In:
Karstologia : revue de karstologie et de spéléologie physique, PERSEE Program, Vol. 48, No. 1 ( 2006), p. 1-22
Abstract:
The speleothems of trou Noir cave (Gironde, France) : the role of their situation in registering climatic signals The trou Noir is an active cave system (sinkhole-resurgence) situated in the Oligocene porous limestone of the plateau of Entre-deux-Mers near Bordeaux (Gironde). Six stalagmites have been sampled for analyzing the environmental evolution controlled by local parameters inside the cave. The studied indicators are calcitic microfabrics, lamination, discontinuities, porosity, organic matter, and radioactivity. Because of a narrow passage located in the middle of the cave, three speleothems upstream have recorded the fluctuations of the underground river during floods, especially detritic sedimentation (clay/calcite alternations), erosion (internal corrosion surface), mechanical shocks (fissures). Downstream, the three other stalagmites have not been flooded ; in the small dry passage near the resurgence, two speleothems show, in thin section, many biologic filaments (bacteria or mycelian filaments) because of organic matter (guano from bats). The site is protected (Natura 2000). The trou Noir is an example of a young cave which has recorded the Holocene evolution, particularly the Little Ice Age (detrital/calcitic stalagmite) and the present period.
Type of Medium:
Online Resource
ISSN:
0751-7688
DOI:
10.3406/karst.2006.2584
Language:
French
Publisher:
PERSEE Program
Publication Date:
2006
SSG:
13
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