Shengfa Liu

State Oceanic Administration, Tsingtao, Shandong Sheng, China

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Publications (10)8.21 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: The sedimentary facies of the subaqueous Changjiang (Yangtze) River delta since the late Pleistocene was studied based on lithology and foraminifera analysis for two boreholes, CJK07 and CJK11, along with 14C dating. Four sedimentary facies were identified, namely fluvial, tidal flat, offshore, and prodelta facies. The fluvial sedimentary facies is comprised of fluvial channel lag deposits, fluvial point bar deposits, and floodplain deposits, showing a fining-upward sequence in general with no benthic foraminifera. A layer of stiff clay overlies the fluvial deposits in core CJK07, indicating a long-term exposure environment during the Last Glacial Maximum (LGM). During the postglacial sea-level rise around 13-7.5 cal ka BP, the tidal flat facies was deposited in core CJK11, characterized by abundant silt-clay couplets. Euryhaline species dominate the subtidal flat foraminiferal assemblages, while almost no foraminifera was found in the intertidal flat. The offshore environment was the major sedimentary environment when the sea level reached its highest level around 7.5 cal ka BP, with a maximum accumulation rate of 10 mm/a found in core CJK11. Prodelta sediments have been deposited in core CJK11 since ˜3 cal ka BP, after the formation of the Changjiang River delta. The difference in sedimentary facies between core CJK07 and CJK11 is due to their location: core CJK07 was in an interfluve while core CJK11 was in an incised valley during the LGM. Furthermore, AMS 14 C dating of core CJK07 shows poor chronological order, indicating that the sediments were reworked by strong tidal currents and that sediment deposited since ˜7.7 cal ka BP in core CJK07 was eroded away by modern hydrodynamic forces caused by the southward shift of the Changjiang River delta depocenter.
    Chinese Journal of Oceanology and Limnology 09/2013; 31(5):1107-1119. · 0.58 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: We present a paleoclimatic reconstruction of the mid-Holocene by geochemical analysis of a sediment core MZ01 retrieved from the mud area of the inner continental shelf of the East China Sea (ECS). Our results show that the downcore geochemical variations in the sediments of the core provide a link to historical climate changes. Relatively higher ratios of CIA, Ba/Sr and a lower ratio of CaO/MgO coincide with major regional warm and humid climate episodes, and vice versa. Therefore, these geochemical indicators are useful in reconstructing the paleoclimate in eastern China. Using the geochemical records of core MZ01, which are well constrained by AMS 14C dating, we found that from 8300 yr BP to 4200 yr BP the regional climate was moderately warm and humid, and from 4200 yr BP to 2300 yr BP the climate was cool and dry, with large fluctuations between cool-dry (3700 yr BP, 2850 yr BP and 2400 yr BP) and warm-wet (3250 yr BP and 2650 yr BP). Since 2300 yr BP, our records indicate that the climate has gradually become warmer, although a cold event centered at around 250 yr BP (the Little Ice Age, LIA) interrupted this warming trend. We also found significant 238 yr cycles in our CIA records that imply a possible solar influence on the regional climate changes since the mid-Holocene.
    Journal of Asian Earth Sciences 06/2013; · 2.38 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Heavy metals (Cr, Cu, Zn, Cd, Pb, Hg, and As), grain-size, pH, Eh, and total organic material (TOM and TN) of 59 surficial sediments of mud area from the inner continental shelf of the East China Sea have been analyzed. The relations of the heavy metals to sediment composition, pH, reduction/oxidation conditions and total organic materials were evaluated with multivariate statistics analysis, and the hydrodynamic conditions such as coastal current and Taiwan warm current are the other important controlling factors to the distribution of heavy metals. Sediment enrichment factors and potential ecological hazard index ( E\textRI E_{\text{RI}} ) were used to assess the heavy metals accumulation; the results indicate that moderate contamination of most heavy metals is prevalent, and the contamination level in the estuary is rather high, which is mainly from anthropogenic source. Compared with other areas in China, the contaminant level of the study area is moderate. KeywordsThe East China Sea–Mud area–Surficial sediment–Heavy metals–Contamination
    Environmental earth sciences 01/2011; 64(2):567-579. · 1.45 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Paleoclimate record was revealed in Core MZ01 covering the mid-Holocene in age, located in the mud area of the inner continental shelf of the East China Sea. The ancient environment featured low-energy shallow sea shelf deposition formed mainly by coastal currents. The results show that temporal variation in geochemistry corresponds with the climate changes inferred from historical record. Relatively low MgO/Al2O3, CaO/K2O and high Al2O3/Na2O, K2O/Na2O, MnO/CaO values reflected a warm and humid climate in general, and vice versa. Therefore, these chemical indices could be applied to identify the variation of palaeoclimate in eastern China. The authors reconstructed the history of mid-Holocene climatic variation of the inner continental shelf of the East China Sea. From 8 300 a BP to 4 200 a BP, the climate was moderately warm and humid. From 4 200 a BP to 2 000 a BP, the climate turned cool and dry, and the regional climate frequently fluctuated in alternation of cool-dry periods (3 700 a BP, 2 850 a BP and 2 400 a BP) and warm-wet periods (3 250 a BP and 2 650 a BP). After 2 000 a BP, the climate of the study area gradually turned warm again, while the Little Ice Age, a cold event centered at around 250 a BP was indicated by those geochemical indices as mentioned above. Key wordsHolocene–East China Sea–mud area–major element–palaeoclimate–East Asia monsoon
    Acta Oceanologica Sinica -English Edition- 01/2011; 30(4):43-52. · 0.58 Impact Factor
  • Marine Geology &amp Quaternary Geology 01/2010; 29(6).
  • [show abstract] [hide abstract]
    ABSTRACT: AMS14C dating and analysis of grain size, major elements and clay minerals were applied to Core MZ01 from the mud area on the inner shelf of the East China Sea. Based on the environmentally sensitive grain size, clay mineral and major element assemblages, the history of the East Asia winter monsoon since the mid-Holocene could be reconstructed. These three proxies, mean grain size (>9.71 μm), chemical index of alteration (CIA) and ratio of smectite to kaolinite in particular, show similar fluctuation patterns. Furthermore, 10 extreme values corresponding to the contemporary cooling events could be recognized since the mid-Holocene; these extreme values are likely to have been caused by the strengthening of the East Asia winter monsoon. The cooling events correlated well with the results of the δ18O curves of the Dunde ice core and GISP2, which therefore revealed a regional response to global climate change. Four stages of the East Asia winter monsoon were identified, i.e. 8300–6300 a BP, strong and unstable; 6300–3800 a BP, strong but stable; 3800–1400 a BP, weak and unstable; after 1400 a BP, weak but stable. KeywordsHolocene-inner shelf of the East China Sea-mud areas-grain size-clay mineral-elemental analysis-East Asia winter monsoon
    Chinese Science Bulletin 01/2010; 55(21):2306-2314. · 1.32 Impact Factor
  • Marine Geology &amp Quaternary Geology 01/2010; 30(1):17-24.
  • Marine Geology &amp Quaternary Geology 01/2009; 29(1):1-6.
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Located at the collision boundary between the Philippine Sea Plate and the Eurasian Continental Plate, the island of Taiwan is generally recognized as an important example in the MARGINS Program Science Plan and “source-to-sink” research because of its high tectonic activity, heavy rainfall and unique geography. Large suspended sediment loads are transported to the adjacent ocean by Taiwanese rivers every year, making Taiwan an important source of sediments into the adjacent seas and a natural laboratory for studying the systemic movement of fluvial sediments from source to sink. A detailed study on the clay mineral composition of surface sediments collected from the drainage basins of 12 Taiwanese rivers using X-ray diffraction methods was conducted. Our results indicated that the clay mineral assemblages consisted dominantly of illite (approximately 73%) and chlorite (approximately 24%), with lesser abundances of kaolinite (approximately 3%) and even lower levels of smectite from the Danshuei River sediments in northwestern Taiwan. The Jhuoshuei River sediments from western Taiwan contained clay mineral assemblages that consisted of illite (approximately 75%) and chlorite (approximately 25%), but they lacked kaolinite and smectite. In southwestern Taiwan, the clay mineral assemblages were dominated by illite (approximately 75%) and chlorite (approximately 23%), but had a low abundance of kaolinite (generally < 2%) and no smectite. The clay mineral assemblages in eastern Taiwan are obviously different from those in western parts of the island. The most noticeable difference is that the average abundance of chlorite in the Hualien River from eastern Taiwan was the highest (approximately 48%) of all the Taiwanese rivers. We concluded that, in general, the clay mineral assemblages in Taiwanese rivers were mainly composed of illite and chlorite with kaolinite and smectite being scarce, and these trends are different from those in China’s mainland rivers. The clay mineral composition shown in this study was primarily determined by the properties of the bedrock, and the differential weathering intensities of the drainage area. The surface sediments in Taiwan’s rivers showed a greater abundance of illite and chlorite because the outcropped rocks were mainly composed of Tertiary sedimentary rocks, especially sandstone, shale and slate, and show strong physical weathering. The relatively high relief and more abundant rainfall also caused the clay minerals in the fluvial sediments to be transported to the estuaries down rivers from the mountains and then delivered to the adjacent seas by currents and waves over a shorter time scale.
    Chinese Science Bulletin 57(6). · 1.32 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: The Inductively Coupled Plasma Optical Emission Spectrometer was used to analyze sediment samples collected from the Hangzhou Bay to determine major and trace elemental concentrations. Based on these concentrations, the study area can be classified into three geochemical provinces. Province I covers the northern Hangzhou Bay area and contains high concentrations of Al2O3, Fe2O3, MgO, Na2O, K2O, MnO, Cr, Cu, Ni, Pb, V, Co and Zn. Province III is located in the western Hangzhou Bay, near the Qiantang River mouth, and contains high concentrations of SiO2, Na2O, P2O5, TiO2, Cr, Sr, Zr. Province II is located in the middle and eastern Hangzhou Bay, with the medium concentrations of major and trace elements. The results also demonstrate that the grain size is the dominating factor controlling the spatial variations of elemental concentrations, and the Changjiang River (Yangtze River) and Qiantang River sediments play an important role in the distribution of these elements. Anthropogenic impact on heavy metal concentrations (especially Cr, Sr and Zr) can be detected in the surface sediments near the Qiantang River mouth.
    Acta Oceanologica Sinica -English Edition- 31(4). · 0.58 Impact Factor

Publication Stats

8 Citations
208 Views
8.21 Total Impact Points

Institutions

  • 2011
    • State Oceanic Administration
      Tsingtao, Shandong Sheng, China
    • First Institute of Oceanography
      Tsingtao, Shandong Sheng, China
  • 2010
    • Chinese Academy of Sciences
      • Institute of Oceanology
      Peping, Beijing, China