Geochemical Features Of The Tarim Lip Rocks And Implications For The Magma Evolution

The various igneous rocks in the Tarim LIP can be divided into five major units according to their geochemical and isotopic characteristics, including three earlier erupted basalt groups and two later emplaced intrusive rock units. There is an evolutional trend of the Sr Nd Hf isotopes from enriched mantle components in the earlier basalts towards depleted mantle components in the later intrusive rocks. The three basalt groups in the Tarim LIP have experienced variable degrees of crustal contamination, whereas the intrusive rocks are generally not contaminated. After removing the interference of crustal contamination, the uncontaminated parental magmas of various Tarim LIP rocks exhibit a wide range of ENd(t) values (ca. 5 to 5), reflecting source isotopic heterogeneity, which may be a consequence of plume lithosphere interaction during the generation of the Tarim LIP.