Supporting Information for: "Building the Andean Crust at ~35°S: Arc Geochemistry Resolves Cretaceous Thinning to Rapid Neogene Thickening"

Supporting Information for: "Building the Andean Crust at ~35°S: Arc Geochemistry Resolves Cretaceous Thinning to Rapid Neogene Thickening" This archive contains the supporting datasets for the associated manuscript. Authors: Chance B. Ronemus (1), Caden J. Howlett (1), Peter G. DeCelles (1), Barbara Carrapa (1), Andrés Echaurren (2), Matías Barrionuevo (2), Jesse G. Mosolf (3), Michelle L. Foley (1), and Mihai N. Ducea (1,4) Affiliations: 1. Department of Geosciences, The University of Arizona, Tucson, AZ, USA 2. IANIGLA–CONICET, Mendoza, Argentina 3. Montana Bureau of Mines and Geology, Butte, MT, USA 4. Faculty of Geology and Geophysics, University of Bucharest, Bucharest, Romania Abstract: This study uses zircon trace element and whole-rock geochemistry to reconstruct crustal thickness evolution in the Southern Central Andes (~35°S) from the Late Cretaceous to present. Results document Late Cretaceous crustal thinning followed by rapid Neogene thickening (10.4 ± 6.3 km), with most thickening occurring between ca. 18–6 Ma. The data validate independent structural estimates and provide new constraints on the timing and mechanisms of Andean mountain building. Data Sets: - Data Set S1: Sample locations, geochronology, and stratigraphic assignments - Data Set S2: Zircon U-Pb geochronology and trace element geochemistry (294 analyses) - Data Set S3: New whole-rock major and trace element data (35 samples) - Data Set S4: Combined whole-rock geochemistry and GAME paleomohometry results Analytical Facilities: - Arizona LaserChron Center, University of Arizona (zircon U-Pb and trace elements) - Hamilton Analytical Laboratory, Hamilton College (whole-rock major elements) - Colorado School of Mines (whole-rock trace elements) Funding: NSF EAR-2020935 (TANGO Project) Keywords: Andes, crustal thickness, zircon geochemistry, paleomohometry, arc magmatism, Neogene, Chile, Argentina