LHM) m:\v voinc statk misktm 



[fi*;. 147 J, marked l).v tlio stron«;lv tiilolHHl and piistiilose central 

 portion of I he licad and a slron^ly si)inosc ]>\\i»idinni ; Proetua 

 i'olliccps 1 li^. 14S] and T. c I a r u s [rt,i»-. 140], the former 

 (listin^uislicd l)y its rouiidcd cardinal angles, tumid, faintly fur- 

 rowed jilahclla and ronndcd py<»idium without mar«»inal fold; the 

 hitter by lon«»' cardinal ani»lcs, iilabella without lobes, and short 

 crescentic i)ygidium with marginal fold. 



Marcellus shale 



In all the hills boundiuo- the Srhoharie vallev between Scho- 

 harie and Middloburg, with the excei)tion of West hill, the Onon- 

 daga limestone is succeeded by about 180 feet of black, fissile 

 shales, which split up into thin leaves and become more or less 

 rusty on exposure. These are the Marcellus shales, which repre- 

 sent the mud deposits succeeding the coral reefs of the Onondaga 

 period. They are not extensively exposed in this region, for on 

 ail the hillsides they have weathered so much that the out- 

 crops are covered with soil. They fonn the gentler slopes above 

 the limestone terrace, and are surmounted by the steeper slopes 

 of the arenaceous Hamilton beds overlying them. 



One of the few accessible localities where the Marcellus shales 

 can be examined is on the eastern base of South hill, northwest 

 of Middleburg. North of the farm of Mr Henry V. Tindar and 

 between it and a point opposite Borst Mills (at which locality 

 the top of the Onondaga forms the river bed) several exposures 

 occur in the bottoms of small streamlets which iiudse the slope 

 of the hill. Some of the beds are exi)osed along the road, 

 whei'(» it descends to the Hats of the river. The highest beds are 

 best shown about a (juarter of a mile north of Mr Pindar's 

 house, where an unsuccessful attempt has been made to mine the 

 u|)i)er laycMs for coal [niaj): Vlir i, S7]. This locality is best] 

 ajiproaclied l)y a path wliicli brandies from 1he road where this 

 has readied llie level of llie Hals. At Ihe "coal mine" the shale 

 is Nci'v black and caibonaceons, Ihe ujiiier four feet having suf 

 f<'red s(niie crnshing and inlernal shearing owing lo (he jiressurc 

 of Ihe overlviii'^ lock and lln^ yielding character of these car 



