PREFACE TO THE FIRST EDITION 



During the past fifteen years numerous papers pertaining to methods 

 applied in deciphering subsurface geologic conditions have appeared in periodi- 

 cals such as World Oil, the Oil and Gas Journal, the Petroleum World, the 

 Bulletin of the American Association of Petroleum Geologists, the Bulletin of 

 the Geological Society of America, the Journal of Paleontology, the Journal of 

 Sedimentary Petrology, the Transactions of the American Geophysical Union 

 and publications of the American Institute of Mining and Metallurgical Engi- 

 neers. Commercial organizations have issued in pamphlet form discussions of 

 techniques in the field of subsurface geology that have been highly enlightening. 



Such text and reference books as Petroleum Production Engineering 

 (McGraw-Hill) by Uren, Manual of Sedimentary Petrography (Appleton- 

 Century) by Krumbein and Petti John, Methods of Study of Sediments (Mc- 

 Graw-Hill) by Twenhofel and Tyler, Sedimentary Petrography (Nordeman) by 

 Milner, Sedimentary Rocks (Harper) by Pettijohn and Examination of F rag- 

 mental Rocks (Stanford University Press) by Tickell treat to a degree certain 

 methods applicable to the establishment of subsurface values. 



The need for a publication that would bring together information relating 

 to subsurface geologic techniques that has hitherto been unavailable or scat- 

 tered has long been realized by geologists and petroleum engineers. An attempt 

 to satisfy this need is undertaken in the present text. Subsurface Geologic 

 Methods. Had it not been for the liberal cooperation and interest of the con- 

 tributors to this volume, such a compilation would not have been possible. 

 Special recognition and appreciation are extended to those contributing sections 

 of this text and to the organizations of which they are a part. 



Many illustrations used in this symposium have been obtained from pub- 

 lished sources, credit being given for each. 



The section entitled "Multiple-Differential Thermal Analysis" has been re- 

 printed by permission of the American Mineralogist; those entitled "Induc- 

 tion Logging" and "Dipmeter Surveys" are by permission of the American 

 Institute of Mining and Metallurgical Engineers. The sections "Deep-Well 

 Camera" and "Character of Pores in Oil Sand" are reprinted through the 

 courtesy of World Oil. 



Plans are to revise the symposium periodically as new methods are intro- 

 duced or as the methods discussed are modified. Certain topics in this com- 

 pilation may not be treated as completely as some individuals may wish; those 

 desiring further detail should refer to the articles and publications cited. Criti- 

 cisms and suggestions will be gratefully received by the editor, and these will 

 be considered for subsequent editions. 



It is hoped that Subsurface Geologic Methods will assist geologists and 

 petroleum engineers in the field as well as educational institutions that offer 

 formal courses in subsurface geology. 



June 1, 1949 



