506 GEOLOGY OF OLD HAMPSHIRE COUNTY, MASS. 



For several feet on the border and in the numerous "horses" it is changed 

 to a phiinly kaoHnized white mica-granite, most or all the hornblende being 

 removed. It contains rarely green ttuor and calcite, R'',-iR, weathered to 

 dull gray and both in every stage of change to hollow pseudomorphs of 

 quartz. The main filling of the vein — following the above calcite-fluor 

 stage — was quartz, itself covered by barite, which so abuts against the quartz 

 with its prismatic faces that the latter seems to be the newer mineral, which 

 is rarely the case. Galena, blende, pyrite, chalcopyrite are the ores. A 

 second generation of calcite, R, R^, occurs in the quartz. Cerussite, mala- 

 chite, pyromorphite, limonite, and pyrolusite are the decomposition products. 



Levereft. — One mile northwest of the meetinghouse, on land of Mr. 

 Field, once considerably worked, but abandoned on account of its unprom- 

 ising appearance. (Nash, 1827.) Was worked by a company organized in 

 New York a few years ago, but did not pay.^ Strike north-south; dip 90°. 

 (E. Hitchcock.) The vein is in mica-schist and granite. It is several feet 

 wide, and contains galena, chalcopyrite in masses of the size of one's fist, 

 blende in the best crystals obtained from any of the veins, and pyrophyl- 

 lite. The gangue is baryta. Hollow quartz ]:)seudomorphs after pyro- 

 jjhyllite occur. 



Leverett. — South line, "White Rock quarry." Only few inches wide 

 at surface, but widening below. Galena and chalcopyrite abundant at sur- 

 face, but rare below, worked but few feet down, there 1 foot wide; nearly 

 pure barite. (Nash.) Later a long adit was driven in, but caved many 

 years ago. 



Leverett. — Cut south of railroad crossing next east of last mine; narrow 

 veins of barite, with little galena. 



Noi'thmnpton. — At the quarry east of Florence, in Northampton (south 

 of W. N. Moore's house), the biotite-muscovite-granite is cut bv joints run- 

 ning N. 50° E. and dipping 60° N. These joints are about a foot apart and 

 in this and in the next quarry to the east are often marked bj' fine slicken- 

 sided surfaces. Between two of these fault planes a sheet of the granite 

 is finely crushed and the parts recemented, producing a great crush fault 

 which runs beyond the limits of the quarry in both directions. The 

 fissures thus produced were occupied first by calcite, which is now present 

 only in a few crystals coated with transparent cubes of fluor, but is further 

 represented by negative crystals in barite and quartz. Barite followed the 



' Evert's History of the Connecticut Valley in Massachusetts, Vol. II. 1879. p. T.33. 



