444 REVIEWS 



Kemp and Newland ' make a preliminary report on the geology of 

 Washington, Warren, and parts of Essex and Hamilton counties. New 

 York. Some of the points particularly noted are : 



The excessive mashing and granulation of the gneisses, giving them 

 in places semblance to quartzite. The greenish gneisses, consisting in 

 largest part of microperthite, were originally eruptive rocks. The dis- 

 covery is reported of quartzose gneisses or foliated quartzites which are 

 certainly metamorphosed sediments. They form notable areas along 

 the head of South Bay, Whitehall township. Their presence indicates 

 the probable presence of a considerable series of clastic sediments. 

 The crystalline limestones themselves have been found in small expo- 

 sures over almost all of Warren county, and generally in the crystal- 

 line belt of Washington. They are most extensive in Newcomb and 

 Minerva townships of Essex, and to the south become thinner and 

 more scattered. So far as we have observed they are less common in 

 eastern Hamilton county. There is evidence to show that strati- 

 graphical relations can be proven and that anticlines and synclines can 

 be demonstrated. 



Dikes of basic gabbro usually of moderate width, but lithologi- 

 cally like the larger masses in Essex county, have been met over a wide 

 area — in fact almost every township in Warren, but the basaltic traps 

 almost disappear. 



Kemp"" summarizes the present knowledge of the pre-Cambrian 

 rocks of the Adirondacks. Most of the features have been covered in 

 previous articles. Attention is called to the distribution of the sedimen- 

 tary crystalline rocks, the Oswegatchie series (equivalent to the Gren- 

 ville series of Adams and perhaps the Huronian). These consist of 

 limestones, sedimentary gneisses, and quartzites. They occupy greater 

 area than has been supposed. The limestones are found chiefly in 

 the northwest, and the southeast or eastern portions of the Adirondack 

 area of crystalline rocks. They are in small quantity, or altogether 

 absent in the northern portion, in the broad belt running from 



' Preliminary Rept. on the Geology of Washington, Warren, parts of Essex and 

 Hamilton counties, by J. F. Kemp and D. H. Newland : Rept. of the New York 

 State Geologist for 1897, published in Fifty-first Ann. Rept., New York State 

 Museum, Vol. II, 1899, pp. 499-553. 



^Pre-Cambrian Sediments in the Adirondacks, by J. F. Kemp : Vice Presiden- 

 tial address published in the Proceedings of the A. A. A. S., Vol. XLIX, 1900, pp. 

 157-184. 



