298 PRINCIPLES OF STRATIGRAPHY 



texture or origin. This is already done in the familiar terms 

 limestone, claystone, ironstone, etc. While these terms are good 

 and useful, more euphonious technical terms might be found pref- 

 erable in some cases. Such terms should eird in itli, or yte, to 

 signify that they refer to rock masses rather than minerals. Thus 

 rocks composed chiefly of the mineral calcite, or whatever origin, 

 i. c. limestones, may be termed calciliths or calcilytes. 

 Thus we may have : 



quartz rocks or siliciliths or silicilytes 



limestones or calciliths or calcilytes 



dolomite rock or dolomiths (dolomiliths) or dolomytes (dolomilytes) 



gypsum rock or gypsolith or gypsolytes 



claystones or rocks or argilliths or argillytes 



iron stones or ferriliths or ferrilytes 



carbon rocks (coals, peats, etc.) or carbonoliths or carbonolytes 



rock salt or haliliths or halilytes 



Autochthonous''' and Allochthonous'\ Deposits. These terms 

 were first introduced by Gumbel in 1883 to designate: the first, 

 deposits (especially coal) formed in situ, and the second, deposits 

 made from transported material. The first comprises all hydro- 

 genic and many biogenic deposits, although deep-sea oozes are al- 

 lochthonous. Coal formed from vegetation in situ is autochtho- 

 nous, while transported vegetal matter forms allochthonous coal. 

 Clastic deposits are typically allochthonous. 



BIBLIOGRAPHY VI. 



1. CHAMBERLIN, T. C, £fnd SALISBURY, R. Preliminary paper on the 



driftless area of the Upper Mississippi Valley. Sixth annual report, 

 U. S. Geological Survey, pp. 199-322. 



2. CHAMBERLIN, T C., and SALISBURY, R. 1906. Geology, Vols. I 



and IL 



3. CROSBY, W. O. 1908. Report of the State Water Supply Commission. 



Progress Report for 1907, p. 205. 



4. CROSS, WHITMAN ; IDDINGS, JOSEPH P. ; PIRSSON, LOUIS, V., and 



WASHINGTON, HENRY S. 1903. Quantitative Classification of 

 igneous rocks based on chemical and mineral characters, with a systematic 

 nomenclature. 



5. DAUBREE, A. 1879. Etudes Synthetiques de Geologie Experimentale. 



Paris. 



* avrbs (aiitos), self; x^^^"^ {chthon), the earth; i.e., belonging to the same 

 earth. 



t aXXos (alios), another; x^^"^ {chthon), the earth, i.e., from another region. 



