Title: Compilation of new and previously published geochemical and modal data for Mesoproterozoic igneous rocks of the St. Francois Mountains, southeast Missouri By Edward A. du Bray, Warren C. Day, and Corey J. Meighan 2018 U.S. Geological Survey Data Series 1080 U.S. Geological Survey data release https://doi.org/10.5066/F79W0DSN ABSTRACT: The purpose of this report is to present recently acquired as well as previously published geochemical and modal petrographic data for igneous rocks in the St. Francois Mountains, southeast Missouri, as part of an ongoing effort to understand the regional geology and ore deposits of the Mesoproterozoic basement rocks of southeast Missouri, USA. The report includes geochemical data that is (1) newly acquired by the U.S. Geological Survey and (2) compiled from numerous sources published during the last fifty-five years. These data are required for ongoing petrogenetic investigations of these rocks. Voluminous Mesoproterozoic igneous rocks in the St. Francois Mountains of southeast Missouri constitute the basement buried beneath Paleozoic sedimentary rock that is over 600 meters thick in places. The Mesoproterozoic rocks of southeast Missouri represent a significant component of approximately 1.4 billion-year-old (Ga) igneous rocks that crop out extensively in North America along the southeast margin of Laurentia and subsequent researchers suggested that iron oxide- copper deposits in the St. Francois Mountains are genetically associated with ca. 1.4 Ga magmatism in this region. The geochemical and modal data sets described herein were compiled to support investigations concerning the tectonic setting and petrologic processes responsible for the associated magmatism DISCLAIMERS: This database, identified as DS 1080, has been approved for release by the U.S. Geological Survey (USGS). Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty, expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientific purposes, nor shall the act of distribution constitute such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, product or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Geological Survey. Although this information product, for the most part, is in the public domain, it also may contain copyrighted material as noted in the text. Permission to reproduce copyrighted items for other than personal use must be secured from the copyright owner. REPORT FILES: The map, pamphlet, and readme files for this report are located at and can be downloaded via the Web from at the U.S. Geological Survey publications website at https://doi.org/10.3133/ds1080 List of files: ds1080_00ReadMe.txt ds1080.pdf ds1080_appendix1_MO15_17_Field_Notes.txt ds1080_appendix1_MO15_17_Field_Notes.xlsx ds1080_appendix2_SE_MO_ChemData.xlsx ds1080_appendix2_SE_MO_ChemData_AlteredMineralized.txt ds1080_appendix2_SE_MO_ChemData_FreshUnaltered.txt HOW TO OBTAIN THE DIGITAL PAMPHLET FILES: The pamphlet can be obtained via the Internet from the U.S. Geological Survey publications website. Go to the web page at https://doi.org/10.3133/ds3382/ and follow the directions to download the files. The pamphlet is a Portable Document Format (.pdf) map, which requires Adobe Acrobat for viewing. The Portable Document Format (PDF) file can be downloaded, from which paper copies may be printed. Acrobat software runs on a variety of systems, and is available for download free of charge from Adobe at http://www.adobe.com. Suggested citation: du Bray, E.A. Day, W.C., and Meighan, C.J., 2018,Compilation of new and previously published geochemical and modal data for Mesoproterozoic igneous rocks of the St. Francois Mountains, southeast Missouri: U.S. Geological Survey Data Series 1080, 10 p., https://doi.org/10.3133/ds1080. DATA RELEASE FILES The digital files constituting the data release files that support this report are also available at https://doi.org/10.5066/F79W0DSN and follow the directions to download the files. List of data release files: DS1080_appendix1_MO15_17_Field_Notes.txt DS1080_appendix1_MO15_17_Field_Notes.xlsx DS1080_appendix2_SE_MO_ChemData.xlsx DS1080_appendix2_SE_MO_ChemData_AlteredMineralized.txt DS1080_appendix2_SE_MO_ChemData_FreshUnaltered.txt Suggested citation: Granitto, Matthew, duBray, E.A., Day, W.C., Meighan, C.J., Slack, J.F, and Ayuso, R.A., 2018, Data release supporting compilation of new and previously published geochemical and modal data for Mesoproterozoic igneous rocks of the St. Francois Mountains, southeast Missouri: U.S. Geological Survey data release, accessed March, 2018 at https://doi.org/10.5066/F79W0DSN Excel Viewer runs on a variety of systems, and is available for download free of charge from Microsoft at https://www.microsoft.com/en-us/download/details.aspx?id=10