74 3

0’O

75 0

0’O

41 00’O

74 0

0’O

75 0

0’O

39 00’O

39 30’O

74 3

0’O

40 00’O

74 0

0’O

40 30’O

76 0

0’O

75 3

0’O

Bridgeton

Salem

Woodbury

Camden

Mount Holly

Trenton

Elizabeth

Morristown

Newton

Belvidere

Newark

PatersonHackensack

Jersey City

NewBrunswick

Freehold

Toms River

Mays Landing

Cape MayCourt House

Flemington

Somerville

SUSSEX

PASSAIC

BERGEN

HUDSONESSEX

UNION

MORRIS

WARREN

HUNTERDONSOMERSET

MIDDLESEX

MONMOUTHMERCER

OCEAN

BURLINGTON

CAMDENGLOUCESTER

ATLANTIC

CAPE MAY

SALEM

CUMBERLAND

DelawareWater Gap

Franklin

Phillipsburg

Milford

Andover

Mahwah

Gladstone

Boonton

Carteret

Atlantic City

Asbury Park

0 10 20 30 km

0 5 10 15 20 mi

Scale 1:1,000,000

Department of Environmental Protection

NEW JERSEY GEOLOGICAL AND WATER SURVEY

2016

N

1835

NEW

JER

SEY

GEOLOGICAL AND W

ATER SURVEY

SURFICIAL GEOLOGIC MAPOF NEW JERSEY

PLEISTOCENE GLACIAL

HOLOCENE

LATE MIOCENE

DESCRIPTION OF MAP UNITS

DESCRIPTION OFMAP SYMBOLS

PLEISTOCENE NONGLACIAL

PLIOCENE

beach sandfloodplain alluvium

freshwater wetland depositestuary and salt marsh deposit

postglacial stream terrace

Pensauken Formation

Kittatinny Mountain Till

Rahway Till

Flanders Till

Netcong Till

Port Murray Till

sand and gravel

lake clay

moraine

windblown sand and silt

Lower Stream Terrace

Upper Stream Terrace

colluvium

Cape May 3 Marine Terrace

Cape May 2 Marine Terrace

Cape May 1 Marine Terrace

Bridgeton Formation

Upland Gravel

Beacon Hill Gravel

surficial deposits thin or absent

limit of late Wisconsinan glaciation

limit of pre-Illinoian glaciation

limit of Illinoian glaciation

SURFICIAL GEOLOGY OF NEW JERSEY Surficialdepositsaresedimentslaiddownbyrivers,glaciers,oceancurrentsandwaves,wind,andmovementofsoilandrocksonhillslopes.TheyoverliebedrockandunconsolidatedCoastalPlainformations,andare theparentmaterial foragronomic soils. InNewJersey theyareasmuchas400feetthick,butarelessthan25feetthickovermostofthestate.NewJersey isacoastalstateatthesouthern limitofcontinentalglaciationandsohasavarietyofsurficialdepositsformedduringitsrichhistoryofglaciation,changingsealevel,andevolvingriversystems. TheoldestsurficialdepositinNewJerseyistheBeacon Hill Gravel (italicized names are the deposits shown on the maps), a weatheredrivergravelcomposedmostlyofquartzandchertpebblesthatcapsthehighesthillsintheCoastalPlain,whichisthepartofthestatesouthofalinebetweenTrentonandCarteret.Mostofthegravelhasbeenerodedaway.Remnantsofthegravel,showninredonthemaps,aresufficienttoshowthatitwaslaiddownbyariversystemthat flowed southward across central NewJersey. This river system deposited a gravelplain on coastal deposits exposed when sealevel loweredinthemiddleandlateMiocene,between 15 to 10Ma (millions of years ago).Southward flow is indicated by the declinein the elevation of the plain from350 to 200feetfromnorthtosouth,andbycrossbeddingin sandy parts of the deposit, which recordcurrentdirection. Continued lowering of sea level causedthe river system to cutdown into theBeaconHillplain.Theriveralsoshiftedtothewest incentral New Jersey and swung southeasterlyacross southern New Jersey. It laid down theBridgeton FormationinaplainacrosssouthernNew Jersey. This deposit consists mostly ofquartzandchertgravelerodedfromtheBeaconHill, but it includes traces of schist, gneiss,andsandstone fromnorthernNewJerseyandeastern Pennsylvania. Southeastward flow isdocumentedbycrossbedding,andthedeclineintheelevationoftheplainfrom180to60feetfromnorthwesttosoutheast. As the Bridgeton was deposited, thenorthern Coastal Plain, north and east of theBridgetonriversystem,becameanuplandfromwhich local streams drained eastward to theAtlanticandwestwardtotheBridgetonvalley.Gravel and sand eroded from the Beacon Hill and underlying CoastalPlainformationswasdepositedintheselocalstreamvalleys.Today,duetoerosionof youngervalleys into the intervening,moreeasilyerodedsanduplands,theseUpland Gravelscaphilltopsandridges. By the early Pliocene (5Ma), the river system had again shiftedto the west, and cut down into the Bridgeton plain, forming a valleyacrosscentralNewJerseyandalongthepresentDelawareRivervalleydownstream of Trenton. This river, which included the Delaware, theHudson,andpossiblyriversfromsouthernNewEngland,laiddownsandandgravelinthisvalleytoformthePensauken Formation.ThePensaukenis mostly quartz and chert gravel eroded and redeposited from theBridgetonandBeaconHillbut italso includes tracesofsandstoneandgneiss from northern New Jersey and the Hudson River valley. CrossbeddingandthedeclineofthePensaukenplainfrom160to80feetinelevationfromnorthtosouthshowsouthwestwardriverflow. In the early Pleistocene, sometime between 2.5 Ma and 800 ka(thousandsofyearsago),aglacierenteredNewJerseyandadvancedasfarsouthastheSomervillearea.Thisadvance,knownasthepre-Illinoianglaciation,depositedtill(mixedsedimentlaiddowndirectlyfromglacialice)andafewsandandgraveldepositslaiddownbyglacialmeltwater.Thetill,knownasthePort Murray Till,isreddish-yellow,weathered,andclayey.Itremainstodayonlyonflatuplands,whereitwasprotectedfromerosion. Thepre-IllinoianglacierdivertedthePensaukenRiverfromitsvalleyacrossNewJersey,reroutingitsouthwardfromtheNewYorkCityarea.

Anew local river network formedon the abandonedPensaukenplainnorth of Trenton. South of Trenton, the Delaware River followed theoldPensaukenvalley.Loweredsealevelduringandaftertheglaciationallowed theseandother rivers inNew Jersey to incise their valleysasmuchas200feet,formingtherivernetworkweseetoday.PeriodsofcoldclimateinthemiddlePleistocene(800to125ka)reducedforestcover,causing sediment towash into valleys, formingwhat today areUpper Terraces,20to50feetabovethemodernfloodplain.Inareasofhigherrelief sedimentmoving downslope accumulated at the foot of hills indepositsknownascolluvium. A second glaciation advanced into New Jersey in the middlePleistocene,mostlikelyduringtheIllinoianstageat150ka.DepositsofthisglaciationareexposedinabeltinMorrisandWarrencountiesandlieburiedbeneathyoungerglacialdepositseastandnorthoftheoutcrop

belt. They include the Flanders Till, a brownsandysilttillthatismuchlessweatheredanderoded than the Port Murray Till, and somesandandgraveldeposited inglacial lakesandriverplains. The most recent glacier advanced to itsterminus at 25 ka, during the WisconsinanstageofthelatePleistocene(125to11ka).Itsterminalposition,andsomeretreatpositions,aremarkedbymoraines(ridgesoftilllaiddownalong the glacier margin). Three tills weredepositedby thisglacier:Kittatinny Mountain Till, a gray-brown sandy silt till derived fromsedimentary rocks in northwestern NewJersey,Netcong Till, a yellowish-brown sandytill derived from gneiss in north-central NewJersey, and Rahway Till, a reddish-brownsandy silt till derived from sedimentary rocksin northeasternNew Jersey. In valleys, glacialmeltwaterlaiddownsand and gravelinglaciallakesandriverplains,andlake clayonglacial-lakefloors.Southoftheglaciallimit,sedimentwaswashed into valleys from uplands duringcoldperiodsintheWisconsinan,formingwhattoday are Lower Terraces, 5 to 20 feet abovemodern floodplains. During this and earliercoldperiods,westerlywindblewfinesedimentfrom terraces, glacial riverplains anddrainedlake floors, and exposed Coastal Plain sands.Thesesedimentsweredepositedaswindblown

sand and siltinsheetsanddunefieldstotheeastandsouthofthesourceareas. Sea level dropped as glaciers grew, and rose as glaciers melted.Estuarinesandandsilt,andbeachsandandgravel,depositedduringthehighstandsformtheCapeMayFormation,aseriesofterracesringingthecoast.The terracesdocumentat least threehighstands: onebetween100to80ka,whensealevelwas10-15feethigherthanpresent(Cape May 3),oneat125ka(Cape May 2),whensealevelwas20to30feethigher,andoneat400kaorearlier(Cape May 1),whensealevelwas60to70feethigher. After the Wisconsinan glacier retreated from New Jersey at 20ka, climatewarmed.Forest regrewby15ka.Peat, silt,andclaybeganto accumulate in shallow lakes and ponds left by the glacier to formfreshwater wetland deposits. Rivers eroded into glacial sediments intheirvalleys,depositingpostglacial terracesandthen, in theHolocene(11ka-present),modernfloodplain alluvium.OnfloodplainsinpartsoftheCoastalPlainwhereriverscarriedlittlesediment,peataccumulatedinsteadofalluvium.Throughthistime,risingsealevelwasfloodingthelower reaches of coastal rivers to form estuaries and bays, in whichestuarine and salt-marsh depositsofsilt,sand,andpeatwerelaiddown.Oceanwavesandcurrentswereerodingsandfromheadlandsandfromtheinnercontinentalshelf,depositingbeach sand.Thecoastaldepositswerelaiddownmostlywithinthepast7ka,aftersealevelhadrisentonearitspresentelevation.Thealluvial,wetland,andcoastalsedimentscontinuetoaccumulatetoday,alongwithfilldepositedbyhumans.

GLACIAL LIMITSlate WisconsinanIllinoianpre-Illinoianice flowriver flowHolocene

coastal deposits

Cape May Formation

Pensauken Formation

Bridgeton Formation

Beacon Hill Gravelformer extent

present extent

miles

0 10 20

SomervilleCarteret

Trenton