@article{fdi:010062032,
  title = {{D}istribution and sources of bulk organic matter ({OM}) on a tropical intertidal mud bank in {F}rench {G}uiana from elemental and isotopic proxies},
  author = {{G}ontharet, {S}. and {M}athieu, {O}. and {L}eveque, {J}. and {M}illoux, {M}. {J}. and {L}esourd, {S}. and {P}hilippe, {S}. and {C}aillaud, {J}. and {G}ardel, {A}. and {S}arrazin, {M}ax and {P}roisy, {C}hristophe},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he mobile {F}rench {G}uiana coast is a shoreface region downdrift of the {A}mazon {R}iver, where enormous quantities of inorganic and organic materials are exchanged with the {A}tlantic {O}cean. {T}he rapid accumulation of these materials forms highly unstable shore-attached mud banks, which can be temporally emerged and then rapidly colonized and stabilized by microphytobenthos and opportunistic mangroves (i.e. {A}vicennia germinans). {M}ud banks are preferential sites for the accumulation and significant remineralization of organic matter ({OM}) due to intense erosion/deposition cycles and potential biological colonization. {T}he distribution and sources of bulk sedimentary {OM} were characterized by elemental and isotopic analyses of four sediment cores, together with samples from three potential {OM} sources (mangrove plants, suspended particulate matter ({SPM}) and microphytobenthos), all collected from the landward face of the {M}acouria mud bank ({F}rench {G}uiana). {T}otal organic carbon ({TOC}) and nitrogen ({TN}) concentrations in the sediment cores showed that {OM} sources were characterized by spatio-temporal variations in this mud bank. {T}he relative contributions of mangrove plants, {SPM} and microphytobenthos were estimated using a three end-member mixing model based on [ {TN}/ {TOC}] atomic ratios and delta {C}-13 values. {S}edimentary {OM} is mostly controlled by {SPM} associated with variable amounts of {OM} derived from mangrove plants and microphytobenthos. {T}hese variations could be explained by topography and bed elevation, which decrease submersion time and increase desiccation. {H}igher contributions of microphytobenthos are associated with black {OM}-rich laminae, identified in sedimentary cores and linked to temporal emersion phases of the mud bank, which favor the growth of benthic microalgae. {T}his result is confirmed by the calculation of the average sediment accumulation rate (around 36.7 +/- 14.8 cm yr(-1)), taking into account the emersion of the study site every spring tide (a fortnightly cycle). {T}his value is within the range of the previous results from other mud banks in {F}rench {G}uiana but is more than ten times greater than values generally obtained in other coastal contexts.},
  keywords = {{S}edimentary organic matter sources ; {M}icrophytobenthos ; [{TN}/{TOC}](atomic) ratios ; {S}table carbon and nitrogen isotopes ; {M}acouria mud bank, {F}rench {G}uiana ; {GUYANE} {FRANCAISE} ; {AMAZONE} ; {ATLANTIQUE}},
  booktitle = {},
  journal = {{C}hemical {G}eology},
  volume = {376},
  numero = {},
  pages = {1--10},
  ISSN = {0009-2541},
  year = {2014},
  DOI = {10.1016/j.chemgeo.2014.03.009},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062032},
}