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Home , Nanjemoy Formation, Patapsco Formation, Piscataway Creek

ALLUVIUM -- Interbedded sand, silt-clay, and subordinate gravel. Light- to -- Sand, variably glauconitic, and minor calcareous or Qal dark-gray, tan, or brown; weathers pale-gray, yellow, or brown. Ta ferruginous . Dark greenish gray to medium-gray; "salt and Correlation of Map Units pepper" speckled to rusty brown. Geologic Map of Prince George's County, Alluvium includes very heterogeneous, commonly poorly stratified sediments, with muddy sand and silt the dominant lithology. Organic matter, including The Aquia is composed of sand, fine- to medium-grained, poorly sorted to well Qal Holocene leaves, branches, and logs, is a common component. Thin peats occur in places. sorted, containing as much as 40 percent . Thin layers and Quaternary Dark gray organic muds are prevalent in tidal marsh areas. This unit underlies concretionary zones of calcareous shelly sandstone are scattered through the unit. by John D. Glaser, 2003 the channels and flanking valley floors of all major streams and many minor ones Outcrop sections contain "rusty" ferruginous in places. Bedding is Qt Pleistocene in the County. Much of this sediment is soft and water-saturated due to massive for the most part, with mottling common. Molluscan , And Silt- Loam Soils with Hardpan in Upland Deposits perennially high water tables. The composition of the alluvium in any given chiefly large Turritella and Ostrea , are present in some beds. The Aquia reaches 76°52'30"W stream valley reflects the source sediments; thus, alluvial sand contains a maximum 150 feet (45.7 m) in thickness in Prince George’s County. Aquia Tu upper - Pliocene 410000 considerable glauconite where the source is the Aquia, Nanjemoy, or Severn sands accumulated on the marginal marine shelf in less than 200 feet (61 m) of from Hack (1977) Formations. Small areas of tidal marsh are found bordering the Patuxent and water during late time. Explanation of Map Symbols Potomac Rivers. Alluvial sediment thickness ranges from less than 5 feet (1.5 m) Tc lower and middle Miocene 1 0 to as much as 40 feet (12.2 m), although the average is closer to 15 feet (4.6 m). 0 Scale 1:62,500 Geologic Symbols Sediments mapped under this heading are geologically young, deposited mostly BRIGHTSEAT-SEVERN FORMATIONS, undivided 101230.5 Miles within the past 10,000 . Tn Contact, TKbs approximate, gradational, or inferred BRIGHTSEAT FORMATION -- Sand and silt, clayey in part, variably lower Tertiary ent 5,000 0 5,000 10,000 15,000 Feet tux R Pa iv 100 A' glauconitic. Dark-gray to dark greenish gray; weathering pale-gray to brownish er A Line of Section gray. Tm 1012340.5 Kilometers

-- Interbedded sand, gravel, and silt-clay. Typically 0 39°7'30"N

TERRACE DEPOSITS 39°7'30"N upper Paleocene 2

1 Qt tan, brown, or shades of gray; weathers to yellow, orange, or brown hues, Topographic Symbols commonly limonitic. The Brightseat consists of mostly fine-grained, poorly sorted sand, with up to 30 28 \la 6 Contour Interval 10 Meters 00 percent glauconite, but generally much less. In places, the basal Brightseat Ta 0 Topographic Contour - Index (20- m interval) contains some medium to coarse sand with granules, small pebbles, 1 Included under Terrace deposits are heterogeneous lithologies such as medium lower Paleocene 00 Topographic Contour - Intermediate (10- m interval) phosphatic clasts, and shark teeth. The unit is essentially a fining-upward 0 to coarse sand, pebbly sand, and subordinate silt-clay. These sediments are T 8 C U sequence, with the relatively coarse lower portion grading rapidly upward to fine- D St TKbs E contained in a series of disjunct bodies flanking the major streams in Prince U 160000 1 Q h 160000 Cultural/Transportation Symbols grained clayey sand and finally dense clayey micaceous silt. The abundance of Upper 40 A t George’s County, reaching as high as 160 feet in elevation across some portions 7 d Rd v pring l is characteristic of the upper Brightseat, as is a decided purplish cast in S B of the county, but declining to near sea level along the . A few Cretaceous County Boundary ndy unweathered sediment. The Brightseat is both thin and lithologically similar to Sa Laurel 6 such deposits are as thick as 50 feet (15.2 m), but the average is much less. Kps Kpc Lower Cretaceous 0 the underlying Severn Formation; thus, the two units are mapped together at this n Bedding within these deposits is mostly lenticular, but ranges to massive and to Major roads T g C n scale. It thickens southwestward across the county, reaching a maximum of U i D Kps h unstructured. The Terrace deposits are the product of stream erosion during the E s U a 1 Q about 60 feet (18.3 m) south of the District of Columbia. The Brightseat is a 20 A W Hydrologic Symbols early Quaternary, and are now isolated on the valley walls above the modern \la marine shelf unit of early Paleocene age. Tu floodplain by renewed downcutting. Major terraces are associated with Western 80 (! A Reservoir, treatment Q e v Branch, Piscataway Creek, and , as well as the Patuxent and U A 5 E SEVERN FORMATION -- Sand, fine-grained, variably glauconitic. Pale-gray to 9 D e (! Potomac Rivers. Deposits flanking the Patuxent River tend to be more laterally I- U r Gaging Station C o ¢ 8 T 0 (State Plane Grid North) medium-gray; weathering mottled pale-gray and yellow. im extensive than those along the smaller watercourses, averaging 20 to 25 feet (6.1 to lt a Dam/Weir, nonearthen 7.6 m) in thickness, and have been utilized as a source of construction sand and B E The Severn is composed almost entirely of very fine- to fine-grained glauconitic N gravel in the past. LI E Kps Stream; Connector IP sand, which is moderately to well sorted. The sand grades in places to dense P 0 A 0 1 N clayey micaceous sand and silt. Glauconite may comprise as much as 40 percent 8 Stream, intermittent 0 N 0 E 4 of the sand fraction. The basal few feet of the unit is fine- to medium-grained A R Shore, nonearthen with scattered granules and pebbles, siderite concretions, and shark teeth. Along U UPLAND DEPOSITS -- Sand, pebbly sand, and gravel, capped by sandy pebbly N 0 6 Qal D 0 E loam in places. Pale-gray, tan, or buff in color; weathering to yellow, orange, the Patuxent River and its tributaries in the vicinity of Bowie, a zone of large 6 L 0 420000 Tu Qal C 4 Aqueduct; pipeline Y OU 5 NT lobate or ellipsoidal ferruginous concretions marks the top of the formation. T I-9 Y and shades of brown. N Muirkirk

U 8 76°45'0"W Dump Site, operational Moreover, outcrops along the Potomac may contain considerable selenite. Like O 0 e 1 C v Qt 0 A 0 The Upland deposits (or Brandywine Formation of earlier workers) consist the Brightseat, the Severn Formation is a thin unit, 40 feet (12.2 m) thick at most Y re Foreshore R o Patuxe E n largely of poorly sorted, medium to coarse sand interbedded with pebbly sand along the Patuxent, and reducing to about 13 feet (4.0 m) in outcrop at the im t M Kps lt a y R O k . It is mapped with the Brightseat as a single map unit. The B i Lake/Pond, intermittent and medium to coarse gravel. The sand is predominantly quartz, and the pebbles G P v Tu e T n r quartzite, sandstone, and chert. The basal beds of the deposit include scattered Severn was deposited on the inner marine shelf in Late Cretaceous time. N 60 o d t 4 O R g 0 Water body ll n boulders ranging to several feet in diameter. Bedding is chiefly lenticular, and M i i 0 40 M h 6 6 r 60 s (including lakes, ponds, streams) e 0 d a cross-bedded to massive. Where least dissected, the uppermost portion of the w o W P Tu e deposit consists of as much as 15 feet (4.6 m) of compact yellowish to reddish- r Reservoir o (Patapsco, Arundel, Patuxent Formations) 0 8 Kpc m i brown pebbly loam. Total thickness of the unit reaches a maximum 40 feet (12.2 t l a L Swamp/Marsh a m). The Upland deposits are fluvial sediments, presumably laid down by the 60 B u The Potomac Group includes the Patapsco, Arundel and Patuxent Formations. In re ancestral Potomac River as it swept southward across southern Maryland in late Beltsville l B Prince George’s County these units have not been mapped separately at the ow 40 i e R Miocene and Pliocene time (McCartan, 1989a, 1989b). county scale; instead sediments of the Potomac Group have been mapped Kps 40 d

0

77°0'0"W 0 4 4 0 according to dominant lithology: sand-gravel facies (Kps) or silt-clay facies 4 Silt loam soils with hardpan in Upland deposits (Hack, 1977) -- Silt- (Kpc). Potomac Group strata are Early Cretaceous in age, and record floodplain 2 loam surface soils containing thick hardpan as mapped by Hack (1977) A 0 deposition. A maximum thickness of about 1000 feet (about 305 m) is known in Qt Qt E 430000 within the Upland deposits (Tu) (geologic unit). The hardpan is 400000 \la d the outcrop belt. I-9 m 5 0 described as 3 to 4 feet thick (0.9 to 1.2 m) and approximately 2 feet o Kpc 6 I - 495 n s (0.6 m) below the ground surface. Hack indicates that the hardpan is to n

Sand-gravel facies: 150000 I Qal 4 150000 80 - 0 60 moderately impermeable so "the surface soil is wet in winter months and 4 R 9 d Qal Kps 5 may be excessively dry in summer." Interbedded quartz sand, pebbly sand, gravel, and subordinate silt-clay. Sands Kpc Qt and gravels typically white, buff, yellow to brown; weathered zone commonly Kpc Tu \la t limonitic with ironstone pods and layers. Silt-clay is white, pale gray, or S h Bowie 6 t th St 0 9 11 variegated; dark-gray, where highly organic. 40 e 0 Greenbelt v 6 2 -- Sand, quartz silt, and diatomaceous silt. Olive- d 0 0 A 40 2 R

8 e 6 Kpc green to olive-gray where unweathered; pale-gray, tan, brown, yellow or orange 0 r s 0 Tc i g Kps 40 40 The sand-gravel facies is largely the lower Potomac Group (Patuxent Formation), h Kps s ig Greenbe Tu in weathered sections. p lt R R d

but the upper portion (Patapsco Formation) also contains considerable sand and 39°0'0"N m 39°0'0"N Kps a d 0 Kps 6 H lv some gravel, which is included in this map unit. This coarse facies lies mostly B w Qt P The Calvert Formation consists largely of variably clayey, very fine- to fine- y e e t v Kpc a west of Indian Creek in the north and northwestern area of the county. The i 0 6 t N s 2 A 193 0 u I MD r 0 x grained sand and silt, as well as diatomaceous silt, and minor amounts of clay. e n L 4 e d a n lithology is essentially fine- to coarse-grained sand, grading to pebbly sand and v e i i Qal t r u n a R Near the base of the unit is a bed of diatomaceous silt, as thick as 10 feet (3 m), o TKbs n r i U e G v gravel, coarse to very coarse in places, arranged in thin to very thick lenticular Kps m P C e i l l t a e r 4 l r n B consisting of as much as 40 percent diatoms. The diatomaceous bed thins and 0 in n a e G t 40 o beds. Conspicuous cross-bedding is common, as are clay clasts, channel fills, 6 ek D 0 B le a w 0 0 feathers out both northward and westward. The upper part of the unit is l 6 n e 4 i 40 4 Kpc 0 e and fining-upward sequences. Interbedded with these coarser clastics are B n

r Qal D B R a relatively homogeneous sand and silty sand with obscure bedding, laced with College Park Qal n a l 6 v 0 d scattered thin lenticular bodies of tough massive silt-clay. As is typical of fluvial c le d h d pervasive burrow-mottling. Much of this upper Calvert has been weathered to Kps R R n d sediments, few beds are laterally continuous for any great distance; consequently, r e 0 e

v 4 loosely textured, yellow to orange sand, which makes up the surface sediment ev 0 great variability in outcrop lithology is the rule. A S Kps 6 re 0 m i 4 a over the southeastern part of the county. Most of the Calvert sediments in the h nh Anna s a pol 2 p Cla L is Rd 0 county belong to the lower or Fairhaven Member of the formation. The upper m Ta

a E New Carrollton

Silt-clay facies: as H

t- 0 member, the Plum Point Marls, is confined to the southeastern portion (Benedict W 4

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est Hw w y 6 0

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Kpc quadrangle) of the map area, as are intact molluscan fossils. Here, the Calvert Clay, silt, and subordinate fine- to medium-grained clayey sand. Red, tan, gray, N Tc

4 d A 0 R (!(!!((! C buff, or mottled; dark-gray, where heavily organic. l (!((! o N also attains its maximum thickness of about 100 feet (30.5 m). The Calvert is a e N p ll Kpc a e Rd in E Qt al g lower to middle Miocene marine unit, with most of the Fairhaven having h Riverd C r t o e 6 0 s 6 n A v 0 TKbs The silt-clay facies of the Potomac Group, comprised of the Arundel Clay and n i accumulated in relatively deep water in a restricted basin. The Plum Point Marls e 6 R R R V 0 e 0 d U u e 6 4 t unit is an open shelf deposit laid down in shallower waters. much of the lower Patapsco Formation, lies mostly east of Indian Creek. The Q H Hyattsville e N 4 a 0 0 m r Chi ilt a D llum on n lithology is predominantly compact red and dark-gray clay containing large and S s 60 E

Rd t 60 (! L

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small lenses and pods of sand and minor gravel. Some of the clay is strikingly 2 s P 0 o k c Tc C a y Crain variegated in color. Dark-gray lignitic clay is most characteristic of the Arundel n h A rt O NANJEMOY FORMATION -- Sand, glauconitic, variably clayey; and silt- 3 o U but occurs at other stratigraphic levels as well. Much of the clay is internally 8 lw t i 6 N h 0 0 n U.S. 5 T Tn clay. Glaucontic sand, medium-gray to dark greenish gray, where unweathered; e 6 n Hwy S o 0 0 Hans Y massive and weathers hackly. Silt-clay lenses in the uppermost portion of the K 0 6 John t 4 60 silt-clay, dark-gray to chocolate-brown. Mottled yellow and pale-brown in Kpc unit tend to be whitish or pale-gray, and thinner. Rare bones and teeth Kps urg Bladensb R d

weathered outcrops.

have been found in Potomac silt-clay, as have plant fossils. D d H R Ta IS Kps w e y T s Kpc i The Nanjemoy consists mostly of quartz sand, fine- to coarse-grained, with a R r 2 0 4 p 0 I r 4 0 C 0 variable amount of interstitial silt-clay and as much as 50 percent of green 4 TKbs e T t 4 4 Qt O n 0 0 glauconite, imparting a "salt and pepper" aspect to the sediments. Darker silt- LAUREL FORMATION (Hopson, 1964; Fleming et al., 1995) -- F E Qal C Cheverly clay interbeds are common. Bedding generally appears massive with \la Metasedimentary rock unit, which includes considerable mica gneiss and schist; O Ta 140000 L 2 Mitchellville 140000 U 0 conspicuous burrow-mottling. Fossils, mostly Venericardia , are moderately a metamorphosed sedimentary mélange. M 60 40 0 B common. Indurated beds and concretionary bodies occur in places. The sand 4 IA

0 fraction coarsens upward within the unit. Nanjemoy outcrops are largely Medium- to coarse-grained, moderately to well foliated sedimentary mélange y 6 Ta w H L restricted to the eastern edge of the county adjacent to the Patuxent River where a Qt 4 consisting of a quartzofeldspathic matrix that contains quartz “eyes” and n 0 do r v 0 the unit reaches a maximum 60 feet (18.3 m) thick. Poorer outcrops are found in J e 4 fragments to blocks of metamorphic rocks which specifically include fragments Qal g r 0 6 in W M K e D the southwestern part of the county, especially along Piscataway Creek. The unit of meta-arenite and biotite schist in the mapped area (Fleming et al., 1995). The 2 s 0 Tc t e 1 r 9 n 0 is a marine shelf deposit of early Eocene age. rock weathers to a porous, spongy brown saprolite and grades upward to a sticky r 3 4 B e R r th a micaceous red and gray clay (Withington and Froelich, 1974). u Ta d n L c Tc h

Qt 20 tral Ave Originally thought to be a metamorphosed igneous rock (e.g., gneissic granite, Cen 6 ve 6 0 l A MARLBORO CLAY -- Clay, pale-red to silvery-gray, and minor interbedded n 0 Tc tra migmatite), the unit is now interpreted as a metamorphosed sedimentary unit that ti en r h C a 0 c Tm silt, yellowish gray to pale- gray. M 4 n originated as a “chaotic mixture of fragmental rocks and pebbles in an unsorted a 4 r 0 40 B Tm matrix of sand, silt, and mud” resulting from submarine debris slide and was 0 4 0 W The Marlboro Clay is a thin but highly distinctive unit composed of dense, brittle 4 TKbs Tc subsequently metamorphosed (Hopson, 1964). Kpc a t k clay, ranging from thickly-bedded to finely laminated, lenticular or hummocky in i n s 2 part, containing partings and thin lenses of micaceous and lignitic laminated silt. P Ta 0 Some previous workers have considered the Laurel Formation to be the same unit a r The lowest part of the clay contains thin interbeds of glauconitic sand. Marlboro 40 k n 0 D o as the Sykesville Formation and mapped the Laurel and Sykesville Formations 2 t 6 Qt r g Clay exposures can be found in the same portions of the county as the Nanjemoy 0 n Ta li either as part of the boulder gneiss facies of the Wissahickon Formation 2 l 0 o 1

Formation. The Marlboro reaches 20 feet (6.1 m) in thickness in some places. C 0

(Southwick and Fisher, 1967; Cleaves et al., 1968) or simply as the Sykesville 3 60 ! S Tm 4 0 ( 0 Formation (e.g., Muller et al., 1989). A preliminary geologic map of the U 6 Largo R 4 The contact with the overlying Nanjemoy Formation is typically sharp but highly Tc d 0 Beltsville area (Withington and Froelich, 1974) showed areas that are identified 60 burrowed. Regionally, infilled with Nanjemoy sediments are reported to Tu Qt

on the current map as Laurel Formation mainly as two facies (diamictite gneiss 38°52'30"N y 38°52'30"N Qal 40 extend up to a foot or more into the Marlboro Clay (Glaser, 1971; Gibson et al., Ta w

and pelitic schist) of the Wissahickon Formation. The Laurel Formation 0 H 8

2000; Gibson and Bybell, 1994). In some areas, Marlboro sediments appear to

nomenclature shown on the current map follows the most recent mapping of the 0 2

be reworked into the lower part of the overlying Nanjemoy Formation 0 8 n unit by Fleming et al. (1995). i A 0 a Tc r (McCartan, 1989a; Gibson et al., 2000). The lower contact of the Marlboro with I 8 B C the underlying Aquia Formation is sharp in some outcrops (particularly in updip M Tn The Laurel Formation is considered Early Cambrian in age by Fleming et al. U

L 0 0 sections) but the transition appears gradational over a vertical distance of several O 4 2 (1995). However, the precise age of the unit and the timing of episodes of C 60

0

inches to feet in other outcrops and cores (e.g., Glaser, 1971; Gibson et al., 2000). F 6 5 0 Tc S 9 W 4 2 metamorphism (and intrusives) in the region have been debated for decades (e.g., O ui e 0 tla 4 s 8 nd - t The depositional environment and precise age of this unit have been debated. 0 T e C P I rn Hopson, 1964; Muller et al., 1989; Drake et al., 1989). I 0 R en Tn 8 d ns Tu Qt Based on recent studies focusing on microfossils (foraminifera, calcareous R ylv T an IS ia A nannoplankton, dinoflagellates) and clay mineralogy, the unit is believed to ve Qt D d B 6 r R 0 a represent deposition in an inner to middle marine shelf area that received n 4 0 ill ch er H sediments from river drainage systems (e.g., Gibson et al., 2000). Regional Silv microfossil studies indicate that the Marlboro Clay ranges in age from latest Ta Tn Ta 0 0 8 2 0 4 Paleocene to earliest Eocene (calcareous nannoplankton upper Zone 9 and lower 80 0 Tc 130000 2 130000 Zone 10) (e.g., Gibson et al., 2000). Tn Tn TKbs

0 P

8 e n Qal ns 80 0 y 6 lv 0 20 a 4 n n St Qal i ai 5 a M - 9 6 I d Tn 2 20 B d 0 0 R 80 R A s n ve Map References: a w b to A' a 5 80 n n 49 lle r I - A 8 a 0 Upper Marlboro B Cleaves, E. T., Edwards, J., Jr., and Glaser, J. D. (compilers and eds.), 1968, Geologic map of Maryland: t Kpc S Maryland Geological Survey, scale 1:250,000. 80 Area not mapped for loam, Tn

6

0 0 Military Reserve 2 Drake, A. A., Jr., Sinha, A. K., Laird, J., Guy, R. E., 1989, The Taconic orogen (Chapter 3) in The Geology of

4

Qal 0 North America Volume F-2, The Appalacian-Ouchita Orogen in the : Boulder, Colorado, The Hill Rd 60 Qt I on Tu - Ox Geological Society of America, p. 101-177. 2 9 Qal 5 60

Tc

0 Ta 8 8 0 20 6 0 Fleming, A. H., Drake A. A., Jr., and McCartan, L., 1995, Geologic map of the Washington West quadrangle, 0 6 District of Columbia, Montgomery and Prince George’s Counties, Maryland, and Arlington and Fairfax Counties, 20 40 : U.S. Geologic Survey, Geologic Quadrangle Map, GQ-1748, 1 sheet, scale 1:24,000. I - 495 Qt Tn ek Tc y re 8 0 C 0 w 2 (! n H Gibson, T. G., and Bybell, L. M., 1994, stratigraphy of the Solomons Island, Maryland corehole: U.S. nso in He ra 6 C Qal Geological Survey Open-file Report 94-708, 39p. 0 Qt 80 Cr 0 oo 2 m R 8 d Gibson, T. G., Bybell, L. M. and Mason, D. B., 2000, Stratigraphic and climatic implications of clay mineral 20 Ta 0 0 Qal 6 changes around the Paleocene/Eocene boundary of the northeastern US margin: Sedimentary Geology, volume Tu Tu

D Rd 60 d Qt A M r 134, issue 1-2, pp. 65-92. N I ya D A 80 d 8 N 0 o P 5 I o L a W t G 0 Y 6 u Glaser, J. D., 1971, Geology and mineral resources of southern Maryland: Maryland Geological Survey Report of k x

R Tu R e e e

I

r 0 0 40 n 0

C 8 2 Investigations, no 15, 84 p. A 2 t V Tu B M s Clinton r a Qt n 6 ker c 0 n h _____, 1973, Geologic map of the Bowie quadrangle, Anne Arundel and Prince Georges Counties, Maryland: 6 i 0 Tc Kpc T A v Maryland Geological Survey, scale 1:24,000. e 60

Qt k _____, 1978, Geologic map of the Mount Vernon and Piscataway quadrangles, Maryland: Maryland Geological e Tc e r C Tn 2 Survey Quadrangle Geologic Map QA no. 8, Atlas Map no. 1, scale 1:24,000. 60 d 0 R 2 Tu y 60 0 Qt a Tc Broa w 60 _____, 1981, Geologic map of the Upper Marlboro quadrangle, Prince Georges County, Maryland: Maryland d C 2 ta r 0 eek a y 38°45'0"N 38°45'0"N 6 c a 0 0 120000 is aw 6 60 120000 Geological Survey, scale 1:24,000. P t Tc Tc ca is P 20 Qal 60 0 _____, 1984, Geologic map of the Bristol quadrangle, Prince Georges, Anne Arundel and Calvert Counties, 4 I

n

0

d 2 0 Maryland: Maryland Geological Survey, scale 1:24,000. i 6 Qt a 60 y n 60 w

H H

e in _____, 2002, Geologic map of the Benedict quadrangle, Charles, Prince George’s, and Calvert Counties, Maryland: a ra d C Tu 20 H Maryland Geological Survey, scale 1:24,000 (digital version 2002.1). 0 2 w Qal Tu k y e Qt e 6 r 0 2 6 Matapon 0 0 Qt i C Hack, J. T., 1977, Geologic map for land-use planning, Prince Georges County, Maryland: U.S. Geological 40 Survey Miscellaneous Investigation Map I-1004, scale 1:62,500. C 20 r 60 o o m Hopson, C. A., 1964, The crystalline rocks of Howard and Montgomery Counties, in The Geology of Howard and 0 Qt 6 R

40 d Montgomery Counties: Baltimore, Maryland Geological Survey, p. 27-215. 1 0 40 3 60 60 S 4 U 0 Ta Qt Kuff, K. R., 1980, Mineral resources and mined land inventory map of Prince George’s County: Maryland er Tu 4 Tn Tc iv 0 Fort Washington d 20 Tc Geological Survey, Mineral Resources Investigations County Map, scale 1:62,500. R 0 R 6 2 0 60 c 0 a n 6 McCartan, L., 1989a, Geologic map of Charles County: Maryland Geological Survey, scale 1:62,500. otom gto P Qal in 20 rm Pisc a ataway F _____, 1989b, Atlantic Coastal Plain sedimentation and basement tectonics southeast of Washington, D.C.: Creek Brandywine Rd

American Geophysical Union, 28th International Geological Congress Field Trip Guidebook T214, 25p. R

Qt Tn i 20 v Qt Qal e 20 r 6 Muller, P. D., Candela P. A., and Wylie, A. G., 1989, Liberty Complex; polygenetic mélange in the central 60 0

60 0 Maryland Piedmont: Geological Society of America, Special Paper 228, p. 119-134. Ta 4 6 0 d k R e Tu 2 4 ke 0 0 co Pomeroy, J. S., 1989, Map showing landslide susceptibility in Prince George’s County, Maryland: U. S. Ac Geological Survey Miscellaneous Field Studies Map MF-2051, scale 1:62,500. Tc

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6 Southwick, D. L. and Fisher, G. W., 1967, Revision of the stratigraphic nomenclature of the Glenarm Series in 60 0 4 Maryland: Maryland Geological Survey Report of Investigations No. 6, 19 p. 60

6 Livingston Rd 0 40

0 Withington, C. F. and Froelick, A. J., 1974, Preliminary geologic map of the Beltsville quadrangle, Prince Tu 6 Georges, Montgomery, and Howard Counties, Maryland: U.S. Geological Survey Miscellaneous Field Studies S A Tu q Qt ta u t a MF-582, 2 sheets, scale 1:24000. e Qt 0 s H Qal 6 c ig 40 o h R 0 way d Qal 2 228 Qt Tu 60 0 6 6 0 110000 110000 CH 0 6 A k 0 R 4 ee 6 L 6 Cr 6 0 E 0 an 0 0 S m 6 C wo O 0 ta UN 2 y at T Supplemental Information w M Y H 0

C d 0 4 a 4 0 60 Use Constraints: These data represent the results of data collection/processing for a specific Department of Natural H e 6 H A Resources, Maryland Geological Survey activity and indicate general existing conditions. As such, they are only valid n R ia d for the intended use, content, time, and accuracy specifications. The user is responsible for the results of any L In E 20 application of the data for other than their intended purpose. The Maryland Geological Survey makes no S 410000 Qt C

warranty, expressed or implied, as to the use or appropriateness of the data, and there are no warranties of O 0 76°52'30"W 4 U merchantability or fitness for a particular purpose of use. The Maryland Geological Survey makes no representation to the 60 N

T 6 Base map compiled and extracted from: 6 accuracy or completeness of the data and may not be held liable for human error or defect. Geologic data are only 0 0 Y 2 valid at 1:62500 scale. Data may not be used at a scale greater than that. 8 3 Bl U.S. Geological Survey (USGS): ac Tu D k Swa National Hydrologic Dataset (NHD), high resolution, for hydrographic features M mp Cr Acknowledgements: Production of the digital map was funded, in part, through a memorandum of understanding with 0 eek the United States Department of Agriculture, Natural Resources Conservation Service. The views expressed herein are 2 NHD high resolution dataset generally developed at 1:24,000/1:12,000 scale those of the author(s) and do not necessarily reflect the views of the USDA-NRCS or any of its sub-agencies. Topographic 30 x 60-minute series (1:100,000 scale) digital line graphs (DLGs) for topography 38°37'30"N 38°37'30"N Portions of Washington West, Washington East, Frederick and Baltimore sheets 6 2 0 40 0 Geologic field mapping for the original county geologic map was completed by J.D. Glaser in 1996. The geologic map As shown, topographic features are an enlargement from 1:100,000 to 1:62,500 scale 400000 was compiled in digital form and edited by Heather Quinn, Maryland Geological Survey. Additional digital support Geographic Names Information System (GNIS) database for cultural features/place names shown 4 0 provided by Catherine Luckhardt, Towson University, Center for Geographic Information Sciences. 0 0 4 77°0'0"W Maryland State Highway Administration (MD-SHA): 4 Revisions, corrections and updates to the original geologic map will be completed periodically as needed and as MD Cooperative Centerline Program, Prince George’s County excerpt (2006) for transportation features Original dataset developed at 1:12,000 scale Qal additional data becomes available. The July 2006 release includes an updated county boundary, updated Tc Qt 2 hydrographic features and corresponding changes and corrections to the map layout. The geologic Tu 0

0 layer has been updated to reflect these changes in the base layers and, in the southeastern corner of the county, Estimated 2006 magnetic north declination (center of county): 10 degrees 47 minutes west 4 the geology has been modified to reflect the digital geologic data available for the Benedict quadrangle (mapped (To determine current magnetic declination see: http://www.ngdc.noaa.gov/seg/geomag/jsp/Declination.jsp) B' at a more detailed, larger, 1:24,000 scale) (Glaser, 2002). Corrections to cross-sections have also been made. Current map projection: Maryland State Plane Coordinate System 1987 The facilities and services of the Maryland Department of Natural Resources are available to all without regard to race, Y color, religion, sex, sexual orientation, age, national origin or physical or mental disability. (Projection: Lambert Conformal Conic, 1980 geodetic reference system) T 40 N (Horizontal Datum: North American Datum 1983) U

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C Original digital release April 2003 State Plane 2000-meter grid tics and coordinates shown in black T Version: PGGEO2003.2, release July 2006 R Geographic coordinates (latitude-longitude) shown near corners and 2.5’ intervals also shown in black with larger font E 0 V

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C Schematic Cross Sections 40

STATE OF MARYLAND Pkwy Baltimore-Washington Vertical Exaggeration ≈ 13 x CrainHwy (US 301)

Robert L. Ehrlich, Jr. Branch Western

Governor Kenilworth Ave

4

A Indian Creek A'

0 MD 193 Patuxent River 2

Feet 0 US 50 I-495 I-495 Meters 100000 100000 d Michael S. Steele 300 20 R 80 co Lieutenant Governor 420000 as 430000 200 Tn qu Tm 60 A Qal Ta Qal Qt Qal Tn Tc 40 100 Kpc Qal Qal Kpc Qal Ta Qt crystalline rock Kps Qal 20 0 TKbs Tm 4 0 0 er Kps Tc 0 v Kpc - 20 Qal 2 i - 100 R

40 Qt 76°45'0"W Black Swamp Creek

Crain Hwy (US 301) t Branch Ave (MD 5)

Piscataway Creek Piscataway n e Mataponi Creek

Brandywine Rd x Patuxent River Henson Creek

Tinkers Creek u t Oxen Hill Rd a P 40 MD 382

DEPARTMENT OF NATURAL RESOURCES Feet B I-95 B'Meters C. Ronald Franks 300 Tu Tu 80 Tu Qal Qal Tu Secretary 200 Qal Qal 60 Tc Tn Qal Qt TKbs Ta Tc Tc Qal Qt 40 100 Kps Qal Tm Qal Copies of this map are available in hard copy (paper) and digital form from: Tn Qal Qt 20 Ta Tc Qal MARYLAND GEOLOGICAL SURVEY 0 MARYLAND GEOLOGICAL SURVEY 0 TKbs 2300 Saint Paul Street Ta - 20 Baltimore, MD 21218 Emery T. Cleaves - 100 Kpc Kps Tm - 40 Kpc Ph: 410- 554- 5500 Director TKbs - 60 - 200 Kps Fax: 410- 554- 5502 Kps Kpc - 80 - 300 http://www.mgs.md.gov/