Kavin Wee Keat Siaw Paul C. Hackley Jeremy K. Ray 20260316 tabular digital data Reston, Virginia U.S. Geological Survey https://doi.org/10.5066/P13KZXXF https://www.sciencebase.gov/catalog/item/692f1b99d4be026ff273aa0e Kavin Wee Keat Siaw Paul C. Hackley 2025 publication Reston, Virginia U.S. Geological Survey Measurement of fluorescence parameters such as λ_max (the wavelength of maximum intensity emission), and red-green (R/G) and blue-green (B/G) quotients allows the use of fluorescence color as a thermal proxy in the exploration for and assessment of hydrocarbon-based energy resource accumulations in petroliferous sedimentary basins. Here, we present data supporting the development of a microscope-spectrometer method to measure fluorescence emission of sedimentary organic matter (SOM) and method validation for a standard operating procedure used in the USGS Organic Petrology Laboratory (OPL) in Reston, Virginia. This work reaches toward the overall broader goal of standardization of fluorescence measurement of SOM. Conditions and fluorescence parameters from this study are provided here as three csv files and include λ_max (the wavelength of maximum intensity emission) measurements and red-green-blue (R/G/B) quotients under various environmental conditions, coefficients of variation for the mean λ_max measurements and R/G quotients, and a secondary validation analysis comparing peak wavelength and normalized intensity measurements from 8 major spectral peaks. Data provided here support methodology intended to develop and validate a standard operating procedure for measuring the fluorescence emission of sedimentary organic matter (SOM), a proxy used to assess thermal maturity conditions in petroliferous basins. The file contains data available in comma separated value (.csv) file format. The user must have software capable of opening and viewing a .csv file. 2025 observed Complete None planned -124.8000 -66.9000 49.0000 24.5000 ISO 19115 Topic Category geoscientificInformation None - Free Keywords organic petrology fluorescence spectroscopy method validation thermal indices fossil fuels burial history oil window USGS thermal maturation energy resources USGS Metadata Identifier USGS:692f1b99d4be026ff273aa0e No access constraints. Please see 'Distribution Information' for details. These data are marked with a Creative Commons Zero v1.0 Universal (CC0-1.0) public domain dedication and do not have any use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Paul C. Hackley U.S. Geological Survey - Northeast Region Research Geologist mailing and physical

12201 Sunrise Valley Drive, Mail Stop 954

Reston VA 20192 USA 703-648-6458 phackley@usgs.gov American Institute of Physics (AIP) The attributes in the dataset are accepted as correct and accurate. Please refer to the detailed process steps for more information on measures and tests performed to ensure accuracy of values. No formal logical accuracy tests were conducted. Dataset is considered complete for the information presented, as described in the abstract and process steps. Users are advised to read the rest of the metadata record carefully for additional details. No formal positional accuracy tests were conducted. No formal positional accuracy tests were conducted. B. S. Everitt 1998 publication Cambridge, UK Cambridge University Press Digital and/or Hardcopy 1998 publication date Everitt, 1998 Coefficient of variation calculation Bundesanstalt für Materialforschung und prüfung (BAM) 2014 publication Berlin, Gemany BAM federal Institute for Materials Research and Testing Digital and/or Hardcopy 2014 publication date Bundesanstalt für Materialforschung und prüfung, 2014 Major spectral peak reference profile Method details: This method uses a Zeiss Axio lmager M2m microscope coupled to a desktop TEC5 spectrometer. The system is controlled by a Hewlett Packard Workstation Z2 G9 operating the Hilgers DISKUS 1600 software for image acquisition, microscope control, measurement and management. A Hitachi HVF-203GV digital camera is controlled through the Hilgers DISKUS software for location, imaging, and visualization of microscopic analyte materials. The microscope-spectrometer system employs a customized Hilgers calibration lamp which uses the diffuse light of a halogen bulb reflected from polytetrafluorethylene (PTFE) to create a consistent reproducible spectrum used as an internal calibration. All measurements were conducted under controlled optical conditions, using a 63x magnification water immersion objective with 0.9 numerical aperture and ultraviolet excitation light delivered from a Hg gas-discharge excitation lamp through a bandpass (BP) 365/12 filter set, incorporating a short-pass dichroic filter (FT 395), and a long-pass emission filter (LP 397). To optimize preparation time, this study evaluated various heating durations for the calibration lamp prior to performing spectral measurement (measured immediately, after 5 minutes, 10 minutes, 15 minutes, and 30 minutes warm-up). Each measurement was conducted under consistent environmental conditions, with a black cardboard light barrier between the objective lens and the calibration lamp. This test allows for evaluating whether signal intensity or structure is significantly influenced by instrument preparation time and determines if a standardized waiting period is necessary to ensure consistent calibration performance. This study evaluated the influence of different calibration environments through measurement in complete darkness and under ambient laboratory light. Measurements were made in the presence and absence of a black cardboard light barrier placed between the objective lens and the calibration lamp to test the effectiveness of the barrier in reducing stray light interference. Calibration conditions were also tested in combination with different fiber-optic cable diameters (100 μm and 200 μm) to determine if calibration consistency was affected by collection geometry. 2025 Environmental conditions: This study investigated the influence of dark current correction frequency on the accuracy and consistency of fluorescence spectral data. Dark current correction was performed immediately after powering on the spectrometer, and again after a ten-minute warm-up period. In both scenarios, calibration reference spectra were acquired to evaluate the spectral peak position (λ_max) and the corresponding red-green-blue (R/G/B) intensity quotients. 2025 Coefficient of variation: To optimize measurement precision, this study investigated the appropriate number of analyte measurements required for reliable analysis. A systematic approach was designed to evaluate the stability of repeated measurements across shale and coal samples by calculating the coefficient of variation (CV) for each dataset. The coefficient of variation (Everitt, 1998) is a normalized measure of dispersion expressed as a percentage: CV=(σ/μ)×100, where σ is the standard deviation and μ is the mean of the measurements. This metric enables direct comparison of variability across datasets with different scales. In this study, CV was reported in decimal format (i.e., without multiplying by 100) as shown here: CV=σ/μ. A lower CV value indicates higher consistency and conversely a higher CV suggests greater variability. The study included the analysis of the coefficient of variation (CV) for seven coal samples using 200 μm cable and six using 100 μm cable—measured under the same conditions—and two shale samples—measured under six different conditions. The mean CV and standard deviation for λ_max and red-green quotient under these measurement scenarios are provided here. Everitt, 1998 2025 Spectral peaks - BAM Secondary Validation: A secondary validation analysis was conducted utilizing the BAM-F012 glass reference slide to confirm that measured spectral peaks were within ±5 nm of the certified reference value. Displayed spectra measurements were compared to the expected reference profile provided by Bundesanstalt für Materialforschung und -prüfung (2014). The data provided here summarizes measured and expected λ_max values and normalized intensities for eight major spectral peaks. Bundesanstalt für Materialforschung und prüfung, 2014 2025 Environmental conditions.csv Comma Separated Value (CSV) file containing RGB quotients and λ_max values under different dark current correction and ambient light environmental conditions. Producer Defined Condition Various dark current correction and ambient light environmental conditions Producer Defined Immediately With Light Barrier Immediately with light barrier Producer defined After 10 Minutes With Light Barrier After 10 minutes with light barrier Producer defined Without Light Barrier Without light barrier Producer defined Dark Room With Light Barrier Dark room with light barrier Producer defined Dark Room Without Light Barrier Dark Room Without Light Barrier Producer defined 15 Minutes With Light Barrier 15 Minutes With Light Barrier Producer defined B/G Quotient Blue-green quotient measurement Producer Defined 2.27 2.30 ratio (unitless) 0.01 B/G std Blue-green quotient standard deviation Producer Defined 0.01 0.03 unitless 0.01 R/G Quotient Red-green quotient measurement Producer Defined 3.13 3.19 ratio (unitless) 0.01 R/G std Red-green quotient standard deviation Producer Defined 0.02 0.05 unitless 0.01 λ_max Wavelength of maximum intensity emission Producer Defined 644 647 unitless 1 λ_max std Wavelength of maximum intensity emission standard deviation Producer Defined 0.55 2.35 unitless 0.01 Coefficient of variation.csv Comma Separated Value (CSV) file containing coefficient of variation (CV) and standard deviation of CV for λ_max and RG quotients for different numbers of measurements under various scenarios. Producer Defined Section Coefficient of variation (CV) and standard deviation (std) for λ_max and R/G quotients under various scenarios, categorized into 4 Sections: A, B, C and D Producer Defined A Mean CV and std for λ_max and R/G quotients for 6 coal samples measured under the same conditions using 100 μm fiber optic cables. Producer defined B Mean CV and std for λ_max and R/G quotients for 7 coal samples measured under the same conditions using 200 μm fiber optic cables Producer defined C Mean CV and std for λ_max and R/G quotients for 2 shale samples measured under 6 different conditions Producer defined D Mean CV and std for λ_max and R/G quotients for 2 shale samples measured under 6 different conditions Producer defined Measurements Number of measurements Producer Defined 5 25 count 1 λ_max mean Mean coefficient of variance for the wavelength of maximum intensity emission Producer Defined 0.004 0.093 percent 0.001 λ_max mean std Mean coefficient of variance for the wavelength of maximum intensity emission standard deviation Producer Defined 0.003 0.060 unitless 0.001 R/G mean Mean coefficient of variance for the red-green quotient measurement Producer Defined 0.025 0.292 percent 0.001 R/G std Mean coefficient of variance for the red-green quotient standard deviation Producer Defined 0.011 0.370 unitless 0.001 Spectral peaks.csv Comma Separated Value (CSV) file containing peak wavelength (λ_max) and normalized intensity data for eight major spectral peaks. Producer Defined Expected or Measured Expected and measured average (n=10) peak wavelength (λ_max) and normalized intensity values for eight major spectral peaks. Expected values obtained from a reference profile provided by Certified Reference Material BAM-F012 Glass-based Multi-emitter Fluorescence Standard (Bundesanstalt für Materialforschung und -prüfung, 2014). Producer Defined Expected Data Expected values from a reference profile provided by Bundesanstalt für Materialforschung und -prüfung (2014). Producer defined Measured Data Measured average results (n=10) Producer defined Peak (nm) Peak wavelength of maximum intensity (λ_max) Producer Defined 488 701 nanometers 1 Normalized Intensity (I) Normalized intensity Producer Defined 0.0183 0.2538 percent 0.0001 U.S. Geological Survey - ScienceBase mailing address

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Denver CO 80225 USA 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Digital Data https://doi.org/10.5066/P13KZXXF None 20260316 Jeremy K. Ray U.S. Geological Survey - Northeast Region Data Scientist mailing and physical

12201 Sunrise Valley Drive, Mail Stop 954

Reston VA 20192 USA 703-648-6415 jray@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998