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Geological map of Southeast Asia surrounding the SCS. Modified after Commission for the Geological Map of the World, 1975; major oceanic fault systems after Hall, 2002).
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... the south, the Malay Peninsula consists mainly of Paleozoic- Mesozoic granite and granodiorite and Paleozoic sedimentary rocks (Liu et al., 2012; Fig. 2), similar to the lithology of the eastern part of South China. Minor Mesozoic (mainly Jurassic-Cretaceous) sedimen- tary rocks and sparse basic volcanic rocks are also present. The sedi- mentary rocks mainly contain mudstone, sandstone, and limestone, interbedded with andesitic-rhyolitic volcanic rocks (Hutchison, 1968;Sultan and ...
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... limestone, interbedded with andesitic-rhyolitic volcanic rocks (Hutchison, 1968;Sultan and Shazili, 2009). Borneo is dominated by Tertiary sedimentary rocks, with a wide distribution of Paleozoic-Mesozoic sedimentary rocks in the central part and of Paleozoic-Mesozoic granite and granodi- orite and Tertiary volcanic rocks in the southwestern part (Fig. 2). The sedimentary rocks are mainly sandy shale, partly interbedded with coals, sandstones, and carbonate rocks (Hutchison, 2005). Scattered World, 1975; major oceanic fault systems after Hall, ...
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... confirms the rapid uplift during the late Miocene ( Rangin et al., 1990). Sumatra has been highly tecton- ically active since the Tertiary, controlled by northeastward subduction of the Indian Ocean Plate along the Sunda Trench in the eastern Indian Ocean and the Sumatra strike-slip fault on the mountainous range of the southwestern island ( Fig. 2; Barber and Crow, 2009). The wide distribution of Quaternary (largely Holocene) basic-intermediate volcanic rocks in the mountains and on the slopes shows the extremely active volcanic eruption ...
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... the east, the Eurasian Plate and the Philippine Sea Plate are converging on Luzon across two major subduction zones, the east- dipping Manila Trench in the eastern SCS and the west-dipping Philippine Trench in the western Pacific Ocean ( Fig. 2; Liu et al., 2009b). The island is thus characterized by active intra-arc strike slip faults, active volcanism, and high seismic activity. Cretaceous to Quater- nary sedimentary and extrusive rocks and Cenozoic intermediate intru- sive rocks abound throughout the island (Commission for the Geological Map of the World, 1975; Fig. 2). ...
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... Pacific Ocean ( Fig. 2; Liu et al., 2009b). The island is thus characterized by active intra-arc strike slip faults, active volcanism, and high seismic activity. Cretaceous to Quater- nary sedimentary and extrusive rocks and Cenozoic intermediate intru- sive rocks abound throughout the island (Commission for the Geological Map of the World, 1975; Fig. 2). Pliocene-Quaternary volca- nic deposits, mostly andesites and basalts with associated dacites and rhyodacites, mainly occur in southern Luzon. In contrast, Cretaceous- Paleogene undifferentiated strata, commonly mapped as volcanics, are distributed in most mountainous regions of Luzon. Cenozoic intermedi- ate intrusive rocks are ...
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... The strong tectonic uplift combined with subtropical warm and humid climate can produce the moderate chem- ical weathering, e.g., Taiwan and the Indochina Peninsula ( Liu et al., 2007b). (4) The lithology-dominated control (volcanic rocks) under subtropical climate conditions usually yields low to moderate chemical weathering, e.g., Luzon (Liu et al., 2009b). ...
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... spatial distribution of εNd values of 47 seafloor surface samples and 53 river samples shows rough zonal features indicating that values of seafloor sediments are highly correlated to river sediments in nearby fluvial drainage systems (Fig. 11A, Table 3). The Pearl and Red river systems have similar εNd composition ranges, from − 13.28 to − 10.38 (average − 11.79) and from − 13.07 to − 10.38 (average − 11.83), respectively, presenting a challenge to separate the two sources if using merely the single εNd tracer (Liu et al., 2007b). The εNd values of Taiwan samples range from −12.63 to −11.19 (average − 11.90), also falling within the variation range of the Pearl and Red rivers, suggesting that the neodymium isotope is not an efficient tracer for sediment provenance analysis in the northern SCS. ...
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... correlation of illite and chlorite (Fig. 7), we use illite + chlorite to show their combined distribution (Fig. 12B). The distribution belt with high illite + chlorite content at the 2000-2500 m water depth matches well with the SCS Contour Current, which is thought to flow southwestward along the lower continental slope off southeastern China (Fig. 3) (Qu et al., 2006). Most likely, the deep SCS Contour Current, which enters the SCS through the Luzon Strait, transports Taiwan-sourced illite and chlorite southwestward along the lower continental slope (Fig. 13B). There is a belt of high content of illite + chlorite extending southward to the deep basin (Figs. 12B and 13B). We interpret this southern ...
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... time-series quantitative evaluation of clay mineral contribution from major provenances of Luzon, Taiwan, and South China to Cores MD05-2904 and MD05-2905 is obtained since 28 ka BP in the last glaciation (Fig. 20). The contributions from the same provenance to two different sites can be compared by similar variation trends but different amplitudes, potentially referring to different distances of two sites to the fluvial systems of that provenance (Fig. 17). The contribu- tions from Luzon at two cores display a similar pattern, remaining at ...
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... during late marine isotope stage (MIS) 3 to early MIS 2, with a significant decrease started in middle MIS 2 (~ 22.5 ka BP), reaching the lowest values of 12-21% at 16.5 ka BP coincident with the timing of H1 event (Heinrich Event 1) ( Wang et al., 2001;Partin et al., 2007), and then increasing until it reached the Holocene level of about 25-30% (Fig. 20C, D). In contrast to Luzon, the contribution from Taiwan was relatively steady at an average value of ~ 61% in Core MD05-2905 (Fig. 20E), whereas Core MD05-2904 reveals rapid fluctua- tions with large amplitude (ranging from 43 to 77%) throughout the record, i.e., a gradual decrease (45-25%) during early-mid MIS 2 and then a slow increase ...
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... the lowest values of 12-21% at 16.5 ka BP coincident with the timing of H1 event (Heinrich Event 1) ( Wang et al., 2001;Partin et al., 2007), and then increasing until it reached the Holocene level of about 25-30% (Fig. 20C, D). In contrast to Luzon, the contribution from Taiwan was relatively steady at an average value of ~ 61% in Core MD05-2905 (Fig. 20E), whereas Core MD05-2904 reveals rapid fluctua- tions with large amplitude (ranging from 43 to 77%) throughout the record, i.e., a gradual decrease (45-25%) during early-mid MIS 2 and then a slow increase (25-58%) until the Holocene (Fig. 20F). The South China contribution in both cores exhibits synchronous variations through time, ...
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... Luzon, the contribution from Taiwan was relatively steady at an average value of ~ 61% in Core MD05-2905 (Fig. 20E), whereas Core MD05-2904 reveals rapid fluctua- tions with large amplitude (ranging from 43 to 77%) throughout the record, i.e., a gradual decrease (45-25%) during early-mid MIS 2 and then a slow increase (25-58%) until the Holocene (Fig. 20F). The South China contribution in both cores exhibits synchronous variations through time, increasing from constant values of 10-20% between 28.5 and 20 ka BP, with a significant high level (30-40%) during early stage of the last deglaciation and then a decrease to relatively low values (5-15%) (Fig. 20H, I) during the Holocene. The ...
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... slow increase (25-58%) until the Holocene (Fig. 20F). The South China contribution in both cores exhibits synchronous variations through time, increasing from constant values of 10-20% between 28.5 and 20 ka BP, with a significant high level (30-40%) during early stage of the last deglaciation and then a decrease to relatively low values (5-15%) (Fig. 20H, I) during the Holocene. The quantitative provenance evaluation shows that Taiwan is definitely the most important source (40-60%) of fine-grained terrigenous material to the northern SCS, while Luzon and the Pearl River serve as subordinate sources supplying 20-40%, and 15-25%, respectively. Despite the limitations of using percentage ...
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... westerly Core MD05-2904 received ~40% detrital material from Taiwan during the last glacial period, which increased to 55% during the Holocene (Fig. 20F), in comparison to the easterly Core MD05-2905 with a relative steady level of 60% (Fig. 20E), indicating that the deep- water circulation has increased during the Holocene. The enhanced deepwater transport ability allows for more Taiwan-derived material to be carried to the westerly slope. The Luzon contribution in both cores shows a ...
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... westerly Core MD05-2904 received ~40% detrital material from Taiwan during the last glacial period, which increased to 55% during the Holocene (Fig. 20F), in comparison to the easterly Core MD05-2905 with a relative steady level of 60% (Fig. 20E), indicating that the deep- water circulation has increased during the Holocene. The enhanced deepwater transport ability allows for more Taiwan-derived material to be carried to the westerly slope. The Luzon contribution in both cores shows a good correlation with the Kuroshio Current intensity record in the Japan Sea ( Sawada and ...
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... evaluated from stalagmite δ 18 O records suggest a tropical Pacific hydrological response to the ITCZ shift during H1 ( Wang et al., 2001;Partin et al., 2007), which in turn may have affected the intensity of Kuroshio Current in the northern Pacific, resulting in a great reduction of terrige- nous contribution from Luzon to the northern SCS (Fig. 20C, D). The overall South China terrigenous input to Core MD05-2904 (Fig. 20H) is ~10% larger than to Core MD05-2905 (Fig. 20I), which is reasonable, because Core MD05-2904 is located closer to the Pearl River mouth. Given the broad and shallow shelf off the South China coast, the South China contribution variations correspond with ...
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... response to the ITCZ shift during H1 ( Wang et al., 2001;Partin et al., 2007), which in turn may have affected the intensity of Kuroshio Current in the northern Pacific, resulting in a great reduction of terrige- nous contribution from Luzon to the northern SCS (Fig. 20C, D). The overall South China terrigenous input to Core MD05-2904 (Fig. 20H) is ~10% larger than to Core MD05-2905 (Fig. 20I), which is reasonable, because Core MD05-2904 is located closer to the Pearl River mouth. Given the broad and shallow shelf off the South China coast, the South China contribution variations correspond with glacial-interglacial sea- level changes (Fig. 20G) (Shackleton, 1987). The ...
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... ( Wang et al., 2001;Partin et al., 2007), which in turn may have affected the intensity of Kuroshio Current in the northern Pacific, resulting in a great reduction of terrige- nous contribution from Luzon to the northern SCS (Fig. 20C, D). The overall South China terrigenous input to Core MD05-2904 (Fig. 20H) is ~10% larger than to Core MD05-2905 (Fig. 20I), which is reasonable, because Core MD05-2904 is located closer to the Pearl River mouth. Given the broad and shallow shelf off the South China coast, the South China contribution variations correspond with glacial-interglacial sea- level changes (Fig. 20G) (Shackleton, 1987). The highest value can be found around ~ 16 ka BP (H1), ...
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... China terrigenous input to Core MD05-2904 (Fig. 20H) is ~10% larger than to Core MD05-2905 (Fig. 20I), which is reasonable, because Core MD05-2904 is located closer to the Pearl River mouth. Given the broad and shallow shelf off the South China coast, the South China contribution variations correspond with glacial-interglacial sea- level changes (Fig. 20G) (Shackleton, 1987). The highest value can be found around ~ 16 ka BP (H1), rather than during the Last Glacial Maximum when the sea level stand was lowest, possibly reflecting the influence of a migrating rain front due to the southward shift of ITCZ, which enhances the physical erosion on the exposed shelf. Therefore, the South China ...
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... spatial distribution of high contents of illite and chlorite in the northern SCS displays tongue-shaped patterns extending from Taiwan southwestward offshore along the continental shelf and the lower continental slope, respectively (Fig. 8B, D). Considering the similar distribution and high linear correlation of illite and chlorite (Fig. 7), we use illite + chlorite to show their combined distribution (Fig. 12B). The distribution belt with high illite + chlorite content at the 2000-2500 m water depth matches well with the SCS Contour Current, which is thought to flow southwestward along the lower continental slope off southeastern China (Fig. 3) (Qu et al., 2006). Most likely, the deep SCS Contour Current, which enters the SCS through the Luzon Strait, transports Taiwan-sourced illite and chlorite southwestward along the lower continental slope (Fig. 13B). There is a belt of high content of illite + chlorite extending southward to the deep basin (Figs. 12B and 13B). We interpret this southern belt to have been transported by the bottom current, which is still to be confirmed by in situ observations. Another tongue-shaped distribution of high illite + chlorite content on the eastern continental shelf appears to be formed by the Guangdong Coastal Current in winter (Fig. 13B), because the win- ter monsoon is much stronger than the summer monsoon at present (Chu and . Therefore, illite and chlorite in the lower conti- nental slope and deep basin could be carried by the deepwater/bottom current, while on the shelf they could be mainly transported by the Guangdong Coastal Current during winter ( Liu et al., ...
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... rocks in the northwest ( Liu et al., 2012;Fig. 2). Paleozoic- Mesozoic volcanic, intrusive, and sedimentary rocks and Tertiary basalts are also sparsely distributed. As part of the Sundaland, the Malay Peninsula has been tectonically stable since the Mesozoic (Hutchison, 1968). However, Borneo was tectonically active throughout the Cenozoic with the strongest tectonic uplift during the Oligocene- Miocene period (Hall, 2002;Hutchison, 2005). The magmatism with K-Ar ages of 6-10 Ma at Kinabalu (4218 m) in North Borneo, the highest mountain of Southeast Asia, confirms the rapid uplift during the late Miocene ( Rangin et al., 1990). Sumatra has been highly tecton- ically active since the Tertiary, controlled by northeastward subduction of the Indian Ocean Plate along the Sunda Trench in the eastern Indian Ocean and the Sumatra strike-slip fault on the mountainous range of the southwestern island ( Fig. 2; Barber and Crow, 2009). The wide distribution of Quaternary (largely Holocene) basic-intermediate volcanic rocks in the mountains and on the slopes shows the extremely active volcanic eruption ...
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... the east, the Eurasian Plate and the Philippine Sea Plate are converging on Luzon across two major subduction zones, the east- dipping Manila Trench in the eastern SCS and the west-dipping Philippine Trench in the western Pacific Ocean ( Fig. 2; Liu et al., 2009b). The island is thus characterized by active intra-arc strike slip faults, active volcanism, and high seismic activity. Cretaceous to Quater- nary sedimentary and extrusive rocks and Cenozoic intermediate intru- sive rocks abound throughout the island (Commission for the Geological Map of the World, 1975; Fig. 2). Pliocene-Quaternary volca- nic deposits, mostly andesites and basalts with associated dacites and rhyodacites, mainly occur in southern Luzon. In contrast, Cretaceous- Paleogene undifferentiated strata, commonly mapped as volcanics, are distributed in most mountainous regions of Luzon. Cenozoic intermedi- ate intrusive rocks are associated with the undifferentiated Cretaceous- Paleogene volcanic rocks. Palawan is very different from Luzon, consisting of two major tectonostratigraphic blocks. Northern Palawan is dominated by Jurassic olistostromes containing olistoliths of Permian limestone, Permian and Triassic chert, sandstone, and basaltic rocks, whereas southern Palawan is composed mainly of ophiolitic sequences that were thrust onto the island ( Suzuki et al., 2000;Steuer et al., 2013). Northern Palawan is commonly assumed to have drifted from South China to the present position during the SCS spreading in the Oligocene to early Miocene (Hall, ...
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... the east, the Eurasian Plate and the Philippine Sea Plate are converging on Luzon across two major subduction zones, the east- dipping Manila Trench in the eastern SCS and the west-dipping Philippine Trench in the western Pacific Ocean ( Fig. 2; Liu et al., 2009b). The island is thus characterized by active intra-arc strike slip faults, active volcanism, and high seismic activity. Cretaceous to Quater- nary sedimentary and extrusive rocks and Cenozoic intermediate intru- sive rocks abound throughout the island (Commission for the Geological Map of the World, 1975; Fig. 2). Pliocene-Quaternary volca- nic deposits, mostly andesites and basalts with associated dacites and rhyodacites, mainly occur in southern Luzon. In contrast, Cretaceous- Paleogene undifferentiated strata, commonly mapped as volcanics, are distributed in most mountainous regions of Luzon. Cenozoic intermedi- ate intrusive rocks are associated with the undifferentiated Cretaceous- Paleogene volcanic rocks. Palawan is very different from Luzon, consisting of two major tectonostratigraphic blocks. Northern Palawan is dominated by Jurassic olistostromes containing olistoliths of Permian limestone, Permian and Triassic chert, sandstone, and basaltic rocks, whereas southern Palawan is composed mainly of ophiolitic sequences that were thrust onto the island ( Suzuki et al., 2000;Steuer et al., 2013). Northern Palawan is commonly assumed to have drifted from South China to the present position during the SCS spreading in the Oligocene to early Miocene (Hall, ...
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... these results show that not only climate and tectonism but also the lithologies of parent rocks in drainage systems play signifi- cant roles in the outcome of the weathering processes. Four controlling mechanisms of chemical weathering can be summarized: (1) The long- term tropical warm and humid climate combined with relatively stable tectonic setting leads to strongly intensive chemical weathering regard- less of the variability in parent rocks, e.g., the Malay Peninsula and Sumatra ( Liu et al., 2012). (2) The strong tectonic uplift combined with tropical warm and humid climate or the stable tectonic setting combined with subtropical warm and humid climate can induce moder- ate-intensive chemical weathering, e.g., Borneo and South China ( Liu et al., 2007bLiu et al., , 2012. (3) The strong tectonic uplift combined with subtropical warm and humid climate can produce the moderate chem- ical weathering, e.g., Taiwan and the Indochina Peninsula ( Liu et al., 2007b). (4) The lithology-dominated control (volcanic rocks) under subtropical climate conditions usually yields low to moderate chemical weathering, e.g., Luzon (Liu et al., ...
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... and Sr isotopes are proven tracers for provenance studies of terrigenous particles in marine sediments ( Grousset et al., 1988;Colin et al., 1999Colin et al., , 2006). These tracers have been applied for fluvial sediment provenance studies in the SCS at different time scales, including modern processes by analyzing seafloor surface sediments ( Wei et al., 2012), the glacial-interglacial variation during the Late Quaternary based on studying sediment cores ( Boulay et al., 2005;Liu et al., 2005), and the long-term geological history since the early Oligocene by studying ocean drill cores (Clift et al., 2002;Li et al., 2003). The agreement of these provenance studies of SCS fluvial sediments is remarkable, although some strong debates regarding sediment provenances at the geological time scales are still ongoing (Clift et al., 2002;Li et al., 2003). Here, we synthesize available literature data combined with our new results on εNd and 87 Sr/ 86 Sr isotopes of surface sediments in the SCS and surrounding fluvial drainage systems to obtain basin-wide fluvial sediment provenances. The spatial distribution of εNd values of 47 seafloor surface samples and 53 river samples shows rough zonal features indicating that values of seafloor sediments are highly correlated to river sediments in nearby fluvial drainage systems (Fig. 11A, Table 3). The Pearl and Red river systems have similar εNd composition ranges, from − 13.28 to − 10.38 (average − 11.79) and from − 13.07 to − 10.38 (average − 11.83), respectively, presenting a challenge to separate the two sources if using merely the single εNd tracer (Liu et al., 2007b). The εNd values of Taiwan samples range from −12.63 to −11.19 (average − 11.90), also falling within the variation range of the Pearl and Red rivers, suggesting that the neodymium isotope is not an efficient tracer for sediment provenance analysis in the northern SCS. Surface sedi- ments on the Mekong River delta provide similar εNd compositions, from − 10.85 to − 9.89 (average − 10.38), slightly larger than values in Red and Pearl river systems ( Liu et al., 2007b). However, fluvial sediments in Luzon rivers have the most positive εNd values, ranging from 7.02 to 7.39 (average 7.16), very close to earlier published values from suspended particles collected in same rivers with a range of 6.4-7.1 (average 6.73) (Table 3; Goldstein and Jacobsen, 1988), provid- ing a strong contrast between Luzon and South China and the Indochina Peninsula. In the south, river samples of Borneo provide εNd values ranging from − 7.89 to − 6.62 (average − 7.33), very different from the Mekong River ...
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... time-series quantitative evaluation of clay mineral contribution from major provenances of Luzon, Taiwan, and South China to Cores MD05-2904 and MD05-2905 is obtained since 28 ka BP in the last glaciation (Fig. 20). The contributions from the same provenance to two different sites can be compared by similar variation trends but different amplitudes, potentially referring to different distances of two sites to the fluvial systems of that provenance (Fig. 17). The contribu- tions from Luzon at two cores display a similar pattern, remaining at 22-35% during late marine isotope stage (MIS) 3 to early MIS 2, with a significant decrease started in middle MIS 2 (~ 22.5 ka BP), reaching the lowest values of 12-21% at 16.5 ka BP coincident with the timing of H1 event (Heinrich Event 1) ( Wang et al., 2001;Partin et al., 2007), and then increasing until it reached the Holocene level of about 25-30% (Fig. 20C, D). In contrast to Luzon, the contribution from Taiwan was relatively steady at an average value of ~ 61% in Core MD05-2905 (Fig. 20E), whereas Core MD05-2904 reveals rapid fluctua- tions with large amplitude (ranging from 43 to 77%) throughout the record, i.e., a gradual decrease (45-25%) during early-mid MIS 2 and then a slow increase (25-58%) until the Holocene (Fig. 20F). The South China contribution in both cores exhibits synchronous variations through time, increasing from constant values of 10-20% between 28.5 and 20 ka BP, with a significant high level (30-40%) during early stage of the last deglaciation and then a decrease to relatively low values (5-15%) (Fig. 20H, I) during the Holocene. The quantitative provenance evaluation shows that Taiwan is definitely the most important source (40-60%) of fine-grained terrigenous material to the northern SCS, while Luzon and the Pearl River serve as subordinate sources supplying 20-40%, and 15-25%, respectively. Despite the limitations of using percentage values in a three-variable system (the three provenance regions), with increasing contributions from one provenance when another provenance source decreases, this is still a significant approach for quantifying source-to-sink ...
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... time-series quantitative evaluation of clay mineral contribution from major provenances of Luzon, Taiwan, and South China to Cores MD05-2904 and MD05-2905 is obtained since 28 ka BP in the last glaciation (Fig. 20). The contributions from the same provenance to two different sites can be compared by similar variation trends but different amplitudes, potentially referring to different distances of two sites to the fluvial systems of that provenance (Fig. 17). The contribu- tions from Luzon at two cores display a similar pattern, remaining at 22-35% during late marine isotope stage (MIS) 3 to early MIS 2, with a significant decrease started in middle MIS 2 (~ 22.5 ka BP), reaching the lowest values of 12-21% at 16.5 ka BP coincident with the timing of H1 event (Heinrich Event 1) ( Wang et al., 2001;Partin et al., 2007), and then increasing until it reached the Holocene level of about 25-30% (Fig. 20C, D). In contrast to Luzon, the contribution from Taiwan was relatively steady at an average value of ~ 61% in Core MD05-2905 (Fig. 20E), whereas Core MD05-2904 reveals rapid fluctua- tions with large amplitude (ranging from 43 to 77%) throughout the record, i.e., a gradual decrease (45-25%) during early-mid MIS 2 and then a slow increase (25-58%) until the Holocene (Fig. 20F). The South China contribution in both cores exhibits synchronous variations through time, increasing from constant values of 10-20% between 28.5 and 20 ka BP, with a significant high level (30-40%) during early stage of the last deglaciation and then a decrease to relatively low values (5-15%) (Fig. 20H, I) during the Holocene. The quantitative provenance evaluation shows that Taiwan is definitely the most important source (40-60%) of fine-grained terrigenous material to the northern SCS, while Luzon and the Pearl River serve as subordinate sources supplying 20-40%, and 15-25%, respectively. Despite the limitations of using percentage values in a three-variable system (the three provenance regions), with increasing contributions from one provenance when another provenance source decreases, this is still a significant approach for quantifying source-to-sink ...
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... time-series quantitative evaluation of clay mineral contribution from major provenances of Luzon, Taiwan, and South China to Cores MD05-2904 and MD05-2905 is obtained since 28 ka BP in the last glaciation (Fig. 20). The contributions from the same provenance to two different sites can be compared by similar variation trends but different amplitudes, potentially referring to different distances of two sites to the fluvial systems of that provenance (Fig. 17). The contribu- tions from Luzon at two cores display a similar pattern, remaining at 22-35% during late marine isotope stage (MIS) 3 to early MIS 2, with a significant decrease started in middle MIS 2 (~ 22.5 ka BP), reaching the lowest values of 12-21% at 16.5 ka BP coincident with the timing of H1 event (Heinrich Event 1) ( Wang et al., 2001;Partin et al., 2007), and then increasing until it reached the Holocene level of about 25-30% (Fig. 20C, D). In contrast to Luzon, the contribution from Taiwan was relatively steady at an average value of ~ 61% in Core MD05-2905 (Fig. 20E), whereas Core MD05-2904 reveals rapid fluctua- tions with large amplitude (ranging from 43 to 77%) throughout the record, i.e., a gradual decrease (45-25%) during early-mid MIS 2 and then a slow increase (25-58%) until the Holocene (Fig. 20F). The South China contribution in both cores exhibits synchronous variations through time, increasing from constant values of 10-20% between 28.5 and 20 ka BP, with a significant high level (30-40%) during early stage of the last deglaciation and then a decrease to relatively low values (5-15%) (Fig. 20H, I) during the Holocene. The quantitative provenance evaluation shows that Taiwan is definitely the most important source (40-60%) of fine-grained terrigenous material to the northern SCS, while Luzon and the Pearl River serve as subordinate sources supplying 20-40%, and 15-25%, respectively. Despite the limitations of using percentage values in a three-variable system (the three provenance regions), with increasing contributions from one provenance when another provenance source decreases, this is still a significant approach for quantifying source-to-sink ...
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... time-series quantitative evaluation of clay mineral contribution from major provenances of Luzon, Taiwan, and South China to Cores MD05-2904 and MD05-2905 is obtained since 28 ka BP in the last glaciation (Fig. 20). The contributions from the same provenance to two different sites can be compared by similar variation trends but different amplitudes, potentially referring to different distances of two sites to the fluvial systems of that provenance (Fig. 17). The contribu- tions from Luzon at two cores display a similar pattern, remaining at 22-35% during late marine isotope stage (MIS) 3 to early MIS 2, with a significant decrease started in middle MIS 2 (~ 22.5 ka BP), reaching the lowest values of 12-21% at 16.5 ka BP coincident with the timing of H1 event (Heinrich Event 1) ( Wang et al., 2001;Partin et al., 2007), and then increasing until it reached the Holocene level of about 25-30% (Fig. 20C, D). In contrast to Luzon, the contribution from Taiwan was relatively steady at an average value of ~ 61% in Core MD05-2905 (Fig. 20E), whereas Core MD05-2904 reveals rapid fluctua- tions with large amplitude (ranging from 43 to 77%) throughout the record, i.e., a gradual decrease (45-25%) during early-mid MIS 2 and then a slow increase (25-58%) until the Holocene (Fig. 20F). The South China contribution in both cores exhibits synchronous variations through time, increasing from constant values of 10-20% between 28.5 and 20 ka BP, with a significant high level (30-40%) during early stage of the last deglaciation and then a decrease to relatively low values (5-15%) (Fig. 20H, I) during the Holocene. The quantitative provenance evaluation shows that Taiwan is definitely the most important source (40-60%) of fine-grained terrigenous material to the northern SCS, while Luzon and the Pearl River serve as subordinate sources supplying 20-40%, and 15-25%, respectively. Despite the limitations of using percentage values in a three-variable system (the three provenance regions), with increasing contributions from one provenance when another provenance source decreases, this is still a significant approach for quantifying source-to-sink ...
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... time-series quantitative evaluation of clay mineral contribution from major provenances of Luzon, Taiwan, and South China to Cores MD05-2904 and MD05-2905 is obtained since 28 ka BP in the last glaciation (Fig. 20). The contributions from the same provenance to two different sites can be compared by similar variation trends but different amplitudes, potentially referring to different distances of two sites to the fluvial systems of that provenance (Fig. 17). The contribu- tions from Luzon at two cores display a similar pattern, remaining at 22-35% during late marine isotope stage (MIS) 3 to early MIS 2, with a significant decrease started in middle MIS 2 (~ 22.5 ka BP), reaching the lowest values of 12-21% at 16.5 ka BP coincident with the timing of H1 event (Heinrich Event 1) ( Wang et al., 2001;Partin et al., 2007), and then increasing until it reached the Holocene level of about 25-30% (Fig. 20C, D). In contrast to Luzon, the contribution from Taiwan was relatively steady at an average value of ~ 61% in Core MD05-2905 (Fig. 20E), whereas Core MD05-2904 reveals rapid fluctua- tions with large amplitude (ranging from 43 to 77%) throughout the record, i.e., a gradual decrease (45-25%) during early-mid MIS 2 and then a slow increase (25-58%) until the Holocene (Fig. 20F). The South China contribution in both cores exhibits synchronous variations through time, increasing from constant values of 10-20% between 28.5 and 20 ka BP, with a significant high level (30-40%) during early stage of the last deglaciation and then a decrease to relatively low values (5-15%) (Fig. 20H, I) during the Holocene. The quantitative provenance evaluation shows that Taiwan is definitely the most important source (40-60%) of fine-grained terrigenous material to the northern SCS, while Luzon and the Pearl River serve as subordinate sources supplying 20-40%, and 15-25%, respectively. Despite the limitations of using percentage values in a three-variable system (the three provenance regions), with increasing contributions from one provenance when another provenance source decreases, this is still a significant approach for quantifying source-to-sink ...
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... the south, the Malay Peninsula consists mainly of Paleozoic- Mesozoic granite and granodiorite and Paleozoic sedimentary rocks (Liu et al., 2012; Fig. 2), similar to the lithology of the eastern part of South China. Minor Mesozoic (mainly Jurassic-Cretaceous) sedimen- tary rocks and sparse basic volcanic rocks are also present. The sedi- mentary rocks mainly contain mudstone, sandstone, and limestone, interbedded with andesitic-rhyolitic volcanic rocks (Hutchison, 1968;Sultan and Shazili, 2009). Borneo is dominated by Tertiary sedimentary rocks, with a wide distribution of Paleozoic-Mesozoic sedimentary rocks in the central part and of Paleozoic-Mesozoic granite and granodi- orite and Tertiary volcanic rocks in the southwestern part (Fig. 2). The sedimentary rocks are mainly sandy shale, partly interbedded with coals, sandstones, and carbonate rocks (Hutchison, 2005). Scattered World, 1975; major oceanic fault systems after Hall, ...
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... the south, the Malay Peninsula consists mainly of Paleozoic- Mesozoic granite and granodiorite and Paleozoic sedimentary rocks (Liu et al., 2012; Fig. 2), similar to the lithology of the eastern part of South China. Minor Mesozoic (mainly Jurassic-Cretaceous) sedimen- tary rocks and sparse basic volcanic rocks are also present. The sedi- mentary rocks mainly contain mudstone, sandstone, and limestone, interbedded with andesitic-rhyolitic volcanic rocks (Hutchison, 1968;Sultan and Shazili, 2009). Borneo is dominated by Tertiary sedimentary rocks, with a wide distribution of Paleozoic-Mesozoic sedimentary rocks in the central part and of Paleozoic-Mesozoic granite and granodi- orite and Tertiary volcanic rocks in the southwestern part (Fig. 2). The sedimentary rocks are mainly sandy shale, partly interbedded with coals, sandstones, and carbonate rocks (Hutchison, 2005). Scattered World, 1975; major oceanic fault systems after Hall, ...
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... westerly Core MD05-2904 received ~40% detrital material from Taiwan during the last glacial period, which increased to 55% during the Holocene (Fig. 20F), in comparison to the easterly Core MD05-2905 with a relative steady level of 60% (Fig. 20E), indicating that the deep- water circulation has increased during the Holocene. The enhanced deepwater transport ability allows for more Taiwan-derived material to be carried to the westerly slope. The Luzon contribution in both cores shows a good correlation with the Kuroshio Current intensity record in the Japan Sea ( Sawada and Handa, 1998) and stalagmite δ 18 O records in North Borneo ( Partin et al., 2007), implying a potential hydrological impact from the tropical regions. Dry conditions evaluated from stalagmite δ 18 O records suggest a tropical Pacific hydrological response to the ITCZ shift during H1 ( Wang et al., 2001;Partin et al., 2007), which in turn may have affected the intensity of Kuroshio Current in the northern Pacific, resulting in a great reduction of terrige- nous contribution from Luzon to the northern SCS (Fig. 20C, D). The overall South China terrigenous input to Core MD05-2904 (Fig. 20H) is ~10% larger than to Core MD05-2905 (Fig. 20I), which is reasonable, because Core MD05-2904 is located closer to the Pearl River mouth. Given the broad and shallow shelf off the South China coast, the South China contribution variations correspond with glacial-interglacial sea- level changes (Fig. 20G) (Shackleton, 1987). The highest value can be found around ~ 16 ka BP (H1), rather than during the Last Glacial Maximum when the sea level stand was lowest, possibly reflecting the influence of a migrating rain front due to the southward shift of ITCZ, which enhances the physical erosion on the exposed shelf. Therefore, the South China contributions to the northern slope are primary affect- ed by the sea-level changes, possibly associated with the monsoonal rainfall migration during the H1 ...
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... westerly Core MD05-2904 received ~40% detrital material from Taiwan during the last glacial period, which increased to 55% during the Holocene (Fig. 20F), in comparison to the easterly Core MD05-2905 with a relative steady level of 60% (Fig. 20E), indicating that the deep- water circulation has increased during the Holocene. The enhanced deepwater transport ability allows for more Taiwan-derived material to be carried to the westerly slope. The Luzon contribution in both cores shows a good correlation with the Kuroshio Current intensity record in the Japan Sea ( Sawada and Handa, 1998) and stalagmite δ 18 O records in North Borneo ( Partin et al., 2007), implying a potential hydrological impact from the tropical regions. Dry conditions evaluated from stalagmite δ 18 O records suggest a tropical Pacific hydrological response to the ITCZ shift during H1 ( Wang et al., 2001;Partin et al., 2007), which in turn may have affected the intensity of Kuroshio Current in the northern Pacific, resulting in a great reduction of terrige- nous contribution from Luzon to the northern SCS (Fig. 20C, D). The overall South China terrigenous input to Core MD05-2904 (Fig. 20H) is ~10% larger than to Core MD05-2905 (Fig. 20I), which is reasonable, because Core MD05-2904 is located closer to the Pearl River mouth. Given the broad and shallow shelf off the South China coast, the South China contribution variations correspond with glacial-interglacial sea- level changes (Fig. 20G) (Shackleton, 1987). The highest value can be found around ~ 16 ka BP (H1), rather than during the Last Glacial Maximum when the sea level stand was lowest, possibly reflecting the influence of a migrating rain front due to the southward shift of ITCZ, which enhances the physical erosion on the exposed shelf. Therefore, the South China contributions to the northern slope are primary affect- ed by the sea-level changes, possibly associated with the monsoonal rainfall migration during the H1 ...
Context 35
... westerly Core MD05-2904 received ~40% detrital material from Taiwan during the last glacial period, which increased to 55% during the Holocene (Fig. 20F), in comparison to the easterly Core MD05-2905 with a relative steady level of 60% (Fig. 20E), indicating that the deep- water circulation has increased during the Holocene. The enhanced deepwater transport ability allows for more Taiwan-derived material to be carried to the westerly slope. The Luzon contribution in both cores shows a good correlation with the Kuroshio Current intensity record in the Japan Sea ( Sawada and Handa, 1998) and stalagmite δ 18 O records in North Borneo ( Partin et al., 2007), implying a potential hydrological impact from the tropical regions. Dry conditions evaluated from stalagmite δ 18 O records suggest a tropical Pacific hydrological response to the ITCZ shift during H1 ( Wang et al., 2001;Partin et al., 2007), which in turn may have affected the intensity of Kuroshio Current in the northern Pacific, resulting in a great reduction of terrige- nous contribution from Luzon to the northern SCS (Fig. 20C, D). The overall South China terrigenous input to Core MD05-2904 (Fig. 20H) is ~10% larger than to Core MD05-2905 (Fig. 20I), which is reasonable, because Core MD05-2904 is located closer to the Pearl River mouth. Given the broad and shallow shelf off the South China coast, the South China contribution variations correspond with glacial-interglacial sea- level changes (Fig. 20G) (Shackleton, 1987). The highest value can be found around ~ 16 ka BP (H1), rather than during the Last Glacial Maximum when the sea level stand was lowest, possibly reflecting the influence of a migrating rain front due to the southward shift of ITCZ, which enhances the physical erosion on the exposed shelf. Therefore, the South China contributions to the northern slope are primary affect- ed by the sea-level changes, possibly associated with the monsoonal rainfall migration during the H1 ...
Context 36
... westerly Core MD05-2904 received ~40% detrital material from Taiwan during the last glacial period, which increased to 55% during the Holocene (Fig. 20F), in comparison to the easterly Core MD05-2905 with a relative steady level of 60% (Fig. 20E), indicating that the deep- water circulation has increased during the Holocene. The enhanced deepwater transport ability allows for more Taiwan-derived material to be carried to the westerly slope. The Luzon contribution in both cores shows a good correlation with the Kuroshio Current intensity record in the Japan Sea ( Sawada and Handa, 1998) and stalagmite δ 18 O records in North Borneo ( Partin et al., 2007), implying a potential hydrological impact from the tropical regions. Dry conditions evaluated from stalagmite δ 18 O records suggest a tropical Pacific hydrological response to the ITCZ shift during H1 ( Wang et al., 2001;Partin et al., 2007), which in turn may have affected the intensity of Kuroshio Current in the northern Pacific, resulting in a great reduction of terrige- nous contribution from Luzon to the northern SCS (Fig. 20C, D). The overall South China terrigenous input to Core MD05-2904 (Fig. 20H) is ~10% larger than to Core MD05-2905 (Fig. 20I), which is reasonable, because Core MD05-2904 is located closer to the Pearl River mouth. Given the broad and shallow shelf off the South China coast, the South China contribution variations correspond with glacial-interglacial sea- level changes (Fig. 20G) (Shackleton, 1987). The highest value can be found around ~ 16 ka BP (H1), rather than during the Last Glacial Maximum when the sea level stand was lowest, possibly reflecting the influence of a migrating rain front due to the southward shift of ITCZ, which enhances the physical erosion on the exposed shelf. Therefore, the South China contributions to the northern slope are primary affect- ed by the sea-level changes, possibly associated with the monsoonal rainfall migration during the H1 ...
Context 37
... westerly Core MD05-2904 received ~40% detrital material from Taiwan during the last glacial period, which increased to 55% during the Holocene (Fig. 20F), in comparison to the easterly Core MD05-2905 with a relative steady level of 60% (Fig. 20E), indicating that the deep- water circulation has increased during the Holocene. The enhanced deepwater transport ability allows for more Taiwan-derived material to be carried to the westerly slope. The Luzon contribution in both cores shows a good correlation with the Kuroshio Current intensity record in the Japan Sea ( Sawada and Handa, 1998) and stalagmite δ 18 O records in North Borneo ( Partin et al., 2007), implying a potential hydrological impact from the tropical regions. Dry conditions evaluated from stalagmite δ 18 O records suggest a tropical Pacific hydrological response to the ITCZ shift during H1 ( Wang et al., 2001;Partin et al., 2007), which in turn may have affected the intensity of Kuroshio Current in the northern Pacific, resulting in a great reduction of terrige- nous contribution from Luzon to the northern SCS (Fig. 20C, D). The overall South China terrigenous input to Core MD05-2904 (Fig. 20H) is ~10% larger than to Core MD05-2905 (Fig. 20I), which is reasonable, because Core MD05-2904 is located closer to the Pearl River mouth. Given the broad and shallow shelf off the South China coast, the South China contribution variations correspond with glacial-interglacial sea- level changes (Fig. 20G) (Shackleton, 1987). The highest value can be found around ~ 16 ka BP (H1), rather than during the Last Glacial Maximum when the sea level stand was lowest, possibly reflecting the influence of a migrating rain front due to the southward shift of ITCZ, which enhances the physical erosion on the exposed shelf. Therefore, the South China contributions to the northern slope are primary affect- ed by the sea-level changes, possibly associated with the monsoonal rainfall migration during the H1 ...
Context 38
... westerly Core MD05-2904 received ~40% detrital material from Taiwan during the last glacial period, which increased to 55% during the Holocene (Fig. 20F), in comparison to the easterly Core MD05-2905 with a relative steady level of 60% (Fig. 20E), indicating that the deep- water circulation has increased during the Holocene. The enhanced deepwater transport ability allows for more Taiwan-derived material to be carried to the westerly slope. The Luzon contribution in both cores shows a good correlation with the Kuroshio Current intensity record in the Japan Sea ( Sawada and Handa, 1998) and stalagmite δ 18 O records in North Borneo ( Partin et al., 2007), implying a potential hydrological impact from the tropical regions. Dry conditions evaluated from stalagmite δ 18 O records suggest a tropical Pacific hydrological response to the ITCZ shift during H1 ( Wang et al., 2001;Partin et al., 2007), which in turn may have affected the intensity of Kuroshio Current in the northern Pacific, resulting in a great reduction of terrige- nous contribution from Luzon to the northern SCS (Fig. 20C, D). The overall South China terrigenous input to Core MD05-2904 (Fig. 20H) is ~10% larger than to Core MD05-2905 (Fig. 20I), which is reasonable, because Core MD05-2904 is located closer to the Pearl River mouth. Given the broad and shallow shelf off the South China coast, the South China contribution variations correspond with glacial-interglacial sea- level changes (Fig. 20G) (Shackleton, 1987). The highest value can be found around ~ 16 ka BP (H1), rather than during the Last Glacial Maximum when the sea level stand was lowest, possibly reflecting the influence of a migrating rain front due to the southward shift of ITCZ, which enhances the physical erosion on the exposed shelf. Therefore, the South China contributions to the northern slope are primary affect- ed by the sea-level changes, possibly associated with the monsoonal rainfall migration during the H1 ...
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Citations
... The largest node among them is the United States, followed by China's mainland, England, and Australia. This means that all of these countries have been actively researching this topic, which may be justified by the fact that they all have a long coastline (Liu et al., 2016). Meanwhile, the abundant marine resources also provide important guarantees for research. ...
Internal solitary wave (ISW), as a typical marine dynamic process in the deep sea, widely exists in oceans and marginal seas worldwide. The interaction between ISW and the seafloor mainly occurs in the bottom boundary layer. For the seabed boundary layer of the deep sea, ISW is the most important dynamic process. This study analyzed the current status, hotspots, and frontiers of research on the interaction between ISW and the seafloor by CiteSpace. Focusing on the action of ISW on the seabed, such as transformation and reaction, a large amount of research work and results were systematically analyzed and summarized. On this basis, this study analyzed the wave-wave interaction and interaction between ISW and the bedform or slope of the seabed, which provided a new perspective for an in-depth understanding of the interaction between ISW and the seafloor. Finally, the latest research results of the bottom boundary layer and marine engineering stability by ISW were introduced, and the unresolved problems in the current research work were summarized. This study provides a valuable reference for further research on the hazards of ISW to marine engineering geology.
... an Strait, the southern Chinese shelf, and the Gulf of Tonkin (Gulf of Beibu). This region is influenced mostly by Taiwanese rivers (e.g., Jhuoshuei River, 40 Mt yr 1 ), the Pearl River (84.3 Mt yr 1 ) that discharges in the southern Chinese shelf, and the Red River (130 Mt yr 1 ) that discharges into the Gulf of Tonkin (S. J. Kao & Milliman, 2008;Z. Liu et al., 2016;Milliman & Farnsworth, 2011). To the best of our knowledge, sedimentation rates have not yet been quantified in this region (Table 1). ...
... n the northern Gulf of Thailand has the largest sediment discharge of these rivers (Z. Milliman & Farnsworth, 2011;B. Wu et al., 2020) (Figure 1). Sediments from the Mekong River can also reach Region VI advected by the regional cyclonic current (Xue et al., 2014). However, monsoonal winds can reverse the flow to an anticyclonic circulation (J. T. Z. Liu et al., 2016), which contribute to the formation of mud deposits in the lower area of this region, downcurrent from the main rivers (Bai et al., 2021;B. Lin et al., 2023;B. Wu et al., 2020). Sedimentation rates offshore the Chao Phraya River and in these mud deposits are highest, ranging between 0.4 and 0.7 cm yr 1 whereas lowest sedimentation rates ...
... Finally, Region VII encompasses the deep (200-7,000 m) distal basin known as the South China Sea and receives reworked sediment from regions IV and V through the many submarine canyons that incise the continental slopes (L. Lin et al., 2019;Z. Liu et al., 2016) but also from the direct input of Taiwanese rivers such as the Gaoping River that can channel large fluvial sediment through its connected submarine canyon as hyperpycnal flows (Kao et al., 2014;J. T. Liu et al., 2016;Z. Liu et al., 2016). A general cyclonic current occurs in the South China Sea, although it can often be reversed by sea ...
As major sites of carbon burial and remineralization, continental margins are key components of the global carbon cycle. However, heterogeneous sources of organic matter (OM) and depositional environments lead to complex spatial patterns in sedimentary organic carbon (OC) content and composition. To better constrain the processes that control OM cycling, we focus on the East Asian marginal seas as a model system, where we compiled extensive data on the OC content, bulk isotopic composition (δ¹³C and Δ¹⁴C), total nitrogen, and mineral surface area of surficial sediments from previous studies and new measurements. We developed a spatial machine learning modeling framework to predict the spatial distribution of these parameters and identify regions where sediments with similar geochemical signatures drape the seafloor (i.e., “isodrapes”). We demonstrate that both provenance (44%–77%) and hydrodynamic processes (22%–53%) govern the fate of OM in this margin. Hydrodynamic processes can either promote the degradation of OM in mobile mud‐belts or preserve it in stable mud‐deposits. The distinct isotopic composition of OC sources from marine productivity and individual rivers regulates the age and reactivity of OM deposited on the sea‐floor. The East Asian marginal seas can be separated into three main isodrapes: hydrodynamically energetic shelves with coarser‐grained sediment depleted in OC, OM‐enriched mud deposits, and a deep basin with fine‐grained sediments and aged OC affected by long oxygen exposure times and petrogenic input from rivers. This study confirms that both hydrodynamic processes and provenance should be accounted for to understand the fate of OC in continental margins.
... It is located in the shelf area of the South China Sea and is connected to this sea through the Qiongzhou Strait. Due to its unique geographical location, diverse seabed topography, and complex ocean currents and hydrodynamic environment, its marine sediments preserve rich paleoclimatic information in East Asia [1][2][3][4][5][6][7][8][9][10][11]. ...
... Through calculating the mass of emitted CO 2 , we can calculate the percentage of CO 3 2 and CaCO 3 in the sample. The variation trends of the three groups of data are relatively similar when comparing the CO 3 2 content with the CaO and Ca contents measured by ICP-MS and XRF, respectively. Thus, it can be concluded that carbonate mostly existed in the form of calcium carbonate in the sediment. ...
... Therefore, it was believed that the low terrestrial input and high weathering intensity at this time can serve as indirect evidence for the synchronous start of the MWP-1A and BA warm events. 3 ⃝ During the YD period, δ 18 O of the Greenland ice core decreased, which indicated the cooling of high-latitude regions in the Northern Hemisphere. The SST in the South China Sea showed a decrease in temperature during the YD cold event compared to that during the BA warm event. ...
The geochemical characteristics of a 2.1 m BBW25 core, collected from the Beibu Gulf, have been investigated in terms of the major and trace elements, organic matter, and CaCO3 and AMS 14C dating by XRF, ICP-OES, ICP-MS, and more. We have found through previous research that there are issues with unclear delineation of sedimentary evolution environments and inexact responses between chemical weathering intensity and major paleoclimate events in the Beibu Gulf. The AMS 14C dating results indicate that the sedimentary age at the bottom was 19.24 ky b.p. CaCO3, δ13C, C/N, and Sr/Ba indexes show a sedimentary environment change from terrestrial to marine environments and a “jump” of ~4000 years in continent–ocean changes. The evolution of the sedimentary environment of Beibu Gulf was divided into three environments and five sub-environments. The changes in chemical weathering intensity indicators recorded by the CIX and the Fe/Al ratio respond well to the East Asian monsoon cycle, the meltwater events, and the alternation of cold and warm events. This study explains the chemical weathering intensity and sedimentary environment in the BBW25 core by geochemical characteristics and further reveals the paleoenvironmental characteristics and possible driving mechanisms over the past ~20,000 years.
... The study area is situated in the continental terrace in the north-western part of the South China Sea. Continental terraces serve as crucial pathways for terrigenous materials between continents and oceans, playing a significant role in the Earth's source-sink system [46]. Rivers transport a substantial amount of terrigenous materials to the shelf and slope, where they are deposited, or further carried to the open ocean by ocean dynamics [47]. ...
The acoustic properties of seafloor sediments on continental slopes play a crucial role in underwater acoustic propagation, communication, and detection. To investigate the acoustic characteristics and spatial distribution patterns of sediments on the continental slope, a geoacoustic experiment was conducted in the northwestern South China Sea. The experiment covered two sections: one crossing the shelf and slope in the downslope direction, and the other near the shelf break in the along-slope direction. In situ techniques, sediment sampling, and laboratory measurements were used to acquire data on sediment acoustic properties (such as sound speed and attenuation) and physical properties (including particle composition, density, porosity, and mean grain size). The experimental findings revealed several key points: (1) Acoustic properties of shallow water coarse-grained sediments and deep-sea sediments were higher when measured in the laboratory compared to in situ measurements. (2) Relationships between measured attenuation and physical properties, as well as between sound speed and mean grain size, showed deviations from previous empirical equations. (3) Sediment acoustic and physical properties exhibited significant variations in the downslope direction, while showing gradual variations in the along-slope direction. These variations can be attributed to sedimentary environmental factors such as material sources, hydrodynamic conditions, and water depth.
... The last deglaciation to Holocene is a typical cold and warm transition period, accompanied by the rapid rise of atmospheric CO 2 concentration and sea level (e.g., Clark et al., 2012;Lambeck et al., 2014), surface and bottom current interchanges (e.g., Wan & Jian, 2014;Zheng et al., 2016), and the occurrence of millennial-scale climate events, known as Bølling-Allerød (BA) and Younger Dryas (YD) events (Clark et al., 2012). Marginal sea is one of the most sensitive regions to these global changes (e.g., Liu et al., 2016;Zhong et al., 2021). However, the complex source-to-sink processes in marginal seas make it challenging to effectively extract climate, continental weathering, and marine environment signals from sediments, even for the widely studied last deglaciation and Holocene periods (Kissel et al., 2020). ...
Plain Language Summary
The global climate, which has changed rapidly since the last deglaciation, has been recorded by marginal sea sediments. However, the mixing of environmental factors renders it difficult to isolate individual information. Here, we unmixed the magnetic mineralogical signals of sediments from the northwestern South China Sea since the last deglaciation. We found that a higher hematite to goethite ratio (Hm/Gt) in our core represents higher precipitation in Red River catchment. The Hm/Gt variation indicates a relatively drier mid‐Holocene and a wetter early and late‐Holocene in the Red River catchment, which is consistent with the precipitation records in Southern China but opposite to that of Northern China. The chemical weathering of the Red River catchment was decoupled from the Asian Summer Monsoon, exhibiting a higher weathering extent (more fine‐grained magnetite was generated) during the last deglaciation due to secondary weathering on the continental shelf. Moreover, the relative abundance of magnetofossils in our core was consistent with changes of the sea level and deep‐water environments. Therefore, the isolation of magnetic mineral information from marginal sea sediments can help to reconstruct the continent‐ocean environmental changes.
... Despite that, only a few sand provenance studies focused on sediment accumulation and residence time in intermediate alluvial sinks (Garzanti et al., 2011;Sinha et al., 2009). On the contrary, several researchers investigated the provenance of detritus accumulated in deep marine (Amorosi et al., 2022;Critelli et al., 2003;Li et al., 2021;Limonta et al., 2023;Liu et al., 2016;Schroeder et al., 2015;Tentori et al., 2018;Van Grinsven et al., 2019) and coastal sinks (Goodbred Jr & Kuehl, 2000;Ji et al., 2022;Palamenghi et al., 2011;Xue et al., 2010). ...
Integrated stratigraphic‐compositional studies on alluvial successions provide a valuable tool to investigate the provenance of detritus in multi‐source systems. The Po Plain is an intermediate sink of the Po‐Adriatic source‐to‐sink system, fed by rivers draining two orogens. The Alps are characterized by extensive outcrops of plutonic‐metamorphic and ultramafic rocks to the north‐west and of Mesozoic carbonates to the east (Southern Alps). The Northern Apennines, to the south, are dominated by sedimentary successions. The Po River flows from the Western Alps to the Adriatic Sea, interacting with a dense network of transverse tributaries that drain the two orogens. Stratigraphic, sedimentological and compositional analyses of two 101 and 77.5 m‐long cores, recovered from the Central Po Plain, reveal the stacking of three petrofacies, which reflects distinct provenance and configurations of the fluvial network. A South‐Alpine sedimentary input between MIS 12 and MIS 10 is testified by petrofacies 1, characterized by carbonate‐ and volcanic‐rich detritus from rocks exposed in the Southern Alps. A northward shift of the Po River of more than 30 km is marked by a quartz‐feldspar and metamorphic‐rich detritus (petrofacies 2), similar to modern Po River sands. This dramatic reorganization of the fluvial network likely occurred around MIS 9–MIS 8 and is possibly structurally controlled. A further northward shift of the Po River and the onset of Apennine sedimentation in the Late Holocene is revealed by petrofacies 3, rich in sedimentary lithics from the Apennine successions. The results of this study document how compositional analysis, if framed in a robust stratigraphic picture, may provide clues on the evolution of multi‐source alluvial systems.
... It is bound by the Asian continent to the northwest, the Indonesian and Philippine archipelagoes to the southwest and southeast, respectively, and Taiwan to the northeast (Fig. 1). EASM proxies in the SCS region are highly sensitive to changes in 1) atmospheric circulation, 2) terrigenous input (e.g., Liu et al., 2016), and 3) ocean circulation in the Pacific Ocean that passes through the Luzon Strait (e.g., Qu, 2000;Qu et al., 2006;Tian et al., 2006a). This makes the SCS an area of interest for studying late Cenozoic changes in the EASM system. ...
... Over 700 million metric tons of fluvial sediment representing approximately 3.7% of estimated global fluvial sediment discharge into the SCS ( Fig. 1A; Milliman and Farnsworth, 2011). The main sediment sources to the SCS are the Pearl, Red, and Mekong Rivers, and rivers draining southwestern Taiwan; small mountainous rivers in the Philippines only contribute minor amounts (e.g., Clift et al., 2002;Liu et al., 2016;Milliman and Farnsworth, 2011;Wan et al., 2007;Fig. 1A). ...
... Studies of modern seafloor sediment in the SCS show that sediment composition is strongly controlled by its provenance and records the mixing of sediment from the major fluvial point sources in the region ( Fig. 1) (e.g., Clift et al., 2014;Clift et al., 2022;Horng and Huh, 2011;Kissel et al., 2016Kissel et al., , 2017Liu et al., 2009;Liu et al., 2007;Liu et al., 2010b;Liu et al., 2016;Wan et al., 2010b). Modern-day sediment from the main fluvial point sources to the SCS has distinct magnetic susceptibility (χ) signatures (Horng and Huh, 2011;Kissel et al., 2016Kissel et al., , 2017, and χ values of seafloor sediment in the SCS strongly reflect their provenance. ...
Late Cenozoic changes in the intensity of the East Asian Summer Monsoon (EASM) are reconstructed using both terrestrial and marine proxy records; however, proxies from terrestrial (e.g., loess, pollen, and pedogenic isotopes) and marine environments (e.g., foraminifer assemblages and geochemistry) commonly display large discrepancies both in the direction and timing of changes in the EASM. In part, these discrepancies reflect long-term changes in paleogeography that are independent of climate variations. We assess the influence of a rapidly uplifting orogen on EASM records by comparing temporally constrained gamma-ray, δ13Corg, hematite/goethite, and magnetic susceptibility records from Late Miocene–Early Pleistocene strata of the Taiwan Western Foreland Basin to time-equivalent EASM proxy records in the South China Sea (SCS).
Prior to the emergence of modern Taiwan (~6.3–5.4 Ma), sediment in the SCS was largely derived from Eurasia and transported into the Pacific Ocean. Following its emergence and southwest migration of the collision zone ~5.4 Ma, proto-Taiwan became a major sediment source to the SCS. The uplift and southwest migration of Taiwan and northwest migration of the Luzon volcanic arc resulted in the formation of southwest-flowing deep- (1500–2500 m water depth) and bottom-water (>2500 m water depth) currents and the SCS Branch of the Kuroshio Current. Together these currents transported sediment from Taiwan towards the SCS. Increased sediment input from Taiwan is recorded as a decline in hematite/goethite values in sediment records from the northern and central SCS. By ~3.2 Ma, continued southwest migration and growth of the Taiwan orogen resulted in the formation of the Taiwan Warm Current, which remobilized some sediment from Taiwan towards the East China Sea. Despite strengthening of deep-water currents during the Late Pliocene–Early Pleistocene, relative sediment input from Taiwan to the wider SCS decreased. Consequently, relative contributions from Eurasia and Luzon increased. In the southern SCS, where the Mekong River has dominated sedimentation since the Late Miocene, proxy records show no influence from the Taiwan orogen and instead reflect environmental changes in Mainland Southeast Asia driven mainly by monsoon variability.
Our results show that a rapidly uplifting orogen has the potential to significantly impact paleoclimate records >1000 km away from the collision zone. This highlights the influence of shifting sediment sources on paleoclimate proxy records, which must be considered in interpreting past climate change from the sedimentary record.
... The spatial distribution of 239+240 Pu concentrations and 240 Pu/ 239 Pu atomic ratios in sediments and seawater of the northern SCS and eastern IND have been partially investigated (Lee et al., 2009;Liu et al., 2016;Mulsow et al., 2003;Povinec et al., 2005;Qu et al., 2000;Uddin et al., 2017;Wang et al., 2019;Wu et al., 2018;Wu et al., 2014;Xie et al., 2021;Yamada and Zheng, 2021;Yamada et al., 2006). However, for the overall exploration of the distribution and change of 239+240 Pu throughout the region, information on 239+240 Pu in the SCS and IND still remains scarce. ...
... The SCS is the largest marginal basin of the Pacific, which connects with the IND through a series of straits. The SCS is one of the most important sinks of large river sediments from Asia (Liu et al., 2016;Milliman and Farnsworth, 2011). Seawater with high salinity from the Pacific is transported to the SCS by surface currents and the bottom current of the Kuroshio Current (KC) through the Luzon Strait (LS) (Wu et al., 2018;Wu et al., 2014;Xie et al., 2021). ...
... In addition, the KC bottom invades the northern SCS (NSCS) and turns to the subsurface (~500 m) in the mid-SCS, and the high 239+240 Pu activity at 09E401 on southwest Taiwan Island might be related to high smectite in sediments, 239+240 Pu is carried from Luzon Island by the KC (Jia et al., 2019;Nayak et al., 2021;Wu et al., 2019b). The high 239+240 Pu activity (located at NS-02-13 and activity up to 1.071 ± 0.082 mBq/g) near the eastern Mekong estuary may result from smectite transported from the Thailand Gulf by WBC (Liu et al., 2016;Zhang et al., 2022b). Smectite plays an important role in the Pu removal process (Kumar et al., 2013). ...
... Island make the Taiwan sediments be controlled by source rocks and characterized by lower 87 Sr/ 86 Sr ratios(Garzanti and Resentini, 2016;Liu et al., 2016;Nayak et al., 2022). More ...
... Data of the southwestern Taiwan rivers fromLi et al. (2013), Pearl River fromXu and Han (2009), and Luzon rocks fromMarini et al. (2005); (b) Sr-Nd isotopic compositions. Data of the Pearl River(Cao et al., 2019;Liu et al., 2016), Luzon rivers, Taiwan rivers(Deng et al., 2019;Dou et al., 2016), northeastern SCS shelf(Cao et al., 2019), and core MD12-3434(Zhao et al., 2018b) are plotted for comparison. ...
... The A-CN-K ternary diagram of terrigenous sediments of core MD12-3429. Data of Luzon rivers clay, Pearl River (<63 μm), Pearl River suspended particle matter (SPM), Taiwan rivers (<63 μm), Taiwan rivers clay(He et al., 2020;Liu et al., 2016), and UCC(Rudnick and Gao, 2003) are also plotted for comparison. ...
... The steep slope of the northern SCS hosts perpetual southwestward slope flows and intraseasonal mesoscale eddies, which supply an important conveyor for material transport from the shelf to the slope (Hu et al., 2000;Wang et al., 2020). Moreover, a series of mesoscale anticyclonic eddies distributed along the continental slope from the southwest of Taiwan to the west of the Dongsha Islands are perhaps the detachment of warm rings from the Kuroshio Current (Liu et al., 2016). The eddy-induced cross-slope flow is an important conveyor for water and material (including organic carbon) exchange between the deep basin and shelf (Geng et al., 2021). ...
... In comparison, core D2 has the lowest HA content, likely influenced by the mountainous Gaoping River input from the southwestern Taiwan Island. The Gaoping River catchment has the world's highest erosion rates and transports much highly degraded aged soil OM or petrogenic OM from bedrock (Liu et al., 2016;Zhang et al., 2018). The relict OM transported by the Gaoping River could contribute more aged OM but fewer HAs to the site. ...
... At the deep basin site S9, it is further degraded and aged in sediment. Core D2 has exceptionally old TOC (4777-6417 years) and organic fractions (480-15,060 years), even older than those in the deep basin core S9 (Fig. 4b), further demonstrating that this aged OM is derived mainly from mountainous rivers such as the Gaoping River from the southern Taiwan Island which contributes a large amount of bedrock weathering ancient OM to the steep slope region and is buried in sediment (Blattmann et al., 2019;Kao et al., 2014;Lin et al., 2020;Liu et al., 2016). ...
https://authors.elsevier.com/a/1iMuA26gajkXI
