128 



SCIENCE 



[N. S. Vol. XXVIII. No. 708 



and upper Miocene formations. The petroleum 

 from the Eocene varies in gravity from 20° to 

 42° Baume and the production is usually light, 

 varying from 4 to 75 barrels per day per well. 

 The lower Miocene oil sands are the most im- 

 portant in the field, yielding oil of 14° to 31° 

 Baume. Individual wells produce as high as 

 3,000 barrels a day from the lower Miocene sands. 

 The upper Miocene is petroliferous in the western 

 part of the field, yielding oil of from 14° to 22° 

 Baumg. Wells penetrating this formation seldom 

 yield more than 600 or 800 barrels a day. 



Water occurs in the formation above the oil 

 sands and in some instances sulphur water is 

 interbedded with the petroliferous strata. Little 

 " bottom " or " edge " water has been encoun- 

 tered in the field. The oil is believed to be de- 

 rived from the organic materials in the Eocene 

 shale. There are nearly 400 productive wells in 

 the field, these varying in depth from about 600 

 to over 3,000 feet. Tlie production for 1906 was 

 7,991,039 barrels. The product is marketed by 

 rail and through two long-distance pipe lines, 

 much of it being refined. 



Laramie Formation: Whitman Ceoss. 



It has long been known that the Laramie of 

 King and Hayden has been found to consist of 

 two parts, a lower portion, corresponding to the 

 original definition by King, which is conformable 

 with the underlying Cretaceous section, and an 

 upper portion, separated from the lower by a 

 great unconformity and stratigraphic break in sev- 

 eral localities. In earlier discussions of this ques- 

 tion the author proposed to restrict the use of the 

 term Laramie to such beds as constitute the 

 Tipper conformable part of the Cretaceous section 

 and to apply the term " Post-Laramie " in a 

 tentative way to the group of formations sepa- 

 rated from the Laramie by unconformity or 

 stratigraphic break. 



It has recently been ascertained by A. C. Veatch 

 and others that the long-known formation at 

 Carbon, Wyoming, on the Laramie Plains, is dis- 

 tinctly unconformable upon marine Cretaceous, 

 no true Laramie beds being present at the best 

 known exposures. Governed by the idea that the 

 Carbon section is to be regarded as a type section 

 of the Laramie, as defined by King, Mr. Veatch 

 has proposed to restrict the term Laramie to the 

 formations above the stratigraphic break up to 

 the Fort Union formation. There are thus two 

 Qireetly opposing propositions for the use of the 

 term Laramie. It is claimed by Mr. Cross that 

 the term Laramie was not originally proposed 



especially for strata of southern Wyoming, but as 

 a practical synonym for the term lignitic, and 

 embraced formations known in many places in 

 Montana, Wyoming, Colorado and New Mexico. 

 The definition of Laramie by King mentions no 

 type section and lays emphasis repeatedly upon 

 the conformity of the Laramie with the under- 

 lying Cretaceous section. The Laramie was sup- 

 posed by King to end with the Rocky Mountain 

 revolution, which he assumed to take place pre- 

 ceding the Wasatch epoch. Mr. Cross repeats the 

 proposition previously made to restrict the use 

 of Laramie in accordance with the fvmdamental 

 relations specified in the original definition, rather 

 than to correspond with the local conditions 

 which exist in the Carbon section. 



For the various local formations separated 

 from the Laramie, as thus defined, by uncon- 

 formity or stratigraphic break, and older than 

 the Fort Union beds, Mr. Cross proposes that a 

 new term should be adopted. 



Among the formations to be referred to the new 

 group are the Arapahoe, Denver, Middle Park, 

 Animas, and other local deposits of Colorado; 

 certain beds of Carbon, Evanston and the Con- 

 verse County Ceratops beds of Wyoming; the 

 Livingston and Hell Creek beds of Montana. 

 Certain features of stratigraphy and paleontology 

 were considered and their bearing upon the assign- 

 ment of certain beds to the Laramie or to the 

 new group in certain cases discussed. 



The assignment of the group to the Eocene 

 rather than to the uppermost Cretaceous is ad- 

 vocated by Mr. Cross on the ground that such 

 a division is particularly appropriate viewed 

 from the standpoint of historical geology. The 

 paleontological evidence is not believed to require 

 the assignment of this group to the Cretaceous, 

 and, indeed, much of the evidence is conceived to 

 be in favor of the reference proposed. 



Ralph Abnold, 



THE AMERICAN CHEMICAL SOCIETY. NEW YOEK 

 SECTION 



The ninth regular meeting of the session of 

 1907-8 was held at the Chemist's Club, on Friday 

 evening, June 5. 



Professor Charles F. Chandler addressed the 

 section on " Silk : Natural and Artificial." The 

 lecture was illustrated by stereopticon and by nu- 

 merous samples of raw and finished silk products. 

 C. M. Joyce, 

 Secretary 



