古沙漠沙丘形态定量重建研究

Quantitative reconstruction of ancient dunes morphology in palaeo-deserts

古沙丘定量形态学研究可有效填补古沙漠内部沉积架构和时空演化模型定量数据约束的欠缺,为探究古沙漠沉积机制及对比标准提供新的研究思路,同时可对定量重建古风场等古气候、古地理研究提供重要支撑。本研究以古沙漠沙丘为研究对象,通过综述现代沙丘形态学参数体系及相互关系,“将今论古”,在前人研究成果的基础上,结合古沙漠地层沉积特征,建立古沙丘形态参数体系。现代沙丘各形态参数函数换算关系存在一定的个例性和差异性,综合考虑区域沙丘砂粒性质、地表形态、风力性质和植被覆盖等内外部因素的影响,提出古沙丘形态参数野外实测、计算、重建及对比方法,为全球典型古沙漠沙丘形态学定量研究提供有效的方法学支撑。

Quantitative morphology study of ancient dunes can effectively make up for the lack of the quantitative data constraints of sedimentary architecture and spatial-temporal evolution model of paleo-deserts.It provides a new research idea for exploring the sedimentary mechanism of paleo-deserts and the correlation standard.At the same time,it can also provide important support for quantitative reconstruction of paleoclimate and paleogeography,such as paleo-wind field.Taking ancient dunes as the research object,this study first reviewed the morphological parameter system and the inter-relationship of modern dunes.According to the idea of“observing the present to study the past”,this study established the morphological parameter system of ancient dunes based on previous studies and the sedimentary characteristics of palae-desert strata.It has been found that individuality and difference exist in the morphological parameter function relation of modern dunes.Considering the internal and external influence factors,such as regional dune sand properties,surface morphology,wind and vegetation,this study proposed the method for the field measurement,calculation,reconstruction and comparison of morphological parameters of ancient dunes,providing effective methodological support for quantitative morphological study of ancient dunes in typical palae-deserts.