In world archaeology, there has always been a problem regarding the Middle to Upper Palaeolithic transition. Late twentieth-century research has attempted to address this issue through the recognition of Initial Upper Palaeolithic (IUP) lithic industries. These assemblages were first characterised through evidence from the sites of Boker Tachtit and Ksar Akil (the Levant), and they are now identified in many regions of Eurasia, including Central Asia, the Near East, the Altai Mountains, Transbaikalia, Mongolia and northern China. A characteristic IUP assemblage has also been recently found in Kazakhstan (Ushbulak-1) (Shunkov et al. 2016). Large blades and elongated pointed flakes dominate these assemblages, and there is a prevalence of Upper Palaeolithic tool types in tool sets.

Obi-Rakhmat Grotto is situated 100 km northeast of Tashkent, Republic of Uzbekistan. The site was first studied in the 1960s and excavations through the 1970s yielded more than 40,000 stone artifacts. Excavations were renewed in 1998 with the goal of clarifying the archaeological, geological and environmental sequence. Based on studies of the 1998-1999 collections and a sample of artifacts with accurate provenience from earlier excavations, it is now possible to classify the Obi-Rakhmat industry as initial Upper Paleolithic, showing mixtures of Middle and Upper Paleolithic features. New AMS radiocarbon dates suggest that the local Middle-to-Upper Paleolithic transition began before 50 ka with the majority of lithic assemblages at Obi-Rakhmat spanning the interval from approximately 48 to 40 ka.