| dc.description.abstract | Mangrove swamp is an important intertidal wetland ecosystem with high primary productivity, abundant detritus, and also rich in organic carbon. In order to understand the process and mechanism of organic materials during burial and preservation processes in a mangrove swamp, we evaluated the mineralogy, total organic carbon (TOC %), Rock-Eval pyrolysis, water quality, as well as biomarker to analyze the depositional characteristics. Study site was a mangrove swamp in Tamsui, NW Taiwan. In this area, we chose two sampling sites, F (Far-off land) and N (Near land). Samples were collected from different depths (0-5cm, 5-15cm, 15-30cm, 30-40cm). We found that TOC varied between 0.17% and 0.8%, Tmax values were 364 to 443oC; S1 and S2 were ranging from 0.08 to 0.19 mg HC/g rock and 0.07 to 0.47 mg HC/g rock respectively. Hydrocarbon potential was immature in all samples. Far-off land samples exhibit higher total organic carbon content and S2 value than near land. Major organic matters we found in far-off land are algae and zooplanktons. However, organic materials in surface and bottom layer of the near land are terrigenous and marine materials, respectively. In addition, water quality data showed that both areas were influenced by sea water. F area also exhibited higher dissolved oxygen and electricity conductivity. Mineralogy from XRD indicated that all of the soils were characterized by quartz, feldspar, illite, kaolinite and chlorite. Major clay mineral in F samples is illite. Besides, illite and kaolinite are major clay minerals in N samples. Finally, biomarker analysis indicates an oxic environment of all samples. Based on the above analyses from different localities and depths, we found that the distance to the sea affects the source of organic materials, and redox conditions further affect the accumulation of organic materials. | en_US |