Sedimentation in Cayuga Lake, New York1

Abstract

The sediments in the southern half of Cayuga Lake are generally banded, The couplets arc ca. 2 cm thick at a depth of 1.5 m in the sediment and contain finer laminae approximately 1 mm thick. Major bands can be correlated over a distance of I9 km and apparently correspond to recorded periods of unusually rapid runoff or high lake levels. It is concluded that the deposition of the couplets is controlled by annual variation in the supply of allochthonous organic detritus and elastic sediment. A total of 2 x 1O'l g dry weight of elastic sediment enters the lake annually through its tributaries.Turbidity currents apparently are responsible for the distribution of a large fraction of this material in the lake. INTJ3ODUCTTIONThe geology, geography, and physical limnology of Cayuga Lake, the second largest of the Finger Lakes of central New York State, have been outlined by Henson, Bradshaw, and Chandler ( 1961) . The lake ( Fig. 1) averages 2.8 km wide, has a maximum depth of 133 m, and lies in a glacially deepened valley with oversteepened sides. Relief is greatest in the southern part of the watershed.As a result of selective glacial erosion acting parallel to, the long axis of the lake, many of the streams discharging into the lake occupy hanging valleys. The major creeks in the watershed all enter the southern quarter of the lake and together drain more than half the watcrshed ( Henson et al, 1961). The remaining watershed is drained almost entirely by high-gradient streams, many of them intermittent. A few low-gradient streams enter the lake near its northern extremity.In 1940, a sediment core containing distinct horizontal bands was recovered fro,m the lake by J. Wells (personal communication alternating with paler gray ones, was obtained in 1959 by D. Livingstone and J. Vallentyne (J. Vallentyne, personal communication ) . The origin of these bands and their depositional rate are discussed. If the average length of time necessary for the deposition of a couplet o,f a dark and pale band can be determined, sediment samples can be dated by couplet counts. Lake history studies or studies of postdepositional changes in the sediment can then be placed in an absolute temporal framework.In previous studies of banded sediments, the vertical distribution o,f microfossils within the couplets frequently provided critical evidence to establish the time necessary for deposition ( Nipkow 1920; Welten 1944; Miiller 1962; Gross et al. 1963; Tippett 1964). Unfortunately, in Cayuga Lake, diatom and zooplankton rcmains are too dilute to be concentrated suf ficicntly for statistical study. Little work has been done with pollen because the sediment is primarily allochthonous in origin. Andersen ( 1957) has demonstrated that the amount of secondary pollen contamina ting certain interglacial sediments in Jutland is directly correlated with the amount of allochthonous elastic sediment in his samples.Ileer (1876) 1956>, and Seihold ( 1958). METIIODSTo dctcrminc the distribution of banded sediments in the lake, over 80 c...

Seismic stratigraphy of the Finger Lakes: A continental record of Heinrich event H-1 and Laurentide ice sheet instability

“…In contrast, sequence VI littoral zone (nearshore) sediments are coarser grained massive sands and carbonate-rich marls. Ludlam (1967) examined 72 piston cores (average length, 3 m) from the southern half of Cayuga Lake at water depths exceeding 45 m. All of his cores were recovered from our sequence VI, which significantly exceeds 3 m in thickness throughout the southern half of Cayuga Lake. Ludlam found that the near-surface sediments are distinctly "banded," with centimeter-scale couplets consisting of dark, fine-grained bands separated by light silt and clay layers.…”

“…Ludlam found that the near-surface sediments are distinctly "banded," with centimeter-scale couplets consisting of dark, fine-grained bands separated by light silt and clay layers. Ludlam (1967) interpreted these couplets as annual layers representing spring flood and nonflood conditions.…”

The dominant processes of sediment distribution and focusing in a small, eutrophic, monomictic lake

“…Sedimentation in Kamloops Lake (Pharo and Carmack 1979) is totally dominated by this process. Ludlam (1967) used the varve thickness in the sediments to show that river plume sedimentation is a major depositional process in localized areas of Cayuga Lake. The area of a lake basin dominated by this process can be estimated from the simple formula given by Hakanson and Jansson (1983).…”

“…The definitive evidence for this process comes from lakes with laminated sediments (e.g. Ludlam 1974;Pickrill and Irwin 1983;Sturm and Matter 1978). However, Wetzel and Manny (1978) showed that slumping had occurred to produce intrusions of material with an older 14C date than sediment above and below it in a core.…”

Role of calcium carbonate precipitation in lake metabolism

“…These studies have provided valuable information on the physicochemical quality, as well as the quantity of seston reaching the bottom of lakes (Reissinger, 1932;Scott and Miner, 1936;Wilson, 1936;Rossolimo, 1937;Pechlaner, 1956;Hohne and Olrich, 1966;Ludlam, 1967;Heinemann, Rausch and Campbell, 1968;Emery, 1973).…”