This data release contains a dataset that depicts fault scarps along the Zapata and Blanca sections of the Sangre de Cristo fault zone located in the San Luis basin of southern Colorado. The Zapata and Blanca sections extend from the Great Sand Dunes National Park and Preserve to the Blanca Peak massif and are differentiated by a sharp change in fault zone orientation from north-south to east-west. The fault scarps are the result of Quaternary tectonic extension causing surface rupturing earthquakes estimated to have occurred most recently 8-12 ka with probable Mw 6-7 (Ruleman and Machette, 2007). The dataset represents detailed mapping of probable fault surface rupture on high-resolution (1m/pix) topographic data from USGS 3DEP (U.S. Geological Survey, 2012; U.S. Geological Survey, 2021) mapped at 1:1400 scale. The mapping has been validated with GPS surveys at select locations along the fault zone. Primarily, mapping was conducted between September 2022 and December 2022 with subsequent updates and corrections. The data has undergone peer review but remains subject to revision as more information becomes available. The dataset is provided in shapefile KML, and geoJSON formats.

This dataset provides simplified fault traces for the Gallina, Willow Creek, and West and East Brazos Peak fault systems in north-central New Mexico.

This dataset provides simplified fault traces for the Gallina, Willow Creek, and West and East Brazos Peak fault systems in north-central New Mexico.

This release provides the data for a comprehensive survey of geologic structures in the eastern Española Basin of the Rio Grande rift, New Mexico. The release includes data and analyses from 53 individual fault zones and 22 other brittle structures, such as breccia zones, joints, and veins, investigated at a total of just over 100 sites. Structures were examined and compared from poorly lithified Tertiary sediments, as well as Paleozoic sedimentary and Proterozoic crystalline rocks. Data and analyses, include geologic maps; field observations and measurements; orientation, kinematic paleostress analyses and modeling; statistical examination of 575 fault trace lengths derived from aeromagnetic data in the Española and adjacent basins; mineralogy and chemistry of host and fault rocks; and investigation of fault versus bolide impact hypotheses for the origin of enigmatic breccias found in the Proterozoic basement rocks. Kinematic and paleostress analyses suggest a record of transitional, and perhaps partitioned, strains from the Laramide orogeny through Rio Grande rifting. Normal faults within Tertiary basin fill sediments are consistent with more typical WNW-ESE Rio Grande extension, perhaps decoupled from bedrock structures due to strength contrasts favoring the formation of new faults in the relatively weak sediments. Analyses of the fault length data indicate power law length distributions similar to those reported from many geologic settings globally. Mineralogy and chemistry in Proterozoic fault-related rocks reveal geochemical changes tied to hydrothermal alteration and nearly isochemical transformation of feldspars to clay minerals. In sediments, fault rocks are characterized by mechanical entrainment with minor secondary chemical changes. Enigmatic breccias are autoclastic, isochemical with respect to their protoliths, and occur near shatter cones believed to be related to a pre-Pennsylvanian impact event. A weak iridium anomaly is associated with the breccias as well as adjacent protoliths, thus an impact shock wave cannot be ruled out for their origin. The types of faults, associated brittle structures, and geochemical attributes provided here can aid in development of conceptual models and approaches useful in identifying testable hypotheses grounded in geological data when assessing ground- and surface-water resources.

This release provides the data for a comprehensive survey of geologic structures in the eastern Española Basin of the Rio Grande rift, New Mexico. The release includes data and analyses from 53 individual fault zones and 22 other brittle structures, such as breccia zones, joints, and veins, investigated at a total of just over 100 sites. Structures were examined and compared from poorly lithified Tertiary sediments, as well as Paleozoic sedimentary and Proterozoic crystalline rocks. Data and analyses, include geologic maps; field observations and measurements; orientation, kinematic paleostress analyses and modeling; statistical examination of 575 fault trace lengths derived from aeromagnetic data in the Española and adjacent basins; mineralogy and chemistry of host and fault rocks; and investigation of fault versus bolide impact hypotheses for the origin of enigmatic breccias found in the Proterozoic basement rocks. Kinematic and paleostress analyses suggest a record of transitional, and perhaps partitioned, strains from the Laramide orogeny through Rio Grande rifting. Normal faults within Tertiary basin fill sediments are consistent with more typical WNW-ESE Rio Grande extension, perhaps decoupled from bedrock structures due to strength contrasts favoring the formation of new faults in the relatively weak sediments. Analyses of the fault length data indicate power law length distributions similar to those reported from many geologic settings globally. Mineralogy and chemistry in Proterozoic fault-related rocks reveal geochemical changes tied to hydrothermal alteration and nearly isochemical transformation of feldspars to clay minerals. In sediments, fault rocks are characterized by mechanical entrainment with minor secondary chemical changes. Enigmatic breccias are autoclastic, isochemical with respect to their protoliths, and occur near shatter cones believed to be related to a pre-Pennsylvanian impact event. A weak iridium anomaly is associated with the breccias as well as adjacent protoliths, thus an impact shock wave cannot be ruled out for their origin. The types of faults, associated brittle structures, and geochemical attributes provided here can aid in development of conceptual models and approaches useful in identifying testable hypotheses grounded in geological data when assessing ground- and surface-water resources.

Linework representing fault rupture and ground deformation features interpreted from airborne imagery, lidar, and InSAR interferograms, are combined with digitized field mapping into a single KMZ file.

Linework representing fault rupture and ground deformation features interpreted from airborne imagery, lidar, and InSAR interferograms, are combined with digitized field mapping into a single KMZ file.

This item contains linework that represents fault rupture and ground deformation features interpreted from field-based maps and observations, as well as airborne imagery, lidar, and geodetic imagery products. Provisional maps of fault rupture and ground deformation are composed of a “mashup” of linework from these various sources, obtained and compiled as of December, 2019. If more than one linework representation exists for a segment of the fault rupture, linework showing the most rupture detail or best location accuracy, based on the judgment of the compiler, is preserved. On provisional maps, less than 25% of the linework is derived from high-resolution optical imagery and detailed field mapping. Because line segments from the various sources vary in location accuracy and precision based on the source equipment or imagery, mismatches can occur at the boundaries between linework from different sources. No corrections are made for these mismatches in the provisional maps. Final maps will reconcile all linework to a single registered base map

This item contains linework that represents fault rupture and ground deformation features interpreted from field-based maps and observations, as well as airborne imagery, lidar, and geodetic imagery products. Provisional maps of fault rupture and ground deformation are composed of a “mashup” of linework from these various sources, obtained and compiled as of December, 2019. If more than one linework representation exists for a segment of the fault rupture, linework showing the most rupture detail or best location accuracy, based on the judgment of the compiler, is preserved. On provisional maps, less than 25% of the linework is derived from high-resolution optical imagery and detailed field mapping. Because line segments from the various sources vary in location accuracy and precision based on the source equipment or imagery, mismatches can occur at the boundaries between linework from different sources. No corrections are made for these mismatches in the provisional maps. Final maps will reconcile all linework to a single registered base map

In September 2017, the U.S. Geological Survey acquired high resolution P- and S-wave seismic data across the suspected trace of the West Napa Fault zone in St. Helena, California, approximately 70 m north of the previous seismic survey conducted in April 2017 (Chan et al., 2018). We acquired seismic reflection, refraction, and guided-wave data along a 75-m-long profile across the expected trend of the West Napa Fault zone. To acquire the reflection and refraction data, we co-located shots and geophones, spaced every 1 and 2 m along the profile. We used 77 SercelTM L40A P-wave (40-Hz vertical-component) geophones with a sensitivity of 22.34 volts/meter/second to record 60 P-wave shots, and 77 SercelTM L28-LBH S-wave (4.5-Hz horizontal-component) geophones with a sensitivity of 31.3 volts/meter/second to record 60 S-wave shots. We generated P-wave data using a 3.5-kg sledgehammer and steel plate combination. S-wave sources were generated by horizontally striking an aluminum block with a 3.5-kg sledgehammer. We acquired fault zone guided wave data by generating P-wave (226-kg accelerated weight-drop, AWD) and S-wave (angle AWD) energies approximately 160 m north of the recording arrays. All data were recorded using one 60-channel Geometrics Stratavisor NX-60TM seismograph with a 24-bit analog-to-digital converter (Subcommittee of the SEG Engineering and Groundwater Geophysics Committee, 1990); the seismograph was connected to the P- and S-wave geophones via refraction cables. Each shot was recorded for two seconds, with data recording starting 100 ms before the actual time of the shot. Data were recorded at a sampling rate of 0.5 ms, or 2000 samples per second. This report provides the metadata needed to utilize the seismic data. Reference: Subcommittee of the SEG Engineering and Groundwater Geophysics Committee, Pullan, S. E., Chairman, 1990, Recommended standard for seismic (/radar) data files in the personal computer environment: Geophysics, vol. 55, no. 9, p. 1260-1271.