采自西德Eifel东Laachef Sce晚第四系具不同成份分带的火山碎屑岩层的二十六个全岩、七个基质和五十三个单矿物样品用中子活化仪器进行了分析。这些资料表明喷发前Laacher See岩浆房内的化学变化与其它资料导出的一致。岩浆房顶部是高度分异的晌岩,底部是富含铁镁质的响岩。一些不相容元素如Zn、Zr、Nb、Hf、U、LREE和HREE在顶部相当富集,而相容元素如Sr、Sc、Co、Eu强烈地亏损。中等可溶元素Ta和一些MREE在中间层位被耗损。全岩和基质资料表明,响岩溶体在化学成分上的分带性与斑晶含量无关。混染岩(响岩—碧玄岩)中相容元素的丰度最大。所有元素(除Rb外)对于浮岩地层层位来说,都出现连续的成份变化。依据这些资料我们能划分出三个主要的单元:早期喷出的高度分异岩浆,发生演化的响主体和作为最终产物的铁镁质响岩。九个矿物相的微量元素分配系数(K)的巨大变化就地层层位而论不能用常规的机制进行解释。我们假定响向岩熔体中微量元素含量的明显变化由结晶作用控制着分异作用,而分异同时和(或)之后的液—液两相分异作用所控制。这又引起了斑晶和主岩基质之间不平衡。所以分配系数不同于平衡分配系数,相当于后期结晶作用总和。不同于基质成份。这样,就能利用△K—△M图(K的变化相对于M的变化关系图)讨论变化的分配系数K和基质M之间的关系。这个图的不同部分与不同参数有关(T、P、聚合作用,杂岩建造,分带岩浆柱中的平衡结晶作用晚期结晶作用和非平衡效应),这些参数能大体说明分配系数变化的原因。△K—△M图能够区别由分异岩浆系统产生的天然火山岩中影响分配系数的不同作用。 Twenty-six whole rocks, seven matrices and fifty-three single mineral samples collected from volcaniclastic strata with different compositional zonations from the Late Lafayette Scepter of Eifel, West Germany, were analyzed by neutron activation instruments. These data indicate that the chemical changes in the Laacher See magma chamber prior to eruption coincided with those derived from other sources. The top of the magma chamber is highly differentiated rock, the bottom is rich in iron magnesia rock. Some incompatible elements such as Zn, Zr, Nb, Hf, U, LREE and HREE are quite enriched at the top while compatible elements such as Sr, Sc, Co, Eu are strongly depleted. Middle soluble elements Ta and some MREE are depleted in the middle layer. The data of whole rock and matrix show that the zonation of algicidal rock in chemical composition has nothing to do with the content of phenocrysts. The abundance of compatible elements in the contaminated rock (ring rock - bixuan rock) is the largest. All elements (except Rb) have a continuous compositional change for the pumic beds. Based on these data, we can classify three main units: highly-differentiated magma erupted early, the main body of evolution and the magnesia-bearing rock as the final product. The large variations in the trace element distribution (K) for the nine mineral phases can not be explained by conventional mechanisms in terms of formation horizon. We hypothesize that significant changes in trace elemental concentrations in the ring rock melt control the fractionation by crystallization and that the differentiation is controlled simultaneously and / or after the liquid-liquid two-phase differentiation. This, in turn, caused an imbalance between the plaque and host rock matrix. Therefore, the distribution coefficient is different from the equilibrium distribution coefficient, which is equivalent to the summation of the later crystallization. Unlike the matrix ingredients. In this way, the relationship between the changing partition coefficient K and the matrix M can be discussed using the △ K- △ M diagram (a graph of the change of K relative to M). The different parts of this plot are related to different parameters (T, P, polymerisation, formation of complexes, late crystallization of equilibrated crystallization in zonal magmas, and non-equilibrium effects), and these parameters generally explain the reason for the change in partition coefficient. The △ K- △ M map distinguishes the different effects of the distribution coefficients in natural volcanic rocks produced by the differentiated magmatic system.