Graphic Representations 863 



▲ Chert (fresh) •) Microfossil 



A Chert (oolitic) o Concretion 



A Chert (detritol) w Carbonaceous material 



X Fine-crystalline ♦ Secondary facets 



X X Medium-crystalline l_j Diatoms 



XXX Coarse- crystalline oo Ooliths 



• Fine-grained ^ Washed residue 



• • Medium-grained m Mineral concentrate 



• •• Coarse-grained O Screen analysis 

 D Pyrite I Insoluble residue 



^K Mica ^ Seismometer station 



•^ Macrofossil vw\ Fracturing 



Figure 435. Miscellaneous symbols used on well logs. Symbols are generally placed 



to left of lithologic column. Purpose of these symbols is to minimize written 



text on log. 



