SUMMARY

Characteristics of neotectonic and active tectonic faults at Quảng Nam coastal
zone and effects to accumulation of Quaternary sediments

Hoàng Ngô Tự Do, Trần Thanh Hải, Đặng Văn Bát

The neotectonic and active tectonic faults at Quảng Nam coastal zone are known with four main systems, as follow: The older system trends Northwest - Southeast direction, those trends Northeast - Southwest are younger. Sublongitude faults are of small size and appear to be the branches of the larger systems. Many faults are reactivated during recent regional deformations and some are still active, which strongly affect the modem morphology of the area. The occurrence of numerous fault systems and their cross-cutting relationship have led to dismemberment of the basement into blocks and created local uplift and subsidence blocks. A number of subsided blocks of differing rates has been identified including areas of high subsidence rate (from 100 to 135 m), intermediate (from 50 to 100 m) and weak (from 20 to 50 m). In addition, some uplifted areas have also identified. At least 2 uplifted and 5 subsided blocks are remained active. The formation of local uplifted and subsid zones caused by neotectonic and recent tecronic movements have greatly controled the formation of the coastal basin and deposition of Quaternary sediments as well as their spatial distribution and thickness.

Người biên tập: TS. Nguyễn Tiến Hải.