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NEW YORK STATE MUSEUM 



Catskill sediments of eastern New York and the tacit concession 

 of the Devonic age of the entire series of those deposits. With 

 regard to the phenomena interpreted as evidence of unconformity 

 I should not be disposed to contest Professor Glenn's inferences 

 but to emphasize the fact that these sand reefs constantly dis- 

 play indications of deep decapitation due to shifting of bars and 

 change of direction of currents, or a modification by heavy tidal 

 flow on a shelving coast. Unconformities thus frequently exist 

 which are no indication of unrecorded time. As to the second 

 assumption I feel that we should be specially cautious in taking 

 for proven that Catskill sedimentation even in the typical sec- 

 tion of the Catskill mountains is restricted to Devonic time. 

 The Catskill represents a peculiar phase of sedimentation wide- 

 spread in northern latitudes during the Devonic. The Devonic 

 continent was profuse in great lakes and coastal lagoons whose 

 sedimentation was carried on under conditions so unlike those 

 of the ocean, that causes which would disturb and qualify the 

 latter could not affect the former. We know that at certain 

 places within the continental edge this sedimentation did con- 

 tinue through the Devonic and endured till after the appear- 

 ance of Carbonic faunas. Hencei a certain part of Old Ked 

 sedimentation is in some instances postdevonic and may be so 

 in New York; indeed in face of the paleontologic evidence I am 

 very strongly of the conviction that it is so, and that the Cat- 

 taraugus beds themselves supply the required proof of this fact. 

 It is not a new suggestion that the upper stages of the typical 

 Catskill are postdeyonic ; the restudy of this Catskill area which 

 is now proceeding may give us new light on this point and though 

 it would be the unexpected to find transgression of the Subcar- 

 bonic fauna extending into this lagoon area so far to the east, 

 by some other criteria it may be practicable to affirm this dis- 

 tinction. Time must also elapse before assertions can be made 

 as to whether the Catskill strata of eastern New York are or 

 any part of them is continuous with the Cattaraugus beds of 

 Allegany and Cattaraugus counties. 



The paleontologic evidence .thus far derived from this section 

 and summarized by Mr Butts, indicates one fact with emphasis, 

 thai is, the one substantial change in the succession of organic 

 assemblages occurs with the incoming of the Wolf Creek con- 



