Sedimentary environments of the late Miocene - Pleistocene strata, Tahan River section, northern Taiwan
Speaker: Pan, Tsun You
Abstract
Foreland basin strata deposited during late Miocene to Pleistocene. The strata included Kueichulin formation, Chinshui shale, Cholan formation, and Toukoshan formation. In former research, there were no foreland basin strata in northern Taiwan . This research can realize the sedimentary environments of foreland basin strata in northern Taiwan .
Tahan river section includes the top of Kueichulin formation, Chinshui Shale, and the bottom to the upper part of Cholan formation. The total thickness is 2087 meters. This section can be classified into 4 kinds of depositional systems and 14 kinds of sedimentary environments:
1. offshore system – included outer offshore and inner offshore.
2. shoreface system – included lower shoreface, upper shoreface, and the beach.
3. Barrier island system – included dune, tidal channel, tidal flat, and lagoon.
4. Fluvial system – included channel lag, point bar, levee, flood plain, and crevasse splay.
The sedimentary environments of Kueichulin formation and Chinshui shale indicated that the environments were deepening from shoreface to offshore. After Cholan formation formed, the environments were shallowing from offshore to shoreface, then reach the coastal depositional setting. In upper part of Cholan formation, the strata were deposited in the fluvial environments.
Reference
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