DIFFERENT PROVINCES OF NORTH AMERICA IN LATE PALEOZOIC TIME 61 



near when these fragments of clay were deposited. Just above this bed come 

 about 47 feet of slate and sandstone layers with ripple-mark and some boulderets 

 from 8 to 10 inches in diameter. At this time the ice must have made a temporary 

 halt or retreat. At least, deeper or slower water conditions prevailed." 



Sayles continues his description, arguing for a series of advances and 

 retreats of the ice. 



Opposite page 17 of Bulletin 597, Emerson gives a table of the geological 

 formations of Massachusetts and Rhode Island, from which the portion 

 dealing with the upper Carboniferous and Permo-Carboniferous sedimentary 

 rocks is quoted below: 



Berkshire Hills and — Central 



Eastern Worcester 



Northwestern Massa- 



Southern Massa- 



Massachu- 



County and Merri- 



chusetts, including 



chusetts and Rhode 



setts. 



mac Valley. 



Boylston. 



Island. 









Cambridge slate. 



Dighton conglomer- 









Roxbury conglomer- 



ate at north, Purga- 









ate. 



tory conglomerate 









I. Squantum tillite 



at south. 









member. 









Worcester, phyllite 









(Pennsylvanian ) . 



Unconformity. 





Amherst schist (east 





Dark phyllite. 



(?) 



Rhode Island forma- 



side of Connecticut 





Chiastolite schist. 



2. Dorchester slate 



t i n (Pennsylvan- 



Valley to Worcester 



Brimfield 



Harvard conglomer- 



member. 



ian). 



County). 



schist. 



ate lentil. 

 Boylston schist. 

 Brinfield schist. 

 Oxford schist. 















Wamsutta formation. 



Quabin quartzite. 



Paxton 



Oakdale quartzite. 



3. Brookline con- 



Pondvilleand Belling- 



E r V i n g hornblende 



quartz 



Merrimac quartzite. 



glomerate member. 



ham conglomerates 



schist. 



schist. 







(probably the same). 



From Emerson we have the following comments on the more important 

 of the various beds shown in the table •} 



(Page 66.) The Harvard conglomerate lentil "may be equal in age to the 

 Squantum." 



(Page y2.) . The eastern rocks of the Carboniferous area in Massachusetts 

 are more calcareous than in the western, but "the whole series indicates, when 

 compared with the more eastern beds described above, that the coal-forming 

 conditions of the central and eastern parts of the State were disappearing and 

 that deeper waters existed in the Connecticut region, deep enough for the forma- 

 tion of limestone and in some places near enough to the shore for the formation 

 of conglomerate." 



(Page 76.) Age of the Worcester, Oakdale and equivalent strata: "In the 

 Narragansett Basin the coal-bearing Rhode Island formation overlies a series 

 of coarse-grained strata, largely conglomeratic but including considerable sand- 

 stone and having at the base a conglomerate which rests unconformably on much 

 older rocks. The lower formations contain fossil tree trunks, some of which 



^ Emerson, B. K., Geology of Massachusetts and Rhode Island, U. S. Geological Survey 

 Bull. 597, 1917. 



