w 



t 



Figure 8-3. Electron-microscope picture of Attapulgus clay (X20,000). Note minute 

 fibers and bundles of fibers, with very few larger grains. These average less than 

 Vs fi (= 0.000125 mm) in diameter and are of colloid size. (Courtesy R.C.A. Lab- 

 oratories and Standard Oil Development Company.) 



or even noted under a light microscope could provide the means for bed identifi- 

 cation. This would involve the development of electron micropaleontology, 

 wherein organic forms far below the smallest fossil known would be studied. 



3. Structural details of clays, pertaining to possible physical and physico- 

 chemical properties of the clays, should lend themselves to study in the electron 

 microscope. The importance of this point might be stressed by suggesting that 

 the electron microscope is believed to be capable of resolving giant molecules. 

 At these particle sizes the physical and chemical properties would be dependent 

 one upon the other and should be difficult to separate. 



4. In the same general way, clay residues from limestones might be studied. 

 Identification would depend upon the structural details and perhaps the mineral- 

 ogy. Chemical or spectrographs methods of study would probably be of more 

 value here than would the electron microscope. 



5. Physical studies of the response of clays to the high vacuum in the elec- 

 tron microscope and changes due to the electron bombardment, with subsequent 

 heating of the samples, might yield significant similarities and differences of 

 correlative value. 



146 



