TY - JOUR AU - Anh, Phan Lưu AU - Hằng, Hoàng Việt PY - 2017/03/27 Y2 - 2024/03/29 TI - GRANIT NGUỒN GỐC VỎ KHỐI TAM TAO: CƠ SỞ CỦA TUỔI PERMI MUỘN JF - Vietnam Journal of Earth Sciences JA - Vietnam J. Earth Sci. VL - 27 IS - 2 SE - Articles DO - 10.15625/0866-7187/27/2/9401 UR - https://vjs.ac.vn/index.php/jse/article/view/9401 SP - 115-122 AB - Crustal-derived Tam Tao granite formed a small intrusive, which has a simple composition, mainly of granite biotite. From poin of view of petrochemical composition: SiO<sub>2 </sub>(62,68-68,60 %), Na<sub>2</sub>O (2,46-2,85 %), Al<sub>2</sub>O<sub>3 </sub>(13,78-15,06 %), ACNK = 1,0-1,4 and mineralogical composition (biotite±muscovite±garnet±cordierite) this granite is metaluminous and belongs to S-granite type [1]. According to rareelements, Tam Tao granite could be considered asa classic palingen S-granite. Comparing withpalingen granite of alkaline-calcarius type, this granite complex is characterized by low content of Sr and Ba, high content of lithophile elements.Tam Tao granite has an assimetry spectrum REE with (Ce/Yb)<sub>N</sub> ratio about 100-120. The content oflight lantanoid higher 50-200 time than chondrite,while content heavy lantanoid is higher only 10-40 time and has minimum Eu (t.Eu = 0,46-0 ,52). Absolute dating by isotopic Ar-Ar on biotite shows: T = 250,5 ±1 Ma. Nd-Sm dating shows :  ε<sub>Nd</sub>(t) = -10,1, the ratio <sup>147</sup>Sm/<sup>144</sup>Nd has 0,141146, T<sub>Nd</sub>(CHUR) =1,2 Ga. Combining these absolute datings canmake conclusion that the age of Tam Tao granite is 250,5 Ma (corresponds P<sub>2). This granite belongs tospecific S-granite, formed from stable continentalcrust, that is no younger than 1,2 Ga.</sub> ER -