| dc.description.abstract | The Cenozoic sequences of Taiwan had been studied by many geologists, and recent publish, which gave a new strata division and correlated some of the successions to northern ones, used biostratigraphy and U-Pb dating of pyroclastic deposits. The oldest cropped out stratum in central Taiwan is used to be called Tsukeng Formation, and is now been renamed as Pinglin Tuff and Wuchishan Formation (Huang et al., 2012, 2013). 11 well logs data had been used for helping strata correlation. 14 samples from filed investigate are depositional environments assistants.
The name of the scrutinized oldest stratum is Pinglin Tuff, and other strata in survey included Wuchishan Formation, Shihszeku Formation, Tanliaoti Shale, Shihmen Formation and Changhukeng Shale. Glauconites were found in Wuchishan Formation and Peliao Formation, especially Peliao Formation. The mineral is a wonderful environments indicator stands for warm, shallow water with low depositional rate. Calcite cements often found in transgressive sands.
Sequence stratigraphy and depositional facies analysis had been used for this study, which can built up a time related depositional model and the environmental description. The environmental interpretation result implies that the outcrops remain deposits of four environments, there are: shallow marine volcano apron, Lagoon-wave dominated estuary, Wave-dominated, tidal-influenced coasts and offshore continental shelf, and interpretation of well logs gets addition one is fluvial system. 11 sequences were divided out from outcrops and wells deposits, the sequences are well correlated, and give the perfect result of strata correlation: Tanliaoti Shale to Taliao Formation, Shihmen Formation is equivalence to Shihti and Peiliao Formation, and Changhukeng Shale to Talu Shale.
The northern three well log data were used to be belong to another river system. The field survey area is the closest spot to depositional basin among all check points. The east west profile shows that sequence accumulation at two depocenter in sequence 1 to 4, which deposits thickness doesn’t show regularity, but in the later deposit stages, sediments show stable thinning from source to sink.
The study concluded that: The field survey area shows high relativity to the northern depositional system, that’s makes the field area to be a perfect correlated successions. | en_US |