TWENTY-SEVENTH ANNUAL MEETING. 235 



the penitentiary shaft it had that thickness. But in that mine away from the 

 shaft, also in the three mines to the north, it is thicker. The average of 15 

 measurements in all the five mines gives 22 and five-twelfths inches for the 

 thickness in the whole worked field, witii enough variation to suggest slight 

 thinning off to the south and west. 



Returning to the consideration of the rocks near the surface we get this 

 section as a succession of strata at Ryan's quarry, south of the sugar factory: 



7. Yellow marl slope. 



6. Weathered limestone 5 feet. 



5. Yellowish and greenish shale ... 3 feet. 



4. Irregularly bedded limestone . . . 14i/^ feet. 



3. Black laminated shale 5 feet 6 inches. 



2. Dimension rock 2 feet. 



1. Gray shale below. 



This succession is very persistent on the Missouri river. It is seen down 

 near the Soldiers' Home, and shows at the Home mine, and partly at Fort 

 Leavenworth. Owing to its surface sometimes being eroded off. No. 4 has 

 been found thinner, and by some persons it is known as "the 13 foot." 



The dimension rock, the black shale, and the 13 foot, rough limestone, 

 are companions that give a key to the geology of this part of the county. 

 At Fort Leavenworth the dimension rock is out of sight under water, and 

 the black shales in the water, and the 13 foot is within two feet of the recent 

 stage of low water. But there are variations. In most places the black shale 

 does not exceed four feet, and in some places the yellow shale (No. 5) is re- 

 duced to two feet, and even to a mere shale parting of less than a foot. No. 6 

 is pierced with holes worn by the weather and water when the river was at a 

 permanently higher stage. With shale partings between its irregular layers 

 it runs up to 15 feet or more, 4, 5 and 6 having an aggregate thickness, where 

 fully developed, of over 30 feet. This thickness is shown towards Fort Leav- 

 enworth. 



Above this section we have shown at much higher levels in the different 

 localities another series, which culminates at the top of Pilot Knob. 



This series near the top is singularly like the section just given. We have 

 it shown at Pilot Knob and in the government quarries west of the fort, thus: 



Rough limestone, 10 feet. (14 feet at Pilot Knob.) 



Laminated buff shale, 2.6 feet. 



Laminated black shale, 3 feet. 



Dimension rock, 2 feet. (1 foot 10.) 



Shale. 



Here are dimension rock, black shale and rough limestone just as at the 

 river bank. It is a repetition. There are 250 feet between the two similar 

 sections, and that space is filled mostly with sandstone and shale, with a few 

 thin layers of limestone and a heavy, jimy, yellow sandstone, of which the 

 governor's house at the Home is built. In this horizon of over 200 feet sand- 

 stones prevail as at Brighton over 30 feet thick, and elsewhere shales. But 

 the shales are often laminated and have flaggy and other sandstones among 

 them, as may be seen in the railway cut on the reservation. They are also 

 black and carbonaceous, and in places develop into coal, as on Salt creek and 

 South Stranger. 



The complete section -would be about thus: 



10. Rough limestone (Pilot Knob) 10 feet. 



9. Black and lighter shale 6 feet. 



8. Dimension rock (upper) 2 feet. 



