22 Subsurface Geologic Methods 



(/) In proposing a new name for a subsurface unit, it is desirable to de- 

 scribe for the type section the following features: 



(1) Location of the type locality well; name of operating company or 

 individual; date of drilling; results and present status of the well; elevation 

 of surface at the well and depths to top and bottom of the new unit. 



(2) If all data needed to establish the type section properly cannot be 

 furnished from one well, two or more wells shall be used and the data called 

 for under (1) shall be furnished for each well so used. 



(3) As complete a section as possible shall be described in detail from 

 cores of the new unit. Where sample logs are available, critical portions of 

 them shall be included in written or graphic form or both. The boundaries 

 and subdivisions, if any, of the new unit shall be indicated clearly in these logs 

 and core records. 



(4) Where electrical or other mechanically recorded logs are available, 

 the critical parts of such logs, preferably of several wells located in a single 

 area, shall be published in the article proposing the new named unit. The 

 boundaries and subdivisions, if any, of the new unit shall be marked plainly 

 on these published logs, which shall be on a scale large enough to permit full 

 appreciation of all details of the new unit. 



(5) Fauna and flora. Diagnostic fossils of the new unit shall be described 

 in detail and, if possible, figured. Description and figuring of diagnostic fossils 

 are essential if the new unit is a time-rock unit. 



(6) Nature of underlying and overlying units. 



(7) Correlation and position in the general stratigraphic scale. 



(8) Present location of the cuttings or samples. 



(9) Present location of the fossils. 



(10) Critical parts of written driller's logs of all wells used, unless these 

 are considered to be so inaccurate that their inclusion would be confusing. 



(g) The cuttings and the fossils, accompanied by copies of all available 

 types of logs should be placed in some official, permanent depository. As a 

 rule, the appropriate state geological survey will serve as such a depository. 



(h) The editorial staffs of all publishing agencies are urged to insist that 

 the provisions of this article be followed in detail whenever a subsurface unit is 

 being given a name. 



Facies Concept 



Although the principle of facies and facies changes has long been 

 recognized by stratigraphers, it has only been during the past ten years 

 that more serious consideration has been given the concept. Those in- 

 terested in sedimentary facies are referred to the following: "Intertongu- 

 ing Upper Cretaceous Deposits" by W. S. Pike, Jr., (Geol. Soc. America 

 Mem. 24, 1947), "Sedimentary Facies in Geologic History" (Symposium) 

 (Geol. Soc. America Mem. 39, 1949) and "Sedimentary Facies in Gulf 

 Coast" by S. W. Lowman (Am. Assoc. Petroleum Geologists Bull., vol. 33, 

 no. 12, pp. 1939-1997, Dec. 1949). 



Neglect of the facies concept in stratigraphic geology has led to many 

 questionable and ill-founded correlations. The recognition and evaluation 

 of facies changes are cardinal to the proper establishment of the strati- 

 graphic and structural fabric of any area. 



The term "facies" has been variously interpreted by stratigraphers, 



