Jl. Welcomme et al., Himalayan Forelands: palaeontological evidence for Oligocene detrital deposits in the Bugti Hills (Balochistan, Pakistan), GEOL MAG, 138(4), 2001, pp. 397-405
In the southwestern Sulaiman geological province (Balochistan, Pakistan), t
errestrial detrital facies from the Bugti Hills region have yielded the ric
hest Tertiary vertebrate faunas to be found in Asia thus far. New fossils f
rom five successive and distinct 'bone beds' bridge the supposed Oligocene
sedimentary hiatus within the Sulaiman geological province; the lowermost c
ontinental levels of the previously described Miocene Chitarwata Formation,
known as the Bugti Member, are Oligocene in age in the Bugti area. Neither
a mixture of heterochronic faunal elements nor endemism of any fauna is ev
ident in this area. Additional microfaunal material from the Bugti Member c
onstrains an Oligocene age for the lower Chitarwata Formation in Zinda Pir
(northeast of the Bugti Hills). This Oligocene transition between the marin
e Kirthar (Eocene) and continental Siwalik (Miocene) deposits consists of a
regressive fluvio-deltaic system occupying a vast floodplain. It represent
s an early-stage molasse in the palaeo-Indus Basin which drained western or
ogenic highlands resulting from the collision between the Indian and Eurasi
an plates.