uncorrected proofs
Neotectonic and climatic impressions
in the zone of Trans Himadri Fault (THF),
Kumaun Tethys Himalaya, India:
A case study from palaeolake deposits
Bahadur S. Kotlia and Lalit M. Joshi
with 4 figures and 1 table
Summary. Late Quaternary tectonic activity on a NW-SE trending fault within the Trans Hi-
madri Fault (THF) zone in lower reaches of the Milam glacier (Indian Tethys Himalaya) result-
ed in development of a lake around 23 ka BP. The remnants of the ancient lake are preserved in
form of a 25.6 m thick lacustrine profile, consisting of muds and sands. The palaeolake seems to
have breached around 11 ka BP possibly due to revival of a further event of neotectonic activi-
ty. The geomorphic consequences of the tectonic movements in the fault zone are manifest in
form of palaeo-landslide cones, unpaired terraces, fault facets, soaring waterfalls, deep gorges
and slope failures etc. The soft sedimentary structures, e. g., micro-faulting and flame structures
in the exposed profile also point to a possible reactivation of the THF in the Late Pleistocene.
We present the first palynological results from otherwise a totally unexplored area in the eastern
part of the Indian Tethys Himalaya. The preliminary results indicate that the area experienced
cold desertic climatic conditions from ca. 22.9 to 15.7 ka BP covering a period of Last Glacial
Maximum (LGM) and during which the sediment accumulation rate was also extremely slow.
This phase was followed by deglaciation together with amelioration of climate between ca. 15.7
and 14.5 ka BP. A dry period from ca. 14.5 to 13.8 ka BP can be associated with the Older Dryas.
The area underwent wetter/moist conditions from ca. 13.8 to 12.8 ka BP, followed by a century
scale dry event (ca. 12.8 to 12.7 ka BP) which may be linked to the Younger Dryas episode.
Key words: Trans Himadri Fault, Tethys Himalaya, Neotectonics, Palynological investiga-
tions
1 Introduction
The Indian Himalaya has witnessed the intense Quaternary tectonic movements in
the zones of intracrustal boundary faults/thrusts, resulting in damming of rivers and
formation of lakes. In the Indian Tethys Himalaya, a number of such tectonically
formed lakes been studied from Ladakh (Burgisser et al. 1982, Fort et al. 1989,
Kotlia et al. 1997, 1998, Shukla et al. 2002, Upadhyay 2003), Spiti (Mohindra &
Bagati 1996, Sangode et al. 2007, Singh & Jain 2007, Phartiyal et al. 2009) and
Kumaun sector (Heim & Gansser 1939, Kotlia & Rawat 2004, Basavaiah et al.
2004, Juyal et al. 2004, 2009, Pant et al. 2006, Rawat & Kotlia 2006). Based on the
extensive studies, three prominent pulses of tectonic activity have been established
Zeitschrift für Geomorphologie Fast Track Article
published online March 2013
© 2013 Gebr. Borntraeger Verlagsbuchhandlung, Stuttgart, Germany www.borntraeger-cramer.de
DOI: 10.1127/0372-8854/2013/0057-0101 0372-8854/13/0057-0101 $ 3.75
uncorrected proofs