@article{fdi:010067878,
  title = {{O}rganic matter-clay interaction along a seawater column of the {E}astern {P}acific upwelling system ({A}ntofagasta bay, {C}hile) : implications for source rock organic matter preservation},
  author = {{A}hmat, {A}.{M}. and {B}oussafir, {M}. and {L}e {M}ilbeau, {C}. and {G}uegan, {R}. and {V}aldes, {J}. and {G}uinez, {M}. and {S}ifeddine, {A}bdelfettah and {L}e {F}orestier, {L}.},
  editor = {},
  language = {{ENG}},
  abstract = {{N}atural {O}rganic {M}atter ({OM}) preservation and sedimentary burial mechanisms are still poorly understood despite their importance in oil source rock characterization and carbon cycle issues. {I}t is now recognized that mineral sorption contributes significantly to {OM} preservation by conferring steric protection and preventing enzymatic access. {M}ost of the studies dealing with {OM} preservation have focused on settled {OM}, omitting aggregation in the water column. {F}or the first time, we have tested the complexation of natural {OM} on 3 types of clays in seawater in-situ conditions. {S}amples of {N}a exchanged montmorillonite ({N}a {MM}t), synthetic montmorillonite ({S} {N}a {MM}t) and natural kaolinite ({K}aol) were immersed in an upwelling zone ({A}ntofagasta bay, {C}hile). {T}hree depths were studied: 15 m (photic zone), 40 m (oxygen transition zone) and 80 m (anoxic zone). {T}he clayey samples were kept immersed for different durations and analyzed after removal, via {GC}/{MS}, {P}y-{GC}/{MS}, flash elementary pyrolysis, {DOC} analyzer and {XRD}. {T}he main results are: (1) for the shortest immersion times, {DOC} analyzes performed on clays' proximal water indicated excessive {DOC} concentrations compared to seawater values. {T}his attraction effect was however temporary, as values tended to rebalance with seawater concentrations for the longest immersion times. (2) {M}olecular analyses performed on seawater organic extracts indicated that fatty acids, alkanes, alkyl benzenes and methoxy-benzenes were the main dissolved lipid groups. (3) {T}hese lipids were also the main sorbed compounds identified on immersed clays, with a predominance of fatty acids. {T}his is due to the higher availability and better affinity of fatty acids with the clayey samples. (4) {B}ecause of its higher specific area and {CEC}, {N}a {MM}t exhibited the best sorption rates compared to {K}aol and {SN}a {MM}t. {X} ray analyses performed on {N}a {MM}t indicated d(001)spacing growths, but these growths are not attributed to {OM} intercalation. {S}orbed {OM} is probably located on the external surfaces leaf edges of clays.},
  keywords = {{PACIFIQUE} ; {CHILI}},
  booktitle = {},
  journal = {{M}arine {C}hemistry},
  volume = {179},
  numero = {},
  pages = {23--33},
  ISSN = {0304-4203},
  year = {2016},
  DOI = {10.1016/j.marchem.2016.01.003},
  URL = {https://www.documentation.ird.fr/hor/fdi:010067878},
}