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• Small mountainous rivers are the major sediment sources on the Vietnam Shelf. • Four stages of weathering and erosion occurred in central Vietnam since Younger Dryas. • Weathering and erosion of central Vietnam are controlled by the East Asian monsoon. Clay mineralogy and elemental geochemistry of Core SO18401 on the Vietnam Shelf are used to reconstruct the history of weathering and erosion in central Vietnam over the past 13.2 ka. The variability of the clay species across the 13.2 ka BP together with the age model allows a subdivision into four temporal stages. Provenance analysis based on clay mineralogy indicates that small mountainous rivers in southern-central Vietnam are the major sources of terrigenous sediments on the central Vietnam Shelf. Smectite and kaolinite originated from the chemical weathering of Mesozoic and Neogene-Quaternary basaltic rocks and Paleo-Mesozoic felsic intrusive rocks, respectively, under warm and humid climate conditions; whereas illite and chlorite were mainly derived from physical weathering of Paleo-Mesozoic felsic intrusive rocks and Precambrian metamorphic rocks in central Vietnam. Accordingly, smectite/(illite + chlorite) ratio, together with elemental ratios of Al 2 O 3 /K 2 O, TiO 2 /Al 2 O 3 , and SiO 2 /Al 2 O 3 , can be utilized to reflect the relative importance between chemical weathering and physical weathering/erosion of the parent rocks in southern-central Vietnam. Higher smectite/(illite + chlorite) and Al 2 O 3 /K 2 O ratios indicate a more important role of chemical weathering, and higher TiO 2 /Al 2 O 3 and SiO 2 /Al 2 O 3 ratios suggest enhanced contribution of physical weathering and erosion. A combination of these mineralogical and elemental proxies allows the distinction of four stages of weathering and erosion evolution in southern-central Vietnam over the Holocene and Younger Dryas periods. Enhanced physical weathering and erosion took place during the periods ∼13.2–11.0 ka BP (Stage I) and ∼3.9–2.0 ka BP (Stage III), associated with relatively arid conditions. By contrast, strengthened chemical weathering occurred during the periods ∼11.0–3.9 ka BP (Stage II) and 2.0 ka BP to present (Stage IV), corresponding to more warm and humid climatic conditions. Our study suggests that the weathering and erosion history of southern-central Vietnam over the Holocene is mainly controlled by the East Asian monsoon climate. [ABSTRACT FROM AUTHOR]

• Micaceous, limonites and opaque heavy minerals are useful diagnostic features. • Lim, Lim-Mi-Chl, Opq/Lim-Chl-Tur, Opq-Tur-(Ep-Zr) and Opq-Amp-(Ep) heavy minerals provinces distinguished on the shelf. • Mineral groups: Lim-Chl, Amp-Ep, and Opq-Tur-Zr are attributed to specific source areas and dominant transport paths. • Dominant sediment transport from the Mekong River over the continental shelf is southwestward. • Vast mixing zone of different modern and relict sediments is east of the Mekong River mouth. The continental shelf off southern Vietnam is relatively well studied regarding the dominant transport paths of bulk and fine-grained sediments discharged by the Mekong River. Thus, this region is particularly suitable for testing the applicability of heavy mineral analysis in determining the extent and origin of the sandy fraction of continental shelf deposits supplied mainly by a large river and their distribution over the adjacent extensive shelf. The fine sand fraction of 105 sediment samples from the Mekong River Delta and neighbouring continental shelf is investigated, applying two approaches: i) considering only the transparent non-micaceous mineral assemblage and ii) considering all the identified heavy minerals. The geological complexity of the source areas and local dominance of micaceous and non-transparent heavy minerals require the inclusion of all heavy mineral components when interpreting sediment provenance and dominant transport paths. The most diagnostic heavy minerals, amphibole, chlorite, epidote, limonite, opaques, tourmaline and zircon, are used for this purpose. The investigated continental shelf can be divided into two main regions characterised by various heavy mineral assemblages, namely, SW and NE off the Mekong River Delta. The south-western region is dominated by chlorite and limonite, indicating prevailing southward sediment transport from the Mekong River, whereas the north-eastern region is characterised by amphibole, epidote, opaques, tourmaline and zircon, indicating various sources from SE Vietnam and relict sediments partly covering the continental shelf. Between the two main regions, a large mixing zone is found where sediments from all sources are present, including Mekong River sediments transported eastward. [ABSTRACT FROM AUTHOR]