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.. Geogr. Fis. ~er Plants. .1010 di due .. Boll. Soc. Runoff and ands. north- ;; 20;-225. !I ELSEVIER GfOMDRPIIOlOGY Geomorphology 18 (997) 91-100 River-derived slackwater sediments in caves along Cheat River, West Virginia Gregory S. Springer 1, J. Steven Kite Department of Geology and Geography, West Virginia University. Morgantown. WV 26507. USA Received 31uly 1995; revised 9 March 1996; accepted 28 March 1996 Abstract The November 1985 Cheat River flood produced overbank:. slackwater deposits in caves of the Cheat River canyon. The deposits include loamy silt, loamy sand to very fine sand, and flotsam. Sediments deposited by the November 1985 flood lie within 1 m of the established high water mark, and are good indicators of peak stage. Prehistoric overbank. slackwater deposits are present in one cave. These sediments are inferred to be ;;:: 400.000 years old and are, therefore, unrelated to the modem Cheat River. Overbank slackwater deposits are poorly preserved in the examined caves, because cave streams actively remove sediments and the warm, moist environment of the caves fosters decay of woody flotsam. Deposits of the 1985 flood are projected to survive at most a few centuries. In contrast, slackwater sediments inferred to be .2:: 400.000 years old are preserved within a cave shielded from significant runoff and biogenic activity. Keywords: Cheat River. West Virginia: overbank sedimentation: slackwaler deposits: cave sedimentation 1. Introduction The surficial geology of the Cheat River drainage basin (Fig. J) in north-central West Virginia includes an incomplete record of very high magnitude floods. The lack of data on very high magnitude floods is critical when we consider events like the catastrophic November 1985 flood. which caused 1.4 billion dol- lars in damage and claimed many lives across the region (Teets and Young, 1985; Carpenter. 1990). On Cheat River, peak flow during the 1985 flood was a record 100,000 ft'ls (5.384 m3 Is), nearly twice the discharge of the previous record flood (Kite and Linton, 1993). 1 Present address: Department of Geology, James Madison University, Harrisonburg, V A 22807. USA. E-mail: ~ac...,gspringe_~~ax ~.acs.jmu.edu Preparation for very high magnitude floods de- pends upon determining accurate flood frequency recurrence intervals and developing flood control and siting plans accordingly (Dunne and Leopold, 1978). Within the Cheat River drainage basin. flood records span the last 150 years (Kite and Linton. 1993; Kite and Torres, 1996). Predicting recurrence intervals and planning for very high magnitude floods is complic~ted by the comparatively short observa- tion span. which allows exceptional events such as the 1985 event 10 skew annual flood distributions. Elsewhere, the observational record has been ex- tended by recognizing and dating paleofloods using slackwater deposits (Kochel, 1988). A lack of pre- 1985 slackwater deposits has made such studies im- practical within the Cheat River drainage basin (Lin- ton, 1992). Caves can offer a unique environment where . __OI99-=-5;5.?X/~?l$.17.~~ C;opyright :0 ]997 Elsevier Science B.V_ All rights reserved. PII SOI69,;;5X(96)OOO:!:!.0 - --------- -- - _u -- >~