CHAPTER XIV. 
GEOLOGY OF CENTRAL SHEN-SI, 
By BAILEY WILLIS AND ELIOT BLACKWELDER. 

OBSERVATIONS IN THE HAN PROVINCE. 
TS’IN-LING-SHAN AND HAN VALLEY. 
General statement.—The Ts’in-ling mountains and the Han valley 
constitute a special geologic province, by reason of the regional meta- 
morphism which the rocks have suffered. This province we designate 
simply the Han Province. 
Along our route the T’ai-shan (Archean) complex is not represented. 
Apart from intrusive masses, among which granite predominates, the 
rocks are of sedimentary origin and include some Algonkian, the Paleo- 
zoic from Cambro-Ordovician to Carboniferous, and probably some Meso- 
zoic. They are converted into metamorphic rocks, among which we 
distinguish certain series or formations that we correlate tentatively with 
those of the Yang-tzi province, where the strata are not altered and the 
age is determined by fossils. 
We entered this geologic province at the north, where metamorphism 
is most intense, and proceeded diagonally across it toward the south; 
and we observed the true sequence of formations, as it is exposed on the 
Ta-ning-ho and Yang-tzi sections, only after we had left the region of 
metamorphism. It follows that we reached a partial and tentative under- 
standing of the relations of the schists only through the subsequent study 
of our notes, and we no doubt failed to observe important facts, which 
we might have seen had we known where to look for distinctive evidence. 
The geology of the Ts’in-ling-shan and Han valley will offer but little 
difficulty if thoroughly surveyed. Even the pioneer work of von Rich- 
thofen approximated the true relations, and the supplementary recon- 
naissances by Léczy and ourselves enable us to sketch a reasonably reliable 
outline of the sequence and distribution of the rocks. In the following 
pages we jointly discuss our observations and our inferences of stratigraphy 
and structure, for each locality, thus departing from the plan pursued in 
other chapters of this report. The available data are not sufficient to 
furnish an adequate basis for the more systematic treatment. 
In order to have available a general term for the metamorphic Paleo- 
zoic and Mesozoic rocks of the Han province, we shall designate them the 
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