white: age of the Worcester phyllite 115 



clearly described in great detail, by Perry and Emerson in the 

 "Geology of Worcester, Massachusetts," 1 and is mapped as occu- 

 pying two synclines lying with a northeast trend beneath the 

 city of Worcester. The formation in the eastern syncline is best 

 exposed by the Boston and Albany Railway cut, between the 

 Union Station and Lake Quinsigamond. Another outcrop, clas- 

 sic in the literature, occurs at the "Old coal mine" northwest of 

 Wigwam Hill, in the grounds of the Normal College of the Sisters 

 of Notre Dame. Several times during the last century attempts 

 have been made at this old "mine" to work a thin bed of graphit- 

 ized impure coal. Here the strata, which dip steeply to the north- 

 northwest appear to be less altered than in most places, and 

 the bedding is fairly distinct. 2 The minerals resulting from 

 the metamorphism are fully described by Perry and Emerson. 

 Dark, slaty phyllite and schist, richly carbonaceous, accompany 

 the graphitic bed. A lower stratum still retains certain features 

 which to the writer strongly suggest the so-called fire-clay beneath 

 a coal bed. Veins of quartz or other minerals are inconspicuous 

 at this locality, though the results of deformation are obvious in 

 the slicken-sided layers. The more graphitic portions of the 

 section now consist largely of thin, curly, slicken-sided, carbon- 

 aceous scales. 



The phyllite rests on a quartzite described by the above-named 

 geologists as the Worcester quartzite. The agreement of the 

 quartzite with the phyllite in structure, probable conformity, and 

 comparable alteration, is made a basis for regarding both as 

 probably belonging to the same period. Both the phyllite and the 

 quartzite are reported to be less altered at Worcester than else- 

 where. Away from this point the phyllite is said to change to a 

 mica schist, and the quartzite to a mica quartzite, which, accord- 

 ing to Perry and Emerson, becomes their Paxton schist on the 

 west, in the plateau of central Massachusetts, and the Bolton 



1 "The Geology of Worcester, Massachusetts," by Jos. H. Perry and Benj. K- 

 Emerson. Worcester, 1903, pp. xii and 166, with map and numerous plates. 



2 The outcrop is photographically shown opposite p. 12 of the work just cited. 

 The term "phyllite" is employed in conformity with the usage of Merrill (Rept. 

 U. S. Nat. Mus., 1S90, p. 390). 



