Synthesis of geological, structural, and geochronologic data (phase V, deliverable 53)

Abstract

This report is a companion to the new Geologic Map of Mauritania (Bradley and others, 2015; referred to herein as “Deliverable 51”) and the new Structural Geologic Map of Mauritania (Bradley and others, 2015a; referred to herein as “Deliverable 52”). Section 1 contains explanatory information for these two digital maps. Section 2 covers the analytical methods used in obtaining new U-Pb ages from 9 igneous rock samples, new detrital zircon ages from 40 sedimentary or metasedimentary rock samples, and new 40 Ar/ 39 Ar ages from 12 samples of metamorphic rocks and veins. Sections 3 through 6 present the new geochronological results, organized by region. In Section 7, we discuss implications of the new ages for the regional geology and discuss problematic results. Finally, in Section 8, we summarize the geology and tectonic evolution of Mauritania in narrative form, drawing on new and published information, in the context of global tectonics. The report is being released in both English and French. In both versions, we use the French-language names for formal stratigraphic units.