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(1971). Black lines with arrows show typical calc-alkaline and tholeiitic trend lines. e)
The Ti-Zr variation diagram shows the fields of volcanic arc basalts, MORB and withinplate
basalts for the metavolcanic rocks from the Altyndara valley, Northern Pamirs
(after Pearce 1982). f) A La vs Sm plot used to discriminate the tectonic setting of
island-arc rocks. g) A tectonic discrimination diagram for the separation of volcanic arc
granites (VAG), collision related granites (COLG), within plate granites (WPG), and
ocean ridge granites (ORG) after Pearce et al. (1984). h) Zr+Nb+Ce+Y (ppm) vs
FeO*/MgO discrimination diagram from Whalen et al. (1987). FG = field for fractionated
I-type granitoids. i) The Hf-Rb/30-Tax3 discrimination diagram for granites after Harris
et al. (1986), showing the fields for volcanic arc granites, within plate granites, syncollisional
and late to post-collisional granites.
Fig. 3.6 Chondrite-normalised REE abundance patterns (normalised to values given by
Masuda et al. 1973) for selected samples from different intrusives from the South Tien
Shan (STS) and eastern Pamirs. a) subvolcanic diorites and monzogranites from the
STS, b) MORB-type metabasalts, calc-alkaline andesites, dacites, and a rhyolith from
the Altyndara valley in black colours; a granodiorite and monzogranites from the
Karakul lake batholith are in grey colours, c) Triassic/Jurassic monzogranites from the
Central Pamirs and Rushan Pshart Zone and a leucogabbro from the Central Pamirs,
and d) Cretaceous monzogranites from the Central Pamirs and Rushan Pshart Zone and
a latite-andesite from the Central Pamirs.
Fig. 3.7a-p U/Pb dilution, U/Pb SHRIMP and Pb/Pb zircon ages. See Fig. 3.3 for sample
locations and Appendix A, Tab. A7 for data listing. Data points in concordia diagrams
with sample names in brackets were excluded from age calculation. TIMS results
shown with 2� error ellipses and discordias as thin lines. SHRIMP results plotted in
Terra-Wasserburg concordia diagrams uncorrected for common Pb with 1� error
ellipses. Selected age groups of SHRIMP data are displayed as weighted average
diagrams.
Fig. 3.8a-c Rb/Sr whole rock-white mica two-point isochron diagrams. See Fig. 3.3 for
sample locations and Appendix A, Tab. A5 for data listing.
Fig. 3.9a-p 40 Ar/ 39 Ar age spectra, variation of K/Ca, and correlated isotope ratio
diagrams ( 36 Ar/ 40 Ar vs 39 Ar/ 40 Ar). See Fig. 3.3 for sample locations and Appendix A, Tab.
A3 for data listing. Weighted mean ages (WMA) and weighted mean plateau ages
(WMPA) were calculated using shaded steps. TFA is the total fusion age, and IA the
isochron age. Uncertainties are 1�. “Atm.” is the 36 Ar/ 40 Ar of the atmosphere (1/295.5)
in the correlated isotope ratio diagram. MSWD is the mean square weighted deviation.
Fig. 3.10a-c Correlated �Nd (0) and �Sr (0) data versus the age of the samples.
Fig. 3.11 Summary of the geodynamic evolution and amalgamation history of the
Pamirs and Tibet. The profile across the Pamirs is based on the geochemical and
geochronologycal data and correlations to Tibet and Afghanistan. The Turkestan/North
Tien Shan suture is thought to be of Early- to Mid-Palaeozoic age and the Gissar/South
Tien Shan sutur of Late Palaeozoic age. The northern Pamirs contain the composite
Early Palaeozoic and Late Palaeozoic Kunlun arcs. The southward subducting Jinsha
suture is of Late Triassic/Early Jurassic age, whereas the Rushan Pshart suture most
likely closed in Mid-Jurassic time. The collision of the Karakorum block with the southeastern
Pamirs is thought along the upper Lower Cretaceous Tirich Mir/Kilik (?)suture.