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accompanying detrital material is generally fine-grained and 

 cannot be differentiated from fine quartz-feldspar sand. The 

 average heavy mineral content is 2„4% with a minimum of 0.9% 

 and a maximum of 4<,57o. Shells and shell fragments included 

 in the sediment are generally the tests of Foraminifera. 

 Phosporite may occur, but it is limited to trace amounts, 

 probably because the sediment is fine-grained. 



The glauconite is dark green to light brown in color. 

 It has a globular form, often with surficial suture-like 

 markings which allow recognition of either internal casts 

 of Foraminifera or coprolite casts. The glauconite grains 

 range in roundness from .70 to .80 and in sphericity from 

 .80 to .90, The associated detrital material is angular as 

 are shell fragments. Whole shells, on the other hand, are 

 well-rounded. 



Occurrence 



On the shelf and slope north of Santa Monica Canyon, a 

 large patch of glauconite sand occurs in which the glauconite 

 represents 20-30% of the material, the remainder being fine 

 quartz-feldspar sand. On the basin slope off the outer shelf, 

 glauconite sands virtually ring the entire area of phosphorite- 

 glauconite-shell sand. Here the sand contains the highest 

 amounts of glauconite and some of the sand fractions are 

 composed almost exclusively of this mineral. 



A small accumulation of glauconite sand occurs along the 

 outer edge of the shelf and on the slope south of Redondo 

 Canyon. The sand on the slope has a low glauconite content 

 and is, therefore, similar to those sands on the shelf and 



