18 Annals of the Carnegie Museum. 



Section G, on tributary gully 4, western side of valley. 



Base of gray Madison limestone. 



1. Yellow sandy limestone 44 feet 



2. Finely laminated pale yellow arenaceous shale, lower five 



feet drab colored and argillaceous 28 



3. Fissile purplish black shale 19 



4. Gray limestone 8 



5a. Finely laminated green shales 75 



5b. Yellowish and purplish white shale 45 



6. Yellow limestone with calcite veins 15 



7. Reddish yellow shales 45 



Total 279 feet. 



Section H, between tributary gullies 4 and 5 on the western side of 

 the valley. 



Base of yellow shale No. 2. 



3. Purplish black coaly shale 15.3 feet. 



Top of limestone No. 4. 



Section I, on fifth gully on western side of valley. 



Base of gray Madison limestone. 



1. Yellow sandy limestone, ] 



2. Yellow shales, 1 ^ 



y 93 feet. 



3. Purplish shales, j 



4. Gray limestone, J 



5. Green finely laminated shales 77 feet. 



5a. Purple and yellow soft argillaceous shales 51 



6. Yellow limestone with calcite veins. 

 Lower part of section obscured. 



Section J, at the southern end of this western Three Forks valley. 

 Here the strata have a strike of about N. 40° E. and a dip of 20° W. 



Base of gray Madison limestone. 



1. Yellow standstone 17 feet. 



2. Laminated yellow shale 10 



2a. Yellowish white limestone 2.5 



3. Purplish gray shale 5 



4. Gray nodular limestone 3 



5. Fissile green shales 54 



5a. Whitish yellow argillaceous shales 14 



(Dr. Raymond's white blocky shale?) 

 5b. Finely laminated yellowish green and locally reddish shale 7 



(Dr. Raymond's red shale?) 

 Top of Orange limestone No. 6. 



