TRACING PROTEROZOIC BASIN EVOLUTION ACROSS ARIZONA UTILIZING MULTIDIMENSIONAL SCALING TO EVALUATE RELATIVE PROVENANCE PATTERNS

Multiple unconformity-bound packages of metasedimentary rocks in central Arizona are key markers for models of Proterozoic crustal growth by accretionary orogenesis, but scattered exposures and limited geochronologic constraints have hindered regional correlations. Detrital zircon geochronologic data from these basin successions across a NW-SE transect of Arizona were compared using multi-dimensional scaling (MDS) to evaluate provenance patterns in space and time. Statistical comparisons elucidate common provenance within individual basins and aid in regional correlation of localized outcrops. The results also provide key insight into the evolution of and interactions between basins. The Vishnu Schist of the Grand Canyon region has bimodal detrital zircon age spectra with a distinct neo-Archean age population whereas most other successions to the south have unimodal age spectra with varying peak width and complexity. In MDS space, the main grouping reflects a series of basinal successions that include the Paleoproterozoic Granite Gorge Metamorphic Suite, Yavapai Supergroup, and Tonto Basin Supergroup depo-systems. The geographically juxtaposed systems of Grand Canyon and Jerome areas plot the farthest apart. The Alder and Mazatzal Group systems plot stepwise back towards the Vishnu system. We propose this stepwise transition from the Jerome to the Vishnu represents initially isolated basins that subsequently coalesced, broadening the source region(s) as basin boundaries began to overlap. The Pinal system, similar in age to Tonto Basin Supergroup rocks, represents a discrete grouping in MDS space. The Mesoproterozoic Yankee Joe system represents a major diversion from earlier basins with the presence abundant ca. 1.6 to 1.5 Ga zircon ages interpreted to represent non-Laurentian sources. The Apache system represents the next major depositional system following ca. 1.47-1.38 Ga regional tectonism. Overall, statistical comparisons provide a robust record of variable reworking of juvenile and older crust in older basins into younger successions as the lithosphere stabilized. Our results allow for comparative analyses of similar and perhaps correlative basin systems in New Mexico, Colorado, and California that also evolved along strike of the paleo-Laurentian margin.