Relative Timing of Shear Zone Formation and Granite Emplacement in the Yechon Shear Zone, Korea

走向移動運動에 의해 발달된 醴泉 剪斷帶는 쥬라기 構造運動과 同時에 花崗岩類가 定置된 후, 비교적 高溫狀態에서 生成되었다. 剪斷帶가 花崗岩類 定置후 發達하였음은 花崗岩體 內外에서 葉理와 線構造의 運結性, 粉碎質 構造의 發達, 페그마타이트와 硅長岩脈의 變形作用, 母岩에서 班狀變晶들의 構造前(Pretectonic)成長 등에 의해 확인된다. 剪斷帶의 다양한 剪斷感覺 指時者들은 대부분 剪斷帶 中心部의 强變形岩에서 잘 관찰된다. 이들은 剪斷感覺이 S-C fabric, 形態 選擇配向, 非對稱 Porphyroclast system, Mica fish, 非對稱 伸張構造, 結晶軸 選擇配向 등에 의해 一貫性 있게 右手向(Dextral)임을 보여준다.

The Yechon shear zone developed by strike-slip movement was formed in a relatively high temperature condition just after the Jurassic syntectonic granites had been emplaced during Daebo Orogeny. Post-emplacement formation of the shear zone is favored by continuity of foliations and lineations within and without the granites, development of mylonitic structures in the wallrocks, deformation of pegmatite and felsite dikes, and pretectonic growth of porphyroblasts in the wallrocks. A variety of shear sense indicators in the shear zone are predominantly observed in the intensely to extremely deformed rocks. They show that bulk non-coaxial detormation has occurred, and that the sense of shear is consistently dextral with S-C fabrics, grain shape fabrics, asymmetric porphyroclast systems, mica fish, asymmetric extension structures and quartz C-axis fabrics.