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<br />~--- <br /> <br />96 <br /> <br />G.s. Springer. 1.5. Kilt' /Geomorphnlogy 18 (}997J 9J-]OO <br /> <br /> <br />Svmbol Kev <br />Vadose Facies <br /> <br />~ Gravity Deposits <br /> <br />o OvertlBnk <br /> <br />ca Cave Stream <br /> <br />Fig. 4. Facies map of Coliseum Rapids and Coliseum Tube caves. SJackwater deposits consist of loamy silts. Stratigraphic colwnn GS-92-9 <br />displays 1985 overbank sediments atOp phreatic facies sediments. <br /> <br />and is otherwise devoid of macroorganics. The upper <br />two sands are separated from the underlying sand by <br />a mat of decomposing macroorganics. This mat is <br />similar to one observed at GS-92-9 in Coliseum <br />Rapids Cave (Fig. 4) and may represent decompos- <br />ing flotsam from the 1985 flood or leaf liner brought <br />into the cave by resident Appalachian wood rats <br />(Neotol1Ul sp.) prior to the flood. <br />Thin, blanket-like deposits of mUfl-cracked silts <br />are found in the northern passages of the cave. The <br />silts are laminar to bioturbated and less than 1 cm <br />thick. The silt deposits are present beneath ledges <br />and areas not subject to SCOUT by water entering from <br />the overlying valley wall. The silts contain abundant, <br />macerated organics and were deposited by the 1985 <br />flood. <br />Coliseum Rapids Cave: This cave is 14 m above <br />the river (Fig. 4). The entire cave was inundated by <br />the 1985 flood. A small surface stream flows into the <br />northern part of the cave from a 50 m wide, <br />bedrock-supported terrace. During exceptionally wet <br />periods, the surface stream cascades over a 7 m high <br />waterfall and a portion of the water enters the two <br /> <br />StratigrBphic Column <br />GS-92-9 <br /> <br />wO <br />a: <br />~2 <br />w <br />::; <br />;::4 <br />z <br />w <br />U6 <br /> <br /> <br />Silt Loam <br />worm burrow <br /> <br />.~. <br /> <br />fungal-mat <br />Sandy Loam <br />Diamicton <br /> <br />~. <br /> <br />Bedrock <br /> <br />southeastern entrances of the cave. Cobbles inside <br />these entrances display imbrication into the cave. <br />The 1985 flood washed abundant plastic refuse <br />into the cave, along with considerable amounts of <br />macroorganics. The largest piece of woody debris is <br />a 1.3 m long, 0.3 m diameter log found J3 m inside <br />the cave. A I m high, 0.6 m wide plastic trash can <br />lies 14 m inside the cave, wedged in a passage <br />constriction. The highest flotsam in the cave is styro- <br />foam balls (2-t0-4 mrn in diameter) deposited on the <br />cave walls 15 m above Cheat River. These incon- <br />spicuous balls are held to the cave walls by water <br />surface tension and thin fIlms of macerated organics <br />and silt. The halls provide the most reliable evidence <br />of water levels during the 1985 flood. Were it not for <br />the balls, the films of macerated organics and silts <br />might otherwise be attributed to vadose flow from <br />the slopes above. <br />Isolated patches of bioturbated silts (s 5.5 cm <br />thick) are observed near GS-92-9 (Fig. 4). The silts <br />are bioturbated by worms and contain abundant mac- <br />erated organics. The silts are deposited atop sedi- <br />ments of the phreatic facies. A 3 to 5 mrn thick mat <br /> <br />., <br /> <br />S-92-9 <br /> <br />:-Cliff FBCe <br /> <br />o <br /> <br />5 <br /> <br />10m <br />, <br /> <br /> <br />o <br /> <br />20 <br /> <br />w <br />a: <br />w <br />t:i 40 <br />:; <br />;:: <br />z <br />w <br />U 60 <br /> <br />80 <br /> <br />Fig. 5. 51 <br />Slackwatcr <br />tion. Fine: <br /> <br />of decor <br />The mat <br />are not I <br />terrace, ' <br />of these <br />Cornl <br />m above <br />unconfol <br />cJBSt-su~ <br />streams I <br />The silt> <br />directior <br />gravel it <br />units art <br />(Fig. 5). <br />The J <br />fJoodil\g <br />streamS. <br />cretion <br />accretiol <br />documel <br /> <br />6, Prest <br /> <br />Linte <br />tributaI) <br />tween F <br /> <br />t <br /> <br />