WESTERN HUPEH 13 



5000 feet thick, in the major part composed of dark grey or 

 liver-coloured limestone free from chert and containing both 

 Cambrian and Ordovician fossils. It is, in fact, a great marine 

 limestone in all its phases. It weathers into wonderful escarp- 

 ments, often sheer for 1000 to 2000 feet, with slightly projecting 

 summits, and is frequently many miles in extent. The cliffs 

 on the right bank of the river opposite Nanto, which extend 

 nearly to HwangHng Miao, are typical examples. At one of 

 the major rapids during the low-water season, known as the 

 Hsintan, some 45 miles west of Ichang, a bed of shale is beau- 

 tifully exposed. This bed is some 1800 feet thick, and com- 

 posed principally of olive-green argiUite, with local black shale 

 and quartzite. It is of the Middle Paleozoic age. 



Resting apparently conformably on this series of shale is 

 a vast deposit of Upper Carboniferous limestone 4000 or more 

 feet thick. This is the characteristic formation throughout 

 the Ichang and Mitan Gorges ; it occurs also throughout the 

 western end of the Wushan Gorge and in the Kui Fu (Wind-box) 

 Gorge beyond. The prevailing rock is dark grey or blackish 

 limestone, full of marine fossils and with occasional thin layers 

 of anthracite coal. This also weathers into wonderful escarp- 

 ments, but commonly they are boldly rounded with less linear 

 dimensions. This formation is the most general throughout 

 western Hupeh, on both sides of the river, though greater on 

 the north than on the south, where the Cambrian-Ordovician 

 formation preponderates. Next in succession come the Permo- 

 Mesozoic beds of red shale and sandstone, with thin layers of 

 marine limestone and coal, which were described in reference 

 to Ichang. These beds are characteristic of the country west 

 of the Mitan Gorge, as far as the entrance to the Wushan Gorge, 

 principally on the left bank. Coal occurs in this stretch in many 

 places, more especially around Patung Hsien. Glacial deposits 

 and signs of glacial action are in evidence in many parts of 

 western Hupeh, though nowhere on a large scale. The most 

 accessible of these is on the Yangtsze itself, opposite Nanto, a 

 hamlet situated on the extreme western end of the Ichang Gorge 

 and some 20 miles above Ichang city. At this point can be seen 

 a glacial deposit about 120 feet thick, overlaid by marine lime- 

 stone of the Cambrian-Ordovician age referred to above. All 



