The Oligocene Barail Sandstones of Surma basin from parts of Champhai District of Mizoram, northeast India has been studied for their tectono-provenance setting using petrography and geochemistry. The studied sandstones are poor to moderately sorted, subarkosic to sub-litharenite and show dominance of quartz (avg. 54.46%) followed by feldspars (avg. 7.22%), rock fragments (avg. 4.98%), mica (avg. 5.89%), matrix (avg. 14.47%) and cement (avg. 12.98%). Dominance of polycrystalline and undulatory monocrystalline quartz indicates contribution from medium grade metamorphic sources, primarily of granite gneisses. High concentration of SiO₂ with moderate to low concentration of Al₂O₃, Fe₂O₃, MgO, Na₂O and K₂O resembles the composition of upper continental crust. Moreover, moderate to high concentration of Th and V, depleted value of Ni along with TiO₂/Zr suggests derivation of sediments from felsic sources. The ratios of Eu/Eu* (avg. 0.63) and La_N/Lu_N bears resemblance with the upper continental crust. Overall analyses show that the sediments were derived from the felsic terrain of neighbouring orogens probably represented by granite-gneisses and have undergone a moderate degree of weathering (avg. values of CIA: 70.20, CIW: 81.03, PIA: 77.63, WIP: 38.45, ICV: 1.06, I_w = 2) in a semi-humid to humid climatic conditions [Q_p/(F + RF):Q_t/(F + RF) = 0.20].

中文翻译：

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苏尔马盆地渐新世巴里砂岩的岩石学和全岩石地球化学：对构造起源和古气候条件的启示

利用岩石学和地球化学研究了印度东北部米佐拉姆邦占邦地区部分地区的苏尔马盆地的渐新世巴里尔砂岩的构造背景。所研究的砂岩差至中等分类，亚黑云岩至次石质，显示出石英（平均54.46％），长石（平均7.22％），碎石（平均4.98％），云母（平均5.89％）的优势。 ），基质（平均14.47％）和水泥（平均12.98％）。多晶和起伏的单晶石英的优势表明来自中等等级变质源的贡献，主要是花岗岩片麻岩。高浓度SiO ₂和中低浓度的Al ₂ O ₃，Fe ₂ O ₃，MgO，Na ₂O和K ₂ O类似于上层大陆壳。此外，中等浓度到高浓度的Th和V，Ni的贫化以及TiO ₂ / Zr都表明来自长英质来源的沉积物。Eu / Eu *（平均0.63）和La _N / Lu _N的比率与上地壳相似。总体分析表明，这些沉积物来自可能由花岗岩-片麻岩代表的邻近造山带的长石质地形，并且经历了中等程度的风化（CIA的平均值：70.20，CIW：81.03，PIA：77.63，WIP：38.45， ICV：1.06，I _w = 2）在半湿到湿的气候条件下[Q _p /（F + RF）：Q _t /（F + RF）= 0.20]。