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Abstract. We present a database of cosmogenic radionuclide and luminescence measurements in fluvial sediment. With support from the Australian National Data Service (ANDS) we have built infrastructure for hosting and maintaining the data at the University of Wollongong and making this available to the research community via an Open Geospatial Consortium (OGC)-compliant web service. The cosmogenic radionuclide (CRN) part of the database consists of 10Be and 26Al measurements in modern fluvial sediment samples from across the globe, along with ancillary geospatial vector and raster layers, including sample site, basin outline, digital elevation model, gradient raster, flow-direction and flow-accumulation rasters, atmospheric pressure raster, and CRN production scaling and topographic shielding factor rasters. Sample metadata are comprehensive and include all necessary information for the recalculation of denudation rates using CAIRN, an open-source program for calculating basin-wide denudation rates from 10Be and 26Al data. Further all data have been recalculated and harmonised using the same program. The luminescence part of the database consists of thermoluminescence (TL) and optically stimulated luminescence (OSL) measurements in fluvial sediment samples from stratigraphic sections and sediment cores from across the Australian continent and includes ancillary vector and raster geospatial data. The database can be interrogated and downloaded via a custom-built web map service. More advanced interrogation and exporting to various data formats, including the ESRI Shapefile and Google Earth's KML, is also possible via the Web Feature Service (WFS) capability running on the OCTOPUS server. Use of open standards also ensures that data layers are visible to other OGC-compliant data-sharing services. OCTOPUS and its associated data curation framework provide the opportunity for researchers to reuse previously published but otherwise unusable CRN and luminescence data. This delivers the potential to harness old but valuable data that would otherwise be lost to the research community. OCTOPUS can be accessed at https://earth.uow.edu.au (last access: 28 November 2018). The individual data collections can also be accessed via the following DOIs: https://doi.org/10.4225/48/5a8367feac9b2 (CRN International), https://doi.org/10.4225/48/5a836cdfac9b5 (CRN Australia), and https://doi.org/10.4225/48/5a836db1ac9b6 (OSL & TL Australia).

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sharing services. Thus, OCTOPUS will turn data that was previously invisible to those not within the CRN and luminescence research communities into a findable resource. This aspect is of importance to industry or local government who are yet to 15 discover the value of geochronological data in, amongst others, placing human impacts on the environment into context. The availability of the repository and its associated data curation framework will provide the opportunity for researchers to store, curate, recalculate and re-use previously published but otherwise unusable CRN and luminescence data. This delivers the potential to harness old but valuable data that would otherwise be 'lost' to the research community. The streamlined repository and transparent data re-analysis framework will also reduce research time and avoid duplication of effort, which will be highly 20 attractive to other researchers. OCTOPUS can be accessed at https://earth.uow.edu.au. The data collections can also be ac-1 Earth Syst. Sci. Data Discuss., https://doi

The Indus River, one of Asia's premier rivers , drains the western Tibetan Plateau and the Nanga Parbat syntaxis. These two areas juxtapose some of the lowest and highest topographic relief and commensurate denudation rates in the Himalaya-Tibet orogen, respectively, yet the spatial pattern of denudation rates upstream of the syntaxis remains largely unclear, as does the way in which major rivers drive headward incision into the Tibetan Plateau. We report a new inventory of 10 Be-based basinwide denudation rates from 33 tributaries fl anking the Indus River along a 320 km reach across the western Tibetan Plateau margin. We fi nd that denudation rates of up to 110 mm k.y. -1 in the Ladakh and Zanskar Ranges systematically decrease eastward to 10 mm k.y. -1 toward the Tibetan Plateau. Independent results from bulk petrographic and heavy mineral analyses support this denudation gradient. Assuming that incision along the Indus exerts the base-level control on tributary denudation rates, our data show a systematic eastward decrease of landscape downwearing, reaching its minimum on the Tibetan Plateau. In contrast, denudation rates increase rapidly 150-200 km downstream of a distinct knickpoint that marks the Tibetan Plateau margin in the Indus River longitudinal profi le. We infer that any vigorous headward incision and any accompanying erosional waves into the interior of the plateau mostly concerned reaches well below this plateau margin. Moreover, reported long-term (>10 6 yr) exhumation rates from low-temperature chronometry of 0.1-0.75 mm yr -1 consistently exceed our 10 Be-derived denudation rates. With averaging time scales of 10 3 -10 4 yr for our denudation data, we report postglacial rates of downwearing in a tectonically idle landscape. To counterbalance this apparent mismatch, denudation rates must have been higher in the Quaternary during glacial-interglacial intervals.

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We report a comprehensive inventory of 10 Be-based basin-wide denudation rates (n=160) and 26 Al/ 10 Be ratios (n=67) from 48 drainage basins along a 3,000 km stretch of the East Australian passive continental margin. We provide data from both basins draining east of the continental divide (n=37) and discharging into the Tasman and Coral Seas, and from basins draining to the west as part of the larger Murray-Darling and Lake Eyre river systems (n=11). 10 Be-derived denudation rates in mainstem samples from east-draining basins range between 7.7 ± 1.9 (± 1s; Mary) and 54.6 ± 13.7 mm kyr -1 (North Johnstone). Denudation rates in tributary samples range between 3.0 ± 0.7 (Burdekin) and 70.2 ± 18.9 mm kyr -1 (Liverpool). For west-draining basins, denudation rates are overall lower and with a more restricted range of 4.8 ± 1.2 (Barcoo) to 15.4 ± 3.6 mm kyr -1 (Maranoa) in mainstem samples, and between 4.4 ± 1.0 (Murrumbidgee) and 38.5 ± 7.8 mm kyr -1 (Murray) in tributary samples. East Australian denudation rates (median = 14.5 mm kyr -1 ) are similar to those found in other postorogenic landscapes (global median = 12.4 mm kyr -1 ) and the medians of the top 10% denudation rates recorded here (46.5 mm kyr -1 ) and in other passive margin settings are also similar, despite differences in topography and precipitation.These median denudation rate values are close to the 95 th percentile denudation rate for all tectonically passive basins (≈53 mm kyr -1 ) and are very similar to the global silicate weathering speed limit (≈58 mm kyr -1 ) calculated as the 95 th percentile of global soil weathering rates. The above suggests that in post-orogenic terrain, the overall rates of topographic decay have a 'speed limit' that is imposed by the rate at which rock is converted to soil by chemical weathering. Denudation rates along the East Australian margin correlate with topographic metrics at both the mainstem basin scale and at the smaller tributary basin scale suggesting that topography exerts the main control on rates of landscape lowering in this setting. An important link between denudation rate and rainfall is also inferred: the highest mainstem 10 Be denudation rates all occur in basins which also have the highest rainfall amounts and there is a strong correlation between the distance knickpoints have travelled upstream from the river mouth and basin area -a proxy for discharge and so to some extent also rainfall. On both sides of the divide, in all but a few of the samples, 26 Al/ 10 Be ratios are consistently lower than what is expected in a setting where sediments experience a simple and continuous exposure history. East of the continental divide, the lowest 26 Al/ 10 Be ratios are found in basins that also experience increased flood variability. We posit that there is a causal link between the hydrological variability that characterises the coastal rivers of eastern Australia and the observed non-steady state 26 Al/ 10 Be ratios: the periodic stripping of vertically accreted floodplains by large floods means that deepe...

Rivers draining the semiarid Transhimalayan Ranges at the western Tibetan Plateau margin underwent alternating phases of massive valley infill and incision in Pleistocene times. The effects of these cut-and-fill cycles on millennial sediment fluxes have remained largely elusive. We investigate the timing and geomorphic consequences of headward incision of the Zanskar River, a tributary to the Indus, which taps the >250-m thick More Plains valley fill that currently plugs the endorheic high-altitude basins of Tso Kar and Tso Moriri. In situ 10Be exposure dating and topographic analyses show that a phase of valley infill gave way to net dissection and the NW Himalaya's first directly dated stream capture in late Marine Isotope Stage (MIS) 6, ∼135 ka ago. Headwaters of the Indus are currently capturing headwaters of the Sutlej, and rivers have eroded >14.7 km3 of sediment from the Zanskar headwaters since, mobilising an equivalent of ∼8% of the Indus' contemporary sediment storage volume from only 0.3% of its catchment area. The resulting specific sediment yields are among the rarely available rates averaged over the 105-yr timescale, and surpass 10Be-derived denudation rates from neighbouring catchments three-to tenfold. We conclude that recycling of Pleistocene valley fills has fed Transhimalayan headwaters with more sediment than liberated by catchment denudation, at least since the last glacial cycle began. This protracted release of sediment from thick Pleistocene valley fills might bias estimates of current sediment loads and long-term catchment denudation. Disciplines Medicine and Health Sciences | Social and Behavioral Sciences