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vol. 4, no. 3 Summer 1992 Cacapon

PUBLISHED BY PINE CABIN RUN ECOLOGICAL LABORATORY Geology of the INSIDE Cacapon River Basin 6 Letters to the by Eberhard Werner,Morgantown, WV Editor Let's begin by looking at a map. Any plied slowly the rock layers will bend map will do as long as it shows the streams. (up to a point). 7 A drainage map of , for ex­ As you can see in cross-section (figure Cacapon ample, reveals regional differences. In the 2), the surface of the earth may not mirror T-Shirts center of the state, streams do not form any the folding of the rocks. There are instances for sale! particular pattern - they simply wander where a ridge coincides with an anticline about in the general direction of the nearest and a valley with a syncline, but the reverse larger stream. In our part of eastern West also occurs. It all depends on the resistance Virginia, though, the larger streams run of the various layers to erosion, and how ac­ parallel. Only a few short segments of the tive the erosional process has been. We will mainstems flow in a direction other than discuss this further in a bit. northeast-southwest. If you follow the Fractures - Sometimes forces in the Cacapon (figure 1), you will see that it earth are applied fast enough or the bend­ proceeds for long distances in a north­ ing is so extensive that the rocks break. easterly direction, occasionally jogging Look carefully at an outcrop and you will sharply right or left. see some breaks. Most of these are simple To understand what has caused this fractures with no significant movement of curious drainage pattern we need to ex­ one piece with respect to theother; these plore the rocks underlying the surface. are called fractures or joints. Where there has been significant mQve­ Structure ment along the break, it is called a faull. The field of geology concerned with the What movement is deemed significant arrangement of rocks is known as struc­ depends on many factors. Sometimes it tural geology. The geological structures must be far enough to show up on a map, relevant here are folds and fractures. sometimes just being able to see that the Folds - You may have noticed that layers no longer line up is enough. Basically rock layers in the basin are either flat or it depends on who is looking and why. bent. Keep in mind that most folds are too The major structures of the Cacapon 8 large to be seen in their entirety; you only River basin are shown in figure 3. At this scale only the largest folds show up. Lab see a small part. Folds come in two basic News types: anticlines, where rock layers are Smaller folds and faults can be seen on folded upward at the center and slope more detailed maps (e.g., Tilton and others down away from the center; and synclines, 1927, Dean and others 1985). 9 which are like anticlines turned upside­ Cacapon down (figure 2). Kinds ofRocks Natural Folding comes about when forces Geologists divide rocks into three basic History within the earth compress a piece of the types: igneous - those formed from mol­ earth's crust (See "Cacapon Natural His­ ten ma terial either on the surface or within tory", p. 9 this issue.). If the forces are ap the earth, metamorphic those altered

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lab from previously existing rocks by heat of these and quartz, the normal name is needs: and/or pressure but without actually melt­ sandstone. Sandstone is mostly quartz, but ing them, and sedimentary - those formed it contains other minerals as well. For ex­ from tiney pieces of various kinks of ample, calcite ("lime") and hematite ("iron") canoe trailer materials laid down in water. commonly cement the grains together. The With minor exceptions, the only type of same idea applies to shale and siltstone. photocopy rock that occurs in the Cacapon River basin Limestone is different from other machine is sedimentary. Sedimentary rock usually sedimentary rocks in that it is built of foTITIS in the ocean near shore, or where material taken out of oceanic water by rivers slow down so they no longer carry plants and animals that build their shells or the load. As materials pile up on the bottom skeletons out of calcite ( and other related of the water body, their own weight com­ minerals). These skeletal remains are the presses the bottom layers. Minerals from grains which form limestone. Most caldte water in the pores come out of solution and grains are deposited near where they were ~S-:acapon £~ cement the grains together, and the result is created by organisms, unlike sandstones is published quarterly, rock. whose grains have been carried long distan­ with the arrival of each ces by rivers and ocean currents. equinox and solstice, by Pine Cabin Run Ecological Laboratory, Rock Layers Route 1, Box 469, Cacapon River Basin In the Cacapon River basin, different High View, WV 26808; o IOm!l!!!> FAX & phone kinds of rocks are found at various depths. (304) 856-3911. Rocks of the vertical column can be as­ signed to different formations. The name ap­ BOARD OF plied to a formation is the place where it DIRECTORS Nancy Ailes was first described. For example, the George Constantz is named for the Helder­ Michael Dixon berg escarpment of east-central West Vir­ Ronald Knipling ginia. Identification of layers is based on Jane Licata James Matheson characteristics of the rocks themselves and within, or more recently on ages STAFF determined by the rock's level of radioac­ Dr. George Constantz tivity. Most of the Cacapon River basin's Director rocks, listed below by increasing age, are Nancy Ailes Cacapon Editor ,.. detailed by Cardwell and Erwin (1968) and David Malakoff by Hobba (1985): Senior Associate I. Rocks (formed 360 - 320 million years ago) SCIENTIFIC ADVISORY B.JARD - Pocono Group (570 feet thick) - gray or Dr. Joe Calabrese tan, massive, fairly hard sandstones Dr. Stephen Fretwell topping ridges in the western part of Dr. Robert Kahn Dr. Michael Masnik Figure 1. Stream network of the Cacapon .RIver basin the Cacapon River basin. Dr. Chris Sacchi as shown on the U.S. Geol. Surv. 1:250,000 scale maps. II. Rocks (formed 408 - 360 mil­ The two small arrows show the location of the cross­ lion years ago) COUNSEL section in figure 2. Charles Licata, JD - Hampshire Formation (2000' thick) mostly shales and fine-grained Sedimentary rocks can be classified by PHOTOGRAPHER sandstones, with some coarser grained, James Holmes the materials making them up; and most people recognize their names: shale, massive sandstone beds; mostly red or brown; generally on hillsides in the Pine Cabin Run siltstone, sandstone, and limestone. Al­ Ecological Labortory though that classification looks simple, western half of the basin. is a non-profit, tax­ there are complications. Shale, siltstone, -Chemung Group (2500 - 3000' thick) exempt grassroots alternating sandstone and shale beds, organizaHon and sandstone are named for the size, not dedicated to the composition, of the particles making them with each bed only a few inches thick; ecological preservation up. One can find sandstone made of calcite, mostly yellowish brown in color; very of the Lost, North, and fossiliferous in some places; mostly on Cacapon rivers. quartz, or hematite. Although no one would normally call a rock made entirely of hillsides in the basin. Printed on recycled sand-sized grains of calcite or hema tite a - (1300-2170' thick) ­ @paper. sandstone, most geologists would call them mostly greenish-gray, very thin limestone or rock hematite. If it is a mixture bedded shales and siltstones, other-

2 • Cacapon vol. 4 no. 3, summer 1992 Published by Pine Cabin Run Ecological Laborato?1j wise fairly nondescript; weathers III. Rocks (formed 438-408 mil­ readily and tends to slump into masses lion years ago) of shale chips. • (200-400' thick)­ - 025-300' thick) dark gray, sometimes very dark, thin­ brown or gray to black, thinly bedded limestones or dolomites; often laminated shale; with a few fossils. containing appreciable amounts of - (300-1000' silica. thick)-mostlybrown sanay shales with -Wills Creek and McKenzie formations a few thin beds of sandstones and limy (400-800' thick)-limy shales qr shaly sandstones; may be very fossiliferous. limestones for the most part; most of - Marcellus and Needmore shales (500­ the rock is actually gray but is almost 900'.thick)-dark brown or black shales always stained red from weathered with little variety, splitting easily into material washing onto it; the two for­ thin flakes; one or two limestone beds mations are sometimes separated by about 20 feet thick toward the base of the Williamsport sandstone which the formation. may be up to 100 feet thick. -Oriskany sandstone 000-500' thick)­ - (50-300' thick)­ white to brown sandstone, locally mostly thick-bedded light gray limestone or sandy limestone; cemen­ sandstone, very resistant to weather­ tation varies from very strong to almost ing; tops the highest ridges in the east­ "With none; silica or calcite; chert layers are ern portion of the basin. mmor sometimes found at the top and bottom IV. Rocks (formed 505-438 mil­ of the formation, although either or lion years ago) exceptions, both may be absent. -Juniata and Oswego formations (600­ the only -Helderberg Group (300-600' thick)­ 1200' thick)-mostly red or gray, thick light colored, usually gray limestone; bedded sandstones; not as resistant to type of rock upper portion is thin bedded, with weathering as the Tuscarora, but still that occurs cherty layers at the top and shaly layers quite resistant. below; lower part is massively bedded - 0500-2300' in the pure limestone; some of the lower part thick)-mostly shale, usually sandynear may be Silurian. the top; contains lenses of limestone Cacapon River basin lS sedimentary."

,- , ­ , ,, ~ - - # , -. I , I . ,-- ,. '. , I , , , -, --.... ~ .... -- .. , , .'

Figure 2. Ageneral cross·section of the Cacapon River basin (See figure 1for location.). The vertical scale has been exaggerated to clearly show the folds. The heavy line indicates the land's surface; lighter solid lines are boun­ daries between rock layers; dashed lines indicate where rock boundaries may have been in the past before erosion removed rocks. The patterns on the rock layers are for rocks which are most resistant to erosion: small dots indio cate the Tuscarora formation; lines, the Oriskany sandstone; and small circles, the Pocono Group. Letter abbrevia­ tions are used for the remainder. Some of the units given separately in the text are grouped together here: Om· Martinsburg, Oja - Juniata and Oswego, OS . Helderberg and all the Silurian rocks above the Tuscarora combined (except Smc - McKenzie, shown near the center of the figure), Dbh • Brallier and Harrell (and Mahantango, Marcel­ lus, and Needmore), Dch . Chemung Group, and Ohs· Hampshire Group.

Published by Pine Cabin Run [cl·logical Laboratory Cacapon vol. 4 no. 3, summer 1992 • 3 i

here and there, but not commonly in which hold up some of the gentler, lower the Cacapon River basin; underlies val­ ridges in the western part of the basin. leys in the very eastern part of the Shales underlie the valleys: the Mar­ basin. tinsburg, Brallier, and Harrell shales in the This entire series of rocks, from Missis­ eastern part of our cross-section, and the sippian through Ordovician, can be divided Hampshire in the west. The middle of the into two natural groups. Rocks older than cross-section valleys are also underlain by Oriskany sandstone, shown as the tail side limestones of the Helderberg and of the hachured dash lines (figure 3), are Tonoloway Groups. structurally more competent and therefore Rock type is not the only factor influenc­ occur in large folds. In contrast, younger ing where streams have eroded material to rocks, on the flat side of the hachure form valleys. Fragmented rock is more easi­ dashes, flow more easily and form small, ly weathered than fresh, massive beds. A gentle folds. zone of broken rock forms an easy path for a river to cut through a ridge. Because folds "The most Stream Patterns extending northeast-southwest form nar­ Our world has been classified in many row stripes of the various rock types run­ resistant ways, depending on the interests of the clas­ ning in the same direction, streams are sifier. Geomorphologists (people who mostly aligned in that direction. Where rock, study the characteristics and changes of the streams venture across the grain, there is Tuscarora earth's surface) have placed the Cacapon likely to have been a fracture. Thus, it is River basin within the Ridge and Valley both the rock types and fracture zones that sandstone, province of the Appalachians. This control the regional patterns of streams. forms the province, which features long parallel As I stated at the outset, in areas west of ridges and valleys, is sandwiched between the Ridge and Valley province, streams highest the Appalachian Plateau (e.g., Morgan­ wander seemingly randomly, forming a pat­ and town) to the west and the Great Valley (lo­ tern known as dendritic (as in the branches cally called the Shenandoah Valley) to the of a tree). In the Cacapon River basin, how­ steepest east. ever, intensely folded rocks cause a dif- ridges." Let us return now to the connection be­ tween the landscape's topography and the underlying rocks. Rocks that resist weather­ ing will remain while softer, m0re chemical­ Cacapon River Basin ly reactive ones will disintegrate. Therefore, you would expect ridges to be made of resistant rocks and valleys to host weak ones. N Applying this idea to the Cacapon River basin, the resistant rocks are sandstones, usually fairly pure ones, and the weak 1 rocks are shales and limestones. The im­ pure (shaly or limy) sandstones are in-be­ tween. Looking at the cross-section (figure 2), you can see how this works out. The most resistant rock, Tuscarora sandstone, forms the highest and steepest ridges. The sandstones and conglomerates (pebbles ce­ mented together) of the Pocono group are FOLDS' next-most resistant, and also underlie high --t-anticline and steep ridges. The McKenzie is not espe­ ~ynclln8 hachured dashed fine cially resistant, but where the Williamsport indicates top of Oriskany sandstone is present on top, it may hold up a ridge, such as Pine Ridge, near the middle of the cross-section. Oriskany sandstone is also a ridge-former because it soaks up water, precluding flow over the surface and Figure 3. Major structures an~ top of Oriskany overlaid the washing away of particles. There are on the drainage network of the Cacapon River basin. also sandstones in the Chemung Group More smaller folds and some faults also exist but are not large enough to show on this map.

4 • Cacapon vol. 4 no. 3, summer 1992 Published by Pine Cabin Run Ecological Laboratory ferent pattern, called trellised drainage (like twenty thousand years. Along the east side the trellis supporting a rose bush). of Lost River, about a half mile north of the Tributaries flow directly down hillsides to town of Lost River, rests one of these giant meet large master streams at rig.!1t angles, prehistoric landslides (Southworth 1987, which in turn flow along the weak rocks in 1988). It appears that the Lost River under­ the parallel folds. cut the hillslope. This removed support As mentioned previously, these weak from the Oriskany sandstone, which was strata have been exposed by erosion at the not securely attached to the rocks below be­ center of synclines, on the flanks of folds, or cause of solution at the top of the Helder­ at the centers of anticlines. Where there is a berg limestone. The steepness of the hillside valley at the center of an anticline or a ridge did the rest and approximately 100,000,000 at the ~enter of a syncline, the term "inver­ cubic feet of Oriskany sandstone slipped off sion of relief" is applied, emphasizing the the mountain into the valley. Most of the fact that the land's surface does not mirror slide's debris is still there today. the rock folds beneath. Conclusion Solution features This has been a general geology of the When sandstones and shales break Cacapon River basin. References below go down, they form particles which are carried into more detaiL The Cacapon River basin off by water. Limestone, on the other hand, has received less study than other areas of can weather without leaving particles - its Appalachia probably because there are few breakdown products go into solution. You economically attractive mineral resources. know this solution as water hardness, Less commercial potential, though, does "Water which is simply calcium and magnesium not make for a less interesting area. Many seeping through dissolved in water. Because this material is aspects of the Cacapon River basin interest dissolved, it does not require fast currents geologists, and some of these features are limestone to carry it off. Where flowing water touches just now being investigated. Meanwhile, dissolved limestone underground, caves and chan­ the Cacapon River basin remains an area nels form. where many interesting rocks are seen and an Features associated with solutional fascinating geologic features can be ap­ underground weathering are called karst. Even though preciated. karst topography is not common in the channel Cacapon River basin, it does not mean the References that process is absent here. The most obvious Card welt D. H., R. B. Erwin, & H.P. Wood­ feature of karst landscape is the sinkhole. ward (1968) Geologic map ofWV. WV often carries Ceol Surv. 2 sheets. Although Davies (1958) reports only ten Davies, W. E. (1958) Caverns of WV. WV Geol the caves in the basin, and none more than a Surv Vol19A 330)2. few hundred feet long, there is considerable Dean, S.L., B.R. Kulanaer and P. Lessing entire flow of (1985) Geology of the Capon Springs, potential for ~ave discoveries in the area, Mountain FaIrs, Wardensville, Woodstock, Lost River." especially in the Helderberg and Tonolo­ and Yellow Springs quadrangles, way groups. In some places in the basin, Hampshire and Hardy counties, WV. WV Geol Burv Map 26. 1 sheet. when water wells are being drilled through Hobba, W. A Jr. (1985) Water in Hardy, Oriskany sandstone, the drill bit drops sud­ Hampshire, and western Morgan Coun­ denly, indicating an open space. ties, WV. WV Geol Surv Env Ceol Bull EGB-19,91 p. One unusual aspect of solutional Southworth, C. S. (1987) Prehistoric giant rock­ landscape in the Cacapon River basin are slides of the Appalachian Valley and the sinks of Lost River at McCauley. Water Ridge province: type and characteristics. seeping through limestone has dissolved an US Ceol Surv Circular 1008:24-32. Southworth, C. S. (1988) Geology: of the Lost underground channel that often carries the River rock slide, WV. US Geol Surv Open­ entire flow of Lost Ri ver. Although under­ file Report 88-0639.22 p. ground water flow in karst regions is nor­ Tilton, J.L, W.V. Prouty, RoC. Tucker and P.H. Price (1927) Hampshire & Hardy counties. mal, the average flow of 90 cubic feet per WV Geol Surv County Report. 624 p. second (Hobba 1985, p. 15) through a single inlet and outlet in an area with few karst Eberhard Werner's masters thesis (Rutgers) is features is uncommon. entitled "Caves of Central Pocahontas Co., Greenbrier River Valley", Currently, Eb is a Landslides consulting geologist at GeoAnalysis, P.O. Box Recent research has revealed that huge 795, Morgantown, WV 26507. landslides have occurred in the last ten or

Published by Pine Cabin Run Ecological Laboratory Cacapon vol. 4 no. 3, summer 1992 • 5 - Cacapon Natural History

~o complement Eb Werner's basin perspective (page 1), we thought you might enjoy this broader Appalachian view.

Appalachian Origins . by George Constantz

Earth was born 4.6 billion years ago as a Today, the seaward portion of the Ap­ hot ball of condensed atoms. It began cool­ palachians includes blocks of terrain from ing immediately and with time its outer what became Africa. These foreign rocks crust began to harden. As the crust cooled were apparently welded onto what became "Appalachia and shrank, it broke into sections called North America during the collision that crustal plates, which began shifting about produced the Appalachians. Today, foreign has been the earth's surface 2.5 billion years ago. Cur­ blocks occur on the east side of the Brevard uplifted rently, seven large and about thirty Zone, which is a long fault, or suture line, medium-sized and small plates slide about caused by the collision of these two con­ from the earth's surface at speeds of up to 5 in­ tinents. The zone trends northeast-south­ the oceans ches per year. west, running through Brevard, North About 600 million years ago, when mul­ Carolina, and connecting Atlanta, for almost ticellular animals arose, two plates of con­ Asheville, and Roanoke. Discontinuous ex­ 600 troversial identity drifted towards each tensions of the Brevard Zone even reach other and collided. While the plates were Staten Island, making part of the Big Apple million years, grinding against one another, three distinct a piece of the Old World. making the episodes of mountain-building uplifted the Since the Period (360 ­ Appalachians. In succession, the Taconic, 286 million years ago), when reptiles arose, Cacapon River Acadian, and Alleghenian orogenies the plate of eastern North America has been (episodes of mountain building) each tectonically quiet and drifting west-south­ basin produced folding, faulting. and metamor­ west at one inch per year. part phism. Each wave of uplifting was fol­ The Appalachian revolution lasted lowed by ~ complete erosional about 300 million years, and ended about of one of the flattening of the mountains. 300 million years ago. Ever since our moun­ oldest The third orogeny, the Alleghenian, tains have been steadily eroding. Al­ which occurred during the Triassic Period together, Appalachia has been uplifted terrestrial (245-208 million years ago), thrust the Ap­ from the oceans for almost 600 million environments palachian Mountains 4 - 6 miles above sea years, making the Cacapon River basin part level. Our round hills are the eroded rem­ of one of the oldest terrestrial environments on earth." nants of this third orogeny. on earth. By comparison, today's great By the end of the Alleghenian orogeny, mountain ranges, like the Andes, the east coast curvature of the United States Himalayas, and Alps, are merely 50 million­ was hooked onto the Atlantic coast bulge of year-old children. Africa, and Canada was jammed against Europe, with Greenland wedged in be­ tween. Thus, as the Mesozoic Era began (245 million years ago), all of the major landmasses were united as one supercon­ This article was adapted from George's tinent, Pangaea. forthcoming book, The Evolutionary Play By the end of the Triassic (208 million in Appalachia (Mountain Press, Missoula, years ago), Pangaea began to break slowly MT). apart so that by the end of the Period (208-144 million years ago) slight gaps opened between the continents.

Published by Pine Cabin Run Ecological Laboratory Cacapon vol. 4 no. 3, summer 1992 • 9