GEOLOGY OF THE PORT LEYDEN QUADRANGLE 33 



Utica shale and the Oswego sandstone, two well marked horizons, 

 are described and mapped in this report as Lorraine. 



The formation consists chiefly of alternating thin bedded shales 

 and sandstones together with some thin layers of limestone. There 

 is no sharp line of separation between the Utica and the Lorraine, 

 the lowermost shale beds of the Lorraine being in every way like 

 those of the Utica. The lower Lorraine, comprising a thickness 

 of approximately 200 feet of shales, is not very fossiliferous and 

 contains occasional thin beds of fine grained sandstone. Among the 

 fossils the Endoceras proteiforme and Triarthrus 

 b e c k i , so common in the Utica shale, are also found here. The 

 lower Lorraine as thus described corresponds in a general way at 

 least to Vanuxem's Frankfort slate and sandstone.^ 



The upper Lorraine, showing a thickness of something over 400 

 feet, is made up of gray, fine grained sandstone beds alternating 

 with black to dark gray shales and occasional thin beds of impure 

 limestone. Passing upward the sandstone content increases greatly 

 and the thin partings of shale become rather sandy and light 

 colored. The upper Lorraine sandstones and limestones are highly 

 fossiliferous and fragments of sandstone full of fossils are strewn 

 over the Tug hill region in great quantities. Among the many 

 fossils some of the more notevv^orthy forms are : P e n t a - 

 crinites hamptonii of the echinoderms, Leptaena 

 s e r i c e a and Orthis testudinaria of the brachiopods, 

 Ambonchyia radiata and M o d i o 1 o p s i s m o d i o 1 a r i ? 

 of the lamellibranchs and Cyrtolites ornatus of the 

 gastropods. A more complete list of fossils for this general 

 region may be found in a paper by Walcott.^ The upper Lorraine 

 as here described corresponds roughly to the sandstone shale of 

 Pulaski as used in Vanuxem's report. 



From the standpoint of both areal extent and thickness the Lor- 

 raine is the principal Paleozoic formation of the quadrangle. Ex- 

 cept for the small Oswego sandstone area, the Lorraine occupies 

 all of Tug and Mohawk hills. Fine sections are exposed along the 

 larger streams which cut across the eastern front of Tug hill, the 

 best one probably being in Whetstone gulf [see pi. 9"]. The whole 

 thickness of the formation is shown in the township of Turin where 

 it is estimated at 630 feet. About 600 feet are shown in Mohawk 

 hill with the top not present. Well records to the west and south 



^ loc. cit. p. 61. 



" Geol. Soc. Am. Bui. 1890. i :348-49, , , 



