118 University Geological Survey of Kansas. 
tion south of Junction City on the Missouri, Kansas & Texas 
railroad, where it was quarried and burned for lime. It lies 
at the top of the Garrison formation and forms the basal part 
of the Permian rocks which lie above it and fill the space until 
the Cretaceous formations are reached. 
Thickness.—Prosser®** says: “Throughout the Flint Hills 
region it varies from 35 to 55 feet.”’ To the north it becomes 
much thinner, as well as to the south near the Oklahoma line. 
Area.—The Wreford, like all the other formations, has its 
peculiar area and differs little from the others except that, 
standing as it does at or near the crest of the Flint Hills from 
southern Marshall to Cowley counties, it is the underlying rock 
of an extended dip slope at times. It trends, like some of the 
other formations, from Nebraska to the Oklahoma line, and 
the escarpment is always in bold relief except where covered 
north of the Kansas river by the glacial drift. 
Characteristics.—The Wreford limestone carries much more 
chert than any of the limestones before mentioned. It is then 
composed of three strata, a cherty limestone above and below 
separated by heavy limestones nearly free from chert. It 
sometimes carries a thin layer of shale between the cherty 
limestones, as at Reece,®® and in its southern extension it is 
characterized by large blocks of imperfectly silicified lime- 
stone, which weather to a reddish-brown and are very porous. 
They are called “sand rock” by the inhabitants. This abund- 
ance of chert, which is slow of disintegration, and this out- 
crop, probably on the axis of an anticlinal, put it on or near 
the crest of an elevation which from the above facts is called 
the Flint Hills. 
Matfield Shales. 
The Matfield shales were named by Prosser and Beede from 
a township in Chase county. They cover the rapid dip slope 
between two heavy flint formations, the Wreford and the 
Florence flint. 
Thickness.—The Matfield shales range from 60 to 70 feet 
in thickness. 
Area.—The area of the Matfield shales is not very exten- 
94. Prosser, Chas. S.: Jour. of Geol., vol. x, p. 718. 1902. 
95. Beede and Sellards: Am. Geol., xxxvi, Nos. 41-52, p. 97. 1905. 
one Prosser, Chas. S., and Beede, J. W.: Jour. of Geol., vol. x, p. 718, diagram. 
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