Carbonate deposition, Pyramid Lake subbasin, Nevada: 3. The use of 87Sr values in carbonate deposits (tufas) to determine the hydrologic state of paleolake systems

Sierran rivers that discharge to the Lahontan basin have much lower (∼4.5‰) δ87Sr values than the Humboldt River which drains northeastern Nevada. The δ87Sr values of tufas deposited during the last lake cycle were used to determine when Humboldt derived Sr entered the Pyramid Lake subbasin. Prior to ∼15,000 yr B.P., the Humboldt River flowed to the Smoke Creek-Black Rock Desert subbasin. During the recession of Lake Lahontan, the Humboldt River diverted to the Carson Desert subbasin. This study has demonstrated that 87Sr can be used to determine drainage histories of multi-basin lake systems if the δ87Sr values of rivers that discharge to the basins are sufficiently different.