Abstract

Presented are the results from investigating the aeolian sand massifs in the Belaya river valley. The Belaya, Kholmushino and Usolye massifs with the area of 2, 1.4 and 269 km, respectively, are singled out. They are differentiated by the degree and magnitude of manifestation of aeolian processes, and by the morphology of landforms. The Belaya massif is characterized by narrow gully‒low ridge topography. The initial fluvial relief is moderately modified because of the isolated location of the area in the spur of the incised meander and its boundedness by the slope of the narrow segment of the valley. In the Kholmushino massif located in the zone of contact of the segment of the incised channel and the broadening of the valley, aeolian forms were able to evolve fully but they occur only along narrow terraced surfaces of the rectilinear segment of the valley. The more favorable conditions emerged for the evolution of the Usolye massif. The broad-floodplain type of Belaya channel promoted accumulation of significant volumes of sandy material and its free transport in the process of aeolian morphogenesis. The most intense aeolian accumulation was observed in the lower reaches of the Belaya at the interface of the Late Glacial and Holocene (from 13.1 kyr BP) and was proceeding throughout the Early Holocene until 8.9 kyr BP when there occurred a decrease in activity of the aeolian processes and an intense soil formation began. The landscape-climatic conditions of the Atlantic period were favorable for the attenuation of aeolian activity and for a gradual fixation of sands by vegetation. The intensification phases of the aeolian processes were replaced by stages of a decrease in activity of the aeolian morphogenesis and soil formation in the intervals 9.3‒8.6; 6.7‒6; 3.5‒2.6 and 1.2‒0.9 kyr BP. The pedogenesis stages coincided with an increase in heat and moisture availability. Analysis of the findings suggests the rhythmic behavior in the evolution of the region’s natural environment in the Late Glacial with the manifestation of aeolian phases every 4‒5 ka and phases of intense soil formation every 1.9‒2.5 ka.

中文翻译：

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全新世安加拉河上游地区森林草原景观的风成过程

摘要

呈现的是调查Belaya河谷的风沙地块的结果。分别选择了分别为2、1.4和269 km的Belaya，Kholmushino和Usolye地块。它们通过风成过程表现的程度和幅度以及地貌形态来区分。Belaya地块的特征是狭窄的沟壑和低脊地形。由于切开的曲折支线上该区域的孤立位置及其受山谷狭窄部分的倾斜度限制，因此初始河道冲刷得到了适度的调整。在切入河道段与河谷拓宽接触区的Kholmushino地块中，风积形态能够完全演化，但仅在山谷的直线段的狭窄梯田表面上发生。乌索里山地块的演化出现了更为有利的条件。Belaya河道的泛洪平原类型促进了风沙形态发生过程中大量砂质物质的积累及其自由运输。在晚冰河和全新世交界处的Belaya下游观测到了最强烈的风积聚（从13.1 yr BP开始），并且在整个全新世之前一直进行到8.9 yr BP，当时风蚀的活动发生了减少。的过程和强烈的土壤形成开始了。大西洋时期的景观气候条件有利于风沙活动的减弱和植被对沙土的逐步固定。在9.3‒8.6的间隔内，风化过程的强化阶段被风化形态活动和土壤形成活动减少的阶段所取代。6.7‒6；3.5 ‒ 2.6和1.2 ‒ 0.9百年BP。成岩阶段与热量和水分的可利用性增加相吻合。对结果的分析表明，晚冰川期该地区自然环境的演变具有节律性，表现为每4‒5 ka出现风沙相，每1.9‒2.5 ka出现强烈土壤形成相。在9.3‒8.6的间隔内，风化过程的强化阶段被风化形态活动和土壤形成活动减少的阶段所取代。6.7‒6；3.5 ‒ 2.6和1.2 ‒ 0.9百年BP。成岩阶段与热量和水分的可利用性增加相吻合。对结果的分析表明，晚冰川期该地区自然环境的演变具有节律性，表现为每4‒5 ka出现风沙相，每1.9‒2.5 ka出现强烈土壤形成相。在9.3‒8.6的间隔内，风化过程的强化阶段被风化形态活动和土壤形成活动减少的阶段所取代。6.7‒6；3.5 ‒ 2.6和1.2 ‒ 0.9百年BP。成岩阶段与热量和水分的可利用性增加相吻合。对结果的分析表明，晚冰川期该地区自然环境的演变具有节律性，表现为每4‒5 ka出现风沙相，每1.9‒2.5 ka出现强烈土壤形成相。