Metasilicate-rich groundwater could meet the high demand of the international community for high-quality water. In order to comprehensively analyze the genetic mechanism of metasilicate-rich groundwater, and help human communities effectively exploit and utilize high-quality water resources, taking the Ji’nan rock mass area as an example, this study carried out systematic research on the spatial distribution and genetic mechanism of the metasilicate-rich groundwater Based on the regional hydrogeological conditions, the influencing factors on the spatial distribution characteristics of the metasilicate-rich groundwater in the study area were systematically sorted out by means of petrogeochemistry, hydrochemistry, and chemical weathering index analysis, and the accumulation mechanism of the metasilicate-rich groundwater was discussed from the perspective of water-rock interaction. The results show that: (1) On the northwest side and part of the northeast side of Ji’nan rock mass, the metasilicate content of the groundwater samples exceeded 25 mg/L; the metasilicate content on the south, west, and east sides were relatively low; (2) Ji’nan rock mass is mainly composed of gabbro easily weathered, with high SiO₂ content and high weathering degree showing obvious characteristics of desilication. FeS₂ developing along the contact zones between the rock mass and surrounding rocks was easily oxidized to form H₂SO₄, which enhanced the solubility of silicate minerals in the groundwater. Ji’nan rock mass was located in the low-lying position of the monocline structure, which presented better water conservation and recharges conditions. The above factors resulted in the metasilicate-rich groundwater accumulating in the area of Ji’nan rock mass and showed different spatial distribution characteristics.

In this study, the periodic evolution and characteristics of the Palaeogene tectonic activity in the deep-water area of the Qiongdongnan Basin were revealed through the identification and analysis of the regional angular unconformity and the characteristics of the periodic fault activity. In addition to a comprehensive analysis of the controls on sedimentary paleogeomorphologic background, sedimentary characteristics and evolution by periodic rifting are systematically discussed. The studies have shown that the tectonic activity of the Paleogene Qiongdongnan Basin underwent three separate rifting phases: Phase-I (T100–T80), Phase-II (T80–T70), and Phase-III (T70–T60). The early phase of rifting was dominated by strong differential block-fault settlement, while the later phase was gradually replaced by homogeneous settlement controlled by regional depressions and a small amount of fault activity, characterized by a weak-strong-weak evolution. From Phase-I to Phase-III, the paleo-geomorphology margin changed from a large gradient to a gentle gradient, the subsidence center moved from the initial basin margin to the later basin center, and the basin-marginal fans extended finitely before developing on a large lateral scale in the later Phase-III. Analyzing the characteristics of periodic tectonic evolution and sedimentation response is important for petroleum exploration in marine basins, such as locating economic reservoirs.