This map can be found in appendix to the second volume of Труды тибетской экспедиции 1889-1890 гг. подъ начальствомъ М. В. Певцова [Works of the Tibetan expeditions 1889–1890 under the authority of M. V. Pevtsov] edited by M. V. Pevtsov and published by the Russian Geographical Society in 1892.
Based on data compiled by the geologist and mining engineer, K.I. Bogdanovich, this sketch-map illustrates gold mines found close to the town of Sorgak, located south of the ancient city of Niya and southeast of Keriya. The gold mines are marked with dots in this map.
Seven other maps can be found in appendix to the same volume: one large-scale overview of Eastern Turkestan and five small-scaled route surveys of areas to the south and west of the Takla Makan Desert, as well as another sketch-map of an area with gold mines.