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德干暗色岩层的上部(布什Bushe—默哈伯莱什沃尔建造Mahableshwar)显示出一种最镁铁质熔岩具有最强的地壳物质混染的统计学的明显趋势。这与伴有分离结晶的混染作用(AFC)演化岩套所表现的关系正相反。在德干地区见到的这种相关关系(即Mg值与Sr同位素初始值间的关系)可由以下事实出现局部的偶然现象,即层序下部更富集最镁铁质熔岩,而层序上部混染程度降低。然而这种关系也可由以下情况得到加强,即岩浆通过岩墙上升时,热的岩浆批(batches)使混染作用增强,而岩浆紊流抑制了分离结晶作用。AFC关系的缺失表明大多数混染作用发生在岩浆上升阶段,而不是在岩浆房中。但其它大陆溢流玄武岩区,如巴拉那(Parana)和埃腾达卡(Etendaka)都显示出AFC关系,可把这种关系推断为岩浆房混染作用和岩浆上升过程中流速足以阻止混染发生这两种作用的共同结果。
The upper part of the Durban dark rock formations (the Mahableshwar built by Bushe-Mahabaleshwar in Bush) showed a clear statistical trend towards the strongest crustal contamination of the most mafic lava. This is in contrast to the relationship shown by the AFC evolution mantle with separation crystallization. This correlation, seen in the Deccan region (ie, the relationship between the Mg value and the initial value of the Sr isotope) can be followed by a local contingency by the fact that the lower part of the sequence is more enriched in the most mafic lava and the upper part of the sequence The degree of contamination decreased. However, this relationship can also be reinforced by the fact that hot magma batches enhance the dye uptake as the magma ascends through the dyke wall, whereas magma turbulence inhibits the fractional crystallization. The absence of the AFC relationship suggests that most of the contamination occurs during the magmatic upweather rather than in the magma chamber. However, other continent-overflow basalts, such as Parana and Etendaka, show an AFC relationship that extrapolates this relationship to the fact that magmatic chamber contamination and magmatic ascent flow rates are sufficient to prevent contamination The common result of both these effects.