江西信江盆地丹霞地貌空间分布及其成因

Spatial Distribution and Its Genesis of the Danxia Landforms in Xinjiang Basin,Jiangxi

信江盆地是我国丹霞地貌发育最典型、最集中的红盆之一。由于控制丹霞地貌演化的红层、构造及外动力等成景要素制约,信江盆地内不同部位丹霞地貌经历了不同的演化进程,发育不同的景观组合。信江盆地边缘主要出露茅店组、河口组和莲荷组巨厚层砾岩、含砾砂岩和砂岩,以铁质胶结和少量钙质胶结为主,可溶性成分含量低,这些红层以发育高大的顶斜型峰林型、峰丛型丹霞地貌组合为特征;盆地中部的河口组上部和塘边组地层岩性以含砾砂岩和砂岩为主,并以钙质胶结为主,可溶性成分含量较低,常发育低矮的圆丘状丹霞地貌组合,大型岩洞是其典型的景观类型,过渡地带主要为河口组上部、塘边组和莲荷组下部的砂岩、含砾砂,丹霞地貌只发育于断层或河流发育地区,以顶平型丹霞地貌组合为特征。

Xinjiang Basin is one of the most typical and concentrated sites of danxia landform distribution in China. Dued to constraints of genesis system including red beds, structures and exogenic geological process that controlled evolution of it, the danxia landforms in different parts of Xinjiang Basin have undergone different evolutionary processes and formed different landscape assembly. In the margins ~f the basin there are exposed very thick bedded rocks including conglomerate, pebbly sandstone and sandstone of Maodian, Hekou and Lianhe formation, the ce- ments are mainly ferric and a small amount of calcareous and the content of the soluble ingredient is low. There de- veloped high cliffs and the Danxia Landforms are characteristic with hoodoos and peak clusters with a tilted top. In the middle of the basin there are exposed the upper of Hekou formation and Tangbian formation along the banks of Xinjiang River, the rocks are compose of thick or huge thick bedded sandsto,：e and pebbly sandstone with large cross bedding, calcitic cement and the content of the soluble ingredient is low, in where have developed lower cliffs with round tops and the typical landscape were big stone caves along the banks. Between the margin and middle, there exposed mainly sandstone of the upper of Hekou formation, Tangbian and the lower of Lianhe formation that developed mesa, narrow valley, stone cliffs with flat top.