Degraded Normal Fault Scarps. The Journal of Geology, 88(3), 353–360.
Pearthree, P. A. (1990). Geomorphic Analyses of Young Faulting and Fault Behavior in Central Nevada [Phdthesis]. University of Arizona.
Pelletier, J. D., DeLong, S. B., Al-Suwaidi, A. H., & others. (2006). Evolution of the Bonneville shoreline scarp in west-central Utah: Comparison of scarp-analysis methods and implications for the diffusion model of hillslope evolution. Geomorphology, 74(1), 257–270. https://doi.org/10.1016/j.geomorph.2005.08.008
Pereira, M. L., Zanon, V., Fernandes, I., Pappalardo, L., & Viveiros, F. (2024). Hydrothermal alteration and physical and mechanical properties of rocks in a volcanic environment: A review. Earth-Science Reviews, 252, 104754. https://doi.org/10.1016/j.earscirev.2024.104754
Pierce, K. L., & Colman, S. M. (1986). Effect of height and orientation (microclimate) on geomorphic degradation rates and processes, late-glacial terrace scarps in central Idaho. Geological Society of America Bulletin, 97(7), 869. https://doi.org/10.1130/0016-7606(1986)97<869:EOHAOM>2.0.CO;2
Pola, A., Crosta, G. B., Fusi, N., & Castellanza, R. (2014). General characterization of the mechanical behaviour of different volcanic rocks with respect to alteration. Engineering Geology, 169, 1–13. https://doi.org/10.1016/j.enggeo.2013.11.011
Rahmidiani, W., Saepuloh, A., & Kriswati, E. (2025). Identification of Alteration Zones Based on Satellite Images and Vegetation Response for Geothermal Exploration in Volcanic Fields. IOP Conference Series: Earth and Environmental Science, 1451(1), 012033. https://doi.org/10.1088/1755-1315/1451/1/012033
Reid, M. E., Sisson, T. W., & Brien, D. L. (2001). Volcano collapse promoted by hydrothermal alteration and edifice shape, Mount Rainier, Washington. Geology, 29(9), 779. https://doi.org/10.1130/0091-7613(2001)029<0779:VCPBHA>2.0.CO;2
Salisbury, J. B., Haddad, D. E., Rockwell, T., & others. (2015). Validation of meter-scale surface faulting offset measurements from high-resolution topographic data. Geosphere, 11(6), 1884–1901. https://doi.org/10.1130/GES01197.1
Sare, R., Hilley, G. L., & DeLong, S. B. (2019). Regional-Scale Detection of Fault Scarps and Other Tectonic Landforms: Examples From Northern California. Journal of Geophysical Research: Solid Earth, 124(1), 1016–1035. https://doi.org/10.1029/2018JB016886
Scharer, K. M., Salisbury, J. B., Arrowsmith, J. R., & Rockwell, T. K. (2014). Southern San Andreas Fault Evaluation Field Activity: Approaches to Measuring Small Geomorphic Offsets–Challenges and Recommendations for Active Fault Studies. Seismological Research Letters, 85(1), 68–76. https://doi.org/10.1785/0220130108
Scott, C. P., Giampietro, T., Brigham, C., & others. (2022). Semiautomatic Algorithm to Map Tectonic Faults and Measure Scarp Height from Topography Applied to the Volcanic Tablelands and the Hurricane Fault, Western US. Lithosphere, 2021(Special 2), 9031662. https://doi.org/10.2113/2021/9031662
Shebl, A., Abdellatif, M., Badawi, M., Dawoud, M., Fahil, A. S., & Csámer, A. (2023). Towards better delineation of hydrothermal alterations via multi-sensor remote sensing and airborne geophysical data. Scientific Reports, 13(1), 7406. https://doi.org/10.1038/s41598-023-34531-y
Silver, E., MacKnight, R., Male, E., Pickles, W., Cocks, P., & Waibel, A. (2011). LiDAR and hyperspectral analysis of mineral alteration and faulting on the west side of the Humboldt Range, Nevada. Geosphere, 7(6), 1357–1368. https://doi.org/10.1130/GES00673.1
Thompson, G. A., & Burke, D. B. (1973). Rate and Direction of Spreading in Dixie Valley, Basin and Range Province, Nevada. Geological Society of America Bulletin, 84(2), 627. https://doi.org/10.1130/0016-7606(1973)84<627:RADOSI>2.0.CO;2
Tucker, G. E., & Bradley, D. N. (2010). Trouble with diffusion: Reassessing hillslope erosion laws with a particle-based model. Journal of Geophysical Research: Earth Surface, 115(F1). https://doi.org/10.1029/2009JF001264
Tucker, G. E., McCoy, S. W., Whittaker, A. C., Roberts, G. P., Lancaster, S. T., & Phillips, R. (2011). Geomorphic significance of postglacial bedrock scarps on normal-fault footwalls. Journal of Geophysical Research: Earth Surface, 116(F1). https://doi.org/10.1029/2010JF001861
Van Der Meer, F., Hecker, C., Van Ruitenbeek, F., Van Der Werff, H., De Wijkerslooth, C., & Wechsler, C. (2014). Geologic remote sensing for geothermal exploration: A review. International Journal of Applied Earth Observation and Geoinformation, 33, 255–269. https://doi.org/10.1016/j.jag.2014.05.007
Vega-Ramírez, L. A., Spelz, R. M., Negrete-Aranda, R., & others. (2021). A New Method for Fault-Scarp Detection Using Linear Discriminant Analysis in High-Resolution Bathymetry Data From the Alarcón Rise and Pescadero Basin. Tectonics, 40(12), e2021TC006925. https://doi.org/10.1029/2021TC006925
Wallace, R. E. (1977). Profiles and ages of young fault scarps, north-central Nevada. Geological Society of America Bulletin, 88(9), 1267. https://doi.org/10.1130/0016-7606(1977)88<1267:PAAOYF>2.0.CO;2
Wallace, R. E., & Whitney, R. A. (1984). Late quaternary history of the Stillwater seismic gap, Nevada. Bulletin of the Seismological Society of America, 74(1), 301–314. https://doi.org/10.1785/BSSA0740010301
Wesnousky, S., Caskey, S. J., & Bell, J. W. (2003). Recency of Faulting and Neotechtonic Framework in the Dixie Valley Geothermal Field and Other Geothermal Fields of the Basin and Range [Techreport]. University of Nevada, Reno (US). https://doi.org/10.2172/808727
Westoby, M. J., Brasington, J., Glasser, N. F., Hambrey, M. J., & Reynolds, J. M. (2012). “Structure-from-Motion” photogrammetry: A low-cost, effective tool for geoscience applications. Geomorphology, 179, 300–314. https://doi.org/10.1016/j.geomorph.2012.08.021
White, D. E. (1955). Violent mud-volcano eruption of Lake City Hot Springs, Northeastern California. Geological Society of America Bulletin, 66(9), 1109–1130. https://doi.org/10.1130/0016-7606(1955)66[1109:VMEOLC]2.0.CO;2
Wintsch, R. P., Christoffersen, R., & Kronenberg, A. K. (1995). Fluid-rock reaction weakening of fault zones. J. Geophys. Res., 100, 13021–13032. https://doi.org/10.1029/94JB02622
Wolfe, F. D., Stahl, T. A., Villamor, P., & Lukovic, B. (2020). Short communication: A semiautomated method for bulk fault slip analysis from topographic scarp profiles. Earth Surface Dynamics, 8(1), 211–219. https://doi.org/10.5194/esurf-8-211-2020
Wyering, L. D., Villeneuve, M. C., Wallis, I. C., Siratovich, P. A., Kennedy, B. M., Gravley, D. M., & Cant, J. L. (2014). Mechanical and physical properties of hydrothermally altered rocks, Taupo Volcanic Zone, New Zealand. Journal of Volcanology and Geothermal Research, 288, 76–93. https://doi.org/10.1016/j.jvolgeores.2014.10.008
Xiong, L., Li, S., Tang, G., & Strobl, J. (2022). Geomorphometry and terrain analysis: data, methods, platforms and applications. Earth-Science Reviews, 233, 104191. https://doi.org/10.1016/j.earscirev.2022.104191
Xu, J., Arrowsmith, J. R., Chen, J., & others. (2021). Evaluating young fluvial terrace riser degradation using a nonlinear transport model: Application to the Kongur Normal Fault in the Pamir, northwest China. Earth Surface Processes and Landforms, 46(1), 280–295. https://doi.org/10.1002/esp.5022
Yang, J., Xu, J., Zhu, Y., Liu, Z., & Zhou, C. (2025). GeomorPM: a geomorphic pretrained model integrating convolution and Transformer architectures based on DEM data. International Journal of Geographical Information Science, 39(2), 422–451. https://doi.org/10.1080/13658816.2024.2414409
Yellowstone Volcano Observatory. (2026). Yellowstone Volcano Observatory 2024 annual report (Techreport No. 1566; Circular, p. 44). U.S. Geological Survey. https://doi.org/10.3133/cir1566
Zhang, H., Xu, J. J., Cui, H. w., & others. (2024). When Geoscience Meets Foundation Models: Toward a general geoscience artificial intelligence system. IEEE Geoscience and Remote Sensing Magazine, 2–41. https://doi.org/10.1109/MGRS.2024.3496478
Zou, J., He, H., Yokoyama, Y., & others. (2022). A comparative study of bedrock fault scarps by s-UAV and t-LiDAR: Insights into site selection criteria for paleo-seismology studies. Geomorphology, 414, 108372. https://doi.org/10.1016/j.geomorph.2022.108372
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