100 THE UNIVERSITY OF OKLAHOMA 



Whi'.e at this particular location the quantity of phosphate pres- 

 ent is limited to a few tons of material, there are strong possibilities, 

 since similar conditions prevail over a widespread area in the 

 Wichita beds of the Permian both in this state and in Texas and 

 since phosphatic rocks have been observed in the same formations 

 of the latter state, that large commercial deposits may, on further 

 search, be located in this territory. However, even if this be not 

 realized, the location above mentioned will probably be extremely 

 interesting as throwing light on the origin of phosphate rock de- 

 posits from a strictly scientific standpoint, as the following observa- 

 tions may disclose. 



The phosphate has evidently come up in water solution and been 



Fig. 3. Phosphate Nodule. NE of SB^ Sec. 33 T. 4 S., R. 



9 W. 1. mile N of extreme SE Corner of Cotton County, Okla- 

 homa. Natural Size. A, C. Shead. 



deposited along with its associated minerals, notably malachite, in 

 cracks of the maroon colored joint clay, which acted as a mould 

 for the phosphate. The fact that it exists in such a material where 

 cracks must necessarily be transient owing to creep, wash, and 

 flowage, argues a rapid deposition of the material and not a long 

 continued geological process in its formation. These veins of 

 mineral, originally continuous, crack transversely at frequent inter- 

 vals into vertebrae or back bone like stringers, presumably under the' 

 influence of the creep of the containing clay along the slopes. Upon 

 further movement of the enclosing clay the thin veins are broken 

 up into blocks of a size dependent upon the interval of the previous 

 jointing and lie scattered over the slope of the hill. Further move- 

 ment causes fragments to chip off the thin edges and corners of the 

 brittle material and the rounded nodular form to develop, that is 

 characteristic of the form in which tliey are now found. All these 



