modification of freeze-core technology for collecting granular fluvial sediment samples

• Published in: Environmental earth sciences Vol. 71; no. 9; pp. 4149 - 4156
• Main Authors: Smith, D, Elmore, A. C
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.05.2014; Springer Berlin Heidelberg; Springer; Springer Nature B.V
• Subjects: Biogeosciences; Carbon dioxide; Cohesive sediments; Contaminated sediments; Contamination; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Science and Engineering; Exact sciences and technology; field experimentation; Fluvial sediments; Geochemistry; Geology; Heavy metals; Hydrology/Water Resources; Laboratory tests; Marine and continental quaternary; Original Article; Pollution, environment geology; Samplers; Sampling methods; sediment contamination; Sediment samplers; sediments; Surficial geology; Terrestrial Pollution; Water pollution; Artificial freezing; Sediment; Freeze-core; Heavy metals; Tailings; Coarse grain; pebbles; heavy metals; testing; fine-grained materials; boulders; silt; pollution; clay; contamination; gravel; sedimentary rocks; drill cores; fluvial environment; sand; depth; freezing; coarse-grained materials; tailings; clastic rocks
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-013-2805-1

The presence of coarse-grained sediment can potentially reduce the effectiveness of conventional sampling methods in recovering fluvial sediments. A modification to freeze-core technology was used to collect fine to coarse sands, silts, and clays in fluvial deposits that contain significant amounts of gravels, cobbles, and boulders for the purpose of characterizing the extent of heavy metal contamination. This modification uses either a 2.5 or 2.9 cm diameter by 30-cm- long finned mechanical or hand-driven samplers. The sediment is frozen to the outside of the sampler by injecting liquid CO₂ into the sampler. The fins protect the sample from coarse material upon removal. Field testing and laboratory testing of the method were completed to establish a methodology and assess possible cross contamination of the sediment layers during the driving of the sampler. The results indicated that this method is effective for recovering non-cohesive sediment samples at depths up to 6 m for the purpose of characterizing the extent of heavy metal contamination.