Notes on the historical phonology of Indo-Iranian loanwords in Northwestern Tibetan dialects

Recent research has shown that the vocabulary of certain Northwestern Tibetan dialects con-tains a significant number of Indo-Iranian loanwords. It is, however, still unclear if these loanwords have been borrowed from a single or from several sources, and whether their presence is the result of substratum or adstratum interference. Likewise, the exact genetic position of the donor-language(s) within the Indo-Iranian group so far remains undeter-mined. The study of all these issues should, no doubt, be based on facts of historical phonology. In this article I attempt to identify the most conspicuous historical-phonological features of the Indo-Iranian elements found in Northwestern Tibetan varieties. Furthermore, I make some preliminary conclusions concerning the linguistic geography of the region in the pre-Tibetan period, as well as the direction and relative chronology of Tibetan migrations.