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Characterizing Meteor Crater Impact Melts Through Geochemistry and Textural Analysis

Open-File Report 2024-1062
By: , , and 
https://doi.org/10.3133/ofr20241062

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Abstract

The U.S. Geological Survey Astrogeology Science Center houses the Meteor Crater sample collection, an assemblage of over 2,500 meters of cuttings from 161 drill holes into Meteor Crater’s rim, flanks, and ejecta blanket. We have utilized this unique collection to study the composition and spatial distribution of impact-generated materials from within the ejecta blanket. Meteor Crater has historically been known to have generated only a relatively small amount of impact melt compared to other terrestrial craters of similar size. A detailed compositional and textural dataset of impact-derived melts from this impact can therefore be a useful asset in improving our understanding of crater formation, and in particular impact melt formation.

We have characterized 42 impact-melt particles from Meteor Crater using a scanning electron microscope and an electron microprobe for textural and compositional analysis. We analyzed samples from six drill holes in the ejecta blanket, situated to the northwest, southeast, south, and southwest of the crater (ejecta northeast of the crater is devoid of impact melts). Impact melts were collected from drill cuttings at various depths within the ejecta blanket, ranging from a few centimeters below the surface down to ~6.5 meters.

Backscattered electron (BSE) images were acquired for each analyzed impact-melt particle. To characterize the various textures and phases present in each impact melt, we also took many detailed BSE images. Our geochemical analyses include full spectral profiles using energy dispersive X-ray spectrometry and well-calibrated wavelength dispersive spectrometry for a number of phases, including minerals (olivine, pyroxene, and so on), pristine glass, and metallic inclusions. The full dataset is available in ScienceBase as a data release (Gullikson and others, 2024), accessible at https://doi.org/10.5066/P9OGAJ8P.

Our goal for this Open-File Report is to provide a summary of this immense dataset, details on data collection, descriptions of the different phases observed within impact-melt particles (both geochemically and texturally), and observable trends.

Suggested Citation

Gullikson, A.L., Gaither, T.A., and Hagerty, J.J., 2024, Characterizing Meteor Crater impact melts through geochemistry and textural analysis: U.S. Geological Survey Open-File Report 2024–1062, 23 p., https://doi.org/10.3133/ofr20241062.

ISSN: 2331-1258 (online)

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Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Geologic Setting of Meteor Crater
  • Purpose and Scope
  • Methods 
  • Results
  • Discussion and Summary
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Characterizing Meteor Crater impact melts through geochemistry and textural analysis
Series title Open-File Report
Series number 2024-1062
DOI 10.3133/ofr20241062
Publication Date April 14, 2025
Year Published 2025
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Astrogeology Science Center
Description Report: vii, 23 p.; Data Release
Country United States
State Arizona
Other Geospatial Meteor Crater
Online Only (Y/N) Y
Additional publication details