Table 1 Major (wt.%) and trace (µg/g) element compositions of the Li-bearing (Li-rich) fine-grained detrital rocks from Baitianba Formation

The analytical procedures were conducted in compliance with a suite of standardized methodologies: "Chemical Analysis of Silicate Rocks (GB/T 14506)," "Chemical Analysis of Limestone and Dolomite (GB/T 3286)," "Chemical Analysis of Limestone, Quicklime, and Hydrated Lime for Construction Materials (GB/T 5762)," and "Analytical Methods for Regional Geochemical Samples (DZ/T 0279)." A burette (acid-style, 50 mL) was selectively employed as required. The concentrations of major element oxides were determined using a "YA172008172" spectrophotometer, a "Hitachi Z-2300" flame atomic absorption spectrophotometer, and a "Thermo Fisher iCAP 7400" inductively coupled plasma optical emission spectrometer (ICP-OES). The analytical error for major elements was generally kept below 5%.Trace elements, including La–Lu, Y, Sc, Zr, Th, Sr, Ba, Co, Ni, Hf, U, Ta, Li, Be, Cs, Cu, Pb, and Bi, were analyzed using a "Thermo X SERIES II" inductively coupled plasma mass spectrometer (ICP-MS). The elements Nb, Ga, V, Cr, Rb, Zn, and Mn were quantified by a "Thermo iCAP 7400" ICP-OES. Se and Ge were measured with an "AFS-8520" atomic fluorescence spectrophotometer manufactured by Beijing Haiguang Instrument Co., Ltd. With the exception of Zr, Hf, U, and Ta, which were analyzed according to method "GB/T 14506.30—2010," all other trace elements were determined using the relevant procedures specified in "DZ/T 0279." The analytical error for trace elements was typically controlled within 5%.