干旱区生态环境知识资源中心(Arid): 西秦岭北缘武山地区上白垩统沙漠相沉积特征

Arid

	西秦岭北缘武山地区上白垩统沙漠相沉积特征
其他题名	Sedimentary Characteristics of the Cretaceous Desert Facies in the Wushan Area, Northern Margin of the Western Qinling Mountains
	惠浪波; 郭进京; 韩文峰; 王丽丽; 毕娜; 向光娅
来源期刊	沉积学报
ISSN	1000-0550
出版年	2017
卷号	35 期号:4 页码:649-663
中文摘要	西秦岭广泛但不连续分布着一套晚白垩世红层地层。这套红层地层所代表的原型沉积盆地是西秦岭中生代陆内造山期发育的相互孤立的山间盆地拟或是整体统一红层盆地新生代以来地壳隆升侵蚀破坏的残留一直存在争议。这个争议问题即关乎到对西秦岭中生代末期的构造地貌状态的认识,也关乎到现今青藏高原东北缘新生代以来地壳隆升初始地质背景。通过对西秦岭北缘武山地区上白垩统红层沉积地层中发育的一套砖红色砂岩的沉积序列、沉积构造、粒度分布等宏观地质特征的较详细研究,结合对这套砂岩的矿物成分和显微结构以及石英颗粒SEM表面结构特征的研究,表明这套砖红色砂岩具有如下特征:1)发育典型的大型风成交错层理;2)粒度均匀,分选好,以中-细砂、极细砂组分为主,缺乏粉砂-黏土颗粒组分;3)石英颗粒磨圆度好,表面发育碟形和新月形坑、溶蚀坑、硅质薄膜等风成砂颗粒具有的独特表面特征。据此提出这套砖红色砂岩是典型的沙漠相沉积的新认识,并根据沙漠相沉积类型的识别标志将其分为沙丘沉积和丘间沉积两种沉积类型。秦岭北缘武山地区晚白垩世沙漠相沉积的存在,结合西秦岭腹地同时代的哈达铺、岷县西江等地分布在山顶面的晚白垩世红层地层中存在类似的沙漠相沉积分析,提出了西秦岭晚白垩世不仅处于干旱炎热气候环境,而且曾呈现出地形相对平缓的泛盆地构造地貌状态。这套红层沉积反映了西秦岭晚白垩世为统一红层沉积盆地而非孤立的山间盆地,现今多不连续分布在山顶面之上是新生代以来地壳不均匀隆升和侵蚀共同作用的结果。
英文摘要	The red beds of late Cretaceous are widely and sporadically distributed in the western Qinling Mts. At late Cretaceous, the tectono-geomorphological features in the area are critical in elucidating the structural and geomorphological situation at the end of Mesozoic and determining the beginning time of the uplifting of the northeastern Qinghai-Tibet Plateau. That is, the red beds deposited in the independent intermontane basins or unified flat basin in the intra-continental orogenesis. In this paper, a suite of brick-red sandstones of the red beds of the upper Cretaceous located in the Wushan area, northern margin of the western Qinling Mts. are studied on the sediments sequence, structure and grain size analyses. Combining the mineral compositions, microscopic and SEM surface textures of quartz of the sandstones, the rocks have been discerned to have the following features: 1) developing macroscopic eolian cross-beddings; 2) the medium-fine grained, extremely fine-grained components dominate, but the siltstone-clay components are absent, with even sizes and well-sorting; 3) quartz is well-rounded and the surface develops typical eolian-origin disc-and crescent-type pits, erosion pits, and siliceous films. Therefore, we put forward that the brick-red sandstones are the typical desert facies deposits. According to the desert deposits symbols, the sediments are further subdivided into sand dune and inter-dune deposits. It is well known that the desert deposits have two essentials, the torrid-arid climate and relatively flat topography. Combining the determination of the desert facies sediments at the Wushan area, northern margin of the western Qinling Mts. similar desert facies sediments on the mount tops at Hadapu, Xijiang of Minxian county in the interior of the western Qinling Mts., it is proposed that the western Qinling Mts. were in torrid-arid climate and flat topography in late Cretaceous. That is the large scale, flat and unified basin developed in the area at that period. This deduction is critical for re-constructing the paleo-topography and climate of the western Qinling Mts. in late Cretaceous, and for geological constraining the geological background before the uplifting of the western Qinling Mts. since the Cenozoic.
中文关键词	西秦岭 ; 上白垩统 ; 沙漠相 ; 风成交错层理 ; 石英砂表面结构
英文关键词	western Qinling Mountains Upper Cretaceous desert facies aeolian cross-beddings surface structure of quartz sands
语种	中文
国家	中国
收录类别	CSCD
WOS类目	GEOLOGY
WOS研究方向	Geology
CSCD记录号	CSCD:6055114
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/235723
作者单位	天津城建大学地质与测绘学院, 天津 300384, 中国
推荐引用方式 GB/T 7714	惠浪波,郭进京,韩文峰,等. 西秦岭北缘武山地区上白垩统沙漠相沉积特征[J],2017,35(4):649-663.
APA	惠浪波,郭进京,韩文峰,王丽丽,毕娜,&向光娅.(2017).西秦岭北缘武山地区上白垩统沙漠相沉积特征.沉积学报,35(4),649-663.
MLA	惠浪波,et al."西秦岭北缘武山地区上白垩统沙漠相沉积特征".沉积学报 35.4(2017):649-663.