摘要
白垩系古沙漠风成砂岩是近年来湖南省新发现的一种沉积类型,该岩石不仅是特色的旅游资源,而且是全球关注的储能、储碳的重要目标储集层,因此对湖南省古沙漠的空间分布规律深入研究意义重大。本文引入遥感技术手段建立古沙漠露头遥感特征的识别及提取方法:以谷歌地球引擎(Google Earth Engine,GEE)为主要处理平台,以Sentinel-2A(哨兵二号)多光谱影像为主要数据源,从光谱、遥感指数和地形地貌三个方面分析古沙漠露头的遥感特征,采用随机森林算法进行古沙漠露头的遥感识别。区别于传统的陡直型丹霞地貌,古沙漠遥感影像色调均匀、连片分布,植被和山体阴影皆不发育,具有“顶圆,坡缓”的地貌特征。同时,深入分析古沙漠地貌的岩性特征,结合地质条件辅助约束,实现古沙漠露头的精准识别。通过上述方法,本文解译出湖南白垩系丹霞地貌区的多处古沙漠露头,并从识别结果中选择面积较大的衡阳盆地东缘(渡口地区)和茶永盆地东南缘(郴州市飞天山-高椅岭地区)地区的古沙漠风成砂岩进行了实地验证,效果理想。本文为研究古沙漠空间分布规律提供了高效的途径,是遥感技术在古沙漠地质领域的重要应用,旨在为国内地学界同行提供技术参考和借鉴。
The Cretaceous palaeo-desert aeolian sandstone is a new type of sedimentary discovered in Hunan Province in recent years.This rock is not only a characteristic tourism resource,but also an important target reservoir for energy and carbon storage of global concern,so it is of great significance to conduct an in-depth study on the spatial distribution pattern of palaeo-deserts in Hunan Province.In this paper,remote sensing technology is introduced to establish the recognition and extraction method of remote sensing features of palaeo-desert outcrops:With Google Earth Engine(GEE) as the main processing platform and Sentinel-2A multi-spectral image as the main data source,by analyzing the remote sensing characteristics of palaeo-desert outcrops from three aspects:spectral,remote sensing index and topography and geomorphology features,and the Random Forest Algorithm was used to identify the palaeo-desert outcrops by remote sensing.Different from the traditional steep and straight Danxia landforms,the remote sensing images of the palaeo-desert are uniform in colour tone,continuously distributed,with undeveloped vegetation and mountain shadows,and with the geomorphological characteristics of‘rounded tops and gentle slopes'.At the same time,deeply analysing the stratigraphic lithology characteristics of the palaeo-desert,the outcrop of the palaeo-desert is characterized accurately by increasing geological constraints.With the methods above,a number of palaeo-desert outcrops in Danxia landform area of various red bed basins in Hunan Province have been interpreted,and two large areas of palaeo-desert aeolian sandstones in the eastern margin of Hengyang Basin(Dukou area) and the southeastern margin of Chayong Basin(Feitianshan-Gaoyiling area of Chenzhou City) have been verified.This study provides an efficient way to study the spatial distribution law of palaeo-desert,which is an important application of remote sensing technology in the field of geology,aiming to provide technical and geoscience references.
作者
周丽芸
黄乐清
ZHOU Li-Yun;HUANG Le-Qing(Geological Survey Institute of Hunan Province,Changsha 410116,Hunan,China;Institute of Geological Survey,China University of Geosciences,Wuhan 430074,Hubei,China;Hubei Key Laboratory of Paleontology and Geological Environment Evolution,Wuhan 430205,Hubei,China)
出处
《华南地质》
CAS
2024年第2期393-403,共11页
South China Geology
基金
湖南省自然科学基金项目(2021JJ30388)
湖南省地质院科研项目(HNGSTP202322)
古生物与地质环境演化湖北省重点实验室开放基金(PEL-202203)。
