Aaron M. Jubb
Palma J. Botterell
Justin E. Birdwell
Robert C. Burruss
Paul C. Hackley
Brett J. Valentine
Javin J. Hatcherian
20181022
High Microscale Variability in Raman Thermal Maturity Estimates from Shale Organic Matter - Data Release
All data not available in tabular form within the primary manuscript have been described here.
Reston, VA
U.S. Geological Survey
https://doi.org/10.5066/P9D5ASO0
Aaron M. Jubb
Palma J. Botterell
Justin E. Birdwell
Robert C. Burruss
Paul C. Hackley
Brett J. Valentine
Javin J. Hatcherian
Stephen A. Wilson
201811
High microscale variability in Raman thermal maturity estimates from shale organic matter
publication
International Journal of Coal Geology
vol. 199
n/a
Elsevier BV
ppg. 1-9
https://doi.org/10.1016/j.coal.2018.09.017
Here the spatial variation in Raman estimates of thermal maturity within individual organic domains from several shale geologic reference materials originating from the Boquillas, Marcellus, Niobrara, and Woodford Formations are assessed from the respective Raman response. We show that for all four shales the thermal maturity parameters extracted from Raman spectra by iterative peak fitting can vary widely across distances of ≤5 µm within the same organic domain.
Data were collected to characterize the heterogeneity of Raman thermal maturity estimates from shale organic matter.
20171003
20180208
20180213
20180618
ground condition
None planned
-77.531
-77.305
38.976
38.853
USGS Thesaurus
microscopy
laboratory methods
petrography
geochemistry
Raman spectroscopy
thermal maturity
vibrational spectroscopy
organic matter
petroleum source rocks
shale
USGS Metadata Identifier
USGS:5b435d1ae4b060350a126cad
Geographic Names Information System
Del Rio, Val Verde County, Texas
Le Roy, Genesse County, New York
CEMEX quarry
Carter County, Oklahoma
Geographic Names Information System
None
USGS Thesaurus
Cretaceous
Devonian
Mississippian
none
none
Aaron M. Jubb
U.S. Geological Survey, Midwest Region
Research Chemist
mailing and physical
Mail Stop 956, 12201 Sunrise Valley Dr
Reston
VA
20192
US
703-648-6481
ajubb@usgs.gov
All Raman spectra were calibrated against the 520.7 cm-1 response of single crystalline silicon.
No formal logical accuracy tests were conducted
Data set is considered complete for the information presented, as described in the abstract. 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
1) Shale samples were supplied by the U.S. Geological Survey Reference Material Project (https://crustal.usgs.gov/geochemical_reference_standards/) as crushed rock fragments. No sample preservation was required.
2) The four GRMs samples were prepared for petrographic analysis according to ASTM method D2797 and all subsequent Raman measurements were collected from individual rock fragments embedded in the petrographic briquettes.
3) All Raman measurements were collected for individual shale ROIs encompassing both organic and mineral grains using a Horiba Xplora Plus Raman microscope system. The Raman microscope was equipped with three excitation lasers with emission wavelengths of 473 nm, 532 nm, and 785 nm. All Raman spectra used for the mapping experiments were collected using the 473 nm laser with perpendicular polarization through a 100 objective (0.9 NA) with 50–500 µW power at the sample surface, 1-10 s acquisition times, and 3 co-averaged scans. Additional Raman spectra from each sample were acquired using the 532 nm and 785 nm lasers with similar settings in order to determine the spectral dispersion of the D1 band exhibited by each shale GRM. The beam diameter at the sample surface for all three lasers was ≤1 µm.
4) Raman spectra were fit with a sum of four Lorentzian peaks between 500-2300 cm-1 with a cubic baseline using the IGOR Pro software suite (Figure 2). No Lorentzian peak or baseline parameters were fixed during the spectral fitting routine. The four Lorentzian peaks used to fit the Raman spectra correspond to the G peak and the D1, D3, and D4 peaks previously reported [Beyssac et al., 2002, 2003; Cheshire et al., 2017; Schito et al., 2017].
5) Iterative fit reports position, amplitude, and full-width-at-half-maximum for each component Lorentzian along with one sigma level of uncertainty for each fit parameter. Fit residuals were calculated by subtracting intensity of fit from spectra intensity at each respective wavenumber.
6) Raman spectra were normalized by dividing spectral intensity at each wavenumber by spectral intensity at 1600 cm-1. This allows for quick visual comparisons of spectral features between spots with varying concentrations of organic matter. Raman band separation was determined for each Raman spectrum by subtracting the D1 peak position from the G peak position. D1/G intensity ratio was determined for each Raman spectrum by dividing the D1 peak intensity by the G peak intensity.
2018
Aaron M. Jubb
U.S. Geological Survey, Midwest Region
Research Chemist
mailing and physical
Mail Stop 956, 12201 Sunrise Valley Dr
Reston
VA
20192
US
703-648-6481
ajubb@usgs.gov
Not applicable
Point
Data for manuscript Figure 2.
The table contains a representative Raman spectrum from the ShNIO sample following normalization to the peak intensity at ~1600 cm-1 with Lorentzian fit, fit residuals, and cubic baseline.
Wavenumber values assigned by Horiba Xplora Plus Raman microscope. Intensity values assigned by Aaron M. Jubb. Baseline, Intensity_Fit, and Fit_Residuals assigned by Igor PRO multipeak fitting algorithm.
Wavenumber (cm-1)
The reciprocal of the wavelength, λ, or the number of waves per unit length along the direction of propagation. The SI unit is m −1, but a commonly used unit is cm −1. Inverse centimeters is used here.
International Union of Pure and Applied Chemistry (IUPAC)
495
2305
inverse centimeters (cm-1)
Intensity (unitless)
A numeric identifier of the intensity of the Raman spectrum divided by the intensity of the spectrum at ~1600 cm-1.
Producer defined
0
1
Not applicable
Baseline (unitless)
A numeric identifier for a cubic polynomial baseline fit to the Raman spectrum.
Producer defined
0
1
Not applicable
Intensity_Fit (unitless)
A numeric identifier of the intensity of the sum of four Lorentzian profiles and the cubic baseline fit to the Raman spectrum.
Producer defined
0
1
Not applicable
Fit_Residuals (unitless)
A numeric identifier of the normalized Raman spectrum intensity minus the intensity of the sum of four Lorentzians and cubic baseline fit to the Raman spectrum at each respective wavenumber.
Producer defined
-1
1
Data for manuscript Figure 3.
Position of the D1 peak center and Raman band separation for representative shale GRM Raman spectra as a function of wavelength.
D1_position and D1_position_err assigned by Igor PRO multipeak fitting algorithm. Raman band separation, Raman band separation error, and wavelength assigned by Aaron M. Jubb.
Shale_GRM
Sample name
Producer defined
A textual description of the sample name abbreviation.
Wavelength (nm)
Distance in the direction of propagation of a periodic wave between two successive points where at a given time the phase is the same. Here given in nanometers (10-9 m)
International Union of Pure and Applied Chemistry
785
Wavelength in nanometers of excitation laser on instrumental apparatus
Producer defined
532
Wavelength in nanometers of excitation laser on instrumental apparatus
Producer-defined
473
Wavelength in nanometers of excitation laser on instrumental apparatus
Producer-defined
D1_position (cm-1)
A numeric identifier for the position of the Lorentzian peak assigned D1 in inverse centimeters.
Producer defined
495
2305
Inverse centimeters (cm-1)
D1_position_err (cm-1)
A numeric identifier for the one sigma level of uncertainty associated with the position of the Lorentzian peak assigned D1 in inverse centimeters.
Producer defined
The one sigma level of uncertainty associated with the the position in inverse centimeters of a Lorentzian profile fit to the data that is automatically generated by the iterative fitting algorithm.
Raman_Band_Separation (cm-1)
Raman band separation in inverse centimeters extracted from Raman spectra of representative organic matter locations for each shale GRM.
Producer defined
-1800
1800
inverse centimeters
Raman_Band_Separation_error (cm-1)
The one sigma precision in the Raman band separation in inverse centimeters extracted from Raman spectra of representative organic matter locations for each shale GRM.
Producer defined
0
1800
inverse centimeters
Data for manuscript Figure 4.
Average Raman spectra from each shale GRM collected across a representative region of interest normalized to peak intensity at ~1600 cm-1.
Wavenumber values assigned by Horiba Xplora Plus Raman microscope. Intensity values assigned by Aaron M. Jubb.
ShBOQ_Wavenumber (cm-1)
The reciprocal of the wavelength, λ, or the number of waves per unit length along the direction of propagation. The SI unit is m −1, but a commonly used unit is cm −1. Inverse centimeters is used here. Corresponding to the ShBOQ sample.
International Union of Pure and Applied Chemistry, Producer defined
495
2305
Inverse centimeters (cm-1)
ShBOQ_Intensity (unitless)
A numeric identifier of the intensity of the average ShBOQ Raman spectrum divided by the intensity of the spectrum at ~1600 cm-1.
Producer defined
0
1
Not applicable
ShNIO_Wavenumber (cm-1)
The reciprocal of the wavelength, λ, or the number of waves per unit length along the direction of propagation. The SI unit is m −1, but a commonly used unit is cm −1. Inverse centimeters is used here. Corresponding to the ShNIO sample.
International Union of Pure and Applied Chemistry, Producer defined
495
2305
Inverse centimeters (cm-1)
ShNIO_Intensity (unitless)
A numeric identifier of the intensity of the average ShNIO Raman spectrum divided by the intensity of the spectrum at ~1600 cm-1.
Producer defined
0
1
Not applicable
ShMAR_Wavenumber (cm-1)
The reciprocal of the wavelength, λ, or the number of waves per unit length along the direction of propagation. The SI unit is m −1, but a commonly used unit is cm −1. Inverse centimeters is used here. Corresponding to the ShMAR sample.
International Union of Pure and Applied Chemistry, Producer defined
495
2305
Inverse centimeters (cm-1)
ShMAR_Intensity (unitless)
A numeric identifier of the intensity of the average ShMAR Raman spectrum divided by the intensity of the spectrum at ~1600 cm-1.
Producer defined
0
1
Not applicable
ShWFD_Wavenumber (cm-1)
The reciprocal of the wavelength, λ, or the number of waves per unit length along the direction of propagation. The SI unit is m −1, but a commonly used unit is cm −1. Inverse centimeters is used here. Corresponding to the ShWFD sample.
International Union of Pure and Applied Chemistry, Producer defined
495
2305
Inverse centimeters (cm-1)
ShWFD_Intensity (unitless)
A numeric identifier of the intensity of the average ShWFD Raman spectrum divided by the intensity of the spectrum at ~1600 cm-1.
Producer defined
0
1
Not applicable
Data for manuscript Figure 6.
Raman band separation (RBS) verus D1/G intensity ratio for each Raman spectrum collected across a representative region of interest for each shale GRM.
Raman band separation (RBS) and D1/G ratio values assigned by Aaron M. Jubb.
ShBOQ_RBS (cm-1)
Raman band separation in inverse centimeters extracted from Raman spectra of the ShBOQ sample.
Producer defined
-1800
1800
Inverse centimeters (cm-1)
ShBOQ_D1/G (unitless)
Intensity ratio of the D1 over the G Lorentzian peaks from iterative fitting of ShBOQ Raman spectra.
Producer defined
0
10
Not applicable
ShNIO_RBS (cm-1)
Raman band separation in inverse centimeters extracted from Raman spectra of the ShNIO sample.
Producer defined
-1800
1800
Inverse centimeters (cm-1)
ShNIO_D1/G (unitless)
Intensity ratio of the D1 over the G Lorentzian peaks from iterative fitting of ShNIO Raman spectra.
Producer defined
0
10
Not Applicable
ShMAR_RBS (cm-1)
Raman band separation in inverse centimeters extracted from Raman spectra of the ShMAR sample.
Producer defined
-1800
1800
Inverse centimeters (cm-1)
ShMAR_D1/G (unitless)
Intensity ratio of the D1 over the G Lorentzian peaks from iterative fitting of ShMAR Raman spectra.
Producer defined
0
10
Not Applicable
ShWFD_RBS (cm-1)
Raman band separation in inverse centimeters extracted from Raman spectra of the ShMAR sample.
Producer defined
-1800
1800
Inverse centimeters (cm-1)
ShWFD_D1/G (unitless)
Intensity ratio of the D1 over the G Lorentzian peaks from iterative fitting of ShWFD Raman spectra.
Producer defined
0
10
Not applicable
ScienceBase
U.S. Geological Survey
mailing and physical
Denver Federal Center, Building 810, Mail Stop 302
Denver
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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.
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.
20200819
Eric A. Morrissey
U.S. Geological Survey
IT Specialist (Internet)
mailing and physical
Mail Stop 956, 12201 Sunrise Valley Dr
Reston
VA
20192
US
703-648-6409
emorriss@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998