# Lithium Concentrations in Saline Brines of the Shu-Sarysu Depression
## 4 Results  
The initial research phase focused on investigating salt flats and salt lakes in the Shu-Sarysu Drainage Basin. Field research involving sample collection was conducted on saline brine deposits located in the lower courses of the Sarysu and Shu rivers, which encompassed notable salt lakes like Karakoin, Tamgaly, and Aktuz.  
The salt lakes such as Karakoin, Tamgaly, and Aktuz are covered by a halite crust approximately one meter thick, with the presence of brine. In contrast, the salt flats in the lower courses of the Sarysu River are characterized by a thinner halite crust, the presence of sylvinites, and takyrs (cracked saline soil). Regarding the large salt flat Ashykol, situated in the lower courses of the Boktykaryn stream, it is completely devoid of water.  
The Sarysu River originates from the Kazakh Usak Shokysy (small hills), and during dry years, it can disappear into the sand before reaching the Telikol-Ashykol depression. Some of its tributaries include Jaman Sarysu, Jaksy Sarysu, Atasu, Taldisai, Kurmanak, Taldymanak, Kumdyespe, and Karakengir. The river's primary source of water comes from snowmelt, with 96.6% of its annual flow occurring in April and May, 3.1% in autumn, and 0.3% in winter. It freezes in December and thaws in late March, with its width varying from 15 to 20 m in the upper course to 40 to 60 m in the middle and 150 to 200 m at the mouth. The valley is narrow in the upper course, and the riverbed and banks consist of sedimentary rocks made up of sand and gravel. Vegetation in the area includes desert plants like wormwood, fescue, and sedge, with a predominance of desert landscape near the river mouth.  
Brine samples were collected from wells in the Amangeldy gas reservoir in 2022, situated 170 km north of Taraz city. An asymmetric brachianticline fold, with a steeper southeastern edge, is present at the top of the Upper Tournaisian-Lower Visean productive layers, measuring 7 \(\times\) 3 km. The structure at the top of the Lower Permian productive layer appears as a northeast-oriented brachianticline, measuring 13.5 \(\times\) 7 km with an amplitude of around 400 m. Commercial gas content is associated with deposits from the Upper Tournaisian, Lower Visean, Lower Serpukhovian, and Lower Permian. The reservoir operates under elastic-gas pressure.  
The reservoir waters from Lower Carboniferous productive layers exhibit chloride-sodium-calcium and calcium-sodium compositions, with a salinity reaching up to 317 g/L. They contain significant concentrations of potassium, lithium, rubidium, cesium, strontium,  
Figure 6: Salt flats sampling: (**A**)—Karakoin, (**B**)—Tamgaly, (**C**)—Aktuz, (**D**)—Telikol (base map from Google Earth).  
bromine, and iodine. Meanwhile, waters from the Lower Permian complex are classified as chloride-sodium, with a salinity level of 258.5 g/L.  
As per the laboratory findings from the Akhmedsafin Institute of Hydrogeology and Geoecology, within co-produced formation brines exhibiting salinity levels between 99.5 and 131.5 g/L, the concentrations of trace elements are as follows, in mg/L: lithium--20.5-25.2 and strontium--188.7-237.1.