SUMMARY

Neotectonic characteristics and modern geodynamic of Hướng Hóa - Đăkrông area of Quảng Trị province

Nguyễn Văn Canh, Phạm Văn Hùng

Based on analysis of remote sensing images, geomorphological distortion, geology, and tectonics, the authors defined neotectonic and modem geodynamic characteristics of Hướng Hóa - Đăkrông area, Quảng Trị province. There is a structural schema of its regional neotectonic including structural blocks and faults. These blocks are Hướng Lập, Hướng Son, Ba Lòng, Triệu Nguyên, Húc Nghi, A Ngô, Hướng Lộc - A Vao and Hướng Phùng. The tectonic fault zones are Đăkrông - Huế, Hướng Hóa - A Lưới, Cam Lộ River, Quảng Trị River, Mò ộ -Tân Lập, and Tà Long - A Vao, in which Hướng Hóa - A Lưới and Đăkrông - Huế fault zones play an important role in forming of the structural schema. Most of NW-SH faults as the Cam LỘ River, Hướng Hóa - A Lưới, Đăkrông-Huế, and Quảng Trị River faults are in northeast with a dip angle of 60-80°. There were two phases of neotectonic geodynamic setting in the area: the first was Early Miocene-Pliocene phase in dynamic compression with sub-latitude direction, the NW- SE faults are Cam Lộ River, Quảng Trị River, Đăkrông - Huế and Hướng Hóa - A Lưới... left and normal-left strike-slip faults; NE-SW Mò Ô - Tân Lập faults are right strike-slip and others submeridian faults were compressed activities. The second phase occurred in Pliocene-Quaternary with compressed activities in submeridian direction, the NW-SE faults were normal right strike-slip faults; NE-SW faults were left strike-slip faults; the subparallel faults were reserved faults, the submeridial faults were normal faults. The geodynamic processes happened along active fault zones in the region including: basalt eruption activity during Pliocene-Quaternary, cracked soils, earthquakes, hot spring outcrops, and geothermal sources.

Người biên tập: PCS. TS Cao Đình Triều.