Showing papers on "Speleothem published in 1975"
TL;DR: In this paper, it was shown that initial U 234 U 238 -dating of older portions of the same speleothem, back to about 10 6 yr B.P., with estimated precision of ±5 per cent.
26 citations
TL;DR: The deep karstic networks as mentioned in this paper show a complex sedimentary sequence with the occurence of some periods of non-deposition, and two speleothems are determined (reddish-brown and white concretions).
Abstract: The deep karstic networks shows a complex sedimentary sequence with the occurence of some periods of non-deposition. The next succession is observed : red silt dumped layers after a villafranchian weathering in an inversed sedimentary deposition order, erosion of the red silts and new opening of the karstic network ; then, we observe the deposition of stalagmitic concretions mass and two speleothems are determined (reddish-brown and white concretions). Closing of the caves at tha wurmian times and local deposition of the phosphatic silts. In a recent and pluvial epoch, at the end of post-glacial times (sub-atlantic) the caves presents a last sort of speleothem with new concretions and the formation of many calcitic subterranean boulder ("gours"). The actual epoch shows a continuous progress to a drying state.
3 citations