Mechanism for mercury deposition at Ngawha Springs, New Zealand

Abstract

Elemental mercury is the source of mercury for current cinnabar deposition at Ngawha Springs, New Zealand. The deposition of cinnabar is strictly weather dependent for most of the area, occurring only during and just after rain. During these periods pH and Eh drop favouring oxidation of mercury at suitable sites; such conditions prove to be necessary and sufficient from laboratory experiments.