@article{fdi:010075268,
  title = {{M}icrobial and geochemical investigation down to 2000 m deep triassic rock ({M}euse/{H}aute {M}arne, {F}rance)},
  author = {{L}eblanc, {V}. and {H}ellal, {J}. and {F}ardeau, {M}arie-{L}aure and {K}helaifia, {S}. and {S}ergeant, {C}. and {G}arrido, {F}. and {O}llivier, {B}ernard and {J}oulian, {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n 2008, as part of a feasibility study for radioactive waste disposal in deep geological formations, the {F}rench {N}ational {R}adioactive {W}aste {M}anagement {A}gency ({ANDRA}) drilled several boreholes in the transposition zone in order to define the potential variations in the properties of the {C}allovo-{O}xfordian claystone formation. {T}his consisted of a rare opportunity to investigate the deep continental biosphere that is still poorly known. {F}our rock cores, from 1709, 1804, 1865, and 1935 m below land surface, were collected from {L}ower and {M}iddle {T}riassic formations in the {P}aris {B}asin ({F}rance) to investigate their microbial and geochemical composition. {R}ock leachates showed high salinities ranging from 100 to 365 g.{L}-1 {N}a{C}l, current temperatures averaging 65 degrees {C}, no detectable organic matter, and very fine porosity. {M}icrobial composition was studied using a dual cultural and molecular approach. {W}hile the broad-spectrum cultural media that was used to activate microbial communities was unsuccessful, the genetic investigation of the dominant 16{S} r{RNA} gene sequences revealed eight bacterial genera considered as truly indigenous to the {T}riassic cores. {R}etrieved taxa were affiliated to aerobic and facultative anaerobic taxon, mostly unknown to grow in very saline media, except for one taxon related to {H}alomonas. {T}hey included {F}irmicutes and alpha-, beta-, and gamma-{P}roteobacteria members that are known from many subsurface environments and deep terrestrial and marine ecosystems. {A}s suggested by geochemical analyses of rocks and rock leachates, part of the indigenous bacterial community may originate from a cold paleo-recharge of the {T}rias aquifer with water originating from ice melting. {T}hus, retrieved {DNA} would be fossil {DNA}. {A}s previously put forward to explain the lack of evidence of microbial life in deep sandstone, another hypothesis is a possible paleo-sterilisation that is based on the poly-extremophilic character of the confined {T}riassic sandstones, which present high salinity and temperature.},
  keywords = {subsurface ; {T}rias sandstone ; microbial communities ; {FRANCE}},
  booktitle = {},
  journal = {{G}eosciences},
  volume = {9},
  numero = {1},
  pages = {art. 3 [26 ]},
  ISSN = {2076-3263},
  year = {2019},
  DOI = {10.3390/geosciences9010003},
  URL = {https://www.documentation.ird.fr/hor/fdi:010075268},
}