INDEPENDENCE SHALE NEAR BRANDON 487 



stone. For some twenty yards below this point the Hmestone is 

 arched up into a low anticline and is considerably broken and jointed. 

 This limestone contains Cedar Valley fossils characteristic of the 

 lower part of that terrane. On the upstream side for a short distance 

 the bank of the stream is sodded over. Still farther upstream the low 

 limestone ledges are more weathered than in the anticline below and 

 contain Cedar Valley fossils similar to those found back of the ceme- 

 tery a half mile or more downstream. 



The shale is dark bluish to gray in color, plastic and where weath- 

 ered is yellowish with reddish streaks. It shows no bedding but 

 there are occasional small blocks that show faint lamination and in 

 some cases smoothed and slicken-sided faces. Irregular blocks of 

 a harder, tougher, and more calcareous shale occur and there are 

 also small nodules of pyrite and angular blocks of hard limestone. 

 Fossils are fairly common and typical ; to some of them cling crys- 

 tals of pyrite as is the case with some of the fossils collected by 

 Calvin and Deering at Independence. In the bend of the stream's 

 bed and almost in contact with the shale is a large block of Lower 

 Diavenport limestone showing the characteristic brecciation and 

 other unmistakable features of that formation. The block is angu- 

 lar, is three by five feet in dimensions, and is larger than any 

 handled by the stream in flood. No exposures of the Lower Daven- 

 port are known up the valley. We must conclude that the block is 

 intimately associated with the shale and is of the same derivation 

 as the smaller angular limestone pieces incorporated in it. 



Exposure No. 2. — This exposure is on the left bank of Lime creek 

 a few rods down stream from No. 1 and near the south line of the 

 northwest quarter of section 26. The bank of the creek here is 

 flanked by a low ledge of limestone, a gap in which makes a sloping 

 declivity for a distance of three or four rods. This slope is much 

 trampled by cattle which, use it as an approach to the water. At 

 three or four places in this gap the shale is exposed, chiefly near 

 the water's edge, but at one point near the upstream end the shale 

 can be traced up the acclivity for six or seven feet. Digging ex- 

 posed a width of nearly as much. At this point, too, the shale and 

 limestone are separated laterally in much the same way as at the 

 downstream end of Exposure No. 1 except that the zone of coarse 

 material between them is narrower. Both the shale and the adja- 

 cent horizontally lying limestone pass beneath the drift. 



The shale is gray, tough and plastic; it is unstratified and con- 

 tains blocks of tougher clay and angular fragments of limestone. 



