The tholeiite with late trassic age has been found in helanshan area on the north part of western margin of ordos basin 在盆地西缘北部贺兰山地区，发现典型拉张环境形成的拉斑玄武岩，测年时代为晚三叠世。
2.
By studying , the main conclusions have been achieved as follows : i . the volcanic rocks , as the result of the partial melting of enriched mantle , comprise calc - alkaline andesite and dacite and a few tholeiite 通过研究，得出以下主要认识： 1 、火山岩为一套以钙碱性安山岩为主，含少量拉斑玄武岩和英安岩。
3.
Two ree distributed pattern , lree - depleted and flat , which display a specific character of typical mid - ocean ridge tholeiite , indicate that primary magma may be derived from near primary or a typical large ion lithophile element ( lile ) - depleted mantle 岩石稀土元素配分模式可分为lree平坦型和lree亏损型两类，指示了其原始岩浆起源于近原始或典型的大离子元素亏损型的地幔，为典型的大洋中脊拉斑玄武岩的特征。
4.
Cu - ni sulfided mine complex locate in baimazai of jinping county is sub alkali iron - super iron , it ' s zoning is clear and it ' s ni - cu - co melting first and enrichment , its rare earth is rich in right lean light rare earth , but eu in olive rock is serious to be bad , gd - tb is tittles negative abnormity . above - mentioned show that the mineral is cone from mantle , and didn " t mix with crustal substance , and continent tholeiite magma turning into continent tholeiite emplacement after by surging 金平白马寨铜镍硫化矿床杂岩体分带明显、属亚碱性铁质-超铁质岩、具ni - cu - co三元素先熔离，后富集的规律、稀土配分为右倾斜轻稀土富集型，但橄榄岩铕亏损显著， gd - tb微小负异常，显示成矿物质来源地幔，与地壳物质无混染和大陆拉斑玄武岩浆上涌后变为大洋拉斑玄武岩浆侵位特点。
5.
On the basis of the study on the petrology , trace element , and isotopic geochemistry , the primary magma of volcanic rocks can be divided into two series according to their originated rocks and degree of partial melting . one is the basanite - alkaline basalt - olivine tholeiite magma series , which are generated by partial melting from spinel iherzolite ; the other is nephelinite magma - alkaline picritic basalt magma , which are generated by partial melting of the garnet iherzolite 岩石化学、微量元素、同位素地球化学证据都表明，华北、华南地区的火山岩根据源岩和局部熔融程度的不同，可以分为两个原生岩浆系列：一个是源岩为尖晶石二辉橄榄岩，随着局部熔融程度的增加，形成的碧玄岩岩浆-碱性玄武岩岩浆-橄榄拉斑玄武岩岩浆；另一个是源岩为石榴石二辉橄榄岩，随着局部熔融程度的增加形成的霞石岩岩浆-碱性苦橄玄武岩系列。
