OPEN FILE REPORT SERIES U.S. DEPARTMENT OF THE INTERIOR MAP 2005-1331, Version 1.0 U.S. GEOLOGICAL SURVEY Report accompanies map Antietam National Battlefield Manassas National Battlefield Bull Run 77° 17' 40'' Parks in the District of Columbia and Corridor 76° 48' 10'' 39° 5' 10'' 39° 4' 58'' 234 Sudley Ford

r Wheaton Sudley Springs Ford ive O?c ac R tom Poplar Ford Po Catharpin Creek ?cbs

A Nicodemus Heights To Keedysville Qa Upper ?e Bridge FT C Rock Creek Park C' FT 1000 1000 270 Pry Ford >bg Pennyfield Park Farm Ford Matthews Bull Run Hill 29 Tc Ttu Hauser QTt Stony Ridge Pry House ?s QTt Youngs Branch Qa Ridge National Zoo Kps Rock Creek Rock Creek LEVEL 705 Jd

SEA Buck Hill 65 Dogan Branch

war SEA

LEVEL Ogr Ogr ? Ok Stone House Ogh ?s ?l Dogan Ridge ?wak Ok A Qa Ogg dgf ?e ?wac A' Lee Highway -1000 -1000 Visitors Center A' Rock Creek Shear Zone J>tm Battery Heights J>tm J>tm Qt Northern

Chinn Branch Community College Rockville Jd Youngs Branch 495 Baltimore-Washington Parkway Antietam Cemetery 495 Stuarts Hill 66 Sharpsburg Greenbelt Conn River Bend Park Island Maryland 34 ?cbs Red Hill Fairfax Co. Great 00.15 0.3 0.6 0.9 1.2 Falls 190 NASA Goddard Miles Space Flight Qs Great Falls Tavern Visitor Center Kilometers Qt Mine Run Branch Center 00.40.81.21.60.2 Ttu To Manassas Burnside Bridge Great Falls Visitor Center Silver Spring Greenbelt Park Qt River Road A A' ?l University of Maryland Indian Creek Park Glade Hill 1000 190 College Park A ?Zms QTt C&O Canal Rock Creek National JTtmR Stony Ridge Qt Bear Historical Park Battery Heights surface Qt Chinn Branch C Rock Creek Park Bull Run Island 495 ab C&O Canal in Potomac Harpers Ferry Road ?Zmg Jo SEA hn LEVEL Jd Jd Caderock Park P Takoma Park a >bg r Bethesda Co. k bedding w Snavely’s Ford American Legion Memorial Bridge a y Walter Reed 00.15 0.3 0.6 0.9 1.2 Ok College Park Miles ?Zmmg Medical Center -1000 J>tm Kilometers P Fort feet 00.40.81.21.60.2 o Clara Barton National Historical Site toPotomacmac Ri vRiverer Stevens New Carrollton ?Zmms Glen Echo Park Park A A' ?Zd District of Columbia?s boundary QUATERNARY SURFICIAL MATERIALS 1000 Park Headquarters Fort DeRussy Kpc ?st Qa Alluvium (Holocene) surface Oc Pinehurst Branch Kps ?Zmmp Ogh ?Zmss Carter Barron Fort Qt Terrace deposit, low level (Holocene and Pleistocene) ?wac Ogus Fort Bayard Fort Reno Park Amphitheatre O?c Slocum Park ?wak Qd Odl Qa SEA EARLY MESOZOIC ROCKS

LEVEL ?war Plummers Island fault ?e ?e 193 Turkey Run Ogh Soapstone ?cbs ?Zu ?l Jd Diabase dikes and sills (Early Jurassic and Late Triassic) ?td Dead Run Dalecarlia Ogh Tenley Valley Fort Totten Kps ?Zt Ogl Park J>tm Thermally metamorphosed rocks (Lower Jurassic and Upper Triassic) -1000 Vienna Reservoir Circle feet McLean Odm Claude Moore Chatham Group Odt American Colonial Farm Melvin Hazen Park Kpc >bg Groveton Member of the Bull Run Formation (Upper Triassic) ?s University Pierce QUATERNARY SURFICIAL MATERIALS Little Falls Battery Kemble Park Mill Qa Alluvium (Holocene) Waynesboro Formation (Lower Cambrian) Odt Fort Marcy Ttu George Washington Memorial Parkway Tc Qs Sinkhole (Holocene) Chewsville Member ?wac QTt ?s Washington Palisades Park Ogb Qt Chain Bridge Cathedral Terrace deposit, low level (Holocene and Pleistocene) ?wak Cavetown Member Turkey Run Park McMillan Reservoir Ql Qa ?war Red Run Member Klingle Ogr Tt Kpc PALEOZOIC ROCKS Qc dgf Tomstown Formation (Lower Cambrian) Tysons Corner O?c Conococheague Limestone (Lower Ordovician and Upper Cambrian) Virginia Tc td Dargan Member Kps cbs Big Spring Station Member (Upper Cambrian) ? Fairfax Co. ? Meridian Hill Park Qfe ?e Elbrook Limestone (Upper and Middle Cambrian) Glover-Archbold Park Ok Rock Creek and Potomac Parkway 50 Arlington Co. dgf Montrose Park Dumbarton Oaks Park QTt Dupont Circle QTt Kenilworth Park Prince William Forest Park Ogh Washington, D.C. and Aquatic Gardens Independent Hill George Washington Memorial Parkway Key Memorial Bridge Virginia Mt. Vernon Square Dale City dgf Catoctin Mountain Park 66 Tt Qc dgf Theodore Roosevelt Isl. Langston Golf Course Visitor Center To Sabillasville 29 The Olj Capitol Hill A White House Lincoln OCp Theodore Roosevelt Bridge Qt U.S. Marine Corps Memorial National Mall U.S. Capitol Kpc War Memorial Netherlands Lake Montclair Carillon Arlington Memorial Bridge Qfe A A' FT FT Great Falls Park Turkey Run Park Arlington House Tidal District of 491 1000 1000 Basin Bend in x-section R.E. Lee Memorial LadyBird Columbia W Johnson Park a ?Zum sh Lyndon Baines Johnson in k South Mountain g uantic e Ordovician or earlier deformation Plummers Island Shear Zone Memorial Grove t S Fork Q o re Owens Creek o Tc Creek C CZa Columbia Isl. n Fort Dupont ells C ow CZd LEVEL P

SEA Anacostia Park CZmg CZmms CZmss Cst Ogh Navy & Marine Memorial h Park CZms CZmmg CZmms Oc a Qte n er Ttu SEA Ogus iv Olr n Lantz LEVEL CZmmp shearing Tt R Ttu 95 CZms e Goodwill

Pentagon l faults a Mary Bird Branch i A Roaches Run t Plummers Island Fault Gravelly Point s Fort Qa Cs Waterfowl o Frederick Douglass U.S. Marine Corps Zc Early Devonian deformation Late Pennsylvanian shearing c Stanton Reservation Sanctuary na National Historical Site Edgemont Creek -1000 -1000 A Park Qa feet feet QTt Kpc Turkey Run Zcr Education Center Ta N QTt Oc TKb Suitland Parkway Bra Happy Land Ocg 234 Sawmill Arlington National nch Piney Mountain of Oi C Cabin Branch Qfe Airport h o p Pyrite Mine National QTt aw Dumfries Qa am sic C Ttu reek Qt Qte Zc Cemetery Qc Blue Ridge 550 Tc Park Headquarters Quantico Creek Summit Overlook Kp Foxville fault Ttu Oq Daingerfield Visitors Center Thurmont Vista Kp Isl. A' Quantico Park Central Road Park National Cemetery Park Entrance Qte Oc ?wb 395 S Branc To Smithsburg h of C and Hagerstown Big hopawam ?lp Maryland sic Creek Brekenridge Reservoir 77 lc 0 0.3 0.6 0.9 1.2 ? QTt Miles Qt Visitor Center ?wm Kilometers U.S. Marine Corps 0 0.4 0.8 1.2 1.6 Reservation To Fredericksburg Cunningham Falls ?h Thurmont Tt A A' Chimney Rock 1000 Park Headquarters ?wo 495 Hunting Creek Lake Hunting Creek Ttu City of Scenic Drive surface fault Cunningham Falls Big Hunting Creek Alexandria Oxon Hill Farm Kp Kp A' South Fork State Park Quantico G. Headquarters

77 SEA

Bear Branch LEVEL Oi Foxville Road 495 Olj OCp Olr Oc Oi Oc Ocg Oq Oq Cat Rock Woodrow Wilson Memorial Bridge

Jones Point Hauver Branch -1000 Lighthouse High Run feet Catoctin Hollow Road

00.511.520.25 Belle Haven Park QUATERNARY SURFICIAL MATERIALS Miles 806 Ttu Kilometers Qa Alluvium (Holocene) 00.751.52.2530.375 Cunningham Falls State Park Tt Dyke Marsh Fort Foote Qt Terrace deposit, low level (Holocene and Pleistocene) A A' QTt Terrace deposit, high level (Pleistocene) 2000 surface CENOZOIC AND CRETACEOUS COASTAL PLAIN DEPOSITS Creek Creek Fluvial and estuarine deposits (Pleistocene) Creek Qte Lower level ?h ?wo Qt Qfe SEA Qc Upper level LEVEL Zcr Zcr Zc ?lp ?lc ?wb ?wm Kp Ttu Upper level upland terrace deposits (Miocene) Kp Potomac Formation (Upper and Lower Cretaceous) 1 Broad Creek -2000 PALEOZOIC ROCKS feet Harmony Hall Oi Felsic igneous rocks (Silurian) Oq Quantico Formation (Upper Ordovician) QUATERNARY SURFICIAL MATERIALS Qfe B B' Olr Lunga Reservoir Formation (Ordovician) Qa Alluvium (Holocene) FT FT Loudoun Formation (Lower Cambrian) Kp 1000 1000 Formation (Upper Ordovician) Qt Terrace deposit, low level (Holocene and Pleistocene) ?lc Conglomerate Ocw Metavolcanic and metasedimentary rocks Qte

Phyllite Fort PALEOZOIC ROCKS ?lp Ocg Breccia and metabasalt QTt Washington Chilhowee Group Tt Mount Vernon Estate and Gardens LEVEL NEOPROTEROZOIC ROCKS Qfe Olj Lake Jackson pluton (Middle Ordovician) Little Hunting Creek Qte Kp Qte Ta Qc Qte SEA Potomac River ?h Harpers Formation (Lower Cambrian) Potomac River Km Tyb Catoctin Formation (Ediacaran) QTt SEA OCp Phyllite (Ordovician and (or) Cambrian)

LEVEL Bedrock 1 ? ? Weverton Formation (Lower Cambrian) Zc Metabasalt PALEOZOIC AND NEOPROTEROZOIC ROCKS ?wo Owens Creek Member Zcr Metarhyolite Riverside Park ?Zum Mafic and ultramafic rocks (Cambrian and (or) Neoproterozoic) wm Maryland Heights Member ? Fort ?wb Buzzard Knob Member Hunt -1000 -1000 Park [3.83 x original vertical exaggeration]

Piscataway Creek Qa Fort Washington Park

Marshall Hall Qc Qt Ta Monocacy National Battlefield Tn

Maryland 270 INDEX MAP & PHYSIOGRAPHIC PROVINCES 355 Tyb Piscataway Park Qte GREAT PIEDMONT

?fl VALLEY Catoctin ?fa Qc Mountain Monocacy Junction 024681 Park Station Miles National Colonial Farm

Qs 38° 39' 2'' 38° 38' 59'' Best Farm 77° 17' 38''Geology mapped from 2001-2004 13 1/2 76° 48' 17'' Antietam MonocacyGambrill’s River Mill Qa Mapping based on 1:24,000-scale Digital Line Graph basemap data. National Visitor Center Projection: Universal Transverse Mercator, zone 18N QUATERNARY AND CENOZOIC SURFICIAL MATERIALS PALEOZOIC ROCKS Datum: North American Datum 1983 dgf Battlefield McGill House Qs ?fr North True Disturbed ground and artificial fill Georgetown Intrusive Suite (Early Ordovician) Magnetic North Qa Alluvium (Holocene) Ogh Biotite-hornblende tonalite Approximate Mean Ford Declination, 1997 Qt Terrace deposit, low level (Holocene and Pleistocene) Ogg Quartz gabbro Monacacy Worthington Qt Farm Qc Colluvium (Holocene and Pleistocene) Ogb Biotite tonalite National A Urbana Pike Ball Rd Qd Debris (Holocene and Pleistocene) Garnetiferous biotite-hornblende tonalite Thomas Farm Ogr Battlefield EXPLANATION Ql Landslide (Holocene and Pleistocene) Ogus Soapstone and talc schist Park boundary Qte Low-level fluvial and estuarine deposits (Pleistocene) Ogu Ultramafic rocks Qfe Upper-level fluvial and estuarine deposits (Pleistocene) Ogp Pyroxenite Contact (dotted where concealed) ?ar ?fr QTt Terrace deposits, upper level (Pleistocene and Tertiary) Sykesville Formation (Lower Cambrian) Fault Qs ?s Diamictite CENOZOIC AND CRETACEOUS COASTAL PLAIN DEPOSITS ?ar ?st Diamictite tectonite frs Tt Terrace deposits (Tertiary) Brooks ? ?sg Metagraywacke and schist Hill Louis House Ttu Highest level upland terrace deposits (Tertiary) BLUE Potomac River fault ?sp Chlorite-sericite phyllonite Tyb Yorktown Formation (Pliocene) and Bacons Castle Formation (upper Pliocene) DC & Potomac River ?l Laurel Formation (Lower Cambrian) RIDGE Qc Tc Calvert Formation (middle Miocene) Corridor Parks Tn Nanjemoy Formation (lower Eocene) PALEOZOIC AND NEOPROTEROZOIC ROCKS Tm Marlboro Clay (lower Eocene and upper Paleocene) ?Zd Diamictite (Lower Cambrian and (or) Neoproterozoic) 00.250.50.750.125 1 Baker Valley Road Miles Martic Ta Aquia Formation (upper Paleocene) Kilometers ?Zi Mather Gorge Formation (Lower Cambrian and (or) Neoproterozoic) TKb Brightseat Formation and Monmouth Group, undivided (lower Paleocene and Upper Cretaceous) 00.15 0.3 0.6 0.9 1.2 To Washington ?Zms Schist Km Monmouth Formation (Upper Cretaceous) A’ ?Zmg Metagraywacke AA' Ks Severn Formation (Upper Cretaceous) 1000 ?Zmm Migmatite Kp Potomac Formation (Lower Cretaceous) Manassas ?Zmmg Migmatitic metagraywacke Kpc Clay-dominated lithofacies National ?fa ?Zmms Migmatitic schist ?frs ?Zi Kps Sand-dominated lithofacies SEA Battlefield LEVEL ?Zmmp Migmatitic phyllonite ?fr fr ?ar ? ?Zmss Sheared migmatitic schist and migmatitic phyllonite PALEOZOIC ROCKS -1000 Metavolcanic and meta-igneous rocks of uncertain origin (Lower Cambrian and Neoproterozoic) feet Pzq Vein quartz bodies (Paleozoic) ?Zu Ultramafic rocks DI Lamprophyre dike (Late Devonian) ?Za Amphibolite QUATERNARY SURFICIAL MATERIALS Op Pegmatite (Ordovician) Prince William ?Zg Metagabbro and metapyroxenite Qa Alluvium (Holocene) Oc Clarendon Granite (Middle Ordovician) Forest Park ?Zt Soapstone, talc schist, and actinolite schist Qs Sinkhole (Holocene) Ok Kensington Tonalite (Middle Ordovician) Qt Terrace deposit, low level (Holocene and Pleistocene) Ogl Granite (Ordovician?) COASTAL Qc Colluvium (Holocene and Pleistocene) Dalecarlia Intrusive Suite (Early and Middle Ordovician) 0 2.5 5 7.5 10 Miles Odm Biotite monzogranite and lesser granodiorite Kilometers PLAIN PALEOZOIC ROCKS 042 81216 Frederick Formation (Upper Cambrian) Odt Muscovite trondhjemite ?fl Lime Kiln Member Ob Bear Island Granodiorite (Early Ordovician?) ?fa Adamstown Member ?fr ?frs Rocky Springs Station Member ?ar Araby Formation (Middle and Lower Cambrian) PALEOZOIC AND NEOPROTEROZOIC ROCKS ?Zi Ijamsville Phyllite (Lower Cambrian? and Neoproterozoic?) GEOLOGIC MAP OF THE NATIONAL PARKS IN THE NATIONAL CAPITAL REGION, WASHINGTON, D.C., VIRGINIA, MARYLAND, AND By For sale by U.S. Geological Survey Map Distribution, Box 25286 Federal Center, Denver, CO 80225 Scott Southworth and Danielle Denenny 1-888-ASK-USGS

2006 Available on the World Wide Web at http://pubs.usgs.gov/of/2006/1331/