AMERICAN GEOLOGY MACLUREAN ERA, 1785-1819. 235 



The Transition class included metalliferous limestone, argillaceous 



and siliceous slate, graywaeke slate, and rubblestone. 



The Secondary class included red sandstone, breccia, compact lime 



stone, gypsum, and rocksalt: ,, _,—^__™»^-_ 



the Superincumbent class, ba- „ ? , ^ * „ r g *» C a«km m«. 



salt, greenstone, trap, and ?ggg£$| .....Eaton* mm. 



amygdaloid, and the Alluvial || || || • . _ KiskeUra 



class, gravel, sand, clay, and i 8 K' = c 2 3 B cautnxkiu. 



" ' g a> © * a B&lBK Catskill. 



loam. ;; B 2 "f ' Hudson rivei 



Illustrative of his ideas £6" | § > 



,1 • ,• i? 13 S "* 55 BBFa^B- Claverack. 



concerning the position ot = 2 ^- £ 



these rocks, a geological jr g, f § 



, • • _r -y ;r I ii^M-/ '^ii/'if' Chatham. 



transverse section was given, - a £ 



extending from Boston on the 3 £ » h ■ 

 east to the Catskill Moun- 

 tains on the west. From a 

 perusal of this section and 



7i . ml Mk/ \ ' Pittsfield. 



the accompanying text many | pU B^f\ 



interesting and, to us, strik- £ £ £ .,= * -, l 



° . ' 5 | ■ ...Hinsdale. 



ing conclusions are drawn. so w 9 >■ g 23 



For instance, in discussing ss'^sES- ^ 



the position of the gneiss of 1 1 1 1 | " f 



the Primitive series as it oc- | ? a § g < 



<B g. S ~ - I ^....Chesterfield. 



curs between Dalton and » g, g 1 j 



Pittsfield, Vermont, he wrote: I § * WBEfa 



•• It sinks laterally under the % WW:::::::::::^7~ 



, , ., " , 5 i Mu.lftr Mt. Holyoke. 



mica-slate to the west, and .£ £ IvA-Av ...Hadiey. 



probably does not rise again j? n Beichenown. 



until it reaches the continent m swiftriver. 



of Asia." The soapstones and 2 



1 "I llUk. Coy s hill. 



serpentines, now known to be * fcffe western. 



i, j ,. , O I IKScm.' Chicapee river. 



altered eruptive rock, were „ j |j^ Brookfieid 



regarded by him as forming S " " ^ " I 



- . , . & , ► 2? SO O O tO > ■ ^ bpencer. 



one ot the concentric coats ot j^w § ^ | § j* 



mechanically deposited mate- £• = ■ g I i j? * 



. l — .- — r A • H I fiWl 1 • Worcester. 



rials, and, as with syenite and f g r k £ Ja[ N Shrewsbury. 



granite, their possible erup- i g 8 „ 1^ Northbury. 



tive origin not dreamed of . ? ^ § > I Wrf w « tb » r y- 



T , . ™ « ? a HHEw^' Suuthbury. 



in his lransition class he *■ | 



would include the marbles of £ 



western Vermont, now con- VwKe; *; ram,n ? ham - 



. I ^^F^JBy" L.. Sudbury. 



sidered to be of Lower Silur- HP^:::::::::::^,^. 



ian and Cambrian age, and 



tilt' rOOfing Slates. uHif Cambridge. 



° UMjtif Boston. 



In the Secondary class he 

 included the red sandstones of the Catskills (Devonian), as well as 

 those of the Connecticut River (Triassic). Discussing the position 

 of the Catskill stone, he wrote: "Bakewell removed this stratum 



