LATE WISCONSIN-HOLOCENE HISTORY OF' THE LOWER HUDSON REGION: NEW EVIDENCE FROM THE HACKENSACK AND HUDSON RIVER VALLEYS STEPHEN P. AVERILL Fairleigh-Dickinson University, Rutherford, N.J., and Pascack Valley Regional High School District, Montvale, New Jersey RICHARD R. PARDI and, WALTER S. NEWMAN, Radiocarbon Laboratory, Department of Earth and Environmental Sciences, Queens College, City University, of New York, Flushing, New York. ROBERT J .. DINEEN New York State Geological Survey, Museum, Science Service State Education Department INTRODUCTION The study area (Fig. 1) is the central and upper Hacken· overdeepened by glacial ice, then mostly filled by pro­ sack River valley of northeastern New Jersey and adja­ glacial lake sediments (Lovegreen, 1974). The present cent New York State with reconaissance study of the terrain is gently rolling, wi,h drumlinoidal hills general­ surrounding area in Bergen County, N.J. and Rockland ly aligned north to south paralleling the strike of the County, N, Y. In the text, town names will be in New bedrock. Essentially glaciation has subdued the pre­ Jersey unless indicated otherwise, Geologically, the area existing topography, even occasionally reversing it. is the northern portion of the Trias·Jurassic Newark basin where a gently dipping (14 OW) homoclinal se­ Previous work: At the turn of the century Salisbury, et quence of Brunswick Formation red sandstones and 'al. (1902) reported the glacial geology in the New Jersey shales form the deeply scarred bedrock surface. The portion of the study area. Geomorphic forms were Palisade sm and basalt lava flows of the Watchungs, in­ described with great detail and accuracy with lesser em 6 terbedded with the Newark series sediments, form pro­ phasis on stratigraphy. There is a notable lack of minent topographic ridges in the region. The western description to distinguish between the two tills and their slope of the Palisade sm, whose well-studied eastern associated outwashes. The latter is not a reflection .on escarpment forms the Hudson Palisades, is at the their abilities but rather on the "state of the art" circa eastern margin of the Hackensack Valley. Resistant 1900, Reeds (1926, 1927) studied and counted the 2,550 sandstones of the Newark group form the ridges and glacial Lake Hackensack varves at Little Ferry, Heusser· cliffs along its western border as wen as the divide be­ (1963) examined the recent vegetational history of the tween it and the parallel drainage system of the Saddle tidal marsh at Secaucus from about 2,000 YBP River. The Ramapo fault system slices northeast at the (radiocarbon years before present). Lovegreen (1974) northern terminus of the basin separating it from the compiled a mass of subsurface data indicating that prior n.lgged Precambrian crystalline mass of the Ramapo , to glaciation, the Hudson River, after passing through Mountain portion of the Appalachian chain. The Hwd­ the Highlands Gap in the Ramapo Mountains, had son Ri:ver and glaciation have carved an impressive flowed westward through the Sparkill Gap in the gorge through the Hudson Highlands, The Ramapo Palisades. Then turning south it excavated channels in River lies in a similar but less spectacular gorge ten miles the Newark series shales approximating the present to the west at Suffern, N. Y. Continental glaciations course of the Hackensack River to the ocean. overdeepened both gorges before overwhelming the Ramapos to push south to their maxima. The deep preglacial Hackensack· Valley has been partially 160 161 SPARKILL GAP e BEECHWOOD PK. f:) MASTODON SITE ;' DRUMLIN AXIS I JERSEY CIT LONG HARBOR HILL TERMlNAL • SUMMIT p '" ' - '---30RAINE o u , JP " ISLAND Q , o C Q ()\)\ o 10 20 40Mi Fig, 1. Study area and adjacent region Key: Watchung lava flows are lined vertically while the ·PaIisacl:e Sill is lined horizontally. LATE WISCONSIN-HOLOCENE HISTORY OF THE LOWER HUDSON REGION 162 Glacial geology of the Hackensack Valley: , late and postglacial history of the Hackensack River. It The present study. breaches the otherwise continuous wall of the Palisades that extends from Jersey City I New Jersey to Within the study area, there is no surficial evidence of Haverstraw, New York. Because of the northward any glaciatioThearlier than late Wisconsin age. However, glacially induced isostatic crustal tilt, it served as the evidence of two earlier glaciations is present from the drainage for the Hackensack River on several occasions. subsurface. Brown drift is known from deep borings For this reason, this detailed study of the Gap is along the New York State Thruway near Mt. Ivy, New presented. York. In River Edge, excavation of red till revealed deeply weathered rock fragments whereas the red till ex­ Seismic Studies R Sparkill Gap amined in Norwood and elsewhere contained much moreo durable "fresh" clasts. This appears to agree with SparKill Gap is underlain by the Triassic Palisades For~ the till and drift sequence found on Staten Island by mation (Peflmutter, 1959). These sandstones and shales Sanders and Rampino (1978). These tills (the brown till are cut by several northeast-southwest trending normal and the "rotten clast" red till) are probably of early faults (Thompson, 1959). Sparkill Gap is on the north Wisconsin age or older. end of a + 180 ft. to + 200 ft. A.S.L. (above sea level) . terrace that was eroded by the southwest-flowing, The late Wisconsinian (Woodfordian) glacial maximum preglacial Hudson River (Fig. 2a, and Woodworth, of the Hudson Valley ice lobe overrode the earlier drifts 1905, Johnson, 1931). The preglacial Hudson was con­ and built the Harbor Hill moraine across western Long sequent on a graben that broke the crest line of the Island, Staten Island 9 New York and at Perth Amboy, Palisades ridge (Thompson, 1959). The Tappan and New Jersey across to Summit (Fig. 1) sometime after Sparkill Moraines lie west of the Gap; these moraines 22,800 B.P, (Sirkin & Stuckenrath, 1975). The thin were deposited by ice lying in the valley between Roslyn till overlies the Harbor Hill Moraine in western Orangeburg and Mt. Nebo (Fig 2a, and Woodsworth, L.t This undated till marks the most recent readvance 1905). Stratified drift (outwash)Iies between the two to the terminal position by the Hudson lobe of the moraines (Woodworth, 1905), Woodfordian ice sheet (Connally & Sirkin, 1973). The Gap is filled by over 60 ft. (18.3 m) of glacial drift, Proglacial lakes Hudson, Flushing and Hackensack, based on test borings and water wells (Perlmutter, conterminous (Reeds, 1926) and dammed on the south 1959). These wells, with supplemental test borings, un~ by the Woodfordian terminal moraine, expanded as the published· USGS water well data, and NYSGS seismic ice beat an oscillating retreat northward. Lake Passaic, refraction data, has been used to generate Figs. 2b and which formed between the First Watchung Ridge and 2e. the Ramapo Mountains to the west, lay at a higher elevation and is presumed to have been es.sentially Geophysics: Seismic refraction was used to provide ad­ coeval with the other three. ditional data points in the Sparkill Gap area. Seismic profiles were run along rights-of-way and in town The preceeding is relatively well known and has been parks. Each of the profiles was reversed, and was 170 to presumed to have been the entire late-glacial history. It 250 ft. (52 to 76 m) long; the length depended on the was thought to have been foHowed only by draining of distance available between power lines, road intersec­ the lakes and the stream flow that presumably deposited tions, and fences. "Shot points" were 10 feet (3 m) a three to six meter thick sheet of sand across· the lake apart in the first 60 ft. (18,3 m) of each profile, and were bed. Both events were believed to have been the result of 20 feet (6.1 m) apart for the rest. The "shot points" postglacial differential isostatic rebound, were impacts of a 161b sledge hammer on a 1 ft.2 (.4 m2) steel plate. The signal was recorded ton a Huntec FS-3 The present study indicates the occurence of a post­ single-channel seismograph: The resulting time-distance Lake Hackensack glacial readvance into the lower Hud­ graph was interpreted using both the critical distance son River Valley region following a significant in­ and time-intercept methods (Mooney, 1973, Zohdy and terstade, and provides details of the post-glacial events. others, 1974), The supporting evidence includes stratigraphic, sedimentologic, geomorphic, seismic and palynologic Two areas were studie'd - The northernmost area was at data as well as a series of supporting C-14 dates, the mouth of the Sparkill (seismic profile 73-13, Fig. 2c), and the southernmost was just southwest of U.S. SPARKILL GAP: SEISMIC STUDY Rt,. 9W crossing of t~e Sparkill (profiles 73-10 t -11, -12, Fig. 2c). Each seismic profile generally 'had th"ree seismic Sparkill (Spar Kill) Gap has been most important to the layers (Fig.2c). The uppermost~ or low-velocity layer 0\ v.> B 8' " \ \ , v '-\ ( Iii J I \\ \ A A' N "., ; r , '-- \ \ . \ \ \ ",,--,+ I '00 o Ul...; t W\~:I, ') J \"-,,_"-:0, \ . ,",' ~/ J"\ \\\ ~"" \:'lJ 1 .. \ J _~"O C \\ -; o .•. ... "" _-.-J S L m ~<~'"O,~\ . '~E~MO", ·~ :~=:1 Ul ~ U "0 . U ,,-~ ... , , •..h '1 " 0\ I D \'~;: J" ..---~_~, o "., C :;-1 f C Z tTl ~ "- tTl \-\ ~ Ul U rrl ---1+ ;L ><: o o S otTl ro o .. --.1_ o ~ N » z o o D' o - I' c C> '" oS I o ,~~C~.~ --jSL tTl o-l ~~±~ :] ('Tl r o I'<>-l SAND 8 ~ SANDS PEAT S TILL DSAND -; 0GRAVEL ~ SILT ~ • Mu(." z: ." iTHVALE Ul !"Xl OUTWASH ro::;] MORAiNE 1;::1+1800' - +200' LQ A ~~. ~TERRACE .A + ;:AULTS. A WOODWORTH, 1905 o 1000 2000 FT.