Cosmogenic in situ 14C-10Be reveals abrupt Late Holocene soil loss in the Andean Altiplano
Kristina Hippe, John D. Jansen, Daniel Skov, Maarten Lupker, Susan Ivy‐Ochs, Florian Kober, Gerold Zeilinger, José M. Capriles, Marcus Christl, C. Maden, Christof Vockenhuber, David Lundbek Egholm
Abstract
Abstract Soil sustainability is reflected in a long-term balance between soil production and erosion for a given climate and geology. Here we evaluate soil sustainability in the Andean Altiplano where accelerated erosion has been linked to wetter climate from 4.5 ka and the rise of Neolithic agropastoralism in the millennium that followed. We measure in situ cosmogenic 14 C directly on cultivated hilltops to quantify late Holocene soil loss, which we compare with background soil production rates determined from cosmogenic 26 Al and 10 Be. Our Monte Carlo-based inversion method identifies two scenarios to account for our data: an increase in erosion rate by 1–2 orders of magnitude between ~2.6 and 1.1 ka, or a discrete event stripping ~1–2 m of soil between ~1.9 and 1.1 ka. Coupled environmental and cultural factors in the Late Holocene signaled the onset of the pervasive human imprint in the Andean Altiplano seen today.