矿区红层与地貌发育特征研究现状及其地质学意义

Research status and geological significance of redbeds and danxia landforms

近年来,由于“中国丹霞”申遗成功和“国际地貌学家协会红层和丹霞地貌工作组(IAG Red Beds and Danxia Geomorphology Working Group)”的推动,启动了全球红层和丹霞地貌调查,开展国际对比研究。红层是形成丹霞地貌的物质基础。本文试图从全球红层的时空分布规律及其地貌发育的差异,本文综述了国内外红层的分布、形成时代、地质构造背景、古地理环境、岩性地貌特征。红层主要分布在东南、西南和西北地区。主要是中生代红层,构造环境主要为古陆块活化时形成的断陷/拗陷盆地;沉积环境几乎为陆相,形成于干旱或半干旱的古气候条件下,岩性复杂,兼具砾岩、砂岩、粉砂岩和泥岩,发育了丹霞地貌、红层高原、红层山地和红层丘陵等多种地貌类型。国外红层的形成年代跨度很大,从前寒武纪到新近纪均有发育,呈现出从老陆块向新陆块扩展的趋势;构造环境分为山前/山间坳陷堆积、台地坳陷堆积、裂谷盆地堆积和弧后盆地堆积;沉积环境以陆相为主,包括滨浅海相和海陆过渡相,也形成于干旱半干旱气候。岩性以砂岩、粉砂岩、泥岩为主,含少量砾岩,地貌类型相对简单。

In recent years,due to the successful application of"China Danxia"for the world heritage site and the promotion of"IAG Red Beds and Danxia Geomorphology Working Group",the global Red Beds and Danxia Geomorphology investigation has been launched to carry out international comparative studies.The red layer is the material basis for the formation of danxia landform.This paper attempts to summarize the distribution,forming age,geological structure background,paleogeographic environment,lithology and geomorphologic characteristics of the global red layer from the perspective of the temporal and spatial distribution law of the global red layer and the difference of geomorphologic development.The red layer in China is mainly distributed in the southeast,southwest,northwest and other regions.The formation age is mainly Mesozoic,especially cretaceous.The sedimentary environment is almost all continental facies,formed in arid or semi-arid paleoclimate conditions.The lithology is complex,including conglomerate,sandstone,siltstone and mudstone,and there are many types of landforms such as danxia landform,red plateau,red mountain and red hill.The age span of the formation of the red layer in foreign countries is very large.The tectonic environment is divided into piedmont/intermontane sag deposits,platform sag deposits,rift basin deposits and back-arc basin deposits.The sedimentary environment is dominated by continental facies,both littoral and neritic facies and transition facies,and also formed in arid and semi-arid climate.Lithology is dominated by sandstone,siltstone and mudstone,with less conglomerate.The developed landform type is relatively simple.