MARINE DEPOSITS OF PATAGONIA 191 



Some white sand grains in the finer grades. Silt yellow to yellowish green. Two samples, WS 83, 

 WS 246 (192 m.). 



Type A 4. Medium grades consist of shell fragments ; grey stones, pebbles and gravel, with large 

 fragments of shell (clam, Pecten and brachiopod), especially in WS 825, in the coarser grades. A large 

 admixture of white and clear sand grains in the finer grades, which are similar to those of group B. 

 Silt buffish grey. This type consists of almost equal parts of types A 1 and B 1. Three samples, WS 84, 

 WS 228, WS 825. 



Type A 5. Finer grades consist of shell, coral, and calcareous polyzoan fragments; brown and 

 grey stones much encrusted with calcareous Polyzoa, small bivalve shells, large fragments of 

 Polyzoa, grey and brown gravel in the coarser grades. Silt yellowish buff. One sample, WS 88. 



GROUP B. WHITE AND YELLOWISH-WHITE SANDS 



Type B 1 . A fine yellowish-white silver sand with very few dark grey grains. Silt yellow. One 

 sample, WS 823. 



Type B2. A fine yellowish-white silver sand with a greenish tint owing to the green or greyish- 

 green colour of the silt. Some small shell fragments and dark and light grey sand grains. In WS 230 

 some small transparent green angular fragments. Six samples, WS 227, WS 229, WS 230, WS 781, 

 WS 782, WS 824. 



Type B3. Fine yellowish-white silver sand with a greenish tint owing to the green or greyish- 

 green colour of the silt, differing from type B 2 in the larger proportion of large shell fragments and 

 dark grey stones and pebbles. In the finer grades a large proportion of transparent greenish grains. 

 One sample, WS 248. 



Type B4. Fine yellowish-white silver sand conspicuously speckled with an admixture of dark 

 grey and black grains, and with a small proportion of transparent green grains. At WS 246 (267 m.), 

 pinkish grey pebbles and some brown and yellow gravel. Silt yellowish brown to greenish brown. 

 Two samples, WS 246 (267 m.), WS 250. 



GROUP C. BROWN SANDS 



Type Ci. Light brown speckled sands, with a few shell fragments in the coarser grades, and an 

 admixture of white, black and grey grains in the finer grades. Silt brown to brownish green. Six 

 samples, WS 219, WS 220, WS 787, WS 796, WS 808, WS 809. 



Type C2. Darker brown sands of less speckled appearance and finer texture than type Ci. 

 A few small bivalve shells and worm tubes in the coarse grades of some samples, and a small ad- 

 mixture of black and white grains in the finer grades. A few Foraminifera in some samples. Silt 

 yellowish to brownish green. Six samples, WS 235, WS 765, WS 771, WS 774, WS 792, WS 801. 



Type C3. Light brown sands with a large proportion of clear and white grains and a small pro- 

 portion of dark ones. Shell fragments and brown pebbles in the coarser grades. Silt brown. Three 

 samples, WS 96, WS 222, WS 772. 



Type C4. Darker brown speckled sands with a large proportion of black grains as well as white 

 ones. Texture coarser than the preceding types of group C. Some samples with shell fragments, or 

 worm tubes made of sand, in the coarser grades. Silt brown to brownish green. Four samples, 

 WS 94, WS 226, WS 240, WS 806. 



Type C5. Darker brown sands with a large proportion of black grains and fewer white ones. 

 Texture coarser than type C4., with black, grey, brown and yellow gravel. In the coarser grades dark 

 grey stones, coral, and calcareous polyzoan fragments, worm tubes both calcareous and made of 

 sand or gravel, small shells and echinoderm spines. Four samples, WS 95, WS 799, WS 807, WS 837. 



Type C6. Brown sands with a large admixture of calcareous matter producing a conspicuous 

 speckling of white. Some brown and grey pebbles in the coarser grades, with coral and calcareous 



