SYNDEPOSITIONAL TECTONICS AND EXTENSION-COMPRESSION RELATIONSHIPS AT THE FRONT OF THE TAIWAN COLLISION BELT - A CASE-STUDY IN THE PLEISTOCENE REEFAL LIMESTONES NEAR KAOHSIUNG, SW TAIWAN

In the Kaohsiung area (SW Taiwan), large lenses of Pleistocene reef li mestones interbedded in elastic layers of the Gutingkeng Formation cov er the crest of the Takangshan and Panpingshan anticlines. Tectonic an alyses carried out on these limestones provide evidence that these ant iclines developed during deposition of the reefs. This is supported by synsedimentary normal faulting related to tensional stresses at the h inge of the anticlines. This synsedimentary extension is subperpendicu lar to the local trends of fold axes and parallel to the compression r esponsible for fold development and which is mainly marked by strike-s lip faults. These observations lead us to propose a model of extension -compression relationships and reef development during Quaternary fold ing in the foreland of the Taiwan collision belt.