Abstract

Of the anomalous (J-type) leads analyzed, those from the Upper Mississippi Valley are most radiogenic, and show greatest variation; a lead from southeast Missouri is intermediate, and leads from the Illinois-Kentucky district are least radiogenic. Four galenas closely associated with igneous intrusions are also J-type. The radiogenic component shows a progressive increase toward the northeast in the Upper Mississippi Valley district, and toward the southeast in the Illinois-Kentucky district; whether this implies variable ratios from a single source or mixing of leads from multiple sources is unresolved. Samples from the Appalachian Valley districts and galena, presumably diagenetic, from shale and clay, have ordinary lead.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.