APPENDIX 
TO THE 
GEOLOGICAL REPORT OF THE FIRST DISTRICT. 
Dr. William Horton, of Craigville, Orange county, New- York, who 
lias for many years been an ardent cultivator of geology and mineralogy, 
and who has investigated with much care the geology and mineralogy of 
Orange county, has been engaged during the past season in developing 
its mineral resources, as one of the Assistant Geologists of the First 
District. He has collected and arranged in the cases of the State col- 
lection in the geological rooms of the First District, 2,888 specimens 
of minerals and rocks, to illustrate the geology and mineralogy of this 
county. Subjoined is a copy of his report on the geology of Orange 
county. 
( B. ) 
REPORT 
Of W. Horton, to W. W. Mather, on the Geology 
of Orange county. 
PRIMITIVE ROCKS. 
The primitive region of Orange county extends from Butter hill, in 
the town of Cornwall, along the Hudson river to Fort Montgomery; 
thence along the line of Rockland county to the State of New- Jersey; 
thence along the New- Jersey line to the western base of the Pochunck 
mountain, about one mile southeast of the Walkill. 
