ABSTRACT
Turnover events influence the chemistry of pit lake water by circulating dissolved oxygen and controlling redox conditions at depth. To investigate the role of lake morphology on turnover and lake chemistry, three pit lakes that varied only in morphology were studied. Duncan, Blackhawk and Blowout lakes in Utah, have corresponding depths of 9, 26.5, and 71 m. Temperature, dissolved oxygen, conductivity, and water chemistry data were collected from each lake between 1997 and 1998. Results indicate holomictic behavior in the largest lakes due to the absence of strong vertical density gradients, while Duncan Lake is believed to circulate throughout the year owing to its shallow depth. Blackhawk and Duncan lakes behave similarly to other pit lakes of equivalent morphology, while Blowout Lake is unique among pit lakes with very high relative depths. The presence or absence of vertical density gradients may be more influential toward meromictic behavior than morphology alone.
