@article{fdi:010074947,
  title = {{T}he origin of the magnetic record in {E}ocene-{M}iocene coarse-grained sediments deposited in hyper-arid/arid conditions : examples from the {A}tacama {D}esert},
  author = {{P}izarro, {H}. and {R}ousse, {S}onia and {R}iquelme, {R}. and {V}eloso, {E}. and {C}ampos, {E}. and {G}onzalez, {R}. and {B}issig, {T}. and {C}arretier, {S}{\'e}bastien and {F}ernandez-{M}ort, {A}. and {M}unoz, {S}.},
  editor = {},
  language = {{ENG}},
  abstract = {{M}agnetic proxies for paleoclimate are tools widely used to understand climate variability, yet current proxies focus on loess-derived soils in humid to temperate climate zones, whereas coarse-grained sediments in arid-hyperarid climate zones remain poorly investigated. {T}o test the potential paleoclimatic-environmental significance of the magnetic record of coarse-grained sediments deposited in a region with a mean annual precipitation ({MAP}) < 200 mm yr(-1), we selected three previously studied sedimentary sequences from the {A}tacama {D}esert ({C}entinela area) and explored their magnetic properties, paedogenic features, salt chemistry and mineralogy. {T}hese sequences were deposited under different climate-environmental conditions from the {E}ocene to the {M}iocene, and correspond, from oldest to youngest, to the {A}travesados {II} gravels ({A}tli), the {A}rrieros gravels ({A}rr) and the {R}atones sediments ({R}at). {T}he magnetic susceptibility values (k) obtained in the stratigraphic record of the gravels are mainly controlled by the concentration of detrital (titano)magnetite, which is concentrated in the finest fraction ( < 0.5 mm) of sediments. {T}he values decrease in the coarse sediments from {A}tli to {A}rr following a climatic transition from arid to hyperarid conditions, an interpretation that is supported by the transition from carbonate-rich ({MAP} similar to 40 mm yr(-1)) to sulfate-rich paleosols ({MAP} < 10 mm yr(-1)), and changes in the tectonic conditions and/or sedimentary source. {I}n contrast, the {R}at fine-grained sediments record changes in paleo-wetland dynamics. {T}he high frequency-dependent magnetic susceptibility (kfd%) values obtained from these layers are mainly controlled by the concentration of authigenic magnetite-maghemite and/or hematite crystals of superparamagnetic/single magnetic size. {T}he increase in kfd% is linked to an increase in the authigenic degree, which is related to variations in the depth of the local water table. {T}hese results demonstrate the potential of magnetic proxies to reveal climatic/environmental signals in coarse-grained sediments deposited under desert climate conditions.},
  keywords = {{A}tacama paleoclimate ; {M}agnetic proxies ; {A}tacama gravels ; {P}aleoenvironment ; {W}etland deposits ; {P}aleosols ; {CHILI} ; {ATACAMA}},
  booktitle = {},
  journal = {{P}alaeogeography {P}alaeoclimatology {P}alaeoecology},
  volume = {516},
  numero = {},
  pages = {322--335},
  ISSN = {0031-0182},
  year = {2019},
  DOI = {10.1016/j.palaeo.2018.12.009},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074947},
}