Geochemistry Data of the Nadergul Granodiorite of the Late Archean Hyderabad Granite Batholith, part of Eastern Dharwar Craton, India; Implications for Composition of the Lower Continental Crust.

The Nadergul granodiorite (NG), is a part of Hyderabad Granite Batholith (HGB), exposed at ground level covering an area of 6 km2. Field observational data suggests that the NG is involved in the magma mixing mingling process. Petrographical data shows holocrystaline, phaneritic, coarse grained, inequigranular, mesocratic characteristics, essentially consists of quartz, orthoclase, plagioclase and microcline. The common accessory minerals are hornblende, biotite, clinopyroxene, zircon, fluorite, apatite and opaque. The myrmekitic texture is the most common intergrowth texture which seems to be magmatic origin. Geochemical data suggest that the NG is metaluminous and show calc-alkaline trend. It is charecterised by SiO2 content ranging from 63.55 % to 64.54%, moderate alkali content (Na2O + K2O = 5.6%), relatively high MgO content ranging from 2.8 % to 3.5 %. The total CaO-Na2O-K2O content ranges from 9.5 % to10.4 %. The normalised REE patterns show LREEs enrichment with slight negative europium anomaly. The High Field Strength Elements such as Zr (67.3 to 114.3 ppm), Y (21.1 to 30.1 ppm), Nb (6.3 to 8.5 ppm) and Th (8.4 to 13.8 ppm) are relatively enriched. The granodiorite is I type, falls in the Volcanic Arc Granitoid (VAG) field in tectonic discrimination diagram

纳达尔古尔花岗闪长岩（NG）属于海得拉巴花岗岩地块（HGB），在地表露出，覆盖面积达6平方公里。实地观测数据表明，NG参与了岩浆混合作用过程。岩石学数据揭示其具全晶质、显晶质、粗粒、不等粒、中酸性特征，主要由石英、正长石、斜长石和微斜长石组成。常见的副矿物包括角闪石、白云母、斜方辉石、锆石、氟石、磷灰石和不透明矿物。菌丝状构造是最常见的共生结构，似有岩浆成因。地球化学数据表明，NG为金属铝质，显示出钙碱性趋势。其二氧化硅含量介于63.55%至64.54%之间，碱含量适中（Na2O + K2O = 5.6%），氧化镁含量相对较高，介于2.8%至3.5%之间。总氧化钙-氧化钠-氧化钾含量介于9.5%至10.4%之间。标准化稀土元素（REE）模式显示轻稀土元素（LREE）富集，略呈负铕异常。高场强元素如锆（67.3至114.3 ppm）、钇（21.1至30.1 ppm）、铌（6.3至8.5 ppm）和钍（8.4至13.8 ppm）相对富集。该花岗闪长岩属于I型，在构造判别图中位于火山弧花岗岩（VAG）区域。