and side slopes. We can assume that second 

 layer depths exceed 40 feet where the depth 

 is not indicated. Several "ridges" of high 

 velocity (8,000 to 9,000 f.p.s.), unweathered 

 material are present along the bottoms of 

 both vi^atersheds. The velocity of the third 

 layer ranged from 9,000 to 20,000 f.p.s., indi- 

 cating consolidated granitic and unweathered 

 gneiss. 



SoUs 



Soils on the two study watersheds were 

 described and mapped in a medium intensity 

 survey which defined 11 soil mapping units 

 shown on page 52. No attempt was made to 

 place soils in established series. Soil profile de- 

 scriptions are presented in the Appendix, and 

 laboratory analysis of the soils is presented in 

 table 7 of the Appendix. 



A wide variety of soils is found on the two 

 study watersheds. They range from very deep 

 loamy alluvial soils in the valley bottoms (unit 

 16) to very deep clayey soils in colluvium on 

 side slopes (unit 13) and shallow gravelly 



loam on the ridges (unit 10). Soils developing 

 from the metamorphic rocks range from me- 

 dium texture to moderately fine texture, 

 while those developing from sedimentary ma- 

 terial range from moderately fine texture to 

 fine texture. Generally, the soils are deep and 

 have good moisture-holding capacities, except 

 on the ridges. 



Soil units 12 and 13 comprise nearly 55 

 percent of the soils on both watersheds (table 

 2). These soils are very deep loamy and very 

 deep clayey soils, respectively, developed in 

 colluvium on the side slopes. Soil unit 21 

 comprises 15 percent of the total area, but oc- 

 curs mostly in the West Branch. This is a very 

 deep loamy soil found on the side slopes in 

 the lower part of the watershed, but differs 

 from unit 12 in that the parent material is silt- 

 stone and shale instead of the mixed meta- 

 m^orphic parent material of unit 12. Soil unit 

 16, the fourth largest, is a very deep loam de- 

 veloping on alluvial material in the bottom of 

 both drainages. 



The descriptive depths refer to the pedo- 

 logical development and do not necessarily re- 

 flect the hydrologic behavior or water-holding 

 characteristics of the area. The ridge soils 



Table 2. — A comparison of the size and occurrence of the various soil mapping units on the 

 Chicken Creek Watersheds 



Percent of watershed areas 

 exhibiting each soil unit 



Total size 



Soil unit 



(both watersheds) 



East Branch 



West Branch 





Acres 







10 



16.15 



6.7 



3.2 



11 



31.93 



13.6 



6.1 



12 



113.12 



40.4 



26.5 



13 



80.78 



20.3 



24.3 



14 



9.32 



3.3 



2.2 



16 



33.68 



7.4 



10.8 



18 



4.80 





2.2 



19 



2.62 





1-2 



20 



8.93 





4.1 



21 



51.48 



8.3 



18.4 



22 



2.19 





1.0 



8 



