热带地理
熱帶地理
열대지리
TROPICAL GEOGRAPHY
2014年
5期
663-671
,共9页
彭学敏%贾玉连%胡亚萍%邢娜%龙进%赖忠平
彭學敏%賈玉連%鬍亞萍%邢娜%龍進%賴忠平
팽학민%가옥련%호아평%형나%룡진%뢰충평
下蜀土%粒度特征%芙蓉-周溪断面%赣北地区
下蜀土%粒度特徵%芙蓉-週溪斷麵%贛北地區
하촉토%립도특정%부용-주계단면%공북지구
Xiashu Loess%grain-size features%profile of Furong-Zhouxi%Northern Jiangxi Province
赣北鄱阳湖地区沙山南部近南北向的芙蓉-周溪断面上,分布由FZ-01、FZ-02~FZ-05和FZ-06~FZ-12三部分组成的下蜀土剖面,粒度分析结果表明:1)下蜀黄土砂粒组分自北往南变化为27.29%、1.94%~7.23%和0.45%~7.27%;粉砂组分质量分数大,且存在差异变化,分别为68.23%、81.71%~87.20%和66.9%~79.39%;黏土组分自北向南质量分数增加,变化为4.48%、8.46%~16.35%和18.13%~32.07%,总体表现为砂黄土-黄土-黏黄土等相态的逐渐过渡;2)粒度三组分、粒度参数散点图等均表现为从北而南的阶段性系统渐变特征;3)各种粒度参数与距长江的远近,均服从对数函数变化关系。这些特征初步揭示研究区的下蜀黄土是风成的,并可能与同样是风成堆积的沙山的形成存在某种联系,属于区域性风沙-风尘堆积体系。
贛北鄱暘湖地區沙山南部近南北嚮的芙蓉-週溪斷麵上,分佈由FZ-01、FZ-02~FZ-05和FZ-06~FZ-12三部分組成的下蜀土剖麵,粒度分析結果錶明:1)下蜀黃土砂粒組分自北往南變化為27.29%、1.94%~7.23%和0.45%~7.27%;粉砂組分質量分數大,且存在差異變化,分彆為68.23%、81.71%~87.20%和66.9%~79.39%;黏土組分自北嚮南質量分數增加,變化為4.48%、8.46%~16.35%和18.13%~32.07%,總體錶現為砂黃土-黃土-黏黃土等相態的逐漸過渡;2)粒度三組分、粒度參數散點圖等均錶現為從北而南的階段性繫統漸變特徵;3)各種粒度參數與距長江的遠近,均服從對數函數變化關繫。這些特徵初步揭示研究區的下蜀黃土是風成的,併可能與同樣是風成堆積的沙山的形成存在某種聯繫,屬于區域性風沙-風塵堆積體繫。
공북파양호지구사산남부근남북향적부용-주계단면상,분포유FZ-01、FZ-02~FZ-05화FZ-06~FZ-12삼부분조성적하촉토부면,립도분석결과표명:1)하촉황토사립조분자북왕남변화위27.29%、1.94%~7.23%화0.45%~7.27%;분사조분질량분수대,차존재차이변화,분별위68.23%、81.71%~87.20%화66.9%~79.39%;점토조분자북향남질량분수증가,변화위4.48%、8.46%~16.35%화18.13%~32.07%,총체표현위사황토-황토-점황토등상태적축점과도;2)립도삼조분、립도삼수산점도등균표현위종북이남적계단성계통점변특정;3)각충립도삼수여거장강적원근,균복종대수함수변화관계。저사특정초보게시연구구적하촉황토시풍성적,병가능여동양시풍성퇴적적사산적형성존재모충련계,속우구역성풍사-풍진퇴적체계。
Xiashu loess is distributed over the southern dune in Poyang lake region,the north of Jiangxi province. The color of the loess becomes darker and darker from south to north, but the layer and sedimentology characters in different places are similar. It is homogeneous,unstratified and blocky in structure. Xiashu loess lies on the bedrock formed in different times and with different causes, or lies on the palaeo-landform which is formed from accumulation and suffered from serious erosion. Thick loess normally deposited in the front parts of mountains, while lesser loess on the peaks and steep slopes. On the whole, the thickness of the Xiashu loess reduces gradually from north to south. The granularity data of the section from Furong (located on the south bank of the Yangtze River) to Zhouxi (located on the shore of Poyang Lake) along a N-S direction shows that: 1) Sand grain component changes from north to south, and the concrete data are 27.29%, 1.94%~7.23%and 0.45%~7.27%. The silt component varies greatly, the data are 68.23%, 81.71%~87.20% and 66.9%~79.39%. The clay component increases gradually from north to south, the data are 4.48%, 8.46%~16.35% and 18.13%~32.07%. The overall performance is that the sedimentary facies of the Xiashu loess change from sandy loess to loess to clayey loess;2) Change characteristics of triangular chart of clay-silt-sand and granularity parameters scatter diagrams vary systematically from north to south; 3) All kinds of granularity parameters have involvement with the distance from the Yangtze river, which conform to logarithmic function. According to the index system and using the acquirable data, we consider that the Xiashu loess is an eolian deposit, it may have a certain relation with the formation of the sand dune in Poyang Lake region, belonging to regional sand-dus eolian deposition system.