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3.7 Conclusions
Based on new own and published data it is for the first time possible to develop a
comprehensive model of the amalgamation history of the Pamirs and to integrate and
correlate this model into existing geodynamic models from Tibet and Afghanistan. This
thesis closes the gap of the Palaeo- and Neo-Tethyan closure history from the Alps to
Eastern Asia. Suture zones offer a variety of tectonic contexts from subduction to
collision to mountain building. Diachronous development of structures produced by
these processes provides a unique overview of Tethyan closure since in many cases
several stages exist simultaneously in the suture zone (Fig. 3.11, 3.16) and can be
directly compared. Detailed regional studies about the structure of crustal, lithospheric,
or whole-mantle scale, on the P-T-t evolution of metamorphic domains, on magmatic
and volcanic products related to the Tethyan closure, and on Tethyan marginal and
continental basin evolution form the basis for a useful synthesis of Tethyan and Central
Asian mountain belt tectonics. The detailed analyses and regional syntheses of the
Pamiran amalgamation are pertinent to the modelling of the large-scale general
structures and form the basic understanding for the Tertiary deformation and
exhumation history.
The Early Permian, calc-alkaline South Tien Shan samples described in this study, are
correlated with the Garm-Turkestan-Alay zone granitoids, and correspond to a mature
calc-alkaline arc north of the South Gissar suture. The Baysunta and Garm basements,
which crops out in the Gissar range and Garm-Turkestan-Alay zone may be interpreted
as part of the Tadjik continental block that connects with the Tarim block underneath
the northern Pamirs. It follows, that any westward extension of Early Paleozoic sutures
of northern Tibet, e.g. the Kudi suture, must be located south of the Tadjik massif.
The northern Pamirs and north-western Tibet contain the north-facing Kunlun suture,
the south-facing Jinsha suture, and the intervening Carboniferous to Triassic Karakul-
Mazar subduction-accretion system; the latter is correlated with the Sonpan-Ganze
mélange of Tibet. The Kunlun arc is the juxtaposition of an Early Palaeozoic (north
Kunlun) and a Late Palaeozoic-Triassic (south Kunlun) arc. In the northern Pamirs, the
~370-320 Ma old metavolcanic Altyndara rocks are representatives of the north Kunlun
arc. Arc activity most likely extended into a Triassic back-arc basin setting.