Mercury colonial footprint in Darién Gulf sediments, Colombia

• Published in: Environmental earth sciences 2014-02, Vol.71 (4), p.1781-1789
• Main Authors: Rúa, Alex, Liebezeit, Gerd, Palacio-Baena, Jaime
• Format: Article
• Language: English
• Subjects: Anthropogenic factors; Atmospherics; Biogeosciences; Central America/Caribbean; Coastal; Coastal morphology; Coastal zone; Deposition; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Science and Engineering; Exact sciences and technology; Geochemistry; Geology; Gulfs; Holocene; Hydrology/Water Resources; Marine and continental quaternary; Mercury; Mercury (metal); Ocean floor; Original Article; Pollution, environment geology; Sediments; Surficial geology; Terrestrial Pollution; Trace elements; Trapping; Water circulation
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-013-2583-9

The mercury (Hg) deposition history in the Darién Gulf is reconstructed from three sediment cores spanning up to 1,000 years. Knowledge on the contribution to global Hg budget from the Caribbean is limited. Patterns of water circulation, sediment deposition rates, cataclysmic atmospheric inputs, and post-depositional migration have been considered in Hg trapping in the seabed. The sediment delivery rates to the coastal zone over the Late Holocene have increased from 0.2 to 1 cm year −1 owing to anthropogenic influence. This alteration took the form of geological effects, like coastal morphology change, that played a major role in Hg downcore signal preservation. Natural background Hg levels in Southern Caribbean sediments (77.0 μg kg −1 ) are up to three times higher than preindustrial signals at other latitudes, because of volcanic contributions from the Pacific ring of fire. Enrichment factors rose from 0.9 to 1.5 (70.1–113.5 μg kg −1 ) within profiles related to Hg usage since Spanish colonial times between the calendar years 1550 and 1811.