1892. | NEW YORK ACADEMY OF SCIENCES. 61 
by J. P. Kimball,’ and a zircon syenite (so- ealled) 1 is mentioned by 
Wadsworth from “Marblehead, Massachusetts. 
The Arkansas areas have long been known as a prolific source of 
many rare and interesting minerals, and in connection with these 
and in the old geological reports of the State some mention of the 
rocks is made; but only the recent report of the late Dr. J. Francis 
Williams treats the matter with thoroughness. Although usually 
colored as Archaean on the geological maps in the past, they are 
now known to be late Cretaceous. 
The Beemerville area was first noted by E. Haeusser, an assistant 
on the New Jersey survey under Dr. Kitchell, and from his notes a 
brief description is taken for the New Jersey Report for 1868, p. 
144. The notes are valuable as announcing the existence of the 
great dike, but subsequent investigation has shown that the chief 
minerals (hypersthene and labradorite) mentioned by Haeusser are 
entirely lacking. The true nature of the rock was thus overlooked 
by him. The remarks, however, were fruitful in bringing it to the 
attention of Prof. B. K. Emerson,* who visited it in 1881 and 
recognized the true character of the portion traversed by him. 
Prof. Emerson seems, however, to have touched the dike at only 
one or two points at the nor thern end; and as it extends nearly 
three miles in a northeast and southwest direction, much the greater 
part has remained to be subjected to the microscope. 
Several outcrops of a curious basic rock occur east of the syenite, 
which were mentioned in the New Jersey Report for 1882, p. 67. 
‘These were subsequently more fully investigated by myself‘ and 
ealled porphyrite. Investigations and papers which have since : ap- 
peared have much enlarged our knowledge of the basic rocks associ- 
ated with elaeolite syenites in other localities, and the true relations 
of these so-called porphyrites are with the extreme basic non-feld- 
spathic end of the lamprophyre division. 
Rosenbusch bas created the name monchiquite as applied to those 
with much olivine from Brazil, and J. Francis Williams has called 
others from Arkansas, with no olivine but with prevailing augite, four- 
chite ; and I have named still another variety from Arkansas, with 
great amounts of biotite, ouachitite. The Beemerville basic rocks are 
ouachitite. 
The elaeolite-syenite dike lies on the southeastern slope of the 
Kittatinny Mountain ridge; and some eight miles west of Decker- 
town, the nearest railway station. Deckertown is situated at the 
crossing of the New York, Susquehanna and Western, #y the Penn- 
1 J. P. Kimball, On Sodalite and Elaeolite from Salem, Mass., A. J.S., ii 
xxix. 65, quotes G. L. Streeter, in Proc. Essex Inst., li, 153. 
2 Zircon syenite from Marblehead, Mass., Proc. B.S NY. H., xxi, 406, 1880-82. 
3 B. K. Emerson, On a Great Dike of F oy aite or Elaeolite Syenite in North- 
western New Jersey, A. J. 5., iii, xxiii, 302. A full quotation of Haeusser’s 
notes is made in the paper. 
4 J. F. Kemp, On Certain Porphyrite Bosses in Northwestern New Jersey, 
Avid s9-, il, xxxvill, 130: 
