ABSTRACTS OF PAPERS 149 



or aquatic, coals, ami consequently are of similar origin. The conclusion is 

 reached that all the main types of coal represent organic deposits slowly 

 accumulated under open water in more or less tranquil lakes, lagoons, or 

 estuaries. The in situ hypothesis of the origin of coal is based on complete 

 ignorance of the organization of coal, which has been revealed by improved 

 methods in recent years. 



Presented without notes, with the use of lantern slides. 



ORGANIZATION OF PENNSYLVANIAN ANTHRACITE AND THE PEAT 

 HYPOTHESES OF THE ORIGIN OF COAL 



BY EDWARD C JEFFREY 



(Abstract) 



The author, after repeated efforts, has devised methods of making trans- 

 parent sections of Pennsylvania anthracite. Photomicrographs of these are 

 shown and conclusions are drawn as to the conditions of formation of anthra- 

 cite. The bearing of the facts, for the first time set forth, upon the hypothesis 

 of the derivation of anthracite as the end product of the metamorphosis of 

 peat is discussed. 



Presented extemporaneously. Illustrated by lantern slides. 

 Discussed by James F. Kemp, with reply by the author. 



ORE DEPOSITS OF LEADVILLE, COLORADO 

 BY G. F. LOUGHLIN 



(Abstract) 



A summary of features in the new Leadville monograph, namely, the work 

 of the late Prof. J. D. Irving, that differ from those in Emmons' original 

 monograph. The principal topics considered are (1) pre-mineral deformation, 

 including igneous intrusions, Assuring, and normal faulting and overthrust 

 faulting; (2) ore deposition and the relations of the three classes of deposits 

 (contact nietamorphic bodies, "blankets," and fissure veins) ; (3) post-mineral 

 faulting; (4) ore reserves. 



Presented by title in the absence of the author. 



ANTIMONY MINES OF SHIU CHO^Y, CHINA 

 BY GKORGE D. HUBBARD 



(Abstract) 



Shiu Chow is located at the north end of a railroad leading north from 

 Canton toward Hankow, in the province of Kwangtung. The topography is 

 advanced mature in Paleozoic rocks ranging in age probably from Ordovician 

 to Carboniferous, inclusive. 



The ores are stibnite below and cervantite in the weather zone. The former 



