@article{fdi:010077872,
  title = {{C}ontrols on the provenance of late {E}ocene to {Q}uaternary {M}ozambique {C}hannel shales ({DSDP} 25 {S}ite 242)},
  author = {{R}oddaz, {M}artin and {N}auton-{F}ourteu, {M}. and {S}antos, {R}. {V}. and {D}antas, {E}. {L}. and {C}alves, {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{P}rovenance determination of late {E}ocene to {Q}uaternary sediments deposited at the {DSDP} 25 {S}ite 242 may help to evaluate the mechanisms that have controlled the sediment deposition in the {M}ozambique {C}hannel. {T}o determine the provenance of the clay fraction, we measure major and trace element concentrations as well as strontium ({S}r-87/{S}r-86) and neodymium isotopic compositions (expressed as epsilon({N}d(0))) of thirty-six sedimentary samples from {DSDP} 25 {S}ite 242 on the eastern flank of the {D}avie {F}racture {Z}one. {L}ight {R}are {E}arth {E}lement ({LREE}) enrichment and {H}eavy {REE} ({HREE}) depletions against {P}ost {A}rchean {A}ustralian {S}hales ({PAAS}) associated with {C}e anomalies higher than or equal to 0.90 for all the analyzed samples suggest very little influence of authigenic smectite incorporation. {T}he absence of correlation of {A}l/{S}i and {CIA} with {REE} content, {E}u/{E}u*, {C}r/{T}h, {T}h/{S}c, and {S}r-87/{S}r-86 and epsilon({N}d(0)) suggests that chemical weathering has not modified these provenance proxies. {S}light increase of {E}u/{E}u*, {C}r/{T}h ratios, epsilon({N}d(0)) values associated with slight decrease in {S}r-87/{S}r-86 and {T}h/{S}c ratios from the late {E}ocene to the {Q}uaternary point to input of less differentiated and younger detritus to the {DSDP} 25 {S}ite 242 with age. {B}ased on variations in epsilon({N}d(0)) and {N}d concentrations, we estimate an overall decrease of the {S}outheast {A}frican rivers ({C}ongo/{Z}ambezi) contribution from similar to 65.7% ({S}tandard {D}eviation ({S}.{D}.) similar to 13.2) in the late {E}ocene to similar to 28.5% ({S}.{D}. similar to 10.0) in the early {P}liocene. {T}he causes for the low epsilon({N}d(0)) values and high {S}outheast {A}frican contribution between the late {E}ocene and the early {O}ligocene remain to be determined. {I}t could record the onset of modern sedimentation in the {Z}ambezi delta or the discharge of the {P}aleo {C}ongo river in the {I}ndian {O}cean. {T}he decrease of {Z}ambezi contribution between the late {O}ligocene and early {P}liocene is attributed to the cumulative effect of increasing tectonic activity of the {D}avie {F}racture {Z}one and intensification of the {M}ozambique {C}urrent. {T}he late {P}liocene to {Q}uaternary glacial-interglacial cycles promoted higher {Z}ambezi contribution during glacial sea-level lowstands and in turn lower epsilon({N}d(0)) detrital values, whereas low {Z}ambezi contributions are favored during interglacial highstand causing higher epsilon({N}d(0)) values. {H}ence, the modern dispersal pattern of fine-grained sediments within the {M}ozambique {C}hannel is no younger than late {P}liocene.},
  keywords = {{MADAGASCAR} ; {MOZAMBIQUE} {CANAL} ; {LIMPOPO} {COURS} {D}'{EAU} ; {ZAMBEZE} {COURS} {D}'{EAU} ; {CONGO} {COURS} {D}'{EAU}},
  booktitle = {},
  journal = {{M}arine {G}eology},
  volume = {421},
  numero = {},
  pages = {106090 [17 ]},
  ISSN = {0025-3227},
  year = {2020},
  DOI = {10.1016/j.margeo.2019.106090},
  URL = {https://www.documentation.ird.fr/hor/fdi:010077872},
}