ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

KANGNING XIONG, CAIHUA HE & XING CHENG
Analysis of structural features of rimstone in karst caves
Department of Geography, Guizhou Normal University,
Waihuandong Rd, 550001Guiyang, China
This paper, based on fieldwork and experiments, looks at
structural types and features of rimstone in karst caves.
The rimstones developed in caves are quite different from
those formed on river beds, the former appear porous, like
tufa, which are resulted from higher temperature and biological
process. The rimstones in caves, apart from their
features similar to river rimstone, obviously appear compacted
and graded. Three types of rimstone are identified
according to different conditions of water movement and
different shapes of water recharge distribution, water-way
model, fan model and circle model. Each reflects different
408
condition of water movement. Water of the water-way model
is from stream or intermittent stream for recharge. Plan
distribution of the fan model rimstone appears fan-shaped
and the relevant recharge type is mainly fissure water or
dripping flow. The circle model rimstone looks semi-circle-shaped
on plan, which is a rare type developed in a
special mini-topographic environment, formin from dripping
recharge. Hydraulic conditions of these types above
are respectively changing from strong to weak. The cave
rimstons are also classified, from profile shape, dip angle
and inner structure of lamination, as vertical dam, steep
dam (60°-90°) and slope dam «60 0).These dip changes also
reflect the conditions of water movement from strong to
weak respectively. In addition, the paper notes some special
rimstone types such as double dam, dam-in-dam, ect.
and the relevant hydrogeological significance, presents relationship
between cave rimstone structure, inner lamination
and flow conditon of recharge water, reveals factors of
water movement in rimstone formation, and disscuses initial
morphological problems of rimstones.