SEDIMENTARY ROCKS 



quartz i tic , red 



conglomeratic 



XJ Siltstone 

 gray 



sandy ,red 



mottled , 

 red S gray 



psuedo oolitic 

 grainy 

 lithographic 

 sub - lithographic 



dolomitic , red 



mottled , red 

 and gray 



METAMORPHIC ROCKS 



i 



IGNEOUS ROCKS 



Acid-r«d pattern 



-, s /> 



Basic- black pattern 



ACCESSORIES 



-r* Orthoclase 



+ Plagioclase 



■^ Glauconite 



v Mica 



□ Pyrite 



x Bentonite 



0* Concretion, nodule <=. o Micro- and-mega- fossils 



C3 Inclusion raa 3*Cool , corb. matter 



j*vH Stylo! ite 

 <M Fractures 



COMBINATIONS 



Dolo- sdy , 

 glauconitic 



Sh- sdy, large 

 qtz. grains 



Poor samples 

 Ls , dolo. 



Covings 



No samples 



Cored 



Plate 3-1. Color chart for well log symbols. The basic lithology color for sandstones is 

 yellow, but the color of the rock is shown by stippling, as in numbers 2 and 5. Only a 

 few lithologic combinations are shown, although a great many additional ones may be 

 indicated by the method illustrated. Occasionally, a new accessory symbol must be 

 devised. The new symbol must not conflict with one already in use, but represent a 

 dissimilar feature. Symbols not representing rocks or minerals, such as oil stains or 

 water, should be plotted adjacent to, but not within, the lithology column. The same 

 hues of blue and yellow must be used for carbonate and coarse clastic rocks; otherwise, 

 the symbol might be confused with the color representation of certain shales. 



