Work Description

Date: 2 April, 2025

Dataset Title: Early Eocene Green River Basin Microbialites: Morphological and Geochemical Data

Dataset Contact: Nathan Sheldon [email protected]

Dataset Creators:
Name: Cecilia M. Howard
Email: [email protected]
Institution: University of Michigan Department of Earth and Environmental Sciences
ORCID: https://orcid.org/0000-0001-7293-162X

Name: Nathan D. Sheldon
Email: [email protected]
Institution: University of Michigan Department of Earth and Environmental Sciences
ORCID: https://orcid.org/0000-0003-3371-0036

Name: Zachary Loveall
Email: [email protected]
Institution: University of Michigan Department of Earth and Environmental Sciences

Name: Katarina A. Keating
Email: [email protected]
Institution: University of Michigan Department of Earth and Environmental Sciences
ORCID: https://orcid.org/0000-0002-4363-2927

Name: Jungpyo Hong
Email: [email protected]
Institution: University of Michigan Department of Earth and Environmental Sciences

Name: Selena Y. Smith
Email: [email protected]
Institution: University of Michigan Department of Earth and Environmental Sciences
ORCID: https://orcid.org/0000-0002-5923-0404

Name: Benjamin H. Passey
Email: [email protected]
Institution: University of Michigan Department of Earth and Environmental Sciences
ORCID: https://orcid.org/0000-0002-3483-4148

Funding: Award #1812949 (NSF); University of Michigan (Department of Earth and Environmental Sciences Turner Award); Geological Society of America (Graduate Research Grant)

Key Points:
- The Green River Basin, WY, USA preserves lacustrine microbialites deposited during the Early Eocene Climatic Optimum, a period of high CO2 and temperatures
- Morphological and geochemical analyses of these microbialites preserve variable local, regional, and global environmental conditions
- Measurements of environmental conditions can be inverted to understand ancient microbial processes, which could be used to inform modeling of microbial influences on carbon cycling

Research Overview:
This study uses an array of stratigraphic, morphological, and geochemical tools to investigate lateral and temporal variability in environmental records preserved by microbialites during a global hothouse environment. It also inverts tools for reconstructing environmental conditions to elucidate ancient microbial processes.
Abstract: The Green River Basin, WY, USA, contains extensive lacustrine microbialite beds that formed during the hothouse Early Eocene Climatic Optimum (53–49 Ma). The records of biological, chemical, and physical processes preserved in these microbialites can inform our understanding of terrestrial conditions in this warm climate, but separating the competing signals of local, regional and global changes is difficult. Studies focusing on individual localities may miss spatial drivers of differences in microbialites. In this study, we used stratigraphic, morphological, and geochemical techniques to study microbialites deposited in the Green River Basin across three million years spanning the peak of the EECO, including samples from two beds covering 13–25 km of lateral extent. These samples cover a broad set of lake conditions as well as local differences such as spring deposits. We found that these microbialites preserved a mixture of conditions such as global hothouse temperatures, regional shifts in lake level, and local variability from sediment and water sources. Morphological and elemental variability were driven primarily by local and regional conditions such as stream, spring, and clastic inputs and water depth. Isotopic data preserved these local and regional changes as well as evidence of global hothouse conditions. Comparison of past [CO2] estimates to reconstructions using organic and inorganic carbon isotopes with clumped isotope-derived temperatures provides evidence for low to moderate microbial growth rates in these microbialite building communities, demonstrating that environmental tools can be inverted to better understand ancient microbial processes. A diverse toolkit was necessary to isolate the individual controls on microbialite records, and comparing across both space and time enabled us to identify local drivers that lead to significant differences from the expected regional signal.

Geographic Location:
Green River Basin, WY, USA

Field Sites and Stratigraphic Locations:
Site (abb.): Site name (full): Longitude: Latitude: Age (Ma): StratUnit (Abbs.) Stratigraphy:
BTS Boar's Tusk (Scheggs Bed site) 109.2534430°W 41.9528400°N 52.280 GRFTS Scheggs Bed, Tipton Shale Member, Green River Formation
BTR Boar's Tusk (Rife Bed site) 109.2503630°W 41.9965840°N 51.30±0.30 GRFTR Rife Bed, Tipton Shale Member, Green River Formation
YR Yellowstone Road 109.3058030°W 41.7365300°N 51.30±0.30 GRFTR Rife Bed, Tipton Shale Member, Green River Formation
HS,HS3 Homestead (site 3) 108.9893900°W 42.1214400°N 51.30±0.30 GRFTR Rife Bed, Tipton Shale Member, Green River Formation
HS4 Homestead (site 4) 108.98077°W 42.14399°N 51.30±0.30 GRFTR Rife Bed, Tipton Shale Member, Green River Formation
HS5 Homestead (site 5) 108.9641490°W 42.1314440°N <51.30±0.30 WCB,GRFL,GRF Cathedral Bluffs Tongue, Wasatch Formation; Laney Member, Green River Formation
LB La Barge 110.1596020°W 42.2749840°N 49.925±0.060 GRFWP Wilkins Peak Member, Green River Formation
LBN1/LB La Barge North (site 1) 110.2743270°W 42.3674550°N 49.925±0.060 GRFWP Wilkins Peak Member, Green River Formation
LBN2/LB La Barge North (site 2) 110.2397860°W 42.3761470°N 49.925±0.060 GRFWP Wilkins Peak Member, Green River Formation

Age References:
Scheggs Bed - 52.280 Ma (Alan Carroll; pers. comm.)
Rife Bed - 51.30±0.30 Ma - Smith, M.E., et al. (2008) GSA Bulletin.
Wilkins Peak Mbr. (Layered Tuff) - 49.925±0.060 Ma - Bruck, B.T. et al. (2023) GSA Bulletin.

Data Type List:
- Morphological Character Data
- XRD Data (processed calcite and dolomite peaks, raw data)
- Electron Microprobe (WDS) Data
- Organic Carbon and Nitrogen Data
- Clumped Isotope Data (raw and processed)

Methodology:
Sample Collection and Processing: Microbialite samples were collected in the field with associated stratigraphic measurements during two field seasons in 2023 and 2024. Samples were cut with a water-cooled rock saw to expose inner faces. Some samples were subsequently polished with a lapidary polishing wheel for clearer visualization of the internal structure. Samples for XRD (n = 28) and isotopic analysis (n[clumped] = 14; n[org] = 14) were drilled from exposed faces to enable targeted sampling of features of interest and avoid modern contamination on the exteriors of the sample. Drilling was done at low speeds to prevent bond reordering that might alter the clumped isotope results. One to six layers from individual microbialites were drilled to capture internal changes. Representative samples were sent to Spectrum Petrographics for microprobe polished thin sections.

Morphological Characterization: 26 samples from 8 sites were μCT scanned in the University of Michigan CT in Earth and Environmental Science (CTEES) Facility using a Nikon XT H 225 ST industrial μCT scanner with a Perkin Elmer 1620 X-ray detector panel and a tungsten reflection target. Scans were acquired with the program Inspect-X (Nikon Corporation, Tokyo, Japan) and reconstructed with CT Pro 3D (Nikon Metrology, USA), which uses a Feldkamp-Davis-Kress (FDK) type algorithm. Scans were analyzed using the program Dragonfly, versions 2022.2 and 2024.1 for Windows (Object Research Systems, Inc., Montréal, Canada; academic license). Additionally, 15 samples from 7 sites (representing 5 beds) were used for thin sections, which were analyzed on a Leica DM EP petrographic microscope with a Leica DFC290 camera attachment. Sample macro- and mesostructure were described following a modified version of the framework of descriptive terms in Grey and Awramik (2020), which is described in detail in Appendix C of Howard (2025), while microstructure was identified in thin sections using their terminology. Hand samples, μCT scans, and thin sections were used to characterize morphology; a total of 60 samples were described for macro- and mesostructure. μCT scans are deposited in the database MorphoSource under the Project ID 000714632.

Mineral and Elemental Characterization: 28 samples from seven microbialites were drilled for XRD analysis. Powdered samples were analyzed at the University of Michigan Electron Microbeam Analysis Lab on a Rigaku Ultima IV diffractometer using Cu Kα radiation at 40 kV and 44 mA intensity, with scan steps of 0.05 degree step-1 and 1.0 degree min-1. Initial data analysis was done using the program QualX 2.0 (Altomare et al., 2015). The background was estimated using the default settings (a Chebyshev polynomial function) and subtracted from the pattern. The Peak Search function in QualX2.0 was used to identify likely phases. Phase data for all samples except HS12 (which was identified as primarily quartz) were then exported as .dat files with the background removed and loaded into R for additional analysis of calcite and dolomite (R Core Team, 2023). Percent calcite and percent dolomite were determined using the area under the dominant calcite peaks (between 29.30° and 30.00° 2θ) and dominant dolomite peaks (between 30.40° and 31.10° 2θ), as described by Doebbert et al. (2010). Percent calcite and percent dolomite were calculated using Eq. 1 of Doebbert et al. (2010). Eight sample thin sections were selected for wavelength-dispersive X-ray spectrometry (WDS) at the University of Michigan Electron Microbeam Analysis Lab. Samples were analyzed at 100 points along selected transects on a Cameca SX100 Electron Probe Microanalyzer using a PAP intensity correction at 15 kV and 10 nA, with a beam size of 5 μm. Transects were chosen to span multiple visible features (e.g., branching and laminated layers, color changes). The elements measured were SiO2, Al2O3, FeO, CoO, NiO, Cu2O, MnO, MgO, CaO, SrO, and Na2O. For non-silicified samples, points with totals below 98.5% or above 101.5% were excluded from further analyses. For silicified samples, points with totals below 90% or above 101.5% were excluded due to much higher variability in totals, which is assumed to be due to hydration during the chert formation process.

Clumped Isotope Analysis: Fourteen samples from five microbialites were used for clumped isotope analysis (four each for HS, LB, and YR, and one each for BTR and BTS). Samples were treated overnight with 3 wt% NaOCl to remove organic carbon and nitrates (Fiebig et al., 2024), then triple rinsed with DI water and dried at 30°C for several days. Samples were analyzed in the University of Michigan Isotopologue Paleosciences Lab on a Nu Perspectives isotope ratio mass spectrometer following the method described in Passey et al. (2010). Each sample was run in triplicate; 8–10 mg of sample was used for each run. Measurements included δ13Ccarb, δ18Ocarb, Δ47, and Δ48, and were calibrated using gas (heated and room temperature) as well as carbonate (ETH1–4; Bernasconi et al., 2021) standards. Calibration data included sample measurements for unrelated projects during the same analytical session as well as standards run with those analyses. Corrections were made based on sample mineralogy (calcite or dolomite) as determined by XRD; samples with mixed mineralogies (40–60% calcite) were corrected as calcite. Measured data were projected to absolute values using the combined gas and carbonate standard residuals (Δ47,ICDES+). Temperature was calculated from Δ47 using Equation 1 of Petersen et al. (2019) adjusted for a 90°C acid digestion temperature.

Organic Carbon and Nitrogen Isotope Analysis: Fourteen samples from six microbialites were analyzed for organic carbon and nitrogen isotopes. Powdered samples were acidified three times using 5% HCl to remove carbonate, then rinsed three times with DI water to remove acid and dried in a 50°C oven. 0.2–7 mg of material was weighed into tin capsules; if there was insufficient material, samples drilled from the same stromatolite were combined. Samples were analyzed at the University of Michigan in the Microbial Biogeochemistry Lab on a Thermo Fisher Flash EA interfaced with a Conflo IV Delta V Plus IRMS. Samples were calibrated to lab and USGS (USGS-40 and 41) standards.

Instrument and/or Software Specifications:
microCT Scanning: Nikon XT H 225 ST industrial μCT scanner with a Perkin Elmer 1620 X-ray detector panel and a tungsten reflection target
microCT Acquisition and Reconstruction: Inspect-X (Nikon Corporation, Tokyo, Japan); CT Pro 3D (Nikon Metrology, USA)
microCT Analysis: Dragonfly versions 2022.2 and 2024.1 for Windows (Object Research Systems, Inc., Montréal, Canada; free academic license)
XRD Analysis: Rigaku Ultima IV diffractometer using Cu Kα radiation at 40 kV and 44 mA intensity, with scan steps of 0.05 degree step-1 and 1.0 degree min-1
Wavelength-dispersive X-ray Spectrometry: Cameca SX100 Electron Probe Microanalyzer using a PAP intensity correction at 15 kV and 10 nA, with a beam size of 5 μm
Clumped Isotope Analysis: Nu Perspectives isotope ratio mass spectrometer calibrated to ETH and gas standards, with data processing done in MATLAB and R
Organic Carbon and Nitrogen Isotope Measurements: Thermo Fisher Flash EA interfaced with a Conflo IV Delta V Plus IRMS calibrated to lab and USGS (USGS-40 and 41) standards

Analytical Facility Acknowledgements:
This study includes data produced in the CTEES facility, the Robert B. Mitchell Electron Microbeam Analysis Lab, the Isotopologue Paleosciences Lab, and the Microbial Biogeochemistry Lab at University of Michigan, supported by the Department of Earth and Environmental Sciences and College of Literature, Science, and the Arts. Zhongrui Li and Owen Neill conducted XRD and electron microprobe measurements, and Thea Bartlett conducted organic carbon isotope measurements.

Citations:
Altomare, A., Corriero, N., Cuocci, C., Falcicchio, A., Moliterni, A., and Rizzi, R., 2015, QUALX2.0: a qualitative phase analysis software using the freely available database POW_COD: Journal of Applied Crystallography, v. 48, p. 598–603, doi:10.1107/S1600576715002319.
Bernasconi, S.M. et al., 2021, InterCarb: A Community Effort to Improve Interlaboratory Standardization of the Carbonate Clumped Isotope Thermometer Using Carbonate Standards: Geochemistry, Geophysics, Geosystems, v. 22, p. e2020GC009588, doi:10.1029/2020GC009588.
Bruck, B.T., Singer, B.S., Schmitz, M.D., Carroll, A.R., Meyers, S., Walters, A.P., and Jicha, B.R., 2023, Astronomical and tectonic influences on climate and deposition revealed through radioisotopic geochronology and Bayesian age-depth modeling of the early Eocene Green River Formation, Wyoming, USA: GSA Bulletin, doi:10.1130/B36584.1.
Doebbert, A.C., Carroll, A.R., Mulch, A., Chetel, L.M., and Chamberlain, C.P., 2010, Geomorphic controls on lacustrine isotopic compositions: Evidence from the Laney Member, Green River Formation, Wyoming: GSA Bulletin, v. 122, p. 236–252, doi:10.1130/B26522.1.
Fiebig, J. et al., 2024, Carbonate clumped isotope values compromised by nitrate-derived NO2 interferent: Chemical Geology, v. 670, p. 122382, doi:10.1016/j.chemgeo.2024.122382.
Grey, K., and Awramik, S.M., 2020, Handbook for the study and description of microbialites: Geological Survey of Western Australia, Bulletin 147, 278 p., https://www.dmp.wa.gov.au/Geological-Survey/Handbook-for-the-study-and-26950.aspx (accessed October 2023).
Passey, B.H., Levin, N.E., Cerling, T.E., Brown, F.H., and Eiler, J.M., 2010, High-temperature environments of human evolution in East Africa based on bond ordering in paleosol carbonates: Proceedings of the National Academy of Sciences, v. 107, p. 11245–11249, doi:10.1073/pnas.1001824107.
Petersen, S.V. et al., 2019, Effects of Improved 17O Correction on Interlaboratory Agreement in Clumped Isotope Calibrations, Estimates of Mineral-Specific Offsets, and Temperature Dependence of Acid Digestion Fractionation: Geochemistry, Geophysics, Geosystems, v. 20, p. 3495–3519, doi:10.1029/2018GC008127.
Smith, M.E., Carroll, A.R., and Singer, B.S., 2008, Synoptic reconstruction of a major ancient lake system: Eocene Green River Formation, western United States: GSA Bulletin, v. 120, p. 54–84, doi:10.1130/B26073.1.

Files contained here:

Dataset filename: GRB_Microbialite_MorphologicalCharacters.xlsx
Dataset description: Spreadsheet of macroscale and mesoscale morphological characterization of Green River Basin microbialites. An explanatory key for using this dataset is included as a second tab within the spreadsheet. The morphological descriptive categories are described in Appendix C of the associated publication Howard (2025). NA in a feature column indicates that a feature was not present; in the notes and analyses columns, NA indicates that there are no additional notes or analyses associated with a sample.

Dataset filename: GRB_Microbialites_XRD_Data.zip
Dataset description: Zip folder of unprocessed X-ray Diffraction (XRD) data from 28 samples collected from seven microbialites. The contents of the zip folder are 28 .xy files, for which the two columns are 2θ (angle in degrees) and Intensity. More detailed sample information is available in the associated publication Howard (2025). The .xy file extension can be opened using notepad or similar apps. The list of samples and their source microbialites are as follows:
Sample file: Source microbialite:
BTR9-1.xy GRB24-BTR-9
BTS10-1.xy GRB24-BTS-10
HS12_A.xy GRB23-HS-12
HS12_B.xy GRB23-HS-12
HS12_C.xy GRB23-HS-12
HS12_D.xy GRB23-HS-12
HS12_E.xy GRB23-HS-12
HS19_A.xy GRB23-HS-19
HS19_B.xy GRB23-HS-19
HS19_C.xy GRB23-HS-19
HS19_D.xy GRB23-HS-19
HS19_E.xy GRB23-HS-19
LB1_A.xy GRB23-LB-1
LB1_B.xy GRB23-LB-1
LB1_C.xy GRB23-LB-1
LB1_D.xy GRB23-LB-1
LB1_E.xy GRB23-LB-1
LB1_F.xy GRB23-LB-1
LB3_A.xy GRB23-LB-3
LB3_B.xy GRB23-LB-3
LB3_C.xy GRB23-LB-3
LB3_D.xy GRB23-LB-3
YR11_A.xy GRB23-YR-11
YR11_B.xy GRB23-YR-11
YR11_C.xy GRB23-YR-11
YR11_D.xy GRB23-YR-11
YR11_E.xy GRB23-YR-11

Dataset filename: GRB_Microbialite_XRD_Processed.csv
Dataset description: Spreadsheet of processed calcite and dolomite peaks for Green River Basin microbialites. More detailed sample information is available in the associated publication Howard (2025).
Column name: Units: Description:
Site none Sampling site (YR, BTR, BTS, HS, LB; see Field Sites and Stratigraphic Information for details)
Stromatolite none The individual stromatolite from which the sample originated
Sample none The subsample from the particular stromatolite. Alphanumeric for samples that had related isotopic data to enable crossreferencing between the isotopic sample and the XRD sample.
sample.name none Full sample name (Stromatolite column concatenated with the Sample column with an underscore)
calcitearea intensity^2 Area under the primary calcite peak
dolomitearea intensity^2 Area under the primary dolomite peak
calcitepercent % Percent of the sample composed of calcite
dolomitepercent % Percent of the sample composed of dolomite

Dataset filename: GRB_Microbialite_MicroprobeData.xlsx
Dataset description: Spreadsheet, three tabs. Includes cleaned microprobe data for all samples in the first tab (593 rows), summary data grouped by morphological zones within the samples in the second tab (zones are listed in the first tab as well), and analytical conditions in the third tab. More detailed sample information is available in the associated publication Howard (2025).

Sheet 1: AllData - the full cleaned dataset. Measurements of 0 wt% were below the detection limit for the instrument.
Column name: Units: Description:
SampleName none Sample name
Sample none Abbreviated sample name
Site none Sampling site (YR, BTR, BTS, HS, LB; see Field Sites and Stratigraphic Information for details)
SampleNumber none Analytical sample number
PointCount none Tally of sample points for analytical purposes
LineNumber none Count of sample points within individual samples. Analytical.
Zone none Assigned morphological zonations within samples, used for analysis and averaging (Z1-4 for each sample)
TransectDistance µm Distance along the sampling transect
SiO2 wt% Measured silica
Al2O3 wt% Measured aluminum
FeO wt% Measured iron
CoO wt% Measured cobalt
NiO wt% Measured nickel
Cu2O wt% Measured copper
MnO wt% Measured manganese
MgO wt% Measured magnesium
CaO wt% Measured calcium
SrO wt% Measured strontium
Na2O wt% Measured sodium
CO2 wt% Calculated analytical CO2; calculated as 1 atom of C per 3 atoms of O, and included in matrix correction iterations for samples with <10wt% SiO2
Total wt% Total measured elements

Sheet 2: ZoneSummary - the averages across sample zones, as well as notes on morphology and silicification
Sheet 3: Analytical_Conditions - Analytical information, including calibration standards for each element.

Dataset filename: GRB_Microbialite_EA-IRMS_Corg.csv
Dataset description: Spreadsheet with organic carbon and nitrogen isotope data for Green River Basin microbialites. Measurements of 0 were below the detection limit.
Column name: Units: Description:
Sample none Sample name
Site none Sampling site (HS, YR, LB, BTR, BTS; see Field Sites and Stratigraphic Information for details)
weight_ug µg Analyzed sample weight
d13Corg_permil ‰ Measured δ13Corg
d15N_permil ‰ Measured δ15N
Nmg mg Measured weight of N
Cmg mg Measured weight of C
N% % Measured percent N
Corg% % Measured percent Corg
Corg/N unitless Ratio of Corg to N. NA is used when N was below the detection limit.

Dataset filename: GRB_Microbialite_ClumpedIsotopeData_Raw.csv
Dataset description: Spreadsheet of raw clumped isotope data, including standards and anonymized other samples used for calibration within the same session.
Column name: Units: Description:
Sample none Sample name
Type1 none Sample or standard type (Sample, Equilibrated Gas, Heated Gas, Standard (carbonate))
Type2 none Secondary sample or standard type. Standard types: Enriched/Depleted gas, carbonate standard name (ETH1-4, 102-GC-AZ01). Sample types: Sample (other users, anonymized), GRB Strom (this study)
Mineralogy none Mineralogy used for corrections (calcite or dolomite). Gases are assigned to calcite, which was ignored in the processing
sam44current A Current during sample analysis
ref44current A Current during reference gas analysis
d13C.PDB ‰ δ13Ccarb relative to the VPDB standard
d13C.err ‰ δ13Ccarb error
d18O.rawPDB ‰ δ18Ocarb relative to the VPDB standard
d18O.err ‰ δ18Ocarb error
d18O.rawSMOW ‰ δ18Ocarb relative to the SMOW standard
d45 ‰ δ45 (raw)
d45.err ‰ δ45 error
d46 ‰ δ46 (raw)
d46.err ‰ δ46 error
d47 ‰ δ47 (raw)
d47.err ‰ δ47 error
d48 ‰ δ48 (raw)
d48.err ‰ δ48 error
d49 ‰ δ49 (raw)
d49.err ‰ δ49 error
D47 ‰ Δ47 (raw)
D47.err ‰ Δ47 error
D48 ‰ Δ48 (raw)
D48.err ‰ Δ48 error
D49 ‰ Δ49 (raw)
D49.err ‰ Δ49 error

Dataset filename: GRB_Microbialite_ClumpedIsotopeData_Processed.csv
Dataset description: Spreadsheet of processed clumped isotope data, including standards and anonymized other samples used for calibration within the same session.
Column name: Units: Description:
Sample none Sample name
Type1 none Sample or standard type (Sample, Equilibrated Gas, Heated Gas, Standard (carbonate))
Type2 none Secondary sample or standard type. Standard types: Enriched/Depleted gas, carbonate standard name (ETH1-4, 102-GC-AZ01). Sample types: Sample (other users, anonymized), GRB Strom (this study)
d13Cpdb ‰ δ13Ccarb relative to the VPDB standard
d18Opdb ‰ δ18Ocarb relative to the VPDB standard
D47iCDESp ‰ Δ47 relative to the ICDES+ projection (using combined gas and carbonate standards)
D47iCDESp_cc ‰ Δ47 relative to the ICDES+ projection (using combined gas and carbonate standards) with an additional correction using carbonate and gas residuals from accepted values
D48iCDESp ‰ Δ48 relative to the ICDES+ projection (using combined gas and carbonate standards)
TiCDESp_cc °C Temperature calculated from Δ47ICDES+_cc using Petersen et al. (2019) Eq. 1 adjusted for 90°C acid digestion temperature
TiCDESp °C Temperature calculated from Δ47ICDES+ using Petersen et al. (2019) Eq. 1 adjusted for 90°C acid digestion temperature
d18Osmow ‰ δ18Ocarb relative to the SMOW standard, calculated from δ18Opdb

Related publication(s):
Howard, C.M. (2025). Unraveling Records of Time and Environment in Microbial Ecosystems from the Archean to Today (Ph.D. Dissertation). University of Michigan.
Howard, C.M., et al. (in prep). Disentangling Morphological and Chemical Records of Climate, Hydrology, and Diagenesis in Microbialites from the Eocene Green River Basin, WY, USA.

Use and Access:
This data set is made available under a Creative Commons Attribution 4.0 International license (CC BY 4.0).

To Cite Data:
Howard, C.M., Sheldon, N.D., Loveall, Z., Keating, K.A., Hong, J., Smith, S.Y., and Passey, B.H. (2025). Early Eocene Green River Basin Microbialite Morphological and Geochemical Data [Data set]. University of Michigan - Deep Blue Data. DOI: https://doi.org/10.7302/mtgm-xb86