CAJ | 학술논문

通过水槽试验模拟扇三角洲的形成过程,考察湖平面变化对扇三角洲发育的影响.试验结果表明:湖平面上升期扇面以片流沉积为主,分流河道不明显;湖平面稳定期扇面分流河道侧向侵蚀作用较强,改道频繁,底砾层在剖面上呈倾斜的月牙状杂乱分布;湖平面下降期扇面分流河道数量少且发育稳定,下切作用明显,剖面上底砾层为平行下凹的月牙形;随着湖平面由上升至稳定再至下降,扇三角洲垂向加积程度减弱、侧向进积程度增强,扇体厚度减薄、范围扩大,扇缘由圆滑弧形变为不规则弧形,扇面粒度分布差异性亦明显减小.
통과수조시험모의선삼각주적형성과정,고찰호평면변화대선삼각주발육적영향.시험결과표명:호평면상승기선면이편류침적위주,분류하도불명현;호평면은정기선면분류하도측향침식작용교강,개도빈번,저력층재부면상정경사적월아상잡란분포;호평면하강기선면분류하도수량소차발육은정,하절작용명현,부면상저력층위평행하요적월아형;수착호평면유상승지은정재지하강,선삼각주수향가적정도감약、측향진적정도증강,선체후도감박、범위확대,선연유원활호형변위불규칙호형,선면립도분포차이성역명현감소.
The formation of fan delta was simulated by flume experiment, and the effects of lake level change on fan delta development were investigated. The experimental results show that in the period of lake level ascending, sheet deposits develop on fan surface and the distributary channels are indistinct. When the lake level is immobile, the fan-surface channels laterally erode strong and changed the routes frequently. Basal debris beds distribute in a jumble with the shape of angled crescents in profile. In the period of lake level descending, the fan-surface channels develop steadily with obvious vertical erosion. And the basal debris beds develop like parallel and concave crescents in profile. And also, with lake level from ascending to immobile, then to descending, the vertical accretion of fan delta is reduced, but the lateral progradation is intensified. The thickness of fan delta decreases, but the range extends. The boundary of fan delta changes from smoothing arc-like to irregular arc-like. The difference of grain distribution on fan surface decreases.