Unkel, I., Kadereit, A., Machtle, B., Eitel, B., Kromer, B., Wagner, G. and Wacker, L. 2007. Dating methods and geomorphic evidence of paleoenvironmental changes at the eastern margin of the South Peruvian coastal desert (14°30'S) before and during the Little Ice Age. Quaternary International 175: 3-28.
Working in the hyper-arid zone of the northern Atacama Desert of Peru between Pisco/Ica and Nazca/San Juan (~14.3°S, 75.3°W), Unkel et al. employed "geomorphological field-work" and "chronometric analyses" -- consisting of conventional 14C-dating of charcoal, wood and root samples and optical-stimulated luminescence dating of feldspar and quartz -- while investigating "alluvial archives and debris flow deposits." This work, together with that of others, indicated the existence of a period of "fluvial silence" for "the time of the 9th-13th centuries," due to "increased aridification," which they associated with the Medieval Warm Period (~AD 800-1250).