STEELE COUNTY. 397 



Trees and shrubs. Geological structure.] 



2' fees and shrubs of Steele count;/. 



Tilia Americana, L. Basswood. Cornus paniculata. L'Her. Dogwood. 



Bhus glabra, L. Smooth sumac. Symphoricarpus occidentalis, 7?. Br. Wolfben-y. 



Vitis Wild grape. Fraxinus. Ash. 



Ampelopsis quinquefolia, Michs. Virginia I'lmus fulva, Mich. Slippery elm. 



creeper. Ulrmis Americana, L. White elm. 



Ceanothus Americana, L. New Jersey tea. Juglans cinerea, L. Butternut. 



Acer saccharinum, Wang. Sugar maple. Juglans nigra. L. Black walnut. 



Acer dasycarpum, Ehr. Silver maple. Carya. Hickory. 



Acer rnbrum, L. Ked or swamp maple. Quercus macrocarpa. Mn-hx. Bur oak. 



Negundo aceroides, Mnench. Box-elder. Quercus coccinea. WHIKJ.. var. tinrto.ia, Gray. 

 Amorpha frnticosa. L. False indigo. Black oak. 



Frunus Americana, Marshall. Wild yellow or Corylus Americana, Wall. Ha/.elnut. 



red plum. Ostrya Virginica, Willd. 



Primus. Cherry. Populus tremuloides, Mickx. American aspen. 



Rubus strigosus, Michx. Red raspberry. Populus grandidentata. Mii-lu-. L-irge-toothed 

 Kubus villosus. AH. Blackberry. aspen. 



Pirns coronaria, L. American crab-apple. Populus monilifera. Ait. Cottonwood. 



GEOLOGICAL STRUCTURE. 



The glacial drift is so thick that it effectually conceals the underlying 

 strata throughout this county, excepting slight exposures of the bed-rock 

 in the valley of Straight river at and near Lindersmith's, two to three miles 

 north of Owatonna. This rock has been referred, with some doubt, to the 

 Hudson River epoch by Prof. Winchell. It certainly falls within the Tren- 

 ton period, and may be lower than Hudson River. 



The rock is an argillaceous and dolomitic limestone, and is first met at 

 John Abbott's quarry, in section 83. Clinton Falls. It is in the bed and 

 on the low banks of Straight river. The exposure at the time of examina- 

 tion extended only about four feet above the surface of the water. The 

 rock is in horizontal layers, two to six inches thick. It is blue on fresh 

 fracture, yellow when weathered, compact, sparry, and contains many 

 minute fragments of blue shale. The loamy clay overlying was evidently 

 not deposited by glacier ice, the rock in *ifn being rotted with age, like 

 much of the rock in northeastern Iowa. 



Just below, on section 28, is Lindersmith's quarry. The rock is in 

 thicker layers than in Abbott's quarry. The following section was seen 

 in one place, beginning above: 



Loam 2 feet. 



Black clay and limestone, in thin layers 2 feet. 



Compact, blue limestone, in thin layers, to water's surface : 4 feet. 



The rock is like that in Abbott's quarry. Near by was another section 

 as follows: 



