斷層帶之滲透率與內部結構主要控制上部地殼的流體流動。斷層帶可作為阻水帶或導水帶，其滲透率支配流體穿過或沿著斷層遷移，且能與圍岩之滲透率有很大差距。在此，我們研究池上斷層之滲透率與內部結構，我們利用高圍壓孔隙滲透儀(YOKO2)對立吉混同層及礫石層進行滲透率與孔隙率之量測，實驗條件為室溫、均向圍壓、孔隙流體為氦氣。我們利用萬安二號井的岩心，考慮滲透率異向性，製成垂直和平行斷層面之圓柱試體，及垂直和平行地表之圓柱試體。結果顯示，於低圍壓下，利吉層之滲透率應力敏感度相當高，較礫石層之滲透率低；利吉層孔隙率則明顯低礫石層。此一結果能說明潛移行為的季節性變化。我們亦進行微構造觀察及分析，瞭解微裂隙(microcrack)如何影響滲透率。根據滲透率量測、微構造觀察結果，我們提出池上斷層之內部構造與滲透率構造。;Internal structure and permeability structure of fault zone primarily control on fluid flow in upper crust. It indicates faults as the conduct or barrier, dictates fluid flow along or across faults and can be largely different from those of surrounding country rocks. To consider the relation between internal structure and permeability structure in the Chihshang Fault, we performed permeability and porosity measurements on the Lichi Mélange and the Conglomerate. We measured permeability and porosity with an intra-vessel oil pressure apparatus (YOKO2) at room temperature at isotropic confining pressure, using helium as pore fluid. Cylindrical samples were made from retrieved rock cores in WAN-2 borehole sample which represents a borehole sample near the Chihshang fault. The samples were made in dip and normal direction of fault plane, and also in vertical and horizontal direction to investigate the permeability anisotropy. The results showed the Lichi Mélange is impermeable that may be responsible for seasonal fluctuation on creeping Chihshang fault. We conducted the microfratures analysis, used polarizing microscopy to investigate how microstructures influence the permeability of samples. Based on the microstructures, permeability anisotropy and the fault zone architecture we proposed the permeability structures of Chihshang fault to provide the summary of measured results.
