geology the - west virginia · 6 7 (pleistocene epoch of the neogene period) never reached west...

Ken Ashton, GeologistWest Virginia Geological and Economic Survey

West Virginia Geological and Economic SurveyWest Virginia State Parks

The

Geology of

One in a Series of State Parks Bulletins

Cacapon Resort andLost River State Parks

West Virginia Department of Commerce

West Virginia Geological and Economic SurveyMorgantown, WV

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West Virginia State Parks1–800–CALL WVAwww.wvstateparks.com

GEOLOGIC MAPS Cacapon Resort State Park and Lost River State Park A geologic map shows the distribution of different kinds of rocks and structural features (anticlines, synclines, faults, etc.) It is a summary of all the geologist knows in an area, and is usually printed on top of a topographic map, called a base map, for orientation. The base map is printed with light colors so it doesn’t interfere with the geologic features on the map. The geology is represented by colors, lines and special symbols unique to geologic maps. The map itself is usually accompanied by one or more vertical cross sections so that a person can picture rocks at and below the surface in three dimensions.

The rock units depicted on these maps are described in the “Rocks exposed in the parks” sections, beginning on page 9. The base maps used are the standard USGS 7.5 minute topographic maps. Topographic maps of West Virginia are available from West Virginia Geological and Economic Survey.

INFORMATIONAL LINKS Lost River State Park .........................www.lostriversp.comCacapon Resort State Park ..................www.cacaponresort.comWest Virginia Geological and Economic Survey .......................................................www.wvgs.wvnet.eduWest Virginia State Parks ....................www.wvstateparks.comWest Virginia Division of Tourism ........www.wvtourism.comBerkeley Springs State Park ................www.berkeleyspringssp.comBerkeley Springs Tourism ...................www.berkeleysprings.comHardy County, WV .............................www.hardycountywv.comMonongahela National Forest ..............www.fs.fed.us/r9/mnfGeorge Washington/Jefferson National Forests .......................................................www.fs.fed.us/r8/gwjUnited States Geological Survey ..........www.usgs.gov

1

Table of ConTenTs

overview of West Virginia Geology ....................3

Geology of Cacapon Resort and lost River state parks Introduction ................................................8 Rocks exposed in the parks ............................9

Cacapon Resort State Park ........................... 13 •StratigraphicFeatures .............................. 14 •StructuralFeatures ................................... 17 •TopographicFeatures ............................... 20

Lost River State Park ................................... 24 •StratigraphicFeatures .............................. 25 •StructuralFeatures ................................... 31 •LeeSulphurSprings ................................. 34 •“Lost”River ............................................ 35

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oVeRVieW of WesT ViRGinia GeoloGy

West Virginia is called the Mountain State largely because the average elevation is over 1,500 feet above sea level. This is the highest average elevation of any state east of the Mississippi River. The relief, difference between the highest and lowest points, of the state is 4,613 feet. The lowest point is at Harpers Ferry on the Potomac River (247 feet); the highest is at Spruce Knob on the Allegheny Plateau in Pendleton County (4,860 feet).

The geologic history of West Virginia prior to one billion years ago is poorly understood. More recent geologic history can be deciphered from clues found in the exposed bedrock. For example, the oldest exposed rock in the state is a metamorphosed lava deposited 600 million years ago called the Catoctin Greenstone. The Catoctin is found in the Blue Ridge Mountains of the Eastern Panhandle. Most rocks in West Virginia are sedimentary and were deposited during the Paleozoic Era, 542–245 million years ago.

All sedimentary rocks were deposited originally in rivers and streams on older land surfaces (“terrestrial”) or in oceans (“marine”), compressed by the weight of deposits added on top, and generally cemented by quartz or calcite. Clastic sedimentary rocks contain particles and grains of older rocks, disintegrated by weathering and carried by wind or water to the site of deposition. “Calcareous” rocks have been cemented with calcite (calcium carbonate) and “siliceous” rocks by quartz (silicon dioxide). A limestone contains mainly calcite, deposited as grains, nodules or fossils, or formed by chemical dissolution from water.

fiGuRe 1. HarpersFerry—247feetabovesealevel.

fiGuRe 2. SpruceKnob—4,860feetabovesealevel.

aRTWoRK

fiGuRe 1 HarpersFerry,WestVirginia page3 fiGuRe 2 SpruceKnob,WestVirginia page3 fiGuRe 3 GeologicalhistoryofWestVirginia page5 fiGuRe 4 SenecaRocks,WestVirginia page6 fiGuRe 5 PhysiographicProvincesofWestVirginia page7 fiGuRe 6 Crosssectionofphysiographicprovinces page7 fiGuRe 7 Locator map for Lost River and Cacapon Resort stateparks page8 fiGuRe 8 CacaponMountain,CrannyCrowoverlook page9 fiGuRe 9 GeneralizedStratigraphicColumn ofWestVirginiaandRocksFoundintheParks page11 fiGuRe 10 LookingeastfromCacaponMountain page13 fiGuRe 11 CacaponLakedam page13 fiGuRe 12 ArenicolitesonKeeferSandstone page14 fiGuRe 13 Arthrophycus alleghaniensi onTuscaroraSandstone page15 fiGuRe 14 MarinefossilsinOriskanySandstone page15 fiGuRe 15 Differentialweathering,ProspectRocks page16 fiGuRe 16 Potholes,ProspectRocks page16 fiGuRe 17 NortheastdippingbedsofOriskanySandstone page17 fiGuRe 18 CacaponResortStateParkfacilitiesmap pages18-19 fiGuRe 19 CrosssectionofCacaponResortStatePark pages20-21 fiGuRe 20 SoutheastviewofCacaponMountain page21 fiGuRe 21 Streamflowingintosinkholeongolfcourse page22 fiGuRe 22 LookingeastfromCheeksRocks page24 fiGuRe 23 Ripplemarksonbedding,CheeksRocks page25 fiGuRe 24 Crossbedding,HampshireFormation page26 fiGuRe 25 HelmickRock page27 fiGuRe 26 Cabin12withstonechimney page27 fiGuRe 27 CrannyCrowoverlook page27 fiGuRe 28 LostRiverStateParkfacilitiesmap pages28-29 fiGuRe 29 SteeplydippingHampshireFormationbeds page30 fiGuRe 30 CheeksRocks,nearaxisofSidelingHillSyncline page31 fiGuRe 31 CrosssectionofLostRiverStatePark pages32-33 fiGuRe 32 LeeSulphurSprings page34 fiGuRe 33 HangingRock page35 fiGuRe 34 LostRiver page36

4 5

West Virginia contains little igneous rock (molten or volcanic source) or metamorphic rock (changed from preexisting rock by heat, pressure, and time). Exceptions include igneous bodies in Pendleton County and the Catoctin Greenstone in the Eastern Panhandle.

Movements of the earth’s crust (tectonic plates) cause episodes of mountain building, called orogenies, which have major effects on the land surface of an area. The Taconic Orogeny was the first of these to affect West Virginia. This event formed mountains to the northeast of the state that subsequently became a source of sands and silts (clastics) and marine (carbonates) sediments deposited during the Ordovician, Silurian and early Devonian periods. Highlands to the northeast were again uplifted during the Devonian Period in an episode called the Acadian Orogeny, which provided a source of clastic sediments in the Middle and Late Devonian. Shallow seas covered West Virginia in the Middle Mississippian Period (about 330 million years ago), during which time carbonate sediments (limestones) were deposited. During the Pennsylvanian Period, West Virginia was a low-lying and swampy coastal plain that allowed the deposition of sandstone, shale, and most importantly, the numerous coal deposits for which West Virginia is famous.

The Appalachian Orogeny began during the Permian Period. This was the dominant geologic event in the formation of the Appalachian Mountains. Europe, Asia, and North America (Laurasia) and Africa, South America, Australia, Antarctica, and India (Gondwanaland) all came together forming a supercontinent called Pangea. This collision resulted in folding and thrust-faulting, especially in the eastern part of the state, as the Appalachian Mountains rose to heights approaching the modern Alps. Erosion then became the predominant geological process; hence, there are no sedimentary rocks younger than the late Paleozoic Era found in West Virginia. There are, however, several Mesozoic (Jurassic) igneous bodies of rocks found in Pendleton County.

Although the mile-thick ice sheets of the “Ice Age” fiGuRe 3.GeologicalhistoryofWestVirginia.

nuGGeTThedominant

geologicevent in the

formation of the

AppalachianMountains

beganduringthe Permian

Period —morethan

250millionyearsago.

6 7

(Pleistocene Epoch of the Neogene Period) never reached West Virginia, they impacted the state by damming rivers, forming lakes and creating new drainage patterns. Lake Monongahela formed when advancing ice sheets and glacial sediments dammed the ancestral Monongahela River system near Pittsburgh. Farther south, Lake Tight was formed when the ancestral Kanawha River, known

as the Teays River, was blocked by ice and/or glacial sediments.

During the Jurassic Period of the Mesozoic Era, tectonic activity associated with the opening of the Atlantic Ocean caused fracturing of the earth’s crust in the Pendleton County area of eastern West Virginia and

subsequent intrusion of mafic (iron rich) igneous dikes. In the early Cenozoic period, more extensive igneous activity in the same area resulted in the intrusion of numerous igneous sills and dikes. A dike is an igneous body that cuts across layers of adjacent rock. Sills are igneous bodies that parallel adjacent beds. No known tectonic event has been linked to the Cenozoic intrusives.

Physiographic ProvincesA physiographic province is a landform region underlain by similar geologic structure where the terrain has been shaped by a common geologic history. Most of West Virginia is a dissected, westward-tilting plateau called the Appalachian Plateau Province. In the northeast part of this province, a subprovince called the Allegheny Mountain Section combines elements of the folded mountains to the east and the dissected plateau. The eastern boundary of the Appalachian Plateau, called the Allegheny Front, is a prominent geological and topographic feature that runs northeast-southwest across the state. East of the Allegheny Front are a series of long folded mountains and valleys defining the Valley

fiGuRe 5.PhysiographicprovincesofWestVirginia.

fiGuRe 6.Crosssectionofphysiographicprovinces.

fiGuRe 4.Seneca Rocks,

aTuscaroraSandstone

formation in Pendleton

County.

and Ridge Province. East of the main group of folded mountains and valleys is the Great Valley subprovince. Along the eastern state boundary in Jefferson County is the Blue Ridge Province.

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GeoloGy of CaCaPon ResoRT sTaTe PaRK and losT RiVeR sTaTe PaRK

introductionCacapon Resort and Lost River state parks are the two largest parks located in West Virginia’s eastern panhandle. Separated by about 53 miles, each park

has its own beauty and character. However, they are geologically similar in that both are located within the Valley and Ridge physiographic province and the topography is typical of this region. Folded bedrock, combined with differing rates of rock weathering, has led to the development of long, parallel northeast trending mountain ridges separated by broad valleys.

All bedrock in these two parks is of sedimentary origin. Sedimentary

rocks usually have a layered or bedded appearance, and are commonly seen in road cuts or exposed hillsides in West Virginia. Loose sand became sandstone. Mud compacted to form shale. Calcareous shells or chemical precipitations from sea water became limestone. Thick peat deposits from swamps compacted to form coal. While there are some non-commercial coals found in Devonian and Mississippian-aged rock, there is no coal occurring in either park.

Much of the scenic splendor of Cacapon Resort State Park and Lost River State Park is a direct result of what underlies the surface. Bedrock type and character, combined with the effect of the forces that have altered the rock since the sediments were deposited and the rock

fiGuRe 8. Cacapon Mountain rises above thelodgeat Cacapon Resort State Park. Inset, theviewfromtheCrannyCrowoverlookat Lost River State Park.

fiGuRe 7. Cacapon

Resort State Park and Lost

River State Parklocator

map.

formed, have contributed to the topographic features seen today in these beautiful parks.

Geological descriptionsThe following section lists rock units found in Cacapon Resort and Lost River state parks with descriptions of each unit. Geologists describe rocks based on constituents, such as grain and cement type; grain size (for instance, sand and shale); color; thickness of the layers that make up sedimentary rocks (massive, thin-bedded); how resistant the rocks are to weathering; depositional environment (terrestrial, marine); and diagnostic features, such as characteristic way of breaking or presence of nodules, fossils, and particular bedding patterns (cross-bedding). With this information, a person can recognize the units in the field. The meaning of many of these terms should become clear in the text that follows.

Rocks exposed within lost River state Park Rockwell formation (Mr) — Light gray to dark gray sandstone with conglomeratic zones. Occasionally iron

10 11

fiGuRe 9. GeneralizedStratigraphicColumnofWestVirginia andRocksFoundinLostRiverandCacaponResortstateparks.

stained; cross-bedded. Occasional plant fossils found. Underlies Big Ridge north of Howards Lick in Lost River State Park.

Hampshire formation (Dhs) — Composed of terrestrial, fine-grained red and reddish-gray sandstone and shale with minor tan and light-green shale and sandstone beds; mostly unfossiliferous. The Hampshire underlies most of Lost River State Park.

Rocks exposed within Cacapon Resort Mahantango formation (Dmt) — Contains dark-gray siltstones and mudstones with minor fine-grained sandstone. These units frequently weather spheroidally, separating along fractures and bedding into small chips. Some beds of the Mahantango contain marine fossils consisting of brachiopods, crinoids, tentaculites, and trilobites. Underlies U.S. Route 522 outside of Cacapon Resort State Park.

Marcellus-needmore shale (Dmn) — The Marcellus is composed of black to dark-gray marine shales that easily split along close planes. The Needmore Shale is medium to dark greenish-gray to brownish-black with dark-gray limestone nodules.

oriskany sandstone (Do) — The Oriskany is a white to light-gray, medium- to coarse-grained, quartz sandstone with quartz pebble conglomeratic zones. It frequently exhibits cross-bedding and contains abundant marine fossils (brachiopods). Carbonate and silica cement is common. Devonian and upper silurian-aged carbonates and shales (Ds) — These beds are subdivided into the Helderberg group, the Tonoloway Limestone and the Wills Creek Formation. The Helderberg Group is a marine deposit composed mainly of massive gray limestone with fossils. The Tonoloway Limestone is a thinly bedded fine-grained, laminated gray argillaceous (clay-rich) limestone that breaks into small, platy fragments. Occasionally, salt crystal casts and mud cracks can be seen in the

Tonoloway, indicating deposition in repeatedly exposed mudflats. The Wills Creek Formation is an assemblage of gray and sometimes red shales, thin-bedded limestones, and friable (easily crumbled) yellow-tan sandstone.

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CaCaPon ResoRT sTaTe PaRK

Cacapon Resort State Park was acquired by the state in 1934. Since that time additional purchases have enlarged the park to its present area of 6,115 acres. The park extends 12 miles along the summit and southeastern slopes of Cacapon Mountain from the northwestern corner of Frederick County, Virginia, northeastward to within one mile of the Potomac River and the state of Maryland, nearly all the way across Morgan County. Many of the buildings, Cacapon Lake dam, and other facilities of the park were constructed in the mid 1930s by the Civilian Conservation Corps.

The relief (the difference between the highest and lowest points) of the park is nearly 1,500 feet. The highest altitude of 2,300 feet is near the southwestern end of

fiGuRe 10. Lookingeast from the Cacapon Mountain overlook.

fiGuRe 11. Cacapon Lake dam.

bloomsburg formation (sb) — The Bloomsburg Formation is a zone of thin-bedded, dark-red sandstones with occasional red siltstones and shales that break with an irregular fracture.

McKenzie formation (smc) — This formation is made up of dark calcareous shales and thin-bedded, dark-gray argillaceous limestones with marine fossils. The most common fossils in the McKenzie limestones are ostracods that appear as abundant tiny black oval shells.

Keefer sandstone (sk) — The Keefer is a relatively erosion-resistant, dense, fine-grained, gray-white marine sandstone; parts are iron stained, containing minor cross bedding. It is marine in origin and commonly contains traces of vertical (relative to bedding) worm burrows.

Rose Hill formation (srh) — The Rose Hill Formation is a relatively thick assemblage of yellow-tan and red marine shales with thin siltstone and sandstone layers. It occasionally contains dense, red, hematitic (iron-laden) sandstone layers.

Tuscarora sandstone (st) — The Tuscarora is a white to light-gray, resistant marine sandstone containing occasional cross-bedded layers and conglomeratic zones of quartz pebbles. It underlies the highest points on Cacapon Mountain.

Juniata formation (oj) — The Juniata Formation consists of thin- to thick-bedded red, cross-bedded terrestrial sandstone and siltstone. Contains interbedded shale and occasional thin light-gray sandstone. Underlies the upper parts of the northwest slope and occasionally the crest of Cacapon Mountain.

oswego sandstone (oo) — The Oswego, the oldest bedrock exposed, is a gray to light-green cross-bedded sandstone with occasional pebble conglomerate zones. It weathers to a tan color and is void of fossils. Underlies the northwest slope of Cacapon Mountain in the southwest corner of Cacapon Resort State Park.

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the park, where Batt Road turns to the northeast at the summit of Cacapon Mountain; the lowest is about 850 feet, near the park entrance.

stratigraphic featuresBoulders and blocks of Keefer Sandstone are numerous throughout the main recreational areas of the park. Many of the boulders contain what looks like small rounded white pebbles, one-eighth to one-quarter of an inch across. These are actually regular-shaped, long, thin, quartz-filled tubes extending into or completely through the sandstone layers. These features are burrows called Arenicolites made by worms that lived in the unconsolidated sands on the bottom of the shallow Silurian seas. The tubes have since been filled with milky-quartz, precipitated from solutions seeping through the sand, to give the appearance of pebbles when seen in cross section. Similar, although less common fossil markings, are found in the Tuscarora Sandstone.

Larger interlaced grooves, frequently one-half of an inch wide, on the original upper side of beds in the Tuscarora and corresponding ridges on the under side of the adjacent beds, are trails and feeding tubes of unknown ancient organisms. These features are called trace fossils, which are important as they preserve evidence of how animals lived and interacted with their environment. The trace fossil Arthrophycus alleghaniensis differs from Arenicolites by running parallel to, instead of across,

the bedding. This fossil is characteristic of the Tuscarora Sandstone and is used as a guide (guide fossil) in the identification of that formation.

Fossils are more numerous in the Helderberg Limestone and Oriskany Sandstone. Some layers in these rocks consist almost entirely of shells of marine animals. Button-like forms are impressions of parts of the stems of plant-like animals known as crinoids; flat shells are those of brachiopods and bivalves, ancestors to present-day clams; and coiled forms are remains of gastropods (snails).

Inorganic features of rocks found in the park include ripple-marks (shallow depressions and ridges) formed by water currents moving across loose sediment. Some bedding planes of the thin-layered Tonoloway Limestone, cropping out along the main road and North Fork of Indian Run near the Old Inn, are marked with a polygonal pattern of cracks or lines. These are called mud cracks, caused by the shallow sea bottom drying and shrinking from time to time. These structures are identical to the cracks that form when a mud puddle dries.

Curved, parallel streaks of persistent color may be seen occasionally in the Keefer and Tuscarora sandstones. These represent thin layers of sand of different mineral content deposited at variable angles to the sea floor, much as sand is deposited in sandbars today. Layering at

fiGuRe 12. Arenicolites onbedding

surface of Keefer

Sandstone.

fiGuRe 13.Arthrophycus alleghaniensi onbeddingsurface of TuscaroraSandstone.

fiGuRe 14.Marine brachiopod (fossilshell)remains in OriskanySandstone.

nuGGeTHighest

point—2,300feet—nearthesouth-

westernend of the

park.Lowestpoint—850feet—near

the park entrance.

Relief—1,450feet.

16 17

an angle to and between, bedding planes is called “cross-bedding” and is a common feature of many sandstone formations throughout the state.

Variation in the composition and amount of cement bonding grains together often leads to interesting rock shapes through “differential weathering.” The effects of differential weathering can be seen at Prospect Rock. Variations in the cementing material between successive beds resulted in the deep horizontal grooves and “table rock” feature. Variations in cementing material laterally within a single bed have caused rounded depressions. These hollows are similar in form to “potholes” formed by erosion in rock floored stream channels at the sites of rapids and waterfalls.

The Oriskany Sandstone’s constituent quartz grains are held together by calcareous (limy) cement, which is weaker than the silica cement bonding the grains of the Keefer and Tuscarora. The limy cement is easily removed by weathering so that quarries in the Oriskany yield a very fine sand from the crumbly, weathered layer. Oriskany sand has been hauled in from quarries to form the beach of Cacapon Lake. The Oriskany also is noted for its high-silica content and is produced for making glass and other silica products from quarries in Warm Springs Ridge, seen along Route 522 northeast of Berkeley Springs.

structural featuresNear the end of the Paleozoic Era, a collision between sections of the earth’s crust, called tectonic plates, exerted great horizontal pressure from the southeast on the rocks of West Virginia. This caused an upward buckling of the bedrock, resulting in the formation of the Appalachian Mountains. In the eastern portions of the state, this uplift caused the rocks to wrinkle or fold into upwarps and downwarps called anticlines and synclines. The ridge of Cacapon Mountain directly overlies the axis (center line) of the Cacapon Mountain Anticline. The bedrock under the park to the southeast of the anticlinal axis dips (tilts) to the southeast. Over the ridge, on the northwestern slope of Cacapon Mountain, the rocks dip to the northwest.

Anticlines are commonly bordered on either side by downfolds called “synclines” (beds concave to the surface). The axis or center line of the first major syncline northwest of the park is approximately on the crest of Sideling Hill, where rocks of Mississippian age are exposed. There is a spectacular exposure of the axis of this syncline where Interstate 68 cuts through Sideling Hill, just west of Hancock, Maryland. The axis of the first major syncline to the southeast of the park is six miles distant from the park entrance and about one mile beyond Sleepy Creek Mountain, the first major ridge visible looking eastward from the park. While the axes of anticlines and synclines tend to control the trend or direction of valleys and ridges, the crests and troughs of the underlying bedrock

fiGuRe 17. Northeast dippingbedsofOriskanySandstone near park entrance.

fiGuRe 15. Above,

differentialweathering

ofTuscaroraSandstone

at Prospect Rocks.

fiGuRe 16. Above right,

potholesonbedding

surface of Tuscarora

Sandstone at Prospect

Rocks.

CaCaPon ResoRT sTaTe PaRK

fiGuRe 18. CacaponResortStateParkfacilitiesmap.

20 21

do not always correspond to topographic highs and lows. The adjacent synclines to the Cacapon Anticline underlie highly elevated ridges, and it is not uncommon for anticlines to underlie valleys (as at Canaan Valley). Rather, the earth’s topographic features also result from differences in the erosion and weathering rates of the rock sections exposed. Where less resistant formations were at the surface, they were worn away to valleys; where there were more resistant ones, ridges remain.

Topographic featuresThe recreation hall and entrance to the beach are on the lowest ridge known as Warm Spring Ridge. The resistant formation is the Oriskany Sandstone. An outcrop of the Oriskany can be seen along the north side of the road just after entering the park. This gap in the ridge, eroded

by Indian Run, has provided an easy access route from the main entrance to the lodge and cabin areas.

Along the northwestern slope of Warm Spring Ridge, outcrops of blue-gray Helderberg Limestone can be seen. Some of these beds consist mostly of fossils of marine animals, ancestors to present-day clams, oysters, and snails.

The golf course and main lodge are underlain by thin-bedded limestones and shales of the Upper Silurian and Lower Devonian. Limestone and shale generally weather and erode faster than sandstone. Weathering of these soft rocks has formed the valley between Warm Spring and Piney Ridge.

Limestone is chemically weathered as weak acids

fiGuRe 19.Generalized

cross section of Cacapon

Resort State Park and Cacapon

Mountain.

22 23

dissolve the soluble calcium carbonate. Rain and stream water dissolve carbon dioxide, forming carbonic acid. Forest vegetation can contribute tannic acid to stream and groundwater. Groundwater can become acidified from carbon dioxide in soils. Dissolving of limestone occurs not only at the surface, forming valleys and small depressions, but also in the sub-surface. As acidic groundwater moves through fractures in the limestone, it dissolves the rock, forming voids. Over time, these voids grow larger, forming caverns. When the ceiling of a cavern nears the surface, it can become weak and collapse. The surface feature which develops is called a sink hole. There are some shallow sink holes in the park in the northeast part of the golf course.

Shale, composed of extremely fine-grained clay minerals, is not soluble by weak acids; however, the bedding is much thinner than in most limestone or sandstone. Therefore, shale is easily broken into platy fragments by frost and water.

Piney Ridge is a line of knobby hills and terraces along the upper slopes of Cacapon Mountain. Here, the resistant Keefer Sandstone has slowed the wearing away of the land. The most spectacular outcrops of Keefer Sandstone in the park are southeast of the parking

overlook on Batt Road about half a mile below the summit where the South Fork of Indian Run has cut through Piney Ridge. Boulders and blocks of Keefer Sandstone are abundant throughout the park below Piney Ridge. They have been widely used in construction of the buildings, retaining walls, gate-posts, and Cacapon Lake dam.

The Rose Hill Formation underlies the area between Piney Ridge and the summit of Cacapon Mountain. The Rose Hill consists of several hundred feet of red, olive, or buff shales interbedded with red sandstone layers less than a foot thick in most places.

The summit of Cacapon Mountain is underlain by the oldest and toughest formation in the park, the Tuscarora Sandstone, a very hard, erosion-resistant rock. The Tuscarora consists almost entirely of medium- to thick-bedded white, gray, or pinkish sandstone that weathers to a dirty gray and is often covered with leathery-leaved plant growths called “lichens.” The grains of sand in the Tuscarora are firmly cemented with silica (quartz) which creates a strong enough bond that breaks occur across, rather than around, the constituent grains. This results in fresh fractures appearing smoother and brighter than in the weaker calcite-cemented Oriskany Sandstone. Exposures of Tuscarora may be observed closely for several hundred feet along Batt Road below the summit where they form the northwest bank of the road. Prospect Rocks, near the northeastern end of the park, are a series of northwest-facing cliffs also cut into the Tuscarora.

fiGuRe 20.Southwestviewfrom

golfcourseshowing

PineyRidgeand Cacapon

Mountain.

fiGuRe 21.Stream flowingintosinkholedevelopedinlimestonesundergolfcourse.

nuGGeTTheoldestrock formation in the park isTuscaroraSandstone under Cacapon Mountain.

24 25

losT RiVeR sTaTe PaRK

Lost River State Park, located in south-central Hardy County, covers an area of 3,712 acres. The park extends northeast from Howards Lick Run for five miles along the summit and slopes of Big Ridge, one of the highest ridges in the vicinity. The park continues for 1.5 miles to the southwest of Howards Lick Run. This section includes most of the recreation facilities and cabin sites along Cabin Fork, and also extends up the slopes of Piney Ridge to the west and East Ridge to the southeast. These ridges are essentially lower, southwestward continuations of Big Ridge. Many of the buildings and other facilities of the park were constructed by the Civilian Conservation Corps.

Altitudes in the park range from 1,750 to 3,210 feet, thus the “relief” of the park (the difference between the highest and lowest points) is 1,460 feet. The highest point is about one mile northeast of the Cranny Crow overlook at the summit of Big Ridge, and the lowest is along Howards Lick Run at the main entrance to the

park. The scenery, topography, and geology of the park area is typical of the Valley and Ridge physiographic province with parallel northeast-trending mountain ridges and broad valleys visible eastward from summits in the park.

stratigraphic featuresThe Hampshire Formation underlies most of the park and generally consists of mostly six- to 12-inch layers of brownish-red sandstone, which are interbedded in many places with thin layers of red and green shales and less frequently with conglomerate. The colors are caused by different forms of iron oxide distributed between the grains of the rocks. Red shows the presence of ferric oxide (Fe2O3) and green indicates ferrous iron (FeO). Ferrous iron may form from ferric iron by the reducing action of organic matter such as decaying plants buried with the sediments and now almost completely consumed. Differing amounts of original organic matter from place to place may explain the presence of both colors in one rock layer. Individual blocks long separated from the parent layer may appear gray through leaching of the surface iron, but broken open they usually show the original red.

The Hampshire and Rockwell were deposited by streams that flowed across a low coastal plain along the eastern

fiGuRe 23.Ripplemarkson underside ofbedding,RockwellFormationsandstone at Cheeks Rocks.

fiGuRe 22.Looking

east from Cheeks Rocks,

RockwellFormation.

nuGGeTHighestpoint—3,210feet—summitofBigRidge.Lowestpoint—1,750feet—atthe park entrance.Relief—1,460feet.

26 27

side of a broad arm of the ocean that covered large areas of North America during the late Devonian and early Mississippian. As the sand grains, pebbles, and clays were being deposited, currents sometimes swept the loose sediments into parallel shallow depressions and ridges (ripples). These were frequently preserved by burial and cementing of the grains. Now they are exposed on bedding planes at many places in and near the park as ripple marks.

As the channels carrying these streams migrated across the coastal plains, the sediments deposited would record changing channel positions in the form of cross-bedding. Cross-beds can be seen in some outcrops of the Rockwell Formation.

Some of the bedding planes are marked by a roughly polygonal pattern of cracks, ridges, or lines. These are impressions of mud cracks caused by the occasional drying and shrinkage of sediments in the shallow streams and lakes on the ancient coastal plain, similar to the cracks formed when a mud puddle dries. At times of low flow, mud cracks can be seen on bedding plane surfaces of Hampshire Formation rocks in the bed of Howards Lick Run.

Most of the sandstone seen in the chimneys and walls of park buildings was brought from Helmick Rock

fiGuRe 24. Cross beds in

Hampshire Formation

outcrop above first sharp turn

onFireTowerRoad.

fiGuRe 25. HelmickRockonSouthBranchMountain.200feetofreliefinRockwellFormation.Talusslopeatbaseprovidedstoneformanybuildingsat Lost River State Park.

fiGuRe 26. SilurianTuscaroraSandstonewasusedtomakethebaseofthechimneyof Cabin 12 at the park.

fiGuRe 27. CrannyCrowoverlook.

losT RiVeR sTaTe PaRK

fiGuRe 28. LostRiverStateParkfacilitiesmap.

30 31

structural featuresNear the end of the Paleozoic Era, a collision between tectonic plates of the earth’s crust caused great horizontal pressure from the southeast to be exerted on the rocks of West Virginia. This caused a buckling upward of the bedrock resulting in the formation of the Appalachian Mountains. In the eastern portions of the state, this uplift caused the rocks to wrinkle or fold into upwarps and downwarps called anticlines and synclines.

The formation of the Appalachian Mountains caused the originally flat-lying deposits of the Hampshire and Rockwell to be greatly deformed. At the road junction just below the swimming pool, layers of red and green shale stand nearly vertical, a result of localized folding of the weak shales as stronger sandstones above and below slid against them. Polished and grooved fractures (slickensides) found in some of the sandstone sections show that those beds broke across the bedding, as well as slipped along bedding planes.

A major structural feature, the Sideling Hill Syncline, passes through the park. The axis of the fold is centered along the summit of Big Ridge. It continues northeastward through Maryland, where the axis can easily be seen in a spectacular roadcut through Sideling Hill on Interstate 68, west of Hancock. The crests and troughs of folded formations do not nessessarily

fiGuRe 29. Steeplydipping

beds of the Hampshire Formation

at road intersection.

fiGuRe 30. Cheeks Rocks, near axis of theSidelingHillSyncline.RockwellFormationsandstones dippingsouthwest.

on the northwest slope of South Branch Mountain. Helmick Rock is a sandstone outcrop of the Rockwell Formation, the same rock unit underlying Big Ridge. As weathering and erosion remove material from joints and bedding planes, large sandstone blocks fall from the two-hundred-foot cliffs and are strewn along the northwestern side to form a “talus slope.” Helmick Rock is about seven miles from the park, on the road to Moorefield (county Route 12).

Silurian Tuscarora Sandstone also has been used in some of the park buildings, for instance, the base of the chimney of Cabin 12. This probably came from the gap east of Mathias where the Tuscarora surfaces. Not all of the flat flagstones of the walks are of local origin. Slabs of red sandstone forming the porch of the restaurant in the administration building were brought from Watoga State Park in Pocahontas County. The most distant source for rock used in the park would be the algae-covered marble blocks lining Lee Sulphur Spring. It is believed that these were imported from Italy and installed by General Henry Lee in 1801.

32 33

the northwest side they dip southeast. The exact axis or line of reversal of dip also may be seen in the Rockwell sandstone outcrops about 650 feet northeast of the fire tower on the summit of Big Ridge. Along the axis at Cheeks Rocks and Millers Rocks dips are relatively flat. Many unusual rock shapes can be found along the extremities of Big Ridge. These are formed by differential weathering. Variations in the strength of the material cementing the grains together have resulted in deep horizontal grooves and “table rock” features. Vertical cracks or joints in the layers have been widened to form miniature canyons and, in a few cases, small natural bridges. Joints were formed by tension that pulled the rock layers apart across the bedding as they were folded. They are common structures throughout the park.

fiGuRe 31. GeneralizedCross Section of Lost River State Park area.

correspond respectively to mountains and valleys. Rather, the topography results from differences in erosion and weathering rates of the rock sections which were exposed in linear belts after the folding. Resistant formations such as the upper Hampshire and Rockwell form ridges; whereas, less resistant rocks generally underlie valleys. The valley of Cabin Run in the area of the administration building and cabins follows the upended shale mentioned before, while the wide valley of Lost River from Mathias to Baker follows the much broader belt of nonresistant Middle Devonian shale.

The synclinal structure of Big Ridge can be seen from the trails in the vicinity of Cheeks Rocks. On the southeast side the sandstone layers tilt (dip) northwest, while on

nuGGeTTheaxisoftheSidelingHillSynclinecan be seen in a spectacularroadcut on Interstate 68, east of Hancock, Md.

34 35

lee sulphur springs

Ever since the first Lee ownership, the spring has been a center of health-seeking and recreation. General Henry

(Light Horse Harry) Lee, father of Robert E. Lee, is said to have built the family cabin in 1800. It still stands in restored condition near the spring. He later built a two-story, 100-by-49-foot log hotel that stood up-slope from the present swimming pool. The hotel burned in 1910. Many more curative results were ascribed to drinking and bathing in this and other mineralized

spring water in the 19th century than today, which made the area a popular destination for visitors from throughout the middle Atlantic states.

The principles controlling such springs are fairly simple. Rainwater seeps into a porous and permeable bed, such as sandstone, at points higher on a structure, in this case perhaps to the west along the Whip Cove anticline. Water flows beneath the surface due to gravity between impermeable beds like the interbedded shale in the Hampshire until the carrier bed (aquifer) is exposed at a lower level or the water can work its way to the surface along faults or joints. In its passage through the rocks it dissolves mineral matter and may pick up gases, additional water, and other liquids from the pores of surrounding rocks. The flow rate of Lee Sulphur Spring is less than one gallon per minute, small compared with a giant spring, such as Berkeley Springs in Morgan County (Berkeley Springs State Park) that discharges as much as 2,000 gallons per minute. The water is pleasant tasting but the odor of sulfur and hydrogen sulfide, which gives it a “rotten egg” smell, can be strong.

“lost” River

The Lost River, for which the park takes its name, parallels state Route 259 in a northeast trending valley, underlain by less resistant Devonian shales, which is typical of the Valley and Ridge physiographic province. Howards Lick Run, the main stream in the park, empties into Lost River at Mathias. North of the town of Baker, Lost River turns eastward, cutting a narrow gap through the ridge underlain by the Hanging Rock Anticline, exposing rocks older than those found in the park. Old state Route 55 follows Lost River through this gap.

Entering the gap from the west, late Silurian/early Devonian carbonates (limestone and dolomite) are exposed. Being on the western side of the axis (centerline) of the anticline, these rocks dip to the northwest. Continuing eastward through the gap, across the axis, rocks dip to the southeast. It is on this side that an exposure of the Silurian-aged Tuscarora Sandstone nearly overhangs the road in a feature called Hanging Rock, also the source name of the anticline. This structure is nicely exposed by roadcuts made in construction of new Route 55.

Four miles east of Hanging Rock, the Lost River flows over an exposure of limestone. Eroded voids in the bedrock cause some of the river’s water to be diverted

fiGuRe 32. LeeSulphur

Springs.Marbleblocksliningspringare reported

to have been imported

fromItaly.

fiGuRe 33. HangingRock.

36

underground for about two miles before it reemerges. The water follows joints and bedding planes in the Tonoloway Limestone that have been enlarged by acids in the water, dissolving the soluble limestone. During periods of very low flow, all water in the Lost River channel may be diverted underground. This feature is what gives the river its name. The river flows underground in a northeast direction to its resurgence east of Sandy Ridge, paralleling the strike (direction of the axes of anticlines and synclines) of the bedrock. Pressure is built up as the water is confined underground, causing it to emerge with force forming Cacapon River.

fiGuRe 34. Lost River,

lookingdownstream

from beneath theoldstate

Route 55 bridge.Duringtimesofverylowflow,the

river sinks at this point into voids in

underlyinglimestone.

West Virginia Geological and Economic SurveyMorgantown, WV

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West Virginia State Parks1–800–CALL WVAwww.wvstateparks.com

GEOLOGIC MAPS Cacapon Resort State Park and Lost River State Park A geologic map shows the distribution of different kinds of rocks and structural features (anticlines, synclines, faults, etc.) It is a summary of all the geologist knows in an area, and is usually printed on top of a topographic map, called a base map, for orientation. The base map is printed with light colors so it doesn’t interfere with the geologic features on the map. The geology is represented by colors, lines and special symbols unique to geologic maps. The map itself is usually accompanied by one or more vertical cross sections so that a person can picture rocks at and below the surface in three dimensions.

The rock units depicted on these maps are described in the “Rocks exposed in the parks” sections, beginning on page 9. The base maps used are the standard USGS 7.5 minute topographic maps. Topographic maps of West Virginia are available from West Virginia Geological and Economic Survey.

INFORMATIONAL LINKS Lost River State Park .........................www.lostriversp.comCacapon Resort State Park ..................www.cacaponresort.comWest Virginia Geological and Economic Survey .......................................................www.wvgs.wvnet.eduWest Virginia State Parks ....................www.wvstateparks.comWest Virginia Division of Tourism ........www.wvtourism.comBerkeley Springs State Park ................www.berkeleyspringssp.comBerkeley Springs Tourism ...................www.berkeleysprings.comHardy County, WV .............................www.hardycountywv.comMonongahela National Forest ..............www.fs.fed.us/r9/mnfGeorge Washington/Jefferson National Forests .......................................................www.fs.fed.us/r8/gwjUnited States Geological Survey ..........www.usgs.gov

Ken Ashton, GeologistWest Virginia Geological and Economic Survey

West Virginia Geological and Economic SurveyWest Virginia State Parks

The

Geology of

One in a Series of State Parks Bulletins

Cacapon Resort andLost River State Parks

West Virginia Department of Commerce

geology the - west virginia · 6 7 (pleistocene epoch of the neogene period) never reached west...

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