114 PROCEEDINGS OF THE AMERICAN ACADEMY 



hills, and I know of one instance only, namely, the Ta-ho range, where 

 they can be observed in an almost undisturbed position ; generally 

 they are inclined at steep angles, and contorted. Granite, in most 

 instances, enters into the structure of these ranges, though in a varying ■ 

 way, now intersecting the strata in large intrusive masses and veins, 

 now accompanying them separately. It has, however, had a compara- 

 tively slight metamorphosing influence. The purer limestone is con- 

 verted into a coarse white marble ; the impure qualities are represented 

 by thick beds of a highly silicious, slightly dolomitic, and imperfectly 

 crystalline limestone of yellow color. The sandstone is partly con- 

 verted into quartzite, and the shale into clay-slate. 



The granite also occurs by itself in mountain ranges. A bold range, 

 prominent by its rugged outlines, as well as by its altitude (about three 

 thousand five hundred feet), which rises abruptly out of the alluvial 

 plain of the Yang-tse near the large city of Ngan-king, and accom- 

 panies the river on its left bank for quite a distance, is completely 

 built up of granite; in a few places only, marble and quartzite indicate 

 detached portions of the strata which were intersected by the granite. 



It is probable that this granitic outburst marks one of the main 

 features in the geology of eastern China, as there is little doubt that 

 to it belongs the granite which, together with porphyry, composes 

 almost exclusively the coast of China between Ningpo and Hong- 

 Kong, a distance of seven hundred geographical miles. I observed 

 it at Suchau, in the group of the Chusan Archipelago, and on the 

 island of Hong-Kong. The granite of these three localities resembles 

 that on the lower Yang-tse, not only in its petrographic character, but 

 also in its geological features, as it is accompanied in these different 

 places by detached and quite irregular portions of altered shales and 

 quartzites. These and marble are mentioned, too, from nearly every 

 place along the granitic coast of which I have any information. If 

 the supposition of this identity, or rather contemporaneity, of the 

 granitic outbursts of eastern China should prove correct, we may look 

 for it as a guide in the geology of eastern Asia in general ; although 

 I am inclined to believe, from former observations in Shantung, that 

 there was still an older granitic epoch, connected with the thorough 

 metamorphism of a more ancient series of formations than those here 

 mentioned. 



5th. Tung-ting sandstone. — All the formations which are now 

 to be mentioned were not affected by the disturbances immediately 



