Palynology,Palaeoclimate And Palaeoecology Of The Miocene Shanwang Basin,Shandong Province

The Shanwang palynoflora has been subjected to detailed systematic analysis, documenting palynofloral compositions and distributions from the Shanwang basin. This includes descriptions and ranges for the full range of sporomorph taxa present in the studied section. This includes 130 closely spaced (10-30 cm) and stratigraphically collected samples from the Shanwang profile that have allowed high resolution results to be determined. The list of sporomorphs present includes 111 pollen and spore taxa, their general stratigraphic occurrence and distribution throughout the Shanwang profile as well as their nearest living relatives and their present day distributions. According to the general stratigraphical occurrences of the sporomorph taxa within the fossil bearing deposits, the sediments of the Shanwang Basin can be dated as early Middle Miocene. This age is complimentary to radiometric data ranging from 16.78-14.11 Ma, and Mammal biozones MN4-MN5. Using the coexistence approach of Mosbrugger and Utescher quantitative palaeoclimatic data has been obtained from the Shanwang biota for the first time. This suggests stable climatic conditions persisted throughout the Shanwang profile. Results indicate that the Mean Annual Temperature (MAT) was between 15.6-17.2 0 C, that the mean Temperature of the Coldest Month (TCM) was between 5.0-6.6 0 C and the mean Temperature of the Warmest Month (TWM) was between 24.6~27.80 C. Mean Annual Precipitation (MAP) has been determined in the range of 1162-1308 mm, with Precipitation of the warmest Month (PwarniM) being 108-11 1mm, Precipitation in the Driest Month (PDM) being 16-59 mm and precipitation of 148- 180 mm occurring in the wettest month (PwetM?. Relative Humidity (RH) has been calculated as 72-75 %. This also indicates that there is climate fluctuation between high resolution pollen samples. It is up to 3 0 C for mean annual temperature, up to 4 V Abstract o C for temperature of the coldest month, up to 1 0 C for temperature of the warmest month, up to 100mm for mean annual precipitation. According to modem systems of climate classification the Shanwang Miocene palaeoclimate is classified as Koppen?s 揅fa climate?type that demonstrates a warm, humid and temperate climate. The climate difference between the early middle Miocene Shanwang palaeoclimate and the present day climate of the Shanwang region are mainly associated with significantly reduced levels of precipitation (mean annual precipitation and rainfall distribution) and much colder mean temperatures in the coldest month. Using multivariate statistical analysis the palaeovegetation of the Shanwang profile has been reconstructed. This indicates that the Shanwang Miocene vegetation was a mixed mesophytic forest that experienced remarkably little change throughout the studied section. Small scale changes in sporomorph composition suggest floral changes in the vicinity of the Shanwang basin that are most likely related to Iocalised changes in topography, and these may be fault controlled.