208 



SCIENCE 



rN. S. Vol. XXXVII. No. 945 



both now in manuscript, is indispensable 

 to geology. In these papers the strati- 

 graphic value and the practical application 

 of the results of the paleontologic investi- 

 gations are given much prominence. The 

 two papers last named are based on ma- 

 terials gathered in the course of the study 

 of the Coastal Plain already mentioned, the 

 economic motive for which was the investi- 

 gation of the underground water resources. 

 They are therefore representative of a 

 series of scientific reports resulting from 

 studies whose immediate object is economic. 

 The folios describing and mapping in de- 

 tail the geology of quadrangles in diiferent 

 parts of the country are regarded as mainly 

 scientific, though always giving attention 

 to the economic resources of the region. 

 The areal studies now in progress in the 

 valley region of central Alabama, a part of 

 which has been described by Mr. Butts in 

 the Bessemer-Vandiver and Montevallo- 

 Columbiana folios, now in hand, promise 

 important additions to the geologic history 

 of the southern Appalachian region. On 

 the other hand, the Claysville (Pennsyl- 

 vania) folio, which has been issued during 

 the year, affords a striking example of the 

 first-hand aid in oil and gas development 

 to be derived from the careful delineation 

 of geologic structure and its economic ex- 

 planation. Not inferior in scientific value 

 to the papers just cited, though primarily 

 economic, are such reports as those by 

 Messrs. Brooks and Prindle on the Mount 

 McKinley region, Alaska, and by Messrs. 

 Calkins and Emmons on the geology and 

 ore deposits of the Philipsburg quadrangle, 

 in Montana. 



An important and interesting effect upon 

 the scientific work of the Survey has re- 

 sulted from the work in land classification. 

 The constantly increasing demand for both 

 completeness and exactness of information 

 regarding the mineral resources of the pub- 



lic lands under classification have developed 

 methods and scope of view in this economic 

 work that have exerted a marked influence 

 on the folio work in other areas. 



Thus, the training and methods de- 

 veloped in the course of the classification 

 of the coal lands have brought about 

 higher standards of refinement in strati- 

 graphy, as well as in economic work, 

 in other regions of the country. Another 

 very notable illustration of scientific 

 results springing from the study of eco- 

 nomic problems is found in the adminis- 

 tration of the "Weeks Act. The intensive 

 hydrometrie experimental studies carried 

 on in order actually to show, in accordance 

 with the terms of the law, the degree of 

 protection afforded by forests to soil and 

 water in certain areas proposed for pur- 

 chase as national forests have resulted in 

 empirical determinations and demonstra- 

 tions of high scientific value as well as of 

 tangible economic importance. 



The principles governing the origin and 

 mode of occurrence of petroleum and nat- 

 ural gas are as yet but fragmentarily 

 grasped. Every oil field examined in de- 

 tail contributes its data for use in the 

 eventual interpretation of the problems, 

 and each pool is studied with keen alert- 

 ness for the discovery of some key which 

 may aid in the coordination of the data, 

 which sometimes, according to the region 

 and conditions, seem, on account of our 

 lack of knowledge, even to be in conflict. 

 The observations made by the survey geol- 

 ogists in the oil and gas fields of California 

 and Kentucky promise to further the solu- 

 tion of some of the problems, and by point- 

 ing out the relations of oil and gas occur- 

 rence to the geologic structure of the re- 

 gions examined they have rendered im- 

 portant scientific as well as economic aid 

 in oil and gas development; but the basic 



