Changes

==Characteristics of Alluvial Fan==

==Characteristics of Alluvial Fan==

[[Alluvial]] fans are cone-shape and have many distributary channels. From the fanhead to the fantoe and also from the cross section, it’s concave upward. Alluvial fan deposits are mostly gravel-sized sediments and show down-fan decreased in grain size and bed thickness and an increase in sediment sorting. The characteristics of debris-flow-dominated fan are the poorly sorted sediment with coarse grain sizes and muddy matrix. But the stream-flow- dominated fans are more sheetlike deposits of finer grain sizes and may have well sorted, laminated, cross-bedded or nearly strcutureless. Mostly, alluvial fan deposits have strongly developed thickening and coarsening-upward succesion, which are caused by active fan progradation or outbuilding. But there are some fan deposits have thinning and finning upward succession which are caused by fan retrogradation.

[[Alluvial]] fans are cone-shape and have many distributary channels. From the fanhead to the fantoe and also from the cross section, it’s concave upward. Alluvial fan deposits are mostly gravel-sized sediments and show down-fan decreased in [[grain size]] and bed thickness and an increase in sediment sorting. The characteristics of debris-flow-dominated fan are the poorly sorted sediment with coarse grain sizes and muddy matrix. But the stream-flow- dominated fans are more sheetlike deposits of finer grain sizes and may have well sorted, laminated, cross-bedded or nearly strcutureless. Mostly, alluvial fan deposits have strongly developed thickening and coarsening-upward succesion, which are caused by active fan progradation or outbuilding. But there are some fan deposits have thinning and finning upward succession which are caused by fan retrogradation.

==River Systems==

==River Systems==