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MICROPALEONTO 



LOGICAL 



ANALYSIS 



William S. Hoffmeister 



INTRODUCTION Micropaleontology, which is the science con- 



cerned with the study of ancient life, is 

 useful for geologic and ecologic interpretations. Organisms, both animal 

 and plant, that have left their remains or traces in the sedimentary strata of the 

 geologic column are classified as fossils which are conveniently divided into two 

 major groups: (1) macrofossils and (2) microfossils. As the names imply, 

 macrofossils may be studied without a magnifying glass or microscope; micro- 

 fossils are small forms that can be studied only at high magnifications. 



Duties of Micropaleontologist 



Although the duties of an economic micropaleontologist are largely con- 

 cerned with the microfossils, a part of his time must be devoted to other tech- 

 niques that aid in the solution of stratigraphic problems encountered in routine 

 examination of samples. The few macrofossils found in well samples are com- 

 monly so broken by the drilling bit that identification is difficult. By far, the 

 best tools for paleontological and paleoecological interpretations are the micro- 

 fossils, although macrofossils are useful especially in Paleozoic rocks. 



The purpose of this paper is to summarize: (1) the different types of micro- 

 fossils likely to be encountered in well cuttings or cores; (2) their general de- 



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