The samples for this study were adopted from the drilling cores for the slope-stability monitoring project inside the campus of NSYSU. Stratigraphically the strata belongs to the Gutingken Formation and is lain below the Kaohsiung Limestone. Two cores were selected for this research, one is W-2 (N: 2504008.088; E: 174168.943, 60m in length) and the other is S-4 (N: 2503968.458; E: 174009.179, 55m in length). The thickness of the Gutingken Mudstone in cores W2 and S4 is 38.7m and 21.8m, respectively. Each sample was obtained at every 10 cm interval for W2 and 30~40 cm for S4 with an average weight of 40 g. This study mainly contains two parts: analyzing the planktonic foraminifera for their carbon and oxygen stable isotopic compositions and dating the downcore records by correlating with the nannobiostratigraphy. Particular is the stable isotopic compositions of planktonic foraminifera in these terrestrial sedimentary sequences which has not been done in Taiwan before. Overall the mudstone analyzed in this study falls in the biostratigraphic range of small Gephyrocapsa Subchron, which spreads within 1.242 Ma~1.031 Ma. according to previous report. The age range is further constrained at about 1.186~1.065 Ma based on the oxygen isotope record and thus can be regarded as a high-resolution isotopic stratigraphy within the small Gephyrocapsa subchron. The average sedimentation rate inferred by the best age model from these cores is about 31cm/ky. It shows a progressive decrease in sedimentation rates: the younger the strata, the lower the sedimentation rate. On the contrary, the sedimentation rate varies dramatically at the lower part of the record. The turbidity current might be a potential factor responsible for the change. In addition, the spectral analysis of £_18O data presents a comparatively significant cycle of about 2.5ky through out the record. It might indicate a periodic forcing which influenced the environment during sediment depositation. The £_13C record obtained from this study fail to reflect the high productivity during the glacials. The mechanism that might affect the productivity in the area is not clear and still needs advanced research.

The samples in this study were collected from the drilling cores W-2 and S-4 obtained from the slope-stability monitoring project inside the campus of NSYSU. The Sheng-Li (SL) core was drilled for groundwater monitoring project in the northern of Kaohsiung city. The mudstone sections in these three cores were sampled to reconstruct the sedimental history of the southwestern Taiwan. This study mainly contains 3 parts: firstly we dated the downcore records based on nannobiostratigraphy. Secondly, we analyzed the benthic foraminiferal assemblages in sedimentary sequences. Finally we chose specific benthic species and analyzed the shell trace metals, especially Mg/Ca and Sr/Ca ratio with an ICP-MS. Overall the mudstone sections analyzed in this study fall in the biostratigraphic range of small Gephyrocapsa Subchron, which spreads within 1242ka~1031ka according to the previous report. The age range in W-2 was further constrained within 1186ka~1065ka based on the oxygen isotope stratigraphy (Tseng, 2004). There are four dominant benthic species, including Bulimina spp., Uvigerina spp., Brizalina tainanesis and Siphogenerina raphanus in Cores W-2 and S-4. There are five dominant benthic species, including Brizalina spp., Pseudorotalia spp., Siphogenerina raphanus, Amphicoryna scalaris and Brizalina alata in Core SL. The benthic foraminiferal shell Mg/Ca ratios obtained from Core W-2 indicate the bottom water temperature are between 6 - 12¢J, which reflects the paleo water depth had varied between 300 - 700m. It also indicates that strata were uplifted and the deposition depth become shallow.