297 



RECENT FORMATIONS. CONGLOMERATE. 



In the county of Berrien some very extensive forniations of this sin- 

 gular rock occur. They are of recent origin, compared with all the 

 other rocks, and both in age and formation, may be classed with the 

 marls and tufjis. A stratum of gravel, cemented vvith lime, appears to 

 be very universal throughout this county, at depth cff a few feet, and ex- 

 tensive masses, strongly cemented, are frequently found exposed in the 

 faces of ravines and banks of streams, appearing like ledges of rock in 

 place. 



At Millburg, eight miles east of St. Joseph, a rock of this description 

 was traced along the bank of Blue Creek, for half a mile. In appear- 

 ance, it is a continuous ledge of very hard sandrock, varying in thick- 

 ness from ten to fifteen feet. It consists of coarse sand, cemented by 

 the infiltration of carbonate of lime, unbroken by seams, and which has 

 become exceedingly hard on exposure. It may be quarried by blasting, 

 in blocks of any required dimensions, dresses with facility, and will an- 

 swer admirably for many economical purposes. 



About two miles north-east of Berrien, this rock was seen under simi- 

 lar circumstances, in the bank of a small creek, forming an outcropping 

 ledge, exceeding eight feet in thickness. It is found also at several 

 points higher up the stream, and in the sides of hills in the vicinity. 

 Portions of this ledge are of finer grain than that at Millburg, having 

 a stratified appearance, and are disposed to cleave horizontally. Blocks 

 have been removed and used for fire-jambs; in which capacity they 

 have stood the test of two years service. 



Similar formations occur in town three north, eight west, section 

 twenty-four, in town of Oronoko, at Singer's Lake, and in the deep ra- 

 vines east of New Bufi^alo. At the latter places the rock bears more 

 the appearance of crag, being composed mostly of coarse pebbles. 



The conglomerate, at all these places, is in isohited masses, of local 

 origin, and probably does not extend many feet into the hill-sides. 

 Quarries will therefore eventually be found to run out. 



" Hard pans," which may be referred to a similar origin, are not un- 

 common among the diluvial strata even at consitlerable depths. The 

 cementing material is not unfrequently, in part, a carbonate or hydrate 

 of iron. 



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