Fig. 2

Generalized geologic map of the summit area of Mt. Baekdu (modified from Wei et al. 2013). [1; alluvial sandstone and conglomerate bed of modern river-bed, 2; fan earth flow inside and outside the Cheonji caldera lake, 3; gray trachytic pumice and debris sedimentation on No. 6 boundary line monument (1903 AD), 4; mid-term fan earth flow inside the caldera, 5; black trachytic pumice around the Cheonji on No. 5 boundary line monument (AD 1702 eruption), 6; black trachytic welded tuff breccia of upper Palgoimyo (1668 AD), 7; black trachytic pumice of lower Palgoimyo (1668 AD), 8; early fan earth flow inside the caldera, 9; sedimentation side and top of caldera, 10; black and gray–black earth flow outside volcanic cone, 11; black and gray–black trachytic pyroclastic flow (AD 946 eruption), 12; gray–black pumice of the south-side Cheonji, 13; Gisangcheomgi clastic alkali rhyolite, obsidian, welded tuff, 14; light gray and gray–purple alkali rhyolitic cataclastic rock, 15; Baiyunfeng light gray alkali rhyolitic pumice, 16; shanti talus, 17; Bingchang gray–purple and dark grey welded breccia, tuff (erupt five thousand years ago), 18; Cheonmunbong gray–orange alkali rhyolitic pumice, 19; lower orange-yellow pumice, welded tuff breccia, upper trachyte, alkali rhyolite, obsidian, 21; Laohudong (plateau) basalt (0.32–0.35 Ma), 22; Baekdusan lower trachyte, 23; alkali rhyolitic dike, 24; trachytic dike, 25; collapse fault, 26; a paddle wheel fault, 27; fault, 28; border, 29; isobath of Cheonji caldera lake, 30; Cheonmunbong]. Cheonji: Tianch in Chinese, Palgoimyo: Baguamiao in Chinese, Gisangcheomgi: Qixiangzham in Chinese, Cheonmunbong: Tianwenfeng in Chinese