Subsidence history of the Ediacaran Johnnie Formation and related strata of southwest Laurentia: Implications for the age and duration of the Shuram isotopic excursion and animal evolution

The Johnnie Formation and associated Ediacaran strata in southwest Laurentia are ~3000 m thick, with a Marinoan cap carbonate sequence at the bottom, and a transition from Ediacaran to Cambrian fauna at the top. About halfway through the sequence, the Shuram negative carbon isotopic excursion occurs within the Rainstorm Member near the top of the Johnnie Formation, followed by a remarkable valley incision event. At its type locality in the northwest Spring Mountains, Nevada, the Johnnie lithostratigraphy consists of three distinctive sand-rich intervals alternating with four siltstone/carbonate-rich intervals, which appear correlative with other regional ­Johnnie Formation outcrops. Carbon isotope ratios in the sub–Rainstorm Member part of the Johnnie Formation are uniformly positive for at least 400 m below the Shuram excursion and compare well with sub–Shuram excursion profiles from the ­Khufai Formation in Oman. There is historical consensus that the Johnnie and overlying formations were deposited on a thermally subsiding passive margin. Following previous authors, we used Paleozoic horizons of known biostratigraphic age to define a time-dependent exponential sub­sidence model, and extrapolated the model back in time to estimate the ages of the Shuram excursion and other prominent Ediacaran horizons. The model suggests that the Shuram excursion occurred from 585 to 579 Ma, and that incision of the Rainstorm Member shelf occurred during the 579 Ma Gaskiers glaciation. It further suggests that the base of the Johnnie Formation is ca. 630 Ma, consistent with the underlying Noonday Formation representing a Marinoan cap carbonate sequence. Our results contrast with suggestions by previous workers that the Shuram excursion followed the Gaskiers event by some 20–30 m.y. We suggest instead that the Shuram and Gaskiers events were contemporaneous with the biostratigraphic transition from acantho­morphic to leiospherid acritarchs, and with the first appearance of widespread macroscopic animal life, 38 m.y. prior to the Ediacaran-Cambrian boundary

Tectonics in Nevada and Southern California: Subsidence of the Ediacaran Johnnie Formation, Cumulative Offset Along the Lavic Lake Fault, and Geomorphic Surface Development Along the Southern San Andreas Fault

While we know the ages and tectonic histories of many critical geologic events in the history of the Earth, there are still questions regarding the timing of key events and structures that have and continue to influence life on this planet. This thesis includes three separate studies in Nevada and southern California: two potential new methods for measuring/organizing geologic time, and also an analysis of the long-term displacement along an active fault in the eastern California shear zone. In Chapter II, we used tectonic subsidence modeling to find that the Shuram carbon isotopic excursion in the Ediacaran Johnnie Formation likely occurred from 585-579 Ma, and that incision of the Rainstorm Member shelf occurred during the 579 Ma Gaskiers glaciation. The pre-Shuram-excursion chemostratigraphic carbon isotope profiles from the Khufai Formation in Oman and the type locality of the Johnnie Formation in Nevada are both generally positive and therefore possibly correlative. In Chapter III, we determined the cumulative tectonic offset along the Lavic Lake fault, an active structure that ruptured with &gt;5 m of coseismic slip in the 1999 Mw 7.1 Hector Mine earthquake. We calculated a net slip of 960 +70/-40 m, based on the slip vector formed by a vertically separated lithologic contact and a horizontally separated older cross fault. The net slip we calculated is significantly less than a previous estimate that was based on an offset magnetic gradient, a disparity that may be explained by considering off-fault deformation, as well as the unknown depth and nature of the source of the magnetic contrast. In Chapter IV, we explored using a new method for the relative dating of Quaternary geomorphic surfaces, which is based on the positive correlation between increased spectral contrast in thermal hyperspectral airborne imagery and surface age. With field data, we found that desert varnish scores, desert pavement scores, and vegetation spacing estimates also correlate positively with surface age, implying that these factors could contribute to the increased spectral contrast in airborne remote sensing spectra. Additionally, the general increase in the band depth of airborne spectra at 9.16 μm could be due to increasing clay mineral abundance in progressively heavier desert varnish coatings on older surfaces. The positive correlation observed in this study between surface age and spectral contrast in airborne spectra can perhaps be used to develop a method for relative dating of varnished geomorphic surfaces elsewhere. All of the chapters in this thesis are broadly related by the concepts of geologic time and tectonic activity, which are two aspects of modern geology that are intrinsic to the science as a whole.</p

The Lavic Lake Fault: A Long-Term Cumulative Slip Analysis via Combined Field Work and Thermal Infrared Hyperspectral Airborne Remote Sensing

The 1999 Hector Mine earthquake ruptured to the surface in eastern California, with >5 m peak right-lateral slip on the Lavic Lake fault. The cumulative offset and geologic slip rate of this fault are not well defined, which inhibits tectonic reconstructions and risk assessment of the Eastern California Shear Zone (ECSZ). With thermal infrared hyperspectral airborne imagery, field data, and auxiliary information from legacy geologic maps, we created lithologic maps of the area using supervised and unsupervised classifications of the remote sensing imagery. We optimized a data processing sequence for supervised classifications, resulting in lithologic maps over a test area with an overall accuracy of 71 ± 1% with respect to ground-truth geologic mapping. Using all of the data and maps, we identified offset bedrock features that yield piercing points along the main Lavic Lake fault and indicate a 1036 +27/−26 m net slip, with 1008 +14/−17 m horizontal and 241 +51/−47 m vertical components. For the contribution from distributed shear, modern off-fault deformation values from another study imply a larger horizontal slip component of 1276 +18/−22 m. Within the constraints, we estimate a geologic slip rate of <4 mm/yr, which does not increase the sum geologic Mojave ECSZ rate to current geodetic values. Our result supports previous suggestions that transient tectonic activity in this area may be responsible for the discrepancy between long-term geologic and present-day geodetic rates

Mako thermal infrared hyperspectral airborne emissivity image, field photographs, and ground-based spectra of the San Andreas fault and Thousand Palms Oasis in the Coachella Valley, California

Contents: total of 64 files in three folders and one stand-alone file; one folder contains two files, another contains 54 files, and another contains seven files. The folder "airborneEmissivityImage" contains: The Mako thermal infrared hyperspectral airborne emissivity image, and its header file: 1) airborneEmissivityImage 2) airborneEmissivityImage.hdr The folder "fieldPhotographs" contains: 1) 27 .jpg image files of the field sites (overhead views of the one-square-meter frame) 2) 27 .jpg image files of the field sites (overview perspectives of the site locations) The folder "surfaceOutlinesShapefiles" contains the digitized boundary lines of the geomorphic surfaces studied, in a set of shape files: 1) seven surfaceOutlines files (.shp, .shx, .qpj, .prj, .dbf, .cpg, .kmz) The file "groundBasedSpectra.xlsx" contains all of the ground-based spectra for the 27 field sites, along with a summary. Thermal Infrared Hyperspectral Airborne Imagery Acquisition and Processing: We collected thermal infrared hyperspectral airborne imagery on 24 September 2015 (10:50 am PDT) using The Aerospace Corporation's Mako "whiskbroom" sensor. The imagery included here had one-meter spatial resolution from a flight at 1830 m above ground level (2070 m altitude), and 118 spectral bands with wavelengths 8.01-13.15 μm. The complete image scene (a rectangular area, 6.1 km along the flight path, and 4.7 km wide) covered portions of both the Mission Creek and Banning strands of the southern San Andreas fault. The flight path was roughly parallel to, and centered on the Mission Creek strand. The hyperspectral imagery was processed from at-sensor radiance to emissivity using Environment for Visualizing Images (ENVI) software, version 4.8 (Harris Geospatial Solutions, Broomfield, Colorado), in the following sequence: Mako thermal infrared hyperspectral airborne image data cubes delivered by the Aerospace Corporation in Level 2 (L2) files, which had undergone radiometric and wavelength calibration (Buckland et al., 2017; Witkosky et al., 2016), bad pixel replacement, and spectral smile removal; all 114 data cubes concatenated into a super cube for bulk processing; bands 1-10 (wavelengths 7.56-7.96 µm) removed because they were dominated by noise (remaining bands are 11-128, 118 total, with wavelengths 8.01-13.15 µm); in-scene atmospheric compensation (Young et al., 2002), setting the regression pixels to maximum hit, the fitting technique to normalized regression, and using for the noise equivalent spectral radiance (NESR), the median value of the super cube; minimum noise fraction (MNF) forward transformation (Green et al., 1988; Lee et al., 1990); discarded an MNF component that included a significant data artifact (an across-track gradation, perpendicular to the flight direction, was present near the edges of each individual data cube) in an MNF inverse transformation; temperature emissivity separation with the emissivity normalization method (Kealy and Hook, 1993); georeferenced using the geolocation files included with the L2 files. The shape files for the geomorphic surfaces are included so they can be superimposed onto the thermal infrared hyperspectral airborne image, for randomly or manually sampling emissivity spectra (for a given surface) from within the digitized boundaries. We modified the line work from the geomorphic surface boundaries in Blisniuk and Sharp (2014). Field Photographs and Ground-based Spectra From March until May 2017, we visited 27 sites on the geomorphic surfaces to take field photographs and measure ground-based spectra. At each site, a one-square-meter frame was placed on the ground to represent the airborne imagery pixel size. We took two photographs at each site: an overhead view photograph of the one-square-meter frame, and an overview perspective of the site location. We used an Agilent 4100 ExoScan™ portable Fourier Transform Infrared spectrometer (3-5 mm spot size, active source) to measure ground-based diffuse reflectance spectra (some in-situ, some later on collected samples) from exposed top sides of clasts, finer unconsolidated material (we refer to these as "sand" spectra, where "sand" does NOT imply a specific clast size), and vegetation. We converted the ground-based reflectance spectra to emissivity using Kirchhoff's law (Robitaille, 2009) to compare the shape and wavelength positions with the airborne spectra. All of the ground-based spectra (up to ten) and the average (arithmetic mean) were plotted for each site, to exemplify spectral mixtures of materials contained within the airborne image pixel size. The ground-based spectra are not quantitative. References Cited: Blisniuk, K., and Sharp, W.D., 2014, Estimating geologic slip rates on the southern San Andreas Fault, California: U-series and 10Be dating: U.S. Geological Survey Final Technical Report for USGS Award No. G13AP00031, 9 p. Buckland, K.N., Young, S.J., Keim, E.R., Johnson, B.R., Johnson, P.D., and Tratt, D.M, 2017, Tracking and quantification of gaseous chemical plumes from anthropogenic emission sources within the Los Angeles Basin: Remote Sensing of Environment, v. 201, p. 275- 296, https://doi.org/ 10.1016/j.rse.2017.09.012. Green, A.A., Berman, M., Switzer, P., and Craig, M.D., 1988, A transformation for ordering multispectral data in terms of image quality with implications for noise removal: IEEE Transactions on Geoscience and Remote Sensing, v. 26, no. 1, p. 65-74, https://doi.org/10.1109/36.3001. Kealy, P.S., and Hook, S.J., 1993, Separating temperature and emissivity in thermal infrared multispectral scanner data: implications for recovery of land surface temperatures: IEEE Transactions on Geoscience and Remote Sensing, v. 31, n. 6, p. 1155-1164, https://doi.org/10.1109/36.317447. Lee, J.B., Woodyatt, S., and Berman, M., 1990, Enhancement of high spectral resolution remote- sensing data by a noise-adjusted principal components transform: IEEE Transactions on Geoscience and Remote Sensing, v. 28, n. 3, p. 295-304. Robitaille, P. -M., 2009, Kirchhoff's law of thermal emission: 150 years: Progress in Physics, v. 4, p. 3-13. Witkosky, R.D., Adams, P., Akciz, S., Buckland, K., Harvey, J., Johnson, P., Lynch, D.K., Sousa, F., Stock, J., and Tratt, D., 2016, Geologic swath map of the Lavic Lake fault from airborne thermal hyperspectral imagery. Paper presented at 8th IEEE Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS), Los Angeles, California, https://doi.org/10.1109/WHISPERS.2016.8071769. Young, S.J., Johnson, B.R., and Hackwell, J.A., 2002, An in-scene method for atmospheric compensation of thermal hyperspectral data: Journal of Geophysical Research, v. 107, no. D24, p. 4774-4793, https://doi.org/10.1029/2001JD001266

Mako thermal infrared hyperspectral airborne imagery of the Lavic Lake fault: Imagery processed for supervised and unsupervised classifications

Contents: two folders that contain a total of nine files; one folder contains seven files, and the other folder, two files. The folder "redFlakeSite" contains: The thermal infrared hyperspectral airborne image, and its header file, of the Red Flake site, processed to emissivity values: 1) emissivityImage 2) emissivityImage.hdr The lithologic contact boundary lines for the Red Flake site, in a set of shape files: 3) allRFlakeClasses.shp 4) allRFlakeClasses.shx 5) allRFlakeClasses.dbf 6) allRFlakeClasses.prj The thermal infrared laboratory spectra of lithologic sample chips from the Red Flake site, in a spreadsheet: 7) redFlakeSamplesLabSpectra.xlsx The folder "completeHyperspectralImageMNFcomponents" contains the complete thermal infrared hyperspectral airborne image, and its header file, of the Lavic Lake fault, processed to the first fifteen minimum noise fraction (MNF) components: 1) B21to128MnfForB1to15georef 2) B21to128MnfForB1to15georef.hdr For the supervised classifications at the Red flake site, the Red flake site emissivity image (with its header file) and the shape files for the lithologic classes (to randomly or manually choose representative endmember spectra) are included (laboratory spectra from lithologic sample chips are also included, but these were not used in the supervised classifications). The emissivity image was processed using Environment for Visualizing Images (ENVI) software, version 4.8 (Harris Geospatial Solutions, Broomfield, Colorado), in the following sequence: Mako thermal infrared hyperspectral airborne image data cubes delivered by the Aerospace Corporation in Level 2 files, which had undergone radiometric and wavelength calibration, bad pixel replacement, and spectral smile removal; bands 1-20 (wavelengths 7.56-8.40 µm) removed because they were dominated by noise (remaining bands are 21-128, wavelengths 8.45-13.15 µm); in-scene atmospheric compensation (Young et al., 2002); principal component analysis transformation; discarded components that included significant noise or data artifacts in a principal components inverse transformation; temperature emissivity separation with the emissivity normalization method (Kealy and Hook, 1993); georeferenced using the geolocation files included with the Level 2 files; georeferenced again, with more precision, using ground control points that were manually chosen from a National Agriculture Imagery Program (NAIP) satellite image; area outside of the Red flake site masked; image cropped to the areal extent of the Red flake site. The set of shape files that we used for the supervised classifications are digitized representative boundaries between the four distinct lithologic units (1. tuff and tuff breccia, 2. detritus or colluvium, 3. feldspar porphyry, and 4. microcrystalline lava) that we identified and mapped at the Red Flake site. Note that the four files in the set of shape files do not represent the four lithologic classes; all of the line work is encompassed in the complete shape file set, and all of the files are needed together for digitized plotting. The thermal infrared laboratory spectra were taken from the upward-facing weathered surfaces of the lithologic sample chips. Reflectance spectra were measured using the biconical reflectance method on a Thermo-Nicolet 6700 FTIR Spectrometer, with a Harrick Scientific "Praying Mantis" diffuse reflection accessory. All laboratory spectra were measured with a spot size of 1-2 mm, and each final spectrum was an average of 150 scans taken over 4-6 minutes. The laboratory spectra were converted to emissivity using Kirchhoff's law, emissivity=1-reflectance (Robitaille, 2009). For the unsupervised classification of the minimum noise fraction (MNF) components of the complete hyperspectral image swath, the MNF components image (with its header file) is included. The MNF image was processed using Environment for Visualizing Images (ENVI) software, version 4.8 (Harris Geospatial Solutions, Broomfield, Colorado), in the following sequence: Mako thermal infrared hyperspectral airborne image data cubes delivered by the Aerospace Corporation in Level 2 files, which had undergone radiometric and wavelength calibration, bad pixel replacement, and spectral smile removal; all 70 data cubes concatenated for bulk processing; bands 1-20 (wavelengths 7.56-8.40 µm) removed because they were dominated by noise ("B21to128" in file name means the remaining bands are 21-128, wavelengths 8.45-13.15 µm); in-scene atmospheric compensation (Young et al., 2002); MNF forward transformation (Green et al., 1988); discarded all MNF components beyond the first 15; georeferenced using the geolocation files included with the Level 2 files. References Cited: Green, A.A., Berman, M., Switzer, P., &amp; Craig, M.D. (1988). A transformation for ordering multispectral data in terms of image quality with implications for noise removal. IEEE Transactions on Geoscience and Remote Sensing, 26(1), 65-74. https://doi.org/10.1109/36.3001 Kealy, P.S., &amp; Hook, S.J. (1993). Separating temperature and emissivity in thermal infrared multispectral scanner data: implications for recovering land surface temperatures. IEEE Transactions on Geoscience and Remote Sensing, 31(6), 1155-1164. https://doi.org/10.1109/36.317447 Robitaille, P.-M. (2009). Kirchhoff's law of thermal emission: 150 years. Progress in Physics, 4, 3-13. Young, S.J., Johnson, B.R., &amp; Hackwell, J.A. (2002). An in-scene method for atmospheric compensation of thermal hyperspectral data. Journal of Geophysical Research, 107(D24), 4774-4793. https://doi.org/10.1029/2001JD00126

The Lavic Lake Fault: A Long-Term Cumulative Slip Analysis via Combined Field Work and Thermal Infrared Hyperspectral Airborne Remote Sensing

The 1999 Hector Mine earthquake ruptured to the surface in eastern California, with >5 m peak right-lateral slip on the Lavic Lake fault. The cumulative offset and geologic slip rate of this fault are not well defined, which inhibits tectonic reconstructions and risk assessment of the Eastern California Shear Zone (ECSZ). With thermal infrared hyperspectral airborne imagery, field data, and auxiliary information from legacy geologic maps, we created lithologic maps of the area using supervised and unsupervised classifications of the remote sensing imagery. We optimized a data processing sequence for supervised classifications, resulting in lithologic maps over a test area with an overall accuracy of 71 ± 1% with respect to ground-truth geologic mapping. Using all of the data and maps, we identified offset bedrock features that yield piercing points along the main Lavic Lake fault and indicate a 1036 +27/−26 m net slip, with 1008 +14/−17 m horizontal and 241 +51/−47 m vertical components. For the contribution from distributed shear, modern off-fault deformation values from another study imply a larger horizontal slip component of 1276 +18/−22 m. Within the constraints, we estimate a geologic slip rate of <4 mm/yr, which does not increase the sum geologic Mojave ECSZ rate to current geodetic values. Our result supports previous suggestions that transient tectonic activity in this area may be responsible for the discrepancy between long-term geologic and present-day geodetic rates