SYENITE AND PORPHYRY OF NEW JERSEY 573 



Kemp's material was studied by Hussak, who had no hesitation in 

 terming the rock a leucite tephrite, and considered that the sphe- 

 roidal pseudomorphs were pseudoleucite, or were at any rate 

 pseudomorphs after leucite.^ Kemp then visited some newly 

 exposed dykes at Rudeville and obtained material which provided 

 definite proof of the existence of leucite, and came to the conclusion 

 that the "mica-diabase" dykes of Rudeville, Franklin Furnace, and 

 the Hamburg dyke are all related to the Beemerville mass.^ Kemp's 

 papers are illustrated with useful locality maps, but the analyses 

 given are all incomplete and inadequate. 



A complete petrological description of the nephelite syenite of 

 Beemerville and the large dyke at Franklin Furnace, together with 

 good, though incomplete, analyses, is given by Iddings, who recog- 

 nized the Franklin Furnace dyke to be a minette.^ 



In 1899 Ransome described a small occurrence of nepheHte 

 syenite, mica syenite, hornblende syenite, and hornblende granite, 

 associated with Mesozoic gabbro, at Brookville, in Hunterdon 

 County, New Jersey, sixty miles west of south from Beemerville. 

 The relations of these rocks to the gabbro were not clearly ascer- 

 tained, and they were regarded by Ransome as inclusions, though 

 he considered the possibility of an intrusive relation."* Our colleague. 

 Dr. N. L. Bowen, has collected specimens from this locality which 

 suggest differentiation of the nephelite syenite and, on a small 

 scale, an intrusive relation toward the gabbro. 



In 1902 Wolff described an undoubted leucite tinguaite dyke, 

 which cuts the Beemerville nepheHte syenite mass near its southern 

 end, giving a detailed account of the pseudoleucite, and a good and 

 complete analysis of the rock. This is the most satisfactory existing 

 analysis of any rock from the alkahc series of Sussex County.^ 

 Finally, in 1908 Wolff provided a co-ordinated description of the ig- 

 neous rocks of Sussex County,^ in which he points out that the same 



^ E. Hussak, Neues Jahrbuch, II (1892), p. 153. 



^ J. F. Kemp, Amer. Jour. Sci., XL VII (1894), p. 339. 



3 J. P. Iddings, U.S. Geol. Surv., Bull. 150 (1898), pp. 209 and 236. 



4 F. L. Ransome, Amer. Jour. Sci., VIII (1899), p. 417. 



s J, E. Wolff, Bull. Mus. Comp. Zool. Harvard, XXXVIII (1902), p. 273. 

 * J. E. Wolff, Geol. Atlas, New Jersey, Franklin Furnace folio (1908), p. 12. 



