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NEW YORK STATE MUSEUM 



nel of the Genesee river, have attained widespread celebrity 

 for their interesting development of rock geology, the problems here 

 are not those of succession but chiefly of classification, involving 

 subdivision of some of the older and broad geologic groups. It is 

 here that the Clinton group, the so called Protean group of Vanuxem, 

 presents its most variable expression. The different aspects and 

 composition of the successive strata of this group indicate such 

 diverse conditions of sedimentation that to apply the term Clinton 

 to them all is to adumbrate exactitude. The Clinton group of 

 deposits is* therefore now divided in accordance with Mr Hart- 

 nagel's determinations into the following five units in descending 

 order. 



5 Irondequoit limestone 

 4 Williamson shale 

 3 Wolcott limestone 

 2 Furnaceville iron ore 

 i' Sodus shale 



It is still uncertain how far these subdivisions are continuous 

 across western and central New York; the quartzites appearing to 

 predominate in the formations farther to the east are not here well 

 defined but the Furnaceville ore is the representative here of the iron 

 ore at Clinton which apparently extends in continuous beds along the 

 Appalachian mountains of Pennsylvania and farther to the southeast. 

 The value of these subdivisions will be fully discussed and verified 

 by collateral evidence in the report upon this region. 



Auburn quadrangle. The problem presented on this area has 

 been to verify determinations made some years ago as to the order 

 of succession of the strata in and about Union Springs where the 

 region has been considerably disturbed by internal changes in the 

 rocks resulting from the solution of gypsum masses with consequent 

 collapse of the strata and the alteration of anhydrous gypsum with 

 resulting expansion and upheaval. The succession indicated on a 

 previous occasion showed a single definite horizon for the gypsum 

 at Cayuga Junction and a- single definite overlying horizon of water- 

 limes. The opposing contention has been that the gypsum (Camil- 

 lus horizon) lay above the waterlimes with Eurypterus and beneath 

 similar waterlimes with the same fossil. The critical determina- 

 tions of the point in question may be stated thus: 



About midway between Hibiscus point and Cayuga Junction the 

 top of the gypsum beds of Camillus age are found along the Cayuga 

 lake shore. This area is flanked both on the north and the south 

 by Eurypterus-bearing waterlimes, which it is believed are of the 

 same age, namely that of the Bertie horizon. This condition has 



