@article {543, title = {Late Holocene precipitation variability recorded in the sediments of Reloncav{\'\i} Fjord (41{\textdegree}S, 72{\textdegree}W), Chile}, journal = {Quaternary Research}, volume = {84}, year = {2015}, note = {Co0ceTimes Cited:1Cited References Count:93}, month = {Jul}, pages = {21-36}, abstract = {We present reconstructions of late Holocene changes in the source of organic matter and siliceous export production in the Relocanv{\'\i} Fjord (41{\textdegree}S, 72{\textdegree}W), Northern Chilean Patagonia, based on organic carbon content, δ13Corg, N/C ratio, diatom assemblages and biogenic silica contents from three sediment cores. The age models are based on a combination of 210Pb profiles, AMS 14C dating, and on the first occurrence of the diatom Rhizosolenia setigera f. pungens, as a stratigraphic marker in the fjords. The cores span the last 300 to 700 yr. Diatoms dominate the siliceous assemblages in the three cores (98\% on average). Our results suggest that precipitation seasonality in the region of Reloncav{\'\i} was high in CE 1300{\textendash}1400 and CE 1700{\textendash}1850, with a clear decreasing trend since CE 1850. The latter trend is in agreement with instrumental records and tree-ring reconstructions. These fluctuations seem to be associated with the Southern Annular Mode (SAM).}, issn = {0033-5894}, doi = {10.1016/j.yqres.2015.05.006}, author = {Rebolledo, Lorena and Lange, Carina B. and Bertrand, S{\'e}bastien and Mu{\~n}oz, Praxedes and Salamanca, Marco and Lazo, Pablo and Iriarte, Jos{\'e} L. and Vargas, Gabriel and Pantoja, Silvio and Dezileau, Laurent} } @article {172, title = {U-series dating of co-seismic gypsum and submarine paleoseismology of active faults in Northern Chile (23{\textdegree}S)}, journal = {Tectonophysics}, volume = {497}, year = {2011}, note = {id: 2147}, pages = {34-44}, abstract = {The convergence of the Nazca and South American plates along the subduction margin of the central Andes results in large subduction earthquakes and tectonic activity along major fault systems. Despite its relevance, the paleoseismic record of this region is scarce, hampering our understanding about the relationship between the Andes building and earthquake occurrence. In this study, we used the U-series disequilibrium method to obtain absolute ages of paleoearthquake events associated with normal displacements along the active Mejillones and Salar del Carmen faults in the Coastal Range of the Atacama Desert of northern Chile. The 230Th{\textendash}234U disequilibrium ages in co-seismic gypsum salts sampled along the fault traces together with marine evidences indicate that earthquakes occurred at ca. 29.7 {\textpm} 1.7 ka, 11 {\textpm} 4 ka and 2.4 {\textpm} 0.8 ka. When coupled with paleoseismic marine and radiocarbon (14C) records in the nearby Mejillones Bay evidencing large dislocations along the Mejillones Fault, the geochronological dataset presented here is consistent with the notion that gypsum salts formed during large earthquakes as a result of co-seismic dilatancy pumping of saline waters along the major faults. Based on maximum observed cumulative vertical offsets in the studied faults, this phenomena could have occurred episodically at a rate in the order of 1:40 to 1:50 with respect to the very large subduction earthquakes during the latest Pleistocene{\textendash}Holocene period. The results presented here reveal that the U-series disequilibrium method can be successfully applied to date the gypsum salts deposited along faults during seismic events, and therefore directly constrain the age of large paleoearthquakes in hyperarid and seismically active zones.}, issn = {0040-1951}, doi = {10.1016/j.tecto.2010.10.017}, url = {http://www.sciencedirect.com/science/article/pii/S0040195110004506}, author = {Vargas, Gabriel and Palacios, Carlos and Reich, Martin and Luo, Shangde and Shen, Chuan-Chou and Gonz{\'a}lez, Gabriel and Wu, Yi-Chen} }