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长江中下游燕山期中酸性-酸性火山-侵入杂岩大家公认为具有偏碱性到碱性特点，但对富碱原因即碱质来石源则存在不同意见，大多数人认为壳幔亮混源，碱质来源于富集地幔的部分熔融，也受到地壳物质的混染．另一种意见强调富碱是由于岩浆侵位或分异过程中受到蒸发岩（特别是膏盐层）的混染与同化。笔者根据长江中下游有关岩体的大量岩石化学分析数据．分地区、分岩体、也按时代对其K2O、Na2O、CaO、MgO与SiO2的相关性作了直观性对比分析，事实表现出Na2O对SiO2几乎完全没有相关性，Na2O对SiO2可以说是独立变化的；K2O与MgO对SiO2具有不同程度的相关性；而CaO－SiO2则具有明显的直线性相关。据此提出：除了原始岩浆具有的碱质外，在岩浆分导过程中不时地有外来碱质加入，这些外来的碱质主要由中、下三叠统中的膏盐层提供。文中根据岩浆硫的δ34S值偏高、膏盐层主要矿物的自由能在高温下熔融及分解温度与低温下在水中的溶解度、石膏矿山的矿泉水中K＋、Na＋、C1＋、SO32-等的浓度，以及斜长石的环带构造方面作了论证．
Yanshanian middle-lower reaches of the Yangtze River acid-acid volcano-intrusive complex known as having alkaline to alkaline characteristics, but the reason for alkali-rich base that is different from the source of stone, most people think of mixed source Alkalinity originates from the partial enrichment of the mantle and is also contaminated by crustal material. Another suggestion emphasizes that alkali-rich is due to contamination and assimilation of evaporites (especially gypsum salts) during magma emplacement or differentiation. The author based on a large number of rocks in the middle and lower reaches of the Yangtze River rock petrochemical analysis of data. The sub-regions and sub-regions also made an intuitive comparative analysis of the correlations of K2O, Na2O, CaO, MgO and SiO2 according to the times. The facts show that Na2O has almost no correlation with SiO2 at all, and Na2O can be said to be independent of SiO2 K2O and MgO have different degrees of correlation with SiO2; while CaO-SiO2 has a significant linear correlation. It is thus proposed that in addition to the alkalinity of the original magma, exogenous alkalis are added from time to time in the magmatic subduction, which are mainly provided by the gypsum salt layer in the Middle and Lower Triassic. According to the high δ34S value of magmatic sulfur, the solubility of the free energy of the main minerals in the gypsum salt layer at high temperature, the solubility in water at low temperature, the concentrations of K +, Na +, Cl +, SO32- and so on in mineral water of gypsum mine, As well as plagioclase structure of the ring made a demonstration.