A 137 cm sediment core from Fog Lake, a small upland basin that was not glaciated during the Late Wisconsinan, reveals the following stratigraphic succession: (I) basal diamicton, (II) laminated silts, (III) compacted dewatered gyttja, (IV) stratified minerogenic sediments, and (V) overlying gyttja. Units I—III, and most of unit IV, were deposited prior to the Holocene; unit V represents approx...

The organic matter contents of sediments deposited in Lakes Erie and Ontario contribute to the record of changes in the lake watersheds and aquatic ecosystems which have resulted from European settlement and cultural eutrophication of these systems over the past two centuries. Compositions of n-alkanes and n-alkanoic acids extracted from lake sediments track the clearing of the original natural...

Sediments from the Antarctic continental margin may provide detailed palaeoenvironmental records for Antarctic shelf waters during the late Quaternary. Here we present results from a palaeoenvironmental study of two sediment cores recovered from the continental shelf ofT Mac. Robertson Land, East Antarctica. These gravity cores were collected approximately 90 km apart from locations on the inne...

Reliable sedimentation histories are difficult to obtain in sandy or anthropogenically impacted coastal systems with disturbed sediment profiles and low initial radionuclide activities. This study addresses the problem using radionuclides in sediment cores from Naples Bay estuary, Florida, USA. Non-steady sedimentation and nuclide scavenging processes are shown to limit application of tradition...

BACKGROUND: Public laws regulating dredged material disposal (Section 404 of the Clean Water Act and Section 103 of the Ocean Dumping Act) require ecological evaluation prior to the permitting of operations. Assessment of the potential for bioaccumulation of chemical contaminants in sediment, including heavy metals, is required as part of the evaluation process. Metals can represent significant...

Aquatic environmental deterioration is becoming a serious problem due to rapid urbanization and economic development, particularly in developing countries. As two important components of the aquatic environment, water quality and sediment pollution are widely considered to be concerns; however, they are considered separately in most cases. The relationship between water quality and sediment pol...

background: the radioactivity levels in sediment and rock samples of i̇kizdere and kaptanpaşa valley have been determined. to our knowledge, there seems to be no information about radioactivity level in the i̇kizdere and kaptanpaşa valley sediments and rocks so far. materials and methods: the average radium equivalent activity (raeq), the total absorbed dose rate (d), the external risk index (hex...

Heavy metals and some organic substances which are drained into the aquatic environments and cannot be decomposed or eliminated will sink into sediments or find their way into different levels of food chain. Bioaccumulation is the process of continuous deposition and aggregation of these substances into the body tissue of living organisms. Mollusks are remarkably appropriate to be used as bio-i...