Phung Hiep Fm

The type section is established on the basis of material from 602-361 m in the Hau Giang 1 borehole (Phung Hiep Townlet, Hau Giang Province) (N = 9°48’; E = 105°50’).

Synonym: Hệ tầng Phụng Hiệp: Lê Văn Cự 1983; Trịnh Dánh 1985, 1993;(in Vu Khúc và nnk.) 1984, (in Phán Cự Tiến et al.) 1989, (in Vũ Khúc, Bùi Phú Mỹ et al.) 1990, (in VQ Khúc et al.) 2000; Nguyễn Ngọc Hoa et al. 1996. (part.). Hệ tầng Cần Thơ (part.): Lê Đức An et al. 1981 .

Type section: (1). (depth 602-508 m): Yellowish-pinkish, medium- to thick-bedded silty claystone and fine-grained sandstone, about 94 m thick. At 602-588 m the foraminifera Globigerinidae gen. indet. was collected. This member unconformably rests upon the eroded surface of the Ben Tre Fm. (2). (depth 508-419 m): Intcrbedded dark-grey siltstone and lenses of thin-bedded marl grading upward into fine-grained sandstone, 89 m thick. (3). (depth 419-361 m): yellowish-grey to motley-colored, soft massive claystone containing pisolitic lateritic small concretions, 58 m thick. This member unconformably underlies the Can Tho Fm. The total thickness of the formation in this section is 241 m.

Ginkgo, Pinus, Betuia, Juglans, Myrtus, etc. and spores of Lygodium, Dicksonia, Polypodiaceae. There are also the salt-water algae Coscinodiscus donahue, Lepcilindricus danicus.