Cover Image Credits

The article by Jimenez-Rodriquez and others titled “Paleoaltimetry of the western Andes in northern Chile (~18.5–19.5 °$)” (p. 491–533) provides new stable isotope and geochronological data to reconstruct the uplift history of the Western Cordillera in northern Chile and to evaluate the relationship between Andean uplift and the development of extreme dry conditions in the Atacama Desert. The isotopic results indicate that this region reached modern elevations at least since 22.8 Ma. When combined with other paleoaltimetry estimates from surrounding areas, the results presented here indicate that uplift of the Andean plateau was a diachronous process that varied not just from west to east but also from north to south. Moreover, the nonuniform uplift of the Andean Plateau seems that had played a primary role in the gradual development of hyperaridity in the Atacama Desert since the late Oligocene.

Explanation of cover figure: This figure shows the relationship between Andean uplift and the stepwise increase of hyperaridity in the Atacama Desert. The paleoaltimetry reconstruction across the Central Andean Plateau at ~17 to 19 °S seems to be consistent with the progressive development of dry conditions in the Atacama Desert since the late Oligocene-early Miocene. The δ¹⁸O values of soil carbonates from the Atacama Desert are from Rech and others (2019).