This paper focuses on the Landquart drainage basin, where we explore geomorphic signals related to the spatial differences in bedrock lithology and differential uplift. We use concentrations of cosmogenic 10Be to quantify the sediment flux patterns in the region. Furthermore we use the chemical composition of the fine fraction (< 63 μm) of the river sediment to determine the provenance of the material, and we quantify the landscape properties through the calculation of normalized steepness values for the tributary basins. The results show that the upstream segment of the Landquart basin is a glacially imprinted landscape and contributes to about 20–50% of the total modern sediment flux of the Landquart River. Contrariwise, the landscape of the downstream part is dominated by a V-shaped landscape where tributary basins are characterized by a generally high steepness. This downstream area has delivered about 50–80% of the total eroded material. Because this lowermost part of the Landquart basin is c. 50% smaller than the upstream region (200 km2 downstream versus 400 km2 upstream), the sediment budget points to very high erosion at work in this lowermost segment. Interestingly, the bedrock of this area comprises flysch and particularly ‘Bündnerschiefer’ deposits that have a high erodibility. In addition, apatite fission track ages are much younger (c. 5–10 Ma) than in the headwater reaches (10–30 Ma). This suggests the occurrence of ongoing yet long-term rock uplift that has occurred at higher rates in the downstream segment than in the headwaters. It appears that the landscape shape and denudation rate pattern in the Landquart basin reflect the combined effect of tectonic processes and fast surface response, where uplift has promoted the exhumation of bedrock with high erodibilities, and where the low erosional resistance of the exposed lithologies has promoted the streams to respond by fast erosion.

中文翻译：

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陆盆盆地的侵蚀和泥沙通量差异及其与岩性和构造控制的可能关系

本文重点研究了Landquart流域，在那里我们探索与基岩岩性和差异抬升的空间差异有关的地貌信号。我们使用宇宙成因10Be的浓度来量化该区域的泥沙通量模式。此外，我们使用河流沉积物中细小部分（<63μm）的化学成分来确定物质的出处，并通过计算支流盆地的标准化陡度值来量化景观特性。结果表明，Landquart盆地的上游部分是冰川留下的印记景观，占Landquart河总现代沉积物通量的20-50％。相反，下游部分的景观以V形景观为主，支流盆地通常具有较高的陡度。该下游区域已交付了约50-80％的总腐蚀材料。因为Landquart盆地的最下部是c。沉积物预算比上游地区小50％（下游200 km2，而上游400 km2），这表明该最低段的侵蚀非常严重。有趣的是，该地区的基岩包括飞石，特别是具有高侵蚀性的“Bündnerschiefer”矿床。此外，磷灰石裂变径迹年龄（约5-10 Ma）比上游水源年龄（10-30 Ma）要年轻得多。这表明正在进行的但长期的岩石隆起的发生在下游段的发生率高于上游源头。