TY - JOUR
T1 - Provenance of the Phuquoc Basin fill, southern Indochina
T2 - Implication for Early Cretaceous drainage patterns and basin configuration in Southeast Asia
AU - Nguyen, Tu-Ahn
AU - Fyhn, Michael B.W.
AU - Kristensen, Jeppe Ågård
AU - Nielsen, Lars Henrik
AU - Thomsen, Tonny B.
AU - Keulen, Nynke
AU - Lindström, Sofie
AU - Boldreel, Lars O.
N1 - Funding Information:
Tu Ahn Nguyen was funded by a grant from Schlumberger Faculty for the Future Foundation. University of Copenhagen is thanked for housing Tu Ahn Nguyen. Fieldwork and laboratory analyses and the GEUS authors were funded primarily by Shell E & P. Additional funding was obtained through the ENRECA project (Enhanced Research Capacity building) and Geocenter Denmark. Vietnam Petroleum Institute (VPI) and Cambodian National Petroleum Agency helped organize fieldwork aided by the efficient and kind logistic help of Le C. Mai, Hoang A. Tuan, Socheat Chea, Ung Rany and Em Sokhom. Tran V. Tri and the late Phan T. Dien are thanked for generously sharing their expertise on the geology of the region during the fieldwork. The manuscript greatly benefited from the suggestions of two anonymous referees. U/Pb data are available as supporting information.
Funding Information:
Tu Ahn Nguyen was funded by a grant from Schlumberger Faculty for the Future Foundation. University of Copenhagen is thanked for housing Tu Ahn Nguyen. Fieldwork and laboratory analyses and the GEUS authors were funded primarily by Shell E & P. Additional funding was obtained through the ENRECA project (Enhanced Research Capacity building) and Geocenter Denmark. Vietnam Petroleum Institute (VPI) and Cambodian National Petroleum Agency helped organize fieldwork aided by the efficient and kind logistic help of Le C. Mai, Hoang A. Tuan, Socheat Chea, Ung Rany and Em Sokhom. Tran V. Tri and the late Phan T. Dien are thanked for generously sharing their expertise on the geology of the region during the fieldwork. The manuscript greatly benefited from the suggestions of two anonymous referees. U/Pb data are available as supporting information.
Publisher Copyright:
© 2021
PY - 2021/10
Y1 - 2021/10
N2 - Cretaceous basins cover large parts of mainland SE Asia. Yet, the development during the Cretaceous is poorly understood including the establishment of the Cretaceous basin configuration. Based on detrital zircon and heavy mineral analysis, this study investigates the provenance of Lower Cretaceous deposits in the Phuquoc Basin, exposed in Cambodia and SW Vietnam and extending into the Gulf of Thailand. Our results document five major zircon populations with 130–145 Ma, 145–200 Ma, 200–270 Ma, 420–470 Ma, 1800–1900 Ma ages and two subordinate 2400–2700 Ma, 750–1000 Ma age clusters. These ages resemble those of the Qinling-Dabie and the Songpan-Ganzi orogenic belts and differ from other Asian terranes. These ages suggest that the Qinling-Dabie and Songpan-Ganzi orogenic belts were major sources of sediment for the Phuquoc Basin in the Early Cretaceous. Heavy mineral compositions including the presence of almandine, often co-occurring with silimanite and epidote, suggest metamorphic and granitic constituents in the hinterland, compatible with these orogenic belts being the source. The detrital zircon age pattern of the Phuquoc Basin closely resembles the zircon ages in Khorat and the Sichuan basins, suggesting a common sediment source, and bears great similarities with mid-Cretaceous strata in the Lanping-Simao Basin. These basins share a remarkable lithostratigraphic similarity and are confined by erosion. Taken altogether, this supports that the Phuquoc, Khorat, Sichuan, and probably the Lanping-Simao basins, formed part of a Cretaceous basin covering much of central SE Asia segregated by Late Cretaceous and Cenozoic denudation and translation. The absence of 130–145 Ma and 145–200 Ma aged zircons in the Lanping-Simao Basin suggests that another drainage system sprang from the Songpan-Ganzi Orogenic Belt and fed into this basin before merging with the Qinling-Dabie Orogenic Belt drainage system south of the Sichuan Basin. The combined drainage system likely passed through the Khorat Basin before entering the Phuquoc Basin.
AB - Cretaceous basins cover large parts of mainland SE Asia. Yet, the development during the Cretaceous is poorly understood including the establishment of the Cretaceous basin configuration. Based on detrital zircon and heavy mineral analysis, this study investigates the provenance of Lower Cretaceous deposits in the Phuquoc Basin, exposed in Cambodia and SW Vietnam and extending into the Gulf of Thailand. Our results document five major zircon populations with 130–145 Ma, 145–200 Ma, 200–270 Ma, 420–470 Ma, 1800–1900 Ma ages and two subordinate 2400–2700 Ma, 750–1000 Ma age clusters. These ages resemble those of the Qinling-Dabie and the Songpan-Ganzi orogenic belts and differ from other Asian terranes. These ages suggest that the Qinling-Dabie and Songpan-Ganzi orogenic belts were major sources of sediment for the Phuquoc Basin in the Early Cretaceous. Heavy mineral compositions including the presence of almandine, often co-occurring with silimanite and epidote, suggest metamorphic and granitic constituents in the hinterland, compatible with these orogenic belts being the source. The detrital zircon age pattern of the Phuquoc Basin closely resembles the zircon ages in Khorat and the Sichuan basins, suggesting a common sediment source, and bears great similarities with mid-Cretaceous strata in the Lanping-Simao Basin. These basins share a remarkable lithostratigraphic similarity and are confined by erosion. Taken altogether, this supports that the Phuquoc, Khorat, Sichuan, and probably the Lanping-Simao basins, formed part of a Cretaceous basin covering much of central SE Asia segregated by Late Cretaceous and Cenozoic denudation and translation. The absence of 130–145 Ma and 145–200 Ma aged zircons in the Lanping-Simao Basin suggests that another drainage system sprang from the Songpan-Ganzi Orogenic Belt and fed into this basin before merging with the Qinling-Dabie Orogenic Belt drainage system south of the Sichuan Basin. The combined drainage system likely passed through the Khorat Basin before entering the Phuquoc Basin.
KW - Cretaceous drainage pattern
KW - Detrital zircons
KW - Heavy minerals
KW - Phuquoc Basin
KW - Provenance
KW - SE Asia basin configuration
KW - LA-ICP-MS
KW - U-Pb geochronology
UR - http://www.scopus.com/inward/record.url?scp=85108343554&partnerID=8YFLogxK
U2 - 10.1016/j.gr.2021.03.014
DO - 10.1016/j.gr.2021.03.014
M3 - Article
AN - SCOPUS:85108343554
SN - 1342-937X
VL - 98
SP - 166
EP - 190
JO - Gondwana Research
JF - Gondwana Research
ER -
