南极洲万达盐湖水中方解石饱和指数的垂直变化及其控制因素

南极洲万达盐湖为饱和方解石湖水。计算出的方解石饱和指数随水深增加而变化。在Ca^(2+)及HCO_3^-活度值均一的上部氧化环境湖水中,pH及溶解氧(DO)是控制该变化的主要因素,在下部还原环境湖水中,Ca^(2+)及HCO_3^-的活度对方解石的饱和指数SI的变化起主要作用。这充分揭示了湖底部近代沉积物中分布较多方解石矿物的原因。

南极洲赖特谷万达盐湖中铬的垂直迁移

南极洲万达湖湖水上部为氧化环境,铬浓度较低,Cr^(6+)占主导地位,主要以CrO_4^(2-)形式存在;下部为还原环境,铬浓度高,Cr^(3+)为主,以Cr(OH)_2^+和Cr(OH)^(2+)形式存在。湖水中锰、铁的氧化物及氢氧化物颗粒对铬离子的吸附和释放过程,控制了湖水铬浓度的变化。

TRACE METALS IN VANDA LAKE IN ANTARCTICA——A VERTICAL MIGRATION MODEL OF TRACE METALS IN CLOSED BASIN

Vanda Lake, a typical dimictic CaCl_2 type salt lake, is located in the Wright Valley inAntarctica. Based on the chemical and physical features of the salt lake water, the authorsdiscussed the vertical geochemical distribution of Fe, Mn, Pb, Cr, Cu, Co, Ni, Cd in the lake,and their vertical migration in lake waters, and have tried to set up a model of vertical mi-gration of these trace elements in the water of a closed chloride type salt lake.