REVIEWS. 



Geology of the Yancitse Estuary below Wuhu. By V. K. 

 Ting. Whangjjoo Conservancy Board. Shanghai Harbour 

 Investigation, Series 1, No. 1. pj:*. 84. Shanghai, 1919. 



rpHIS work is divided into four sections, deaUng with (1) 

 -■- stratigraphy, (2) structural geology, (3) johysiography, and 

 (4) history of the Yangtse Estuary. 



The greater number of the deposits are Palaeozoic, the earliest 

 fossiliferous beds having yielded an Ordovician fauna. These are 

 succeeded by quartzites doubtfully referred to the Devonian system. 

 The Carboniferous is divided into Lower and Upper Carboniferous 

 Limestones, with Middle Carboniferous containing the Nankao Coal 

 series between. The Limgtan Coal series is referred to the Permian, 

 and a succeeding limestone to the Permian or Triassic system. 

 No undoubted Mesozoic rocks have been determined in the area, 

 though the strata of another coal-bearing group at no great distance 

 away have yielded a fossil flora thought to be undoubtedly of Ehsetic 

 age. The next deposit in order of age is the Tat'ung conglomerate 

 of Tertiary age, concerning the formation of which there is a 

 difference of opinion. The question is discussed by the author. 

 Upon this conglomerate reposes loess, which is the newest deposit 

 except the alluvium. 



An account of the igneous rocks includes descriptions of granites, 

 intrusive porphyritic rocks, rhyolitic and trachytic lavas, and 

 basalts. 



The structural section deals with the tectonics of the region. A 

 general account of the physiography follows. The historical sketch 

 treats of the question of the theory of ancient mouths of the Yangtse, 

 the growth of its delta in historic times, and the origin of the 

 Whangpoo River. 



The area forms part of the ground traversed by Richthofen, 

 whose work is recorded, but much that is new is added, and some of 

 Richthofen's views are criticized. 



The work is illustrated by a coloured folding map of the geology, 

 many other geological maps and sections, and photographic 

 illustrations, and is a valuable descri2:)tion of an area by an up-to- 

 date geologist. 



The work was undertaken for a specific purpose, the investigation 

 of the hydrography of the Yangtse Estuary. We look forward to 

 the production of important geological memoirs of other areas by 

 Mr. Ting (who is Director of the Government Geological Survey) 

 and his assistant surveyors. 



J. E. M. 



