July 1, 1910] 



SCIENCE 



27 



against a salient from the more northerly land 

 area. There is some evidence in favor of the 

 latter view. 



In Miocene time it is definitely known that 

 a cold inshore current found its way south- 

 ward to Florida and westward to Pensacola. 

 This, current may be due to the Miocene sub- 

 mergence of the Hatteras area, which suffi- 

 ciently lowered the sea bottom off Hatteras 

 to permit the Gulf Stream to continue its 

 course unobstructedly northward, at the same 

 time permitting a cold inshore current to 

 move southward. The Miocene southward 

 current, aided by winds and tides, transported 

 quantities of terrigenous material and depos- 

 ited it on the eastern border of the Floridian 

 Pleateau. 



Since Miocene time there have constantly 

 been return currents of warm water (however, 

 not so warm as the Gulf Stream), and they 

 have, aided by the winds and tides, transported 

 terrigenous material which was deposited on 

 the eastward side of the existing land areas, 

 sweeping a portion of it to the soiithern end of 

 the plateau. These currents were active dur- 

 ing Pliocene and Pleistocene times, and are 

 still active to-day. 



The shape of the upper surface of the 

 Floridian Plateau, the land area of its east- 

 ern side, the arrangement of the geologic 

 formations of successive ages, the directions 

 of the stream courses, and the contour of the 

 present coast line, owe their peculiarities and 

 characteristics to the concomitant operation 

 of the forces producing deformations and to 

 oceanic currents. 



T. Wayland Vaughan 



\ 

 ^l glacial lakes of the catskill valley 



The Hudson lobe of the waning Wisconsin 

 ice sheet blockaded the southeastern embou- 

 chure of the Catskill Valley, and sent a blunt 

 " thumb " into this depression, pressing 

 against the northeast front of the Catskills. 

 The highest impounded waters were continu- 

 ous with Schoharie VaUey lakes recognized by 

 Pairchild, by way of the summit col at Prank- 

 linton, Schoharie County. Then eastward 

 escapes were apparently found between the 



ice-margin and the Catskill front, carving 

 three or four sets of roughly parallel channels 

 for eight miles between Hervey Street and 

 Cairo Round Top.^ The series of falling lakes 

 thus determined have as their lower limit the 

 notch behind the Pound Top, at about 600 

 feet, and to this level may be given the name 

 " Lake Durham." The channelings have 

 caused interesting stream diversions, espe- 

 cially of former Shingle Kill headwaters 

 through this notch into the Kiskatom. 



The next escape was east of the Pound Top, 

 at Cairo Junction, and southward by a minor 

 body (" Lake Kiskatom ") into the gorge of 

 the Kaaterskill at Great Falls, and to Lake 

 Albany near Asbury. This lake, at 350 feet, 

 is marked also by a cobble delta of the Cats- 

 kiU north of Cairo, discovered by W. M. 

 Davis. It may be called " Lake Cairo." The 

 hypo-Cairo channels are east of Vedder Hill, 

 near Leeds, between the steep shale slope and 

 a flanking moraine. A mile south of the hiU 

 the waters entered Lake Albany and built a 

 shale-pebble delta now largely submerged 

 under Albany clays. Shortly afterward Lake 

 Albany entered the valley and established a 

 grade-plane of which there are extensive rem- 

 nants at Leeds depot, the mouth of Potuek 

 Creek and at Sandy Plains north of South 

 Cairo. It is significant that these remnants 

 are of much coarser material than the present 

 lower flood-plains of the Catskill, indicating 

 strong drainage from the north, which appar- 

 ently came around the east face of the Helder- 

 bergs via Clarksville, Lawson Lake, etc., and 

 through the Cabin Eiver and Potuek valleys. 

 Heavy seourings at Eesult and Urlton, noted 

 by Fairchild, are probably due to these waters, 

 which may have included even Mohawk 



The delta of the CatskiU in Lake Albany, 

 associated with this grade-plane, is found in 

 Jefferson and West Catskill, now bisected by 

 the creek. It extends four miles south and 

 has crowded the Hudson to the east, but has 

 merely blockaded, without filling, the valley of 

 the Hans Vosen Kill on its north. In the 



' See Durham, Coxsackie, Kaaterskill and Cats- 

 kill topographic sheets. 



