CAJ | 학술논문

粤西阳春地区马山二长闪长岩强烈富集K、Sr和LREE，(87Sr／86Sr)；≈0.7046，εNd(t)≈+1；岗尾-轮水岩体较富集K、Rb、Th和LREE，(87Sr／86Sr)：≈0.7063，εNd(t)≈-2；石岩体较富集Sr，K、Rb、Th和LREE相对较低，(87Sr／86Sr);=0.7084～0.7089，εNd(t)≈-6。马山岩体来源于大离子亲石元素(ULE)和LREE富集的交代地幔；岗尾-轮水岩体来自于放射成因Sr、Nd同位素组成略高或交代时间略早的富集交代地幔，并且经历了明显的结晶分异作用；石岩体则很可能是前存下地壳底垫基性岩重熔形成的。从早侏罗世到早白垩世，南岭西部的岩浆成分和源区的规律性变化反映了区域软流圈地幔上涌和岩石圈伸展-拉张-减薄的演化过程。
월서양춘지구마산이장섬장암강렬부집K、Sr화LREE，(87Sr／86Sr)；≈0.7046，εNd(t)≈+1；강미-륜수암체교부집K、Rb、Th화LREE，(87Sr／86Sr)：≈0.7063，εNd(t)≈-2；석암체교부집Sr，K、Rb、Th화LREE상대교저，(87Sr／86Sr);=0.7084～0.7089，εNd(t)≈-6。마산암체래원우대리자친석원소(ULE)화LREE부집적교대지만；강미-륜수암체래자우방사성인Sr、Nd동위소조성략고혹교대시간략조적부집교대지만，병차경력료명현적결정분이작용；석암체칙흔가능시전존하지각저점기성암중용형성적。종조주라세도조백성세，남령서부적암장성분화원구적규률성변화반영료구역연류권지만상용화암석권신전-랍장-감박적연화과정。
Trace elements and Sr-Nd isotopic data are presented for theMesozoic intrusives in the Yangchun Basin, western Guangdong. The Mashan monzo-diorites are characterized by strong enrichment of K, Sr and LREE, and nearly chondritic isotopic compositions with (87Sr/86Sr)i ≈ 0. 704 6 and εNd(t) ≈ 1. The Gangwei-Lunshui quartz monzonites and granodiorites are moderately enriched in K, Sr, Rb and LREE, but strongly enriched in Th. They have enriched Sr-Nd isotopic compositions with (87Sr/86Sr)i ≈ 0. 706 3 and εNa(t) ≈ - 2. The Shilu granodiorites are enriched in Sr, but less enriched in K, Rb, Th and LREE. They are characterized by more radiogenic Sr-Nd isotopic compositions with (87Sr/86Sr)i = 0. 708 4 ～ 0. 708 9 and εNa(t) ≈ -6. It is concluded, in terms of geochemical and Sr-Nd isotopic features, that the Mashan monzo-diorites were generated from a metasomatism mantle source strongly enriched in LILE and LREE, while the Gangwei-Lunshui plutons were derived from a metasomatism mantle source with more radiogenic Sr-Nd isotopic compositions followed by extensive crystal fractionation. The Shilu pluton was formed by re-melting of pre-existing underplating mafic rocks at the lower crustal level. The secular variation of magma compositions was mostly attributed to the upwelling of asthenosphere and extension of overlying lithosphere in the Nanling Region during the early Jurassic to early Cretaceous.