KARABASH–SHAVAZ MASSIF (SOUTH-WESTERN SPURS OF THE CHATKAL RANGE, MIDDLE TIEN SHAN): HISTORY OF GEOLOGICAL STUDY AND SPECIFIC FEATURES OF ITS GEOLOGICAL STRUCTURE
DOI:
https://doi.org/10.5281/Keywords:
Karabash–Shavaz massif; Shavaz complex; Chatkal–Kurama region; Middle Tien Shan; formational analysis; relative chronology; history of geological study.Abstract
The Karabash–Shavaz massif in the south-western spurs of the Chatkal Range (right bank of the Angren River) has been studied for more than eight decades, yet its age, composition and formational affiliation remain subject to conflicting interpretations. We compare published sources covering 1935–2018 to reconstruct the history of study of the massif and to distinguish broadly accepted features of its structure from unresolved issues. Four stages of study are recognised. The sources agree on the structural setting, host rocks, the eastonite–siderophyllite composition of biotite and the presence of Fe–Ti and Cu mineralisation, but differ on the age of the massif (a Middle Carboniferous assignment accompanied by published K–Ar biotite ages versus a Late Carboniferous–Early Permian assignment), its areal extent (about 50 km² versus gabbroic bodies of 2–10 km²), its phase sequence, the relationship between pyroxenites and gabbroic rocks, and its affiliation to the Shavaz complex. Taken together, these discrepancies may indicate that the Karabash–Shavaz area represents a composite, multi-stage intrusive system. We therefore propose this interpretation as a working hypothesis and outline field, petrographic and geochemical criteria for its evaluation.
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