文象结构(graphic texture)是指石英呈一定的外形(如尖棱状、象形文字形等)有规律地镶嵌在钾长石中(图1a),这些石英在正交偏光下同时消光。在显微镜下可见的称为显微文象结构;肉眼可见的称为文象结构。通常认为,文象结构是长石和石英在共结点同时结晶形成的。但基于实验研究的结果,Fenn(1986)提出了文象结构形成的另外一种观点,他认为:在水不饱和且过 A graphic texture refers to the regular mosaic of quartz in potash feldspar (Figure 1a) with certain shapes (such as sharp edges, hieroglyphs, etc.) that extinction in crossed polarizations. Visible under the microscope known as the microscopic image of the structure; the naked eye can be seen as the textual structure. Generally believed that the image structure is feldspar and quartz at the same time the node formed by crystallization. However, based on the results of the experimental study, Fenn (1986) proposed another view of the formation of the textual structure. In his opinion,