Highly variable sediment distribution in shallow, wind-stressed lakes: a case for sediment-mapping surveys in paleolimnological studies

Citation data:

Journal of Paleolimnology, ISSN: 0921-2728, Vol: 15, Issue: 3, Page: 207-221

Publication Year:
1996
Usage 9
Abstract Views 5
Link-outs 4
Captures 1
Exports-Saves 1
Citations 35
Citation Indexes 35
Repository URL:
https://digital.usfsp.edu/fac_publications/2438; https://login.ezproxy.lib.usf.edu/login?url=https://link.springer.com/content/pdf/10.1007%2FBF00213041.pdf
DOI:
10.1007/bf00213041
Author(s):
Whitmore, Thomas J.; Brenner, Mark; Schelske, Claire L.
Publisher(s):
Springer Nature; Springer Nature America, Inc; Springer; Digital USFSP
Tags:
Agricultural and Biological Sciences; Earth and Planetary Sciences; Sediments; Paleolimnology; Sediments; Paleolimnology; Biology
article description
We examine sediment distribution patterns in seven Florida lakes and discuss implications for paleolimnological studies of shallow, subtropical lakes. The study lakes are highly productive and should exhibit thick organic sediment deposits, but organic sediments are often grossly lacking because basins are shallow, and frequent mixing, lack of stratification, and warm temperatures lead to breakdown of organic material. Organic sediment distribution patterns are highly variable. We observe three types of distribution patterns. When organic sediments are abundant, there may be (1) uniform sediment distribution. In lakes lacking organic sediments, there are (2) distribution to deeper areas if present, or (3) distribution to peripheral areas and embayments when deep waters are absent. We advocate the use of systematic mapping surveys to locate optimal coring sites for paleolimnological studies of shallow, wind-stressed lakes. Because numerous factors affect diagenesis and sediment redistribution, sediment abundance and location are not predictable. Sediment chronologies may be discontinuous and disturbed even in accumulation zones. The extent to which sedimentary records are discontinuous or disturbed is not quantifiable in any practical manner.Pb andCs radioisotopic profiles provide qualitative evidence of the degree of stratigraphic disturbance. Total excessPb inventories show that sediments are focused into depositional zones when sediment distribution is uneven. ExcessPb inventories are not informative about the completeness of sedimentary profiles unless small inventories suggest discontinuous sedimentation or erosional events. We present examples of disturbed and undisturbed profiles, and discuss how we use radioisotopic and geochemical evidence, and multiple cores to assess stratigraphic continuity. © 1996 Kluwer Academic Publishers.