Bài viết Một số đặc điểm môi trường trầm tích biển ven bờ Móng Cái, Quảng Ninh, Việt Nam góp phần bổ sung đặc điểm cấp hạt trầm tích, pH trầm tích (pHTT), thế năng ôxy hóa khử (Eh), oxy hòa tan (DO), độ mặn (S‰), pH nước biển (pHN), tốc độ lắng đọng trầm tích làm sáng tỏ đặc điểm môi trường trầm tích khu vực. | VNU Journal of Science Earth and Environmental Sciences Vol. 38 No. 1 2022 57-70 Original Article Some Sedimentary Environment Characteristics in the Mong Cai Coastal Area Quang Ninh Province Vietnam Bui Thi Thanh Loan1 Nguyen Huy Hoang2 Nguyen Mai Luu2 Le Van Nam2 Pham Tien Dung1 Nguyen Dac Ve2 Le Nhu Sieu3 Dang Hoai Nhon2 Tran Duc Thanh2 1 Institute of Environment Marintime University 484 Lach Tray Street Hai Phong City Vietnam 2 Institute of Marine Environment and Resources VAST 246 Da Nang Hai Phong City Vietnam 3 Dalat Nuclear Research Institute Vietnam Atomic Energy Institute 1 Nguyen Tu Luc Da Lat City Lam Dong Province Vietnam Received 18 March 2021 Revised 15 April 2021 Accepted 05 May 2021 Abstracts The sedimentary environment characteristics in Mong Cai coastal area were assessed through pH Eh grain sizes 226Ra 210Pb S DO parameters. Mong Cai coastal area is mostly influenced by Ka Long river system that makes changes in the salinity pH of water pH and Eh of sediment grain sizes and sedimentation rates in the coastal area. There were six sediment types in the coastal area which were coarse sand medium sand fine sand very fine sand very coarse silt and coarse silt. Fine sand was common in surface sediments very fine sand was dominant in sediment core at Ka Long river mount coarse silt and very coarse silt were common in sediment core at Mui Ngoc. The average sedimentation rate at the Ka Long river mouth cm year was higher than that at the Mui Ngoc cm year . The sedimentary environment was divided into 3 groups the first group was marine characteristics higher than the terrigenous characteristic the second group was terrigenous characteristics higher than marine characteristics and the third group was marine characteristics. In sediment cores showed 3 stages. In stage 1 distribution fine sand very fine sand and very coarse silt from 52 to 80 cm at the Ka Long river mouth and from 40 to 52 cm at the Mui Ngoc. In stage 2 distribution of very .
