5:15 PM - 6:45 PM
[HQR04-P10] Late Pleistocene climate and history of coastline using stable isotopes and Ostracod records from Dapeng Bay, South Taiwan
Keywords:Ostracod, microfossil, coastline
In coastal areas, the composition of ostracod species is influenced by water depth and sediment characteristics. Consequently, fluctuations in water depth can lead to variations in sediment, which in turn can have an impact on ostracod populations. Through the cluster analysis of ostracod population, historical changes in water depth and sediment composition can be reconstructed. The current study aims to infer the evolution process of Dapeng Bay and record extreme climate events through the analysis of microfossils and stable isotopic compositions in a 240-meter-long core collected from Dapeng Bay, covering the time frame from 36000 to present. Through ostracod counts combined with isotope analysis, our aim is to reconstruct changes in coastline, variations in water depth, and records of extreme events. This will aid in predicting the relationship between global warming-induced sea-level rise and its impact on coastline changes.
Preliminary results of pollen records from the same locations showed four distinct periods: Late Pleistocene (38000-16000 years BP) characterized by terrestrial and wetland environments, Last Deglacial (16000-11000 years BP) featuring nearshore continental shelves, Mid-Holocene (11000-5000 years BP) with mangrove ecological environments, and Late Holocene (5000 years BP to present) marked by estuarine and riverine systems.
In the current study, due to unavailability of organic matter, data is missing from 36000 to 16000 years BP. The C/N ratios showed most of values were less than 10, representing the aquatic productivity were dominant in the region from 16000 years BP-present. The δ¹³C values exhibited a decreasing trend from 16,000 to 11,000 years BP, followed by a period of consistently low values until 5,000 years BP. These trends suggest a drier climate during 16000-11000 years BP which gradually improved towards 5000 years BP. From 5000 years BP to the present, data were limited, but δ¹³C indicated slightly higher values, suggesting drier climate conditions in the region. Additionally, during the conference ostracod data will be also discussed.
Preliminary results of pollen records from the same locations showed four distinct periods: Late Pleistocene (38000-16000 years BP) characterized by terrestrial and wetland environments, Last Deglacial (16000-11000 years BP) featuring nearshore continental shelves, Mid-Holocene (11000-5000 years BP) with mangrove ecological environments, and Late Holocene (5000 years BP to present) marked by estuarine and riverine systems.
In the current study, due to unavailability of organic matter, data is missing from 36000 to 16000 years BP. The C/N ratios showed most of values were less than 10, representing the aquatic productivity were dominant in the region from 16000 years BP-present. The δ¹³C values exhibited a decreasing trend from 16,000 to 11,000 years BP, followed by a period of consistently low values until 5,000 years BP. These trends suggest a drier climate during 16000-11000 years BP which gradually improved towards 5000 years BP. From 5000 years BP to the present, data were limited, but δ¹³C indicated slightly higher values, suggesting drier climate conditions in the region. Additionally, during the conference ostracod data will be also discussed.