Benthic Foraminifera Response To Changes In Paleoenviornments Of The Yellow Sea Mud Area Through The High Resolution Of Holocene Stratigraphic Analysis

In this paper, collected from benthic group in the central South Yellow Sea mudarea YS01A cylindrical samples for qualitative and quantitative research and analysis,combined with AMS¹⁴C dating measurement data, the deposition rate in the centralSouth Yellow Sea mud area since the Holocene, depth change, paleoenvironmentalchange the background of a preliminary study.According to the study we found that the content of benthic foraminifera in YS01Acore, shelf shallow water species, rare planktonic foraminifera, benthic foraminifera tothe relatively narrow salt shallow, cold-species and euryhaline nature, semi-dominantsaltwater shore. Through the analysis of the characteristics of the benthic foraminiferafauna can be divided into six benthic foraminiferal assemblages, based on foraminiferalassemblages of the study found:1. YS01A core and the South Yellow Sea mud area cores deposition rate comparedto the high deposition rate, and speculated that the location of the YS01A core. Thedeposition rate has shown a significant decline in the9.7ka BP to6.8kaB.P. The mainreason: the diversion of the Yellow River in central South Yellow Sea sediment input hadan impact on the Yellow Sea circulation and its associated central South Yellow Sea mudthe quality of the area has not yet formed, making the material supply in the period ledto the deposition rate decreases.2. The region has experienced since11kaB.P since the start of the water depthchanges from shallow to deep and then shallow process. In9.7kaB.P. The water depthincreases, until4.8kaB.P. Depth maximum depth faded4.8kaB.P. After, until the waterdepth.3. The region6.8kaB.P.⁵.6kaB.P. During the period by the flow of the Yellow Sea coast current strong;5.6⁴.8kaB.P. During the Yellow Sea coastal current of theinfluence weakened in the Yellow Sea cold water mass the impact of enhanced depthincrease.4.8kaB.P. after the flow impact of the Yellow Sea coast current continue toweaken, the Yellow Sea cold water mass in the region is gradually strengthen, andcontinue to the present.5. Through analysis of the YS01cores foraminiferal assemblages, the regionalHolocene paleoenvironmental changes since divided into the following five stages:Stage One:11.2kaB.P.⁹.7kaB.P. In this stage mainly to the shore in shallowwater species and cold-species also contain a certain amount in the intertidal zone,estuarine areas rich in species. This period, the climate changed from dry and cold towarm and cool transformation, slightly humid climate is mild.Stage Two:9.7kaBP⁶.8kaBP the period-rich continental shelf of shallow waterspecies, and in the South Yellow sea cool species dominated. This stage for a warmperiod, sea level rise.Stage Three:6.8kaBP⁴.8kaBP This period foraminiferal assemblages containedin the main deep-water molecules in the core during this period, the water depth tofurther increase, warm and humid.Stage Four:4.8kaBP³.2kaBP deep foraminiferal assemblages of this periodreflect a near shore shallow marine depositional environment. Cool, dry climate at thistime.Stage Five:3.2⁰kaBP foraminifer to shallow water content of the most abundant,reflecting the period of sea level stability, low seawater temperatures, low temperatures,high humidity, cool and humid climate.