Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/214

 of the older series, which forms, in the south of China at least, the main geological framework of the empire. These rocks are throughout much broken up by faults, the softer portions denuded forming valleys, and then again for the most part filled up by deep deposits of subsequent date. In the valley of the Yangtse the strike generally approaches within a few degrees of E. and W. ; in the southern provinces it is commonly from E.S.E. to W.N.W., or thereabouts ; the strata are constantly either vertical or highly inclined. The series is of considerable thickness, probably from 16,000 to 20,000 feet, or even more. In the central provinces in Kiangsu and Kiangsi the following seems to be the sequence in descending order. From the circumstance of the greater portion of the series being developed in the two Tungting islands in the Taihu, within an easily accessible distance of Shanghai, I have given the formation the provisional title of the Tungting series for future reference.

Tungting series. Limestones Grits

No. 8. Limestones                              Probably 5000 to 6000 feet.

No. 7. Calcareous shales

No. 6. Limestones and dolomites                About 600 to 800 ft. No. 5. Lower coal and iron shales No. 4. Limestone with chert nodules                  800 feet. No. 3. Upper quartzites No. 2. Middle shales and shivery schists            12,000 feet. No. 1. Lower quartzites

The rocks composing this series are thoroughly conformable from first to last, and, as above stated, form the lowest formation I have hitherto been able to fix upon with certainty. They are for the most part destitute of fossils, though in one or two localities they have yielded a few specimens.

No. 1. The Lower Quartzites. — These rocks consist of coarse laminated quartzites or irregular sandstones, sometimes, as in Lower Kiangsu, altered into quartz rock, and occasionally, it is said, containing traces of gold. Occasional oval patches of a lighter colour and finer composition than the matrix occur ; they are totally devoid of structure, but, from their occurrence in Kiangsu and Kiangsi at an interval of 400 miles, as well as in the intermediate district of Nanking, they seem to be characteristic.

No. 2. The Middle Shales. — This may be said to consist of an irregular mass of soft shales, sometimes, as in Lu-shan near Kiukiang, metamorphosed into purple slates of sufficient consistency to be made use of for water-cisterns, &c. ; generally they form a mass of soft shales interspersed with a peculiar series of greenish schists, which split up into small angular spicula on exposure to the air. Though easily shivered into these small fragments, they persistently refuse further disintegration, and often form the surface for many hundred yards, these portions being almost entirely destitute of vegetation. These shales have yielded no fossils within my knowledge.

No. 3. The Upper Quartzites. — These rocks are in a great measure similar to those of No. 1, but are generally of more decidedly arenaceous character, in some of the upper beds forming fine-grained grit- stones, much used by the Chinese for grindstones, set-stones, and