Jahmaine Renzo Yambing¹, David McGee², Kathleen R Johnson³, Salwa Sidahmed⁴, Michael L Griffiths⁵, Elizabeth Weis Patterson⁶, Quốc Đỗ-Trọng⁷, Thanh Bui⁸, Mùi Xuân⁸ and Quốc Hùng Nguyễn⁸, (1)Massachusetts Institute of Technology & Woods Hole Oceanographic Institution Joint Program, Cambridge, United States, (2)Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, Cambridge, United States, (3)University of California, Irvine, Dept. of Earth System Science, Irvine, United States, (4)University of California Irvine, Earth System Science, Irvine, United States, (5)William Paterson University, Department of Chemistry and Environmental Science, Wayne, United States, (6)Lafayette College, Easton, PA, United States, (7)Vietnam National University, Faculty of Geology, Hanoi, Vietnam, (8)Phong Nha Ke Bang National Park, Department of Science and International Cooperation, Phong Nha, Vietnam