ABSTRACTS 103 



Converse county, the Laramie Plains, and Bitter Creek valley are 

 described somewhat in detail, and more general observations are given 

 on other localities treated, including Evanston and Hodge's Pass, Wyo- 

 ming ; Coalville, Utah, and Crow Creek, Colorado. The results are nega- 

 tive so far as the Denver and later related formations are concerned. 

 That is, no division of the beds between the base of the Laramie and the 

 Fort Union was found possible, and the Laramie age of the Ceratops 

 beds of Converse county, as well as of the Black Buttes coal horizon, 

 was confirmed. On the Laramie Plains most of the coal-bearing 

 localities are on a horizon lower than the Laramie, and overlain by 

 marine Fox Hills beds. The coal-bearing series at Point of Rocks is 

 also in a similar position, and the considerable flora it has yielded 

 must now be referred to the Montana formation instead of to the 

 Laramie. In this connection all the non-marine invertebrates and 

 plants now known from the Montana formation are brought together 

 in lists, and the more general questions of the upper and lower delim- 

 itation of the Laramie are discussed. 



A Complete Oil- Well Record i// the McDonald Field between the 

 Pittsburg Coal and the Fifth Oil Sand. By L C. White. 

 Geologists have long desired a careful and accurate measurement 

 of the rocks passed through by the borings for oil in southwestern 

 Pennsylvania. Mr. Carll, during the life of the second geological 

 survey of Pennsylvania, had several careful records kept of the borings 

 in Clarion and adjoining counties, but as the strata dip to the south- 

 west, and thicken somewhat, it was very desirable to have a new 

 standard of comparison in southern Pennsylvania. The writer hap- 

 pily found in Mr. T. J. Vandergrift of Jamestown, N. Y., a successful 

 oil operator of many years' experience, the right man to undertake the 

 work purely as a labor of love in the interest of geology. The well 

 in question was drilled by the Woodland Oil Company, of which Mr. 

 Vandergrift is president, on the S. B. Phillips farm in the famous 

 McDonald field, near the line between Allegheny and Washington 

 counties, Pa., about twenty miles southwest from Pittsburg. The pro- 

 ducing rock of this region is the lowest member of the Venango Oil 

 .Sand group, or what is known to oil operators as the Fifth Oil Sand. 

 This rock, it will be remembered, has yielded petroleum in greater 

 quantity than any other yet found on the American continent, since 

 some of the wells of the McDonald region produced oil for a short 



