Mercury Dispersal to Arroyo and Coastal Sediments from Abandoned Copper Mine Operations, El Boleo,

摘要: Abstract Evidence for mercury dispersal in an aridcoastal region of central Baja California (Mexico) suggeststhat abandoned copper mining operations are a noticeablesource the environment. There is generallyelevated level alluvium arroyos through-out district (0.14–0.18 mg kg -1 ). In firstseveral dozen meters surrounding two biggest mines,mercury levels range from 0.26 to 3.16 , forming ahalo anomalously high concentrations. The coastalmarine sediments, particularly those close coppersmelter town Santa Rosali´a, also display somemercury enrichment.Keywords Mercury halo Abandoned mines El Bole´o Coastal marine sedimentsMercury has long been recognized as potentially valuabletracer when prospecting various types mineraliza-tion, primarily because many its forms naturally displayhigh vapor pressure. Saukov (1946) was main earlyproponent, recognizing that this attribute could produceanomalies around certain mineral deposits. Sincethe 1960s, Hg become important geochemicalexploration tool water, vegetation, soil, bog, streamsediment, and rock studies (Lentz 2005). Weathering ofabandoned metal ore may produce noticeable Hghalo can be traced by examination sediments inthe local drainage basin. While mine pollution hasbeen extensively studied temperate cold regions, theimpact activities on terrestrial eco-systems arid semi-arid regions received muchless attention (Shumilin et al. 2000).The aim present study trace dis-sipation under conditions,namely at miningdistrict near east-central California(Mexico). Intensive smelting werecarried out there between 1885 1985. According toWilson Rocha (1955) Conly (2005), thecopper deposits were formed within geologic formationsrelated Miocene continental rifting (approx. 11 Ma)during early stages opening Gulf Cal-ifornia. area characterized laterally extensivestrata laminated claystone breccia thatcontain finely disseminated Cu–Co–Zn sulfides oxi-dized (Conly 2005).The Rosali´a affected bymaterial discharged serve relevantindicator dissipation. thearroyo below includes waste products thesmelter.