252 BOARD OF AGRICULTTJRE. 



and is of less importance. It is several feet thick, enclosed in 

 schists. 



Brenton Butler owns a quarry of dolomitic limestone near a large 

 marshy bog on West Keag river in South Thomaston, hence it has 

 been called the Marsh quarry. It was not being worked when 

 we visited it in July. Dr. Jackson pronounced this bed to be two 

 hundred and jSfty feet wide, and its outcrop forty or fifty rods long. 

 It is white, granular and compact, producing a lime containing 

 much magnesia which does not injure the quality to any important 

 extent. The dip is about 60° N. W. At the quarry we observed 

 some peculiarity in the stratification, perhaps of the nature of a 

 slide and consequent dislocation of the strata, but had not time 

 to investigate it.* Another body of limestone is said to exist north- 

 east of the dolomite, which we did not examine. 



Another extensive deposit of Eolian limestone over two miles 

 in length, and upon which important quarries are located, oc- 

 curs in Rockland. The most southern exposure of this belt is 

 at Rankins' quarry. The rock is the same as that in the main belt, 

 as is all the rock of this belt. It is traversed by an immense num- 

 ber of small veins of calcite running about north and south. The 

 limestone dips 70° S. 7o°E. At Blackington Corners a number of 

 quarries have been wrought in the limestone, so that very large 

 holes have been excavated. Different observations here show 

 that there is an anticlinal axis in this belt, although the inclinations 

 in both directions are very steep. There is a very large boulder 

 in one of these quarries underlying the road to Rockland. It is 

 thirty-five feet in length and rather ovate shaped. It is a fact to 

 be remembered that the southern end of this belt of limestone as 

 far as it is worked, corresponds very nearly in latitude with the 

 northern end of the Meadows quarries in the principal belt. The 

 limestone has not been traced a great distance north of Black- 

 ington Corners. What if a transverse fault should be indicated 

 here ! 



We had intended to prepare detailed, historical and statistical 

 notices of all the quarries in Rockland and Thomaston, but owing 

 to unforeseen circumstances have been prevented from obtaining 

 the desired information. Such as we have will be presented under 

 Economical Geology. The following are the names of the princi- 

 pal quarries and their locations. In Thomaston, on the principal 

 belt are the State's Prison quarry, in the yard of the State's Prison, 



