DESCRIPTION OF FRANKLIN FURNACE QUADRANGLE. By A. C. Spencer, H. B. Kummel, J. E. Wolff, B. D. Salisbury, and Charles Palache. GEOGRAPHY. are from 50 to 100 feet higher. These hilltops are DESCRIPTIVE GEOLOGY. extends from the Hudson Palisades southwest- By A. C. SPENCER. remnants of a former topography which would be ward across New Jersey and Pennsylvania. GENERAL RELATIONS. restored if the minor valleys of the wide depression -Around the periphery of the pre-Cambrian GENERAL RELATIONS. were filled. The ancient surface thus defined rises By A. C. SPENCER. area on the northwest, north, and east, the The Franklin Furnace quadrangle is bounded gently from the southeast until it meets the steep The rocks of the Franklin Furnace quadrangle rocks are Paleozoic. The boundary between by parallels 41° and 41° 15' north latitude, and slope of Kittatinny Mountain, and is obviously a comprise a series of crystalline gneisses and lime­ the area of ancient crystalline rocks and the meridians 74° 30' and 74° 45' west longitude, feature of later origin than the Kittatinny Plateau. stones older than the Cambrian, stratified forma­ Newark belt is on the whole a simple one, but covering one-sixteenth of a square degree. It is Within the several belts of Kittatinny limestone tions ranging in age from Cambrian to Devonian, the line limiting the older rocks against those of approximately 17 miles in length and 13 miles in most of the hills rise from 50 to 150 feet above the and intrusive rocks later than Ordovician. Paleozoic age is sinuous in the extreme. The width, and has an area of about 225 square miles. stream grades, though a few summits are 50 or 60 The district exhibits the northeast-southwest irregularity of this boundary and the occurrence The district lies- in northwestern New Jersey, feet higher. All the larger streams and many of trends of topography and areal geology which of many strips of the Paleozoic formations within mainly in Sussex County, but including a small the tributaries are bordered by extensive meadows characterize the Appalachian Province southward the general district occupied by the pre-Cambrian part of Morris County on the southeast. The and swamps, and the floors of the minor valleys from Hudson River. Red sandstones and shales rocks result largely from the presence of many principal towns are Newton, the county seat of taken together constitute a well-marked sublevel or occur in the northwest corner of the quadrangle, northeast-southwest corrugations of the sort char­ Sussex County, Sussex (formerly Deckertown), platform below the general floor of the Kittatinny overlying the more massive quartzites and con­ acterizing the Appalachian region, to use that and Branchville. Farming is the principal indus­ depression. glomerates of Kittatinny Mountain. These for­ term in its broadest application. try, but zinc ores are mined and dressed at Frank­ In New Jersey the Highlands occupy a belt mations, which are of Silurian age, dip to the The lower Cambrian formations may have been lin Furnace, limestone is quarried in several places, about 25 miles wide lying between the Kittatinny northwest. Below them are Ordovician shales deposited over the whole region, but they now and slate quarries have been operated in Lafayette Valley and the Piedmont Plateau. The district is which cover the greater part of the Kittatinny appear only in the areas where they were pro­ Township. The scenery and pure air of the High­ roughly a plateau, as the component ridges and Valley. Numerous dikes and a few stocks of tected from erosion by having been infolded or lands and Kittatinny Mountain attract many visitors hills rise to a gently undulating surface. In the nephelite-syenite cut the shale in the western part downfaulted into the older rocks upon which they during the summer, the best-known resorts being southern part of this quadrangle the general eleva­ of Wantage Township. lie. ' Sparta, Stockholm, Branchville, and Sussex. The tion of the summits is about 1200 feet; toward the The southeast side of the main Kittatinny In Pennsylvania, New Jersey, and southeastern main line of the New York, Susquehanna and northeast the hilltops are about 200 feet higher. Valley is occupied chiefly by a belt of Cambro- New York, from Reading on the Schuylkill to Western Railroad traverses the quadrangle from Like the top of Kittatinny Mountain this upland Ordovician limestone, separated from the old crys­ Hudson River, the Paleozoic rocks bordering on east to west and is joined at Sparta Junction by surface was formerly a plain, and if the valleys talline rocks by a thin basal sandstone of Cambrian and included in the pre-Cainbrian area are essen­ the Middletown division from the north. The were filled the plateau would be restored. Within age. Southeast of this belt and well within the tially uumetamorphosed. The Cambro-Ordovician Lehigh and New England Railroad and the the Franklin Furnace quadrangle most of the val­ general area of the older rocks are several outlying limestone is nowhere changed to marble, and the Lehigh and Hudson River Railway extend across leys are shallow and wide, and only the larger strips of limestone, in the upper Wallkill and overlying Ordovician shale, though exhibiting the quadrangle from southwest to northeast, and transverse streams occupy deep gorges. The Vernon valleys. Each of these strips is limited slaty cleavage in many places, has not been con­ the Sussex branch of the Delaware, Lackawanna Pimple Hills and Pochuck Mountain are out­ on the southeast by the basal sandstone and on the verted into schist. Throughout this zone the and Western Railroad connects Franklin Fur­ liers separated from the main area of the High­ west by a fault of considerable displacement. Paleozoic and pre-Cambrian rocks are invariably nace, Branchville, and Newton with the main lands by the upper valleys of Wallkill River Between the Paleozoic stratified formations and exhibited in sharp contrast, because the latter are line at Netcong, N. J. The abandoned iron mines and Pochuck Creek. In the southeast corner of the rocks of the ancient crystalline complex there so completely crystalline. Within the Paleozoic near Edison are reached by the High Bridge the quadrangle Green Pond Mountain, formed is a great unconformity, the older rocks having formations intrusive rocks other than diabase branch of the Central Railroad of New Jersey. of resistant sandstones, rises to the general been deeply eroded previous to the deposition of dikes of late Triassic age occur in one place only, The quadrangle is well netted with wagon roads, level of the Highlands Plateau, and between the Cambrian sandstone. namely, at Beemerville, N. J. some of which, particularly in the Martinsburg this mountain and the gneisses toward the north­ On both sides of the New York-New Jersey East of Hudson River the aspect of the lower shale belt, are excellent. west a broad valley has been excavated in soft boundary the general area of the Highlands is Paleozoic formations is very different. Immedi­ Paleozoic formations. divided longitudinally by a belt of Silurian and ately north of the pre-Cambrian area in Dutchess RELIEF. Devonian formations. This belt traverses the County, N. Y., the rocks of "Hudson" time are DRAINAGE. The Franklin Furnace quadrangle is divisible southeast corner of the Franklin Furnace quad­ almost uniformly slaty, and the limestone which topographically into three parts the Kittatinny The quadrangle is drained by tributaries of three rangle, where Green Pond and Bowling Green occurs between these slates and the pre-Cambrian Mountain region in the northwest corner; the river systems. Wallkill River, flowing northward mountains have been preserved by the presence of rocks is crystallized to a considerable extent. In Kittatinny Valley, a depression 7 to 10 miles to the Hudson, receives the waters of more than resistant Silurian sandstones and conglomerates. eastern Dutchess County and in northeastern Put­ wide and from 600 to 800 feet deep, lying half the area. Its valley heads just beyond the Aside from the inlying strips of Cambro-Ordo- nam County the Paleozoic rocks exhibit even greater immediately to the southeast; and the High­ southern boundary, attains a width of about 5 vician limestone and the belt of Silurian-Devonian alteration. The shale and limestone have been com­ lands, occupying somewhat less than one-half miles south of Ogdensburg, and between this place rocks which have been mentioned, the rocks of the pletely crystallized, the former being converted -of the area, southeast of the valley. These and Franklin Furnace flares out to cover the whole Highlands are gneisses and crystalline white lime­ into mica schist and the latter into marble. Still several features have a northeast-southwest trend, of the Kittatinny depression. stones, with minor masses of coarse-grained granite farther east, in Connecticut, intrusive rocks appear which reflects the structure of the underlying West of an irregularly curving divide the north­ or pegmatite and a few diabasic dikes. The highly and are present generally beyond the eastern bor­ formations. western slope of Kittatinny Mountain is drained metamorphosed limestones occur in a few minor der of the Westchester County pre-Cambrian area. Kittatinny Mountain slopes gently toward the by short streams to the Delaware, the western areas west of Wallkill River, and in a zone extend­ The Paleozoic rocks that lie within the general northwest. Within the quadrangle its crest ranges side of the area is occupied by the headwaters ing from the vicinity of Ogdensburg northeastward pre-Cambrian area in Putnam and Westchester in elevation from about 1400 feet to over 1600 feet, of Paulins Kill, and the southwest corner drains well into Orange County, N. Y. The portion of counties, N. Y., are likewise highly metamor­ a single peak which reaches 1653 feet being the to Pequest River.