Sabkha Matti is a potential discharge point for regional groundwater systems in the Rub’ al Khali topographic basin of Saudi Arabia. The hydrogeochemical evolution of this sabkha (salt flat) and the underlying aquifers were assessed by using a combination of geological, hydraulic, hydrochemical, and isotopic approaches. A compilation of the geologic structure and lithology in combination with boron isotope data attributed the origin of salinity in the regional aquifers underlying Sabkha Matti to the entrapment of ancient seawater in a coastal lagoon environment during the depositional time of the late Oligocene-Miocene formations. Major ionic constituents and strontium isotope ratios from the trapped paleo-seawater were observed to resemble those obtained from the near-surface sabkha brine. These data, along with hydrostatic head measurements, suggest that the origin of the solutes in Sabkha Matti is associated with brines ascending from the underlying formations. The data also show that solute concentrations in Sabkha Matti are increasing over time through a combination of evaporation, mineral dissolution by recharge, and a density-driven convection mechanism that circulates the solutes. On the other hand, stable isotopes of water (δ¹⁸O, δ²H) and radio isotope data (¹⁴C and ³H) suggest that the existing waters in the sabkha and the underlying aquifers are relatively recent and were recharged during the wet phase in the late Pleistocene-Holocene between 3,200 and 14,000 BP. This study shows that the water and solutes in Sabkha Matti area are a combination from different sources.

Sabkha Matti 是沙特阿拉伯 Rub' al Khali 地形盆地中区域地下水系统的潜在排放点。该 sabkha（盐滩）和下伏含水层的水文地球化学演化是通过结合使用地质、水力、水化学和同位素方法进行评估的。地质结构和岩性与硼同位素数据相结合的汇编将 Sabkha Matti 下方区域含水层中盐度的起源归因于渐新世晚期 - 中新世晚期地层沉积期间古代海水在沿海泻湖环境中的滞留。观察到捕获的古海水中的主要离子成分和锶同位素比与从近地表 sabkha 盐水中获得的相似。这些数据，连同静水压头测量，表明 Sabkha Matti 中溶质的起源与从下伏地层上升的盐水有关。数据还表明，通过蒸发、补给引起的矿物溶解以及使溶质循环的密度驱动的对流机制，Sabkha Matti 的溶质浓度随着时间的推移而增加。另一方面，水的稳定同位素（δ¹⁸ O, δ ² H) 和放射性同位素数据（¹⁴ C 和³ H）表明，sabkha 和下伏含水层中的现有水域相对较新，并且在 3,200 至 14,000 年的晚更新世-全新世的湿期补给BP。这项研究表明，Sabkha Matti 地区的水和溶质是来自不同来源的组合。