@article{fdi:010062245,
  title = {{I}ncipient charnockitisation due to carbonic fluid transfer related to late {P}an-{A}frican transcurrent tectonics in {M}adagascar; implications for mobility of {F}e, {T}i, {REE} and other elements},
  author = {{N}{\'e}d{\'e}lec, {A}. and {G}uillaume, {D}. and {C}ourn{\`e}de, {C}. and {D}uran, {C}. and {M}acouin, {M}. and {R}akotondrazafy, {M}. and {G}iuliani, {G}aston},
  editor = {},
  language = {{ENG}},
  abstract = {{I}ncipient charnockitisation of an {A}-type granite protolith has been recognized in a spectacular outcrop 35 km north of {A}ntananarivo. {T}he charnockites form structurally-controlled dark greenish patches suggesting channelized fluid transfer, during and after partial reworking of the granite coeval with the {A}ntananarivo virgation zone (ca 560 {M}a) and/or the {A}ngavo shear zone of late-{P}anafrican age (ca 550 {M}a). {T}hey are characterized by a significant increase of the bulk magnetic susceptibility. {T}he granitic protolith contains quartz, perthitic alkali feldspar, high-{T}i hastingsitand accessory minerals (apatite, allanite, magnetite and zircon). {T}he charnockitic granite contains quartz, perthitic alkali feldspar and ghost (altered) orthopyroxene crystals, as well as secondary low-{T}i hastingsite surrounding orthopyroxene. {T}he large increase of magnetic susceptibility magnitudes is related to the formation of pockets of secondary magnetite, spatially associated with quartz and other accessories, such as fluorine, calcite, bastnaesite, sphalerite, {T}i-oxide and ({C}a, {REE})fluor-carbonates, in fluid percolation zones or in reaction rims around ghost orthopyroxene. {F}luid inclusions entrapped in quartz grains witness the presence of {CO}2-rich hydrocarbonic fluids of low salinity, that are more abundant in charnockites than in granites. {I}t is suggested that the rocks underwent a rather long history of fluid percolation, leading to prograde and then retrograde transformations. {T}he corresponding metasomatic changes point to the mobility of {T}i, {F}e, {C}a, {Z}n, {F} and {REE}. {T}hese changes are consistent with the {CO}2-rich nature of the percolating fluids.},
  keywords = {{C}harnockite ; {CO}2 ; {M}agnetic susceptibility ; {M}adagascar ; {P}an-{A}frican ; {MADAGASCAR}},
  booktitle = {},
  journal = {{J}ournal of {A}frican {E}arth {S}ciences},
  volume = {94},
  numero = {{SI}},
  pages = {86--99},
  ISSN = {1464-343{X}},
  year = {2014},
  DOI = {10.1016/j.jafrearsci.2013.07.005},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062245},
}