Microscopic deformation features of low-strained granitoids.

1. 在上新世晚期，虎府花岗岩风化形成了几米或更厚的表层风化层。口府花岗岩的热液蚀变经历了两个阶段：上新世早期北东北向应力轴作用下的中碱性蚀变和上新世晚期北西北向应力轴作用下的酸性蚀变。寇府花岗岩在风化蚀变过程中，在北向应力轴作用下发生变形。具有代表性的织构为石英、长石的粒内裂隙和黑云母的褶皱。开间花岗岩在除伊藤川—静冈线以外的地区受力较小，而在伊藤川—静冈线附近受力较大。前者表现出与府花岗质岩石相似的变形结构，后者表现为糜棱岩和超长石结构，其特征为石英的塑性变形和长石的断裂，以及高度扭结的黑云母颗粒。筑波花岗岩的风化方式与神府花岗岩相同。筑波花岗岩的石英颗粒中有许多已愈合的裂缝，其总体走向与石英颗粒中未愈合的裂缝不同。除此之外，对Tanzawa、Kitakami、Bathurst和Ryoke的花岗岩进行了显微观察，为我们提供了其他一些低应变花岗岩的例子。

1. The Kofu granitic rocks were weathered to have formed surfacial weathered layers of several meters or more in thickness during Late Pliocene. The Kofu granitic rocks were hydrothermally altered in two stages: Intermediate/alkalline type alteration under the north-northeast trending stress axis during Early Pliocene, and acidic type alteration under the north-northwest trending stress axis during Late Pliocene. The kofu granitic rocks deformed under north-trending stress axis during the time of weathering and alteration. The representative textures are intragranular cracks of quartz and feldspars, and folds of biotite.2. The Kaikoma granites are less strained in the area apart from the Itoigawa-Shizuoka Line, while are highly strained in the vicinity of the Itoigawa-Shizuoka Line. The former shows the deformation textures similar to those of the Kofu granitic rocks, while the latter shows textures of mylonite and ultramylonite, which are characterized by plastically deformed quartz and fractured feldspars, as well as highly kinked biotite grains.3. The Tsukuba granites are weathered in the same manner with those of the Kofu granitic rocks. The Tsukuba granites have many healed cracks in quartz grains, which have a different general trend from non-healed cracks in quartz grains.Besides these examples, granitoids from Tanzawa, Kitakami, Bathurst, and Ryoke were examined microscopically, which give us some other examples of low-strained granitoids.