54 0. II Smyth, Jr. — Gdbbros in the Adirondack Region. 



seen in the Chipola around Bainbridge, at Alum Bluff, nor 

 along the Chipola River. The oyster so common in these 

 clays was also found at Wiley's Landing and the Griffin locali- 

 ties, hut not in the Chipola. For that reason I am still in- 

 clined to consider the Aspallaga clays as the top of the Chatta- 

 hoochee series, at least, until further collecting shows an assem- 

 blage of true Chipola fossils in these clays. Other collectors 

 may have already secured this desired additional material. 



The writer is under special obligations to Mr. Dall and 

 Stanley-Brown, for more precise determinations of the thick- 

 ness of the various Chattahoochee beds, and to Prof. Raphael 

 Pumpelly and Mr. Alfred Brooks for the opportunity to accom- 

 pany them during their various trips down the river and else- 

 where, which made it possible to collect the material for these 

 notes and utilize many of their observations. His obligations 

 to various publications need not be expressed in detail since 

 these publications are too recent to require recalling to memory 

 and are sufficiently indicated in the publications of Mr. Dall. 



On the accompanying sketch map* the course of the Flint 

 and Appalachicola Rivers has been represented in two sections. 

 The Marianna region is mapped and introduced into a corner 

 of the page, so as to show its relations to the Flint River section. 

 All of the mapping being the result of traverse work is sure 

 to have its faults, but being done with considerable care, is cer- 

 tain to be vastly superior to the ordinary maps which fall in 

 the traveler's hands. The railroad east of the River Junction 

 station is only approximately located, so that the position of 

 the Steephead Limesink is not accurately determined, except- 

 ing as regards its location west of Faceville. For the Eocene 

 a slope of 13 feet to the mile is assumed, for the Chattahoochee, 

 one of 9 feet to the mile. The question of dip still awaits 

 more detailed study. Localities starred are suitable for camp- 

 ing when traveling in skiffs. 



Art. IX. — On Gdbbros in the Southwestern Adirondack 

 Region; by C. H. Smyth, Jr. 



The presence of large areas of anorthosite in the Adiron- 

 dack region has long been known, although the igneous nature 

 of the rocks has not been universally recognized. In a recent 

 paper Professor J. F. Kempt has described extensive develop- 

 ments of gabbro in the vicinity of Lake Champlain, which 



- See page 42. 



f Gabbros on the Western Shore of Lake Champlain, Bull. Geol. Soc. America, 

 v, p. 213. 



