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Southern Tien Shan
One Permian granite sample (TS1) and two sandstone samples (TS5a, TS8a) from a SW-
NE striking Tertiary intramontane basin of the southernmost Tien Shan have been
dated (Fig. 4.2). The apparent apatite fission track age of hardrock sample TS1 is
10.9±1.3 Ma. Sample TS5a was probed from ?Neogene sediment strata, sample TS8a
from ?Lower Palaeogene strata (Geological map 1:200.000 of Kyrgyz SSR, 1958). The
apatite and zircon fission track samples of the sandstones do not pass the � 2 test and
therefore denote the occurrence of multiple age populations within the samples.
Modelled peak ages (Appendix C, Tab. C7, Fig. C4) are Lower Carboniferous (333 Ma,
TS8a apatite), Permian (266 Ma, TS5a zircon; 245 Ma, TS5a apatite), Middle to Late
Jurassic (170 Ma, TS8a apatite; 144-145 Ma, TS5a zircon and apatite), and Late
Cretaceous (76 Ma, TS5a apatite).
Northernmost Pamirs, N-Kunlun
Two sandstone samples (AD7d, AD8a) were probed from a Tertiary intramontane basin
along the northern flanks of the Pamirian frontal range (Fig. 4.2). From both samples
zircon fission track grain ages could be determined. Sample AD7d shows again a nonreset
grain age distribution with modelled peak ages at ~243 Ma and ~131 Ma
(Appendix C, Tab. C7, Fig. C4). The sample AD8a offered only 6 datable grains, which
seem to represent only one single age population with a central age of ~152 Ma.
Karakul-Mazar granitoids, Northern Pamirs
Five different granitoid locations (P20, P22, P24, P25, and P26) were probed across the
Karakul-Mazar batholith belt (Fig. 4.2). Two zircon fission track samples P25 and P26
yield apparent ages of 108 Ma and 122 Ma, respectively. Apparent apatite fission track
ages range from Eocene to Miocene (56-18 Ma) with a trend to younger ages towards
the north (Fig. 4.3).
Qiangtang block, Central Pamirs
For a better understanding of the sample localities, the structural units and lithologies
of the Central Pamirs are shortly repeated here: (1) A pre-Late Palaeozoic Qiangtang
basement is inferred from inherited zircons of granitoid sample P17 and correlations
with Tibet. (2) Triassic-Jurassic meta-siliciclasic and metavolcanic rocks are exposed in
the Muzkol and Sares domes and were metamorphosed and deformed during the
Tertiary. They are interpreted to correspond to the Karakul-Mazar-Sonpan-Ganze
accretionary wedge rocks, associated with the subduction of the Jinsha oceanic crust.
Likely remnants of this oceanic crust are small Triassic/Jurassic gabbro bodies within
the Muzkol and Sares domes. (3) Few Cretaceous magmatic rocks are exposed in the
Qiangtang block (e.g., 96A10b, A96S1b). Late Cretaceous sample A96S1b from the
northern margin of the Qiangtang block shows geochemical affinity to the Central
Qiangtang gabbros and to the Karakul-Mazar substratum. Sample 96A10b is of upper
Lower Cretaceous age and from the southern margin of the Qiangtang block. Rock
generation is probably more related to subduction processes along the Shyok arc. The
sample A96S1b yielded a central zircon fission track age of ~64 Ma, whereas sample
96A10b obtained a mean zircon fission track age of ~59 Ma, probably suggesting that
the zircon grains might be partly reset (Fig. 4.2). (4) The Muzkol and Sares domes
provide an outstanding example for India-Asia post-collisional intracontinental
deformation within Central Asia. The domes represent an antiformal structure,
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