COROCORO COPPER DISTRICT OF BOLIVIA 25 



Meters 



7.50 Sandstones and shales 

 1.50 Conglomeratic sandstone 

 12.75 Red shales and interbedded sandstones 



27.75 Gray to light-reddish sandstone ledges with some shale bands 

 4.50 Reddish shales 

 4.50 Pebble conglomerate 



105.00 Grayish sandstones and shales to across the quebrada 

 1.80 Gray irreguarly-bedded sandstone, copper stained for 2 to 



3 feet, with many casts of plant stems 

 3.75 Reddish sandstone 



2.25 Gray sandstone with black stained pockets 

 5.25 Shaly sandstone with non-persistent copper streak at top 

 3.00 Coarse friable light-brownish sandstone with black stained 



bands 



3.00 Soft red shaly sandstone 



6.57 Similar more massive sandstone, the upper 10 inches black 

 2.40 Becoming thin-bedded with narrow shaly bands copper- 

 stained, no plants 

 4.50 Gray sandstone 

 1.50 Red shale 

 i. 80 2.40 Gray cross-bedded hard sandstone with quartz 



gravel below 

 3.90 Red shale 



1.20 Soft, black-stained sandstone 

 6.00 Red shale 

 1.20 Gray sandstone 

 2.40 Red shale 

 .60 Gray sandstone 

 1.20 Red shale 

 3.00 Gray sandstone 

 .15 .30 Copper-stained band with clay pellets, no determin- 



able plants 

 2. ic Gray sandstone 



.20 Shale band 

 2.25 Gray sandstone 

 15.00 Red shale 



6.00 Coarse pinkish-buff sandstone ledge 

 16.50 Interbedded red shales and sandstones 

 .go Thin-bedded gray sandstone, black tilong bedding planes 

 .37 Compact gray sandstone 



.12 Hackly thin-bedded tufaceous sandstone with plant frag- 

 ments 



