LoGaN. | The Upper Cretaceous. 2257 
creek from Brookville to Arcola, we notice a narrow valley, bordered 
on each side by shale banks, capped with sandstone. One of these 
shale banks measured 100 feet, being composed of 80 feet of shale, 
overlaid by 20 feet of sandstone. No fossils were found, but gypsum 
crystals, so characteristic of Upper Dakota shales, were abundant. 
One mile west of Terra Cotta a 10 foot outcrop of white sandstone 
is covered by a 25 foot bed of yellow to purplish shales inter- 
calated with thin layers of red or yellow sandstone, containing 
fossil leaves. A few rods to the south a hill 120 feet high is com- 
posed of alternate layers of sandstone and shale. Beginning at the 
top we find 
4th. 25 feet of sandstone, yellowish brown. 
3d. 25 feet of shales, with thin layers of sandstone. 
2d. 10 feet of white sandstone, compact. — 
Ist. 60 feet of shales and sandstone. 
The country from Terra Cotta to Elisworth is very broken and 
the land is used chietly for grazing purposes. A well one‘and a 
half miles west of Terra Cotta passes through 40 feet of shale and 
sandstone to a layer of white sandstone through which the sheet 
water flows. A hill rises 60 feet above, and is capped with brown 
sandstone. A well one half mile south passed through a 6 inch 
vein of lignite in the same shale horizon. 
Benton.—On the divide between Lincoin Center and Ellsworth, 
the first Benton limestone is found. It covers the Dakota sandstone 
hills along this divide and gradually approaches the Smoky Hill 
river. in Russell county it is found capping the first bluff of that 
river. South of the Smoky Hill river the line of contact between the 
Benton and Dakota passes off toward the southwest through the 
northern part of Barton county and across Pawnee county into 
Ford county to its southern limits. It passes toward the north 
through Lincoin, Mitchell, Cloud and Republic counties. The last 
Dakota outcrop on the Smoky Hill river is found near the confluence 
of Big creek in the western part of Russell county. From the mouth 
of Big creek to the mouth of the Hackberry, we pass through the 
divisions of the Benton, in their order, from lowest to the highest. 
The Limestone Group.—The Benton limestone is found in many 
outcrops in the eastern part of Ellis and the western part of 
