Large Drainage System Research Articles

Fingerprint of Plio–Quaternary detrital zircon geochronology: Implications for sediment provenances and geomorphological evolution of the Yangtze Delta

The Yangtze (Changjiang) Delta serves as a prominent depocenter for siliciclastic sediments from the Tibetan Plateau and Yangtze Craton, providing essential data on sediment source-to-sink dynamics and geomorphological evolution of large river drainage systems. This study presents the detrital zircon geochronology of Plio–Pleistocene sediments in the Yangtze Delta, alongside the data from modern river sediments, to elucidate provenance evolution since the Pliocene. The zircon geochronology reveals a considerable shift in sediment provenance during the Pliocene–Pleistocene transition. The Pliocene sediments exhibit a straightforward and predominant zircon age spectrum characterized by a typical peak age of 100–200 Ma. This spectrum markedly differs from the modern upper–middle Yangtze River sediments but closely resembles those of local rivers in the lower Yangtze River region. This demonstrates that the Pliocene sediments originated from local mountainous rivers, indicating the paleo-Yangtze River channelization prior to the Quaternary. In contrast, the zircon age spectra of Pleistocene sediments in the present-day delta reveal several dominant age groups ranging from 11.9 ± 1 to 3643 ± 30 Ma, similar to those found in present-day upper–middle Yangtze River sediments. This implies that the Pleistocene sediments were mainly derived from the upper–middle Yangtze River, showing a diversity of source rocks with varying geological ages and origins. The presence of the upper Yangtze River provenance signal, characterized by Cenozoic (<65 Ma) zircons, in early Pleistocene strata (ca. 1.6 Ma) of the delta suggests that the paleo-Yangtze River transported Tibet-sourced sediments into the modern delta area no later than that time. These findings indicate the geomorphological evolution of the Yangtze River Delta from an intermontane basin in the Pliocene to an alluvial–fluvial plain during the Quaternary. This geomorphological and geographic evolution, along with changes in sediment source, directly reflect extensive tectonic subsidence in eastern China since the late Cenozoic.

Phylogeography of the freshwater crab Potamon persicum (Decapoda: Potamidae): an ancestral ring species?

The Zagros Mountains, characterized by complex topography and three large drainage systems, harbor the endemic freshwater crab Potamon persicum in Iran. Our study delves into the evolutionary history of P. persicum, utilizing two mitochondrial and one nuclear marker. We collected 214 specimens from 24 localities, identifying 21 haplotypes grouped into two major evolutionary lineages. Substantial differentiation exists between drainage systems and lineages. Historical demographic analysis revealed a significant decrease in population size during the late Holocene, accompanied by a recent population bottleneck. Species distribution modeling has revealed eastward shifts in suitable habitats between the last glacial maximum and the present day. Following the last glacial maximum, habitat fragmentation occurred, resulting in the establishment of small populations. These smaller populations are more vulnerable to climatic and geological events, thereby limiting gene flow and accelerating genetic differentiation within species. Historical biogeographic analysis traced the origin of P. persicum to the western Zagros Mountains, with major genetic divergence occurring during the Pleistocene. Our genetic analyses suggest that P. persicum may have shown a genetic pattern similar to a classical ring species before the Pleistocene. The Namak Lake sub-basin could have served as a contact zone where populations did not interbreed but were connected through gene flow in a geographic ring. Currently, genetic separation is evident between basins, indicating that P. persicum in the Zagros Mountains is not a contemporary ring species. Also, our biogeographical analysis estimated that range evolution may have been driven initially by dispersal, and only during the late Pleistocene by vicariance.

Mesozoic evolution of large-scale drainage systems in the Indochina Block: evidence from palaeomagnetic and U–Pb geochronological constraints

The collage of the Indochina Block to the Eurasian continent during the Mesozoic resulted in major changes in source-to-sink systems of East Asia, whilst the sedimentation in the Khorat–Simao Basin of the Indochina Block transited from marine to continental environments. Previous studies uncovered the existence of transcontinental river systems in the East Asia mainland during the Cretaceous to Early Cenozoic, although there have been few studies on pre-Cretaceous drainage systems. To determine the impact on the evolution of palaeo-drainage systems triggered by tectonic movement of the Indochina Block, we performed palaeomagnetic and U–Pb geochronologic analyses on the Late Triassic to Early Cretaceous sedimentary rocks in the Simao Basin. Palaeomagnetic data indicate stable Jurassic tectonic environments between the Indochina and Songpan–Ganzi–South China blocks, following their Late Triassic collision. Based on detrital zircon U–Pb dating, the Late Triassic age spectra consist mainly of Phanerozoic components, while the Jurassic to Cretaceous age spectra display more Precambrian age peaks. The contribution of potential provenance to the Simao Basin changed during the Early Cretaceous, suggesting several sedimentary provenance transitions. Also, we believe that large continental-scale drainage systems flowing through the North Qiangtang, Sichuan, Simao and Khorat Basins were sourced from the Songpan–Ganzi Block since the end of the Late Jurassic. Supplementary material: The findings of a quantitative statistical study (Fig. S1; Table S5), the location of the Late Triassic to Early Cretaceous samples from the Simao Basin (Table S1), palaeomagnetic poles for Eurasia, South China, Indochina, North Qiangtang and Tarim (Table S2), the result of quantitative analysis for the Late Triassic and Middle Jurassic sedimentary rocks from the Simao and Sichuan basins (Table S3), and results of zircon U–Pb dating (Table S4) are available at https://doi.org/10.6084/m9.figshare.c.6862918 Thematic collection: This article is part of the Mesozoic and Cenozoic tectonics, landscape and climate change collection available at: https://www.lyellcollection.org/topic/collections/mesozoic-and-cenozoic-tectonics-landscape-and-climate-change

Composition, Distribution, and Attribution of Hydrochemistry in Drainage Systems in the North of Tianshan Mountains, China

The characteristics and sources of the hydrochemical composition of natural water are mainly influenced and limited at the basin scale by what factors, this has become a focal issue of environmental change in the middle latitude areas and even globally. In this study, three large drainage systems (Junggar, Yili, and Erlqis) in the north of the Tianshan Mountains were selected to study the hydrochemistry of different river basins and understand the relevant causes and attributions of different water bodies in arid environments in the Central Asian Orogenic Belt (CAOB). Natural water samples from the three drainage systems and their hydrochemical data, combined with literature data of the north and south Tianshan Mountains and surrounding areas, were systematically collected and comprehensively compared with other higher, middle, and low latitude watersheds with different climate conditions. The results show that the total dissolved solid concentrations in the CAOB drainage systems are generally higher than those of rivers in Chinese monsoon and humid regions, and also higher than the world average level. The relative concentrations of different ions are similar to those of rivers in the monsoon region of eastern China and most rivers in the world dominated by carbonate weathering. The ionic compositions of surface water bodies from different sub-basins in the study area are distributed near the Ca apex in the piper diagram, while those of phreatic and confined groundwater samples tend to the Na apex. The compositional differences in the anions are not like those in the cations, rarely distinguishable for these different water types. In a sub-drainage basin scale from I to VIII sub-basins in the study area, major ion concentrations and distributions in these basins are evidently heterogeneous. Almost all the cation and anion concentrations span &gt; 1 order of magnitude, especially sodium and chlorine; however, the calcium and alkalinity concentrations and distributions are relatively homogeneous for some basins in the Junggar and Yili drainage systems. The relative homogeneity between anions and the relative heterogeneity between cations can be recognized in the ion chemistry of natural water samples between different types, indicating that the composition and distribution of cations in water is more conducive than those of anions to identifying the differences and commonalities between different regions. Atmospheric precipitation plays a key role on the hydrogeochemical process in the north of the Tianshan Mountains, and the elevation differentiation of chemical weathering and ion concentrations are closely related to it. The positive correlation between total solute flux and runoff cannot be explained by the dilution effect, indicating that hydroclimatic factors such as runoff and aridity have a strong effect in limiting the hydrochemistry of natural water bodies in the study area.

Evidence of the evolution of the East Antarctic Ice Sheet on the continental slope and rise sedimentary record: Insights from the Sabrina Coast, East Antarctica

Deciphering how the Antarctic Ice Sheet has responded to past climate warming is critical to understanding its sensitivity and role in current and future climate change. In this context, knowledge of the evolution of the Antarctic Ice Sheet in catchments with large potential sea-level contributions plays a key role. The Sabrina Coast of East Antarctica lies seaward of the second largest, but least known, subglacial basin on Earth, the Aurora Subglacial Basin. It is part of the East Antarctic Ice Sheet and drains to the Sabrina Coast via the Totten Glacier, the third largest drainage system in East Antarctica. Our refined, comprehensive seismic stratigraphic analysis of a large multichannel seismic data set collected in this sector of the Antarctic margin shows that sediments deposited on the continental slope and rise of the Sabrina Coast retain a well-preserved record of variations in glacial and oceanographic dynamics. Isobath and isopach maps evidence a complex, asymmetric evolution of the Sabrina slope and rise, with the western sector being the main sediment depocenter since the emplacement of the East Antarctic Ice Sheet, as indicated by the up to 4-km-thick glacial-related sequences and inferred sedimentation rates of up to 300 m/m.y. However, significant sediment accumulation also occurs in the eastern area, particularly in the western levees of the canyons. Our findings highlight the potential of this region for deep ocean drilling that will provide an unprecedented history of the dynamics of the marine-based ice sheet in the Aurora Subglacial Basin and its sensitivity to climate change under different background climate conditions.

Tectonic and climatic controls on sediment transport to the Southeast Indian Ocean during the Eocene: New insights from IODP Site U1514

The Eocene was a critical period of global plate reorganization and it also saw the Earth's climate transition from the warmhouse state to the coolhouse state. Reconstructing the Eocene sedimentary history in the climate-sensitive Southern Ocean is important for understanding paleoenvironmental changes in response to the accelerated Australia/Antarctica separation and global cooling throughout the middle and late Eocene. Here, we present the first detailed multiproxy record of a continuous sequence from International Ocean Discovery Program (IODP) Site U1514 in the Mentelle Basin off southwestern Australia. Our aim is to reconstruct the sediment provenances and paleoenvironmental evolution in response to the abovementioned climatic and tectonic changes in the mid-high southern latitudes during the Eocene. Provenance analyses based on Sr-Nd isotopes, trace elements, and clay mineral assemblages suggest that Eocene sediments at Site U1514 predominantly originated from the southwestern Australian continent and the Naturaliste Plateau. Sediment provenance variations during the middle Eocene indicate that the onset of fast separation between Australia and Antarctica at 43 Ma caused an increased supply of volcanic materials from the Naturaliste Plateau between 43 and 38 Ma. Terrigenous inputs to the Mentelle Basin during the middle Eocene were primarily controlled by paleoclimate changes rather than tectonic processes because coeval clay mineralogical changes (higher kaolinite/smectite ratio and MARkaolinite) indicate a period of stronger physical erosion and chemical weathering on the western Australian continent that resulted in increased terrigenous materials delivered to the Mentelle Basin. Our results reveal a 5 Myr-long (43–38 Ma) warming reversal in the southern mid-high latitudes, providing an exception to the generally short-lived (10–100 kyr-long) hyperthermals that interrupted the long-term global cooling throughout the middle to late Eocene. As for the late Eocene (38–37 Ma), tectonic processes related to the sudden acceleration in seafloor spreading in the Tasman Sea led to the exposure of shallower areas, resulting in rapid detritus accumulation at the study site. During the late Eocene (37–34 Ma), major sediment provenance shifted from distal source areas (e.g., the Yilgarn Craton) to relatively proximal sources (e.g., the Leeuwin Block and Perth Basin). We interpret that the regional uplift in southwestern Australia and coeval climate cooling resulted in the diversion and inactivation of large drainage systems, thus blocking the transportation of sediment from distant regions.

Spatio-temporal variability and controlling factors for postglacial denudation rates in the Dora Baltea catchment (western Italian Alps)

Abstract. Disentangling the influence of lithology from the respective roles of climate, topography and tectonic forcing on catchment denudation is often challenging in mountainous landscapes due to the diversity of geomorphic processes in action and of spatial and temporal scales involved. The Dora Baltea catchment (western Italian Alps) is an ideal setting for such investigation, since its large drainage system, extending from the Mont Blanc Massif to the Po Plain, cuts across different major lithotectonic units of the western Alps, whereas this region has experienced relatively homogeneous climatic conditions and glacial history throughout the Quaternary. We acquired new 10Be-derived catchment-wide denudation rates from 18 river-sand samples collected both along the main Dora Baltea river and at the outlet of its main tributaries. The inferred denudation rates vary between 0.2 and 0.9 mm yr−1, consistent with previously published values across the European Alps. Spatial variability in denudation rates was statistically compared with topographic, environmental and geological metrics. 10Be-derived denudation rates do not correlate with modern precipitation and rock geodetic uplift. We find, rather, that catchment topography, in turn conditioned by bedrock structures and erodibility (lithotectonic origin) and glacial overprint, is the main driver of 10Be-derived denudation patterns. We calculated the highest denudation rate for the Mont Blanc Massif, whose granitoid rocks and long-term tectonic uplift support high elevations, steep slopes and high relief and thus favour intense glacial and periglacial processes and recurring rockfall events. Finally, our results, in agreement with modern sediment budgets, demonstrate that the high sediment input from the Mont Blanc catchment dominates the Dora Baltea sediment flux, explaining the constant low 10Be concentrations measured along the Dora Baltea course even downstream the multiple junctions with tributary catchments.

Revisiting Ice Flux and Mass Balance of the Lambert Glacier–Amery Ice Shelf System Using Multi-Remote-Sensing Datasets, East Antarctica

Due to rapid global warming, the relationship between the mass loss of the Antarctic ice sheet and rising sea levels are attracting widespread attention. The Lambert–Amery glacial system is the largest drainage system in East Antarctica, and its mass balance has an important influence on the stability of the Antarctic ice sheet. In this paper, the recent ice flux in the Lambert Glacier of the Lambert–Amery system was systematically analyzed based on recently updated remote sensing data. According to Landsat-8 ice velocity data from 2018 to April 2019 and the updated Bedmachine v2 ice thickness dataset in 2021, the contribution of ice flux approximately 140 km downstream from Dome A in the Lambert Glacier area to downstream from the glacier is 8.5 ± 1.9 Gt·a−1, and the ice flux in the middle of the convergence region is 18.9 ± 2.9 Gt·a−1. The ice mass input into the Amery ice shelf through the grounding line of the whole glacier is 19.9 ± 1.3 Gt·a−1. The ice flux output from the mainstream area of the grounding line is 19.3 ± 1.0 Gt·a−1. Using the annual SMB data of the regional atmospheric climate model (RACMO v2.3) as the quality input, the mass balance of the upper, middle, and lower reaches of the Lambert Glacier was analyzed. The results show that recent positive accumulation appears in the middle region of the glacier (about 74–78°S, 67–85°E) and the net accumulation of the whole glacier is 2.4 ± 3.5 Gt·a−1. Although the mass balance of the Lambert Glacier continues to show a positive accumulation, and the positive value in the region is decreasing compared with values obtained in early 2000.

Transport and environmental risks of perfluoroalkyl acids in a large irrigation and drainage system for agricultural production.

The quality of irrigation water and drainage water is essential for local ecosystem and human health in agricultural regions. In this study, the transport analysis, source identification, and environmental risk assessment of perfluoroalkyl acids (PFAAs) were conducted in the largest irrigation area in northern China. The concentrations of the total PFAAs (ΣPFAA) ranged from 41.5 to 263ng/L in surface water, and the short-chain perfluoroalkyl carboxylic acids (PFCAs) and perfluorooctanoic acid (PFOA), were dominant with a total contribution of 94%. Generally, the ΣPFAA levels increased from irrigation waters to drainage and receiving lake waters. PFOA showed the highest increase, with potential emission sources located in the catchment of the sub main drainage ditch D5. More PFOA (36.8kg/y) was outflowed from Ulansuhai Lake to the Yellow River than that inflowed from the Yellow River to the irrigation district (6.15kg/y). The results of a risk assessment indicated that avian wildlife living in Ulansuhai Lake were threatened by the PFOA and perfluorobutane sulfonate (PFBS) pollution. The estimated daily intakes (EDIs) of the sum of the PFOA, perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS) through aquatic food consumption for people with the different aquatic food preferences accounted for 6-42% (urban) and 4-27% (rural) of the strictest tolerant daily intake (TDI) value. The results of this study highlight the impact of local emissions of PFAS on massive irrigation and drainage systems, and ultimately, the ecosystem and human health.

A Disaggregation‐Emulation Approach for Optimization of Large Urban Drainage Systems

AbstractMulti‐objective optimization can help identify efficient and appealing designs of urban drainage systems. However, their application to large‐scale problems is hindered by the computational cost of urban drainage simulation. We propose a novel disaggregation approach that allows simulating a portion of a drainage network while the remaining part is represented by a surrogate model that maps changes in the region of interest to hydraulic head time‐series at synthetic nodes shared with the remaining part of the network. The proposed approach is demonstrated with an application to the many‐objective optimization of sustainable urban drainage systems in two urban areas. The design problem's decision variables include the types of sustainable drainage systems, their combination within a subcatchment, their surface areas and spatial distribution, whereas the objectives include the minimization of capital cost, flood volume, flood duration, and total suspended solids or average peak runoff. The results show that the proposed disaggregation‐emulation approach can provide an accurate representation of the system dynamics while significantly reducing the computational time compared to a model that simulates the whole network dynamics. Two alternative surrogate models are considered based on multilayer perceptron (MLP) and generalized regression neural networks (GRNN). MLP is found to be more accurate compared to GRNN at the cost of a larger computational time for the training process.

Developing a 1D-3D model to investigate the effect of entrapped air on pressure surge during the rapid filling of a pipe

An uncontrolled rapid filling or discharging of a pipeline can create compressed air columns in an urban water supply or sewage system. The expulsion of entrapped air out of pipelines is considered as one of the most destructive phenomena. Generally, the air valves are mounted and used to release the air from the pipe. Any failure of the air venting system may lead to a pressure surge inside the pipeline and even damage to the water systems infrastructure. Most of the investigations of multiphase flow during a rapid filling are limited to small distribution systems due to high computational costs. The aim of the present research is to develop a 1D-3D coupled model with the capability to handle multiphase flows. The effects of air pocket length, orifice size and upstream pressure on the flow field and maximum pressure surge inside the pipe are investigated. The classical water hammer equations are solved for the 1D domain using the Godunov scheme while the rest of the system is simulated using the Volume of Fluid (VOF) method. The coupling between 1D and 3D domains are handled using the developed boundary conditions based on flow characteristics. The results of the numerical simulations are compared with available experimental data. The obtained results show that the model can predict the features of the two-phase flow inside the pipeline during a rapid filling. The required computational time decreases by a factor of 4 compared to 3D simulations. This gives the possibility to investigate large scale water distribution or drainage systems.

Heavy and light marker minerals around the East African Rift System (EARS) with special reference to the evolution of Zanzibar Island, Tanzania

Mineral assemblages encompassing heavy (HM), light (LM) and clay minerals (CM) can be used as marker minerals for geodynamic and weathering processes. The highly diverse lithology of the Precambrian basement rocks around and the rift-related magmatic rocks of the East African Rift system (EARS) form an ideal platform to use sediment-mineralogical techniques to study the origin of the Island of Zanzibar, Tanzania, during the Quaternary. Four reference mineral associations have been defined: (1) Precambrian basement rocks (Tanzania Craton + Proterozoic rim), (2) Mesozoic rocks (magmatic rocks of the rift-and-graben system), (3) Cenozoic rocks (magmatic rocks of the rift system), (4) Quaternary placers, duricrusts and soils which form a transition zone between bedrock and the depocenter under study. Detrital grains of pyroxene and amphibole s.s.s. and autochthonous kaolinite group minerals in context with Fe–Al oxide/hydrates play a leading role for the geodynamic and geomorphological-mineralogical correlation of Zanzibar with mainland Tanzania. During the Holocene HM are likely to have been introduced into the beach sands from a magmatic submarine source and assigned Zanzibar to the marginal facies of the EARS, while a central island ridge blanketed by an argillaceous duricrust zone denotes a HM barrier towards mainland Tanzania. The difference between the mineral assemblage along the east coast of Zanzibar and the mineral assemblage of the mainland fed by the large fluvial drainage systems argues for a local magmatic HM source.

Adequacy assessment of an urban drainage system considering future land use and climate change scenario

Abstract Dhaka, the capital of Bangladesh, has been experiencing severe water-logging and urban flooding in the last few decades. In this paper, we estimate the peak storm runoff of Hatirjheel-Begunbari canal – the largest drainage system of the city – under different operational, land use and climate scenarios (2013, 2025 and 2040). Our method includes digital elevation model (DEM) reconditioning, watershed delineation, and development of future land use scenario. We apply HEC-RAS to check the adequacy of Begunbari canal cross-sections to carry peak runoff for the scenarios considered here. The Hatirjheel-Begunbari system is found to drain stormwater from ∼25% of the city. Within the system, built-up areas are increasing linearly by 0.8 Km2/year, whereas water body and wetlands are decreasing exponentially, which might increase the runoff coefficient by 11% in 2040 relative to 2013. Climate-induced change in rainfall intensity along with land-use change show three times higher runoff in 2040 than in 2013. Around 58% of canal cross-sections appear to be overflown at both banks while carrying a 5-year return period peak runoff under the 2013 scenario. For future scenarios, all sections seem to cause an overflow, which is alarming.

The ice flux to the Lambert Glacier and Amery Ice Shelf along the Chinese inland traverse and implications for mass balance of the drainage basins, East Antarctica

Study of the mass balance of the Antarctic Ice Sheet is critical to estimate its potential contribution to global sea-level rise in the future. As the largest drainage system, the Lambert Glacier–Amery Ice Shelf drainage system plays an important role in the mass balance of the Antarctic Ice Sheet. In this study, the ice thickness measured by airborne ice-penetrating radar with high spatial resolution and accuracy and accurate ice velocity measured by in situ GPS stations along the route of the Chinese National Antarctic Research Expedition inland traverse were used to calculate the ice flux with unprecedented accuracy. This transverse is from Zhongshan Station to Dome A, passing through the east side of the Lambert Glacier and the smaller coastal glacier in the C-Cp basin. The results show that the ice flux across the entire traverse is 24.7 ± 2.8 Gt a−1, along which the section in drainage basin B–C (Lambert Glacier) has an ice flux of 20.9 ± 1.9 Gt a−1&nbsp;and the section in drainage basin C–Cp (basin adjacent to Lambert Glacier) contributed 3.8 ± 0.4 Gt a−1. The ice flux values in both regions are coincident with the mass balance calculated from the Ice, Cloud, and Land Elevation Satellite, Earth Observing System. Meanwhile, the C–Cp basin shows an ice flux value of 6.6 ± 0.8 Gt a−1&nbsp;across the grounding line.

Delineation of water potentiality areas at Wadi El-Arish, Sinai, Egypt, using hydrological and geophysical techniques

The position of Sinai Peninsula as an area of transit from Africa to Asia and vice-versa, is so strongly reflected on its importance on the projects of sustainable development in Egypt. Wadi El-Arish basin, largest drainage system in Sinai Peninsula, exhibits variable morphologic features due to the impact of the local lithologic, tectonic, topographic features and arid climatic conditions with intermittent flash floods. The present work attempts to determine the flood parameters: peak discharge, runoff volume and time to peak discharge. Due to lack of runoff measurement, Soil Conservation Service (SCS) unit hydrograph method is used to compute the runoff hydrographs. Rainfall data of all effective rainfall stations for 100 years design storm is incorporated in the Hec-1 hydrologic module. Also, the land use and soil type map are used to estimate the water losses and accordingly the excess rainfall which causes runoff. For that, Wadi El-Arish has been subdivided into nine sub-basins; ranging in area from 509 to 6111 km2. Drainage network, geometry and relief aspects were determined for the different sub-basins. The runoff volume ranges from 4.19 to 59.30 million m3. Additionally, geophysical technique in the form of gravity data with geological and hydrological techniques have been employed to delineate groundwater potential zones in Wadi El-Arish catchment area using GIS-based techniques. The resulting GIS model shows that the most favorable areas for groundwater potentiality are located at the southern part of Wadi El-Arish at Wadi Abu Tareifiya sub-basin and to the south of Wadi El-Azariq sub-basin.

Late Miocene Yellow River formation in Qingtongxia area, North China: Detrital zircon and heavy mineral analysis at Niushou Mountain, Ningxia

The development and formation times of the Yellow River, the second largest drainage system in China, remain controversial. The Ganhegou Formation, a set of Upper Miocene–Pliocene fluvial facies sediments, developed around Niushou Mountain in the outermost edge of the arcuate structural belt in the northeastern margin of the Tibetan Plateau and has a sediment composition very similar to that of the Yellow River. In this article, the relationship between the deposition of the Ganhegou Formation and the Yellow River is confirmed through the analysis and comparison of sediment composition, detrital zircons, and heavy mineral characteristics of the Ganhegou Formation, a Yellow River terrace, and the modern Yellow River. The sediments of the Ganhegou Formation contain abundant well‐ground and sorted fluvial pebbles that are largely consistent with Yellow River sediments. The analysis of the composition of zircons and heavy minerals shows that the age peaks of all detrital zircons are primarily among 200–300 Ma, 400–500 Ma, and 1,700–2,000 Ma and that all the heavy minerals are generally characterized by the combination of ‘haematite + garnet + zircon + epidote + quartz and altered minerals’. Therefore, the Ganhegou Formation in the Niushou Mountain area of Ningxia is a likely sediment of the ancient Yellow River, which has existed at Qingtongxia since at least the Late Miocene.

Sediment supply on the West Greenland passive margin: redirection of a large pre-glacial drainage system

The Mesozoic–Cenozoic separation of Greenland and North America produced the small oceanic basins of the Labrador Sea and Baffin Bay, connected via a complex transform system through the Davis Strait. During rifting and partial breakup sedimentary basins formed that record the changing regional sediment supply. The onshore and offshore stratigraphy of Central West Greenland outlines the presence of a major fluvial system that existed during the Cretaceous and was later redirected in the Early Cenozoic by the formation of the West Greenland Igneous Province. Hydrological analysis of Greenland's isostatically balanced basement topography outlines two major drainage systems that likely flowed across Greenland prior to the onset of glaciation and emptied into the Sisimiut Basin within the Davis Strait, offshore West Greenland. The course of the northern drainage system suggests that it initially flowed NW into the Cretaceous/Palaeocene Nuussuaq Basin, before being redirected SW around the West Greenland Igneous Province in the Mid-Palaeocene. Moreover, characteristics of these two drainage systems suggest they acted as a single larger fluvial system, prior to the onset of glaciation, that was likely the primary source of sediment across Central West Greenland throughout the Cretaceous and Palaeogene. This scenario provides a greater understanding of the West Greenland margin's late Cenozoic evolution, which differs from previous interpretations that hypothesize a period of considerable post-rift tectonism and uplift. This work highlights the importance of large pre-glacial drainage systems across North Atlantic passive margins and their relevance when studying post-rift stratigraphy in rifted margin settings. Supplementary material: Isostatic modelling, hydrological analysis and chi mapping is available at: https://doi.org/10.6084/m9.figshare.c.5050146

Northern limit of Gondwana in northwestern Mexico from detrital zircon data

UPb geochronology along a north-south transect from central Sonora to northern Sinaloa in northwestern Mexico indicates several changes in provenance sources through time and space. Lower Cambrian arenites of the Proveedora Quartzite yield a single main age peak at 1075 Ma with minor Paleoproterozoic contribution. Arenites from the Sonobari Complex of southwestern Sonora-northwestern Sinaloa, purportedly assigned to the early Paleozoic, yield main peaks at 1424, 1662, and 1736 Ma, probably derived from the Yavapai and Mazatzal provinces, which are pervasively intruded by early Mesoproterozoic granites coeval to those forming the Granite-Rhyolite Province. Lower to Upper Ordovician units deposited on shelf, slope, and abyssal environments display very similar zircon age patterns, with main peaks ca. 2700 and 1850 Ma, indicating a large drainage system arising from the Archean cratons of Laurentia such as the Wyoming or Superior Provinces, and Paleoproterozoic sources similar to the Trans-Hudsonian orogen, which are older than the Yavapai Province. The Río Fuerte quartzites from southern Sonora-northern Sinaloa contain main peaks at 534, 542, and 637 Ma whose sources may be peri-Gondwanan blocks similar to Avalonia or Carolina terranes. A minor peak at 475 Ma suggests input from igneous suites reported from the Acatlán Complex in southern Mexico. UPb geochronology permit inference of a late Paleozoic collisional orogen in northwestern Mexico that was originated by the collision of Gondwanan blocks against southern Laurentia and outline the boundary between terranes related to continental blocks in the Pangaea supercontinent.

All mixed up: Pb isotopic constraints on the transit of sands through the Mississippi-Missouri River drainage basin, North America

AbstractPb isotope data from over 2400 detrital K-feldspars in &gt;50 modern sands sampled across the Mississippi-Missouri River drainage basin of North America have been collected in order to construct the first basin-wide provenance model using geochemical signals in a framework, rather than an accessory, mineral. This study represents a critical initial step in understanding the long-term routing of framework sand grains through the Mississippi-Missouri River drainage basin.Four unique Pb isotopic groups, otherwise petrographically and geochemically indistinguishable, are identifiable. Source comparisons reveal two groups corresponding to the Archean Superior and Wyoming terranes to the north of the catchment. The remaining two Pb groups represent a mixture of Appalachian, Grenville and older Granite-Rhyolite, and Yavapai-Mazatzal sourced-grains in the east of the catchment, with noteworthy input from Cenozoic volcanic rocks along the western fringe of the catchment to tributaries west of the Mississippi River, confirming prior assertions of zircon recycling in the lower drainage basin.Tracing suites of Pb isotopic groups provide a detailed map of previously undocumented tributary mixing and reveals the importance of long-lived, naturally formed impoundments in the Upper Mississippi River, which locally sequester and release sand. Tentative proportioning of sediment contributions to the terminus of the Mississippi River from individual tributaries produces similar results to recent U-Pb zircon models, boding well for the use of framework grain based modeling of sediment fluxes.The study is the largest application of Pb-in-K-feldspar fingerprinting to date and advocates its potential as a new and necessary tool for constraining relative source contributions to sinks—which will have wide applicability—especially if combined with provenance information from detrital grains of varying resilience, within large drainage systems.

Identifying fit-for-purpose lumped surrogate models for large urban drainage systems using GLUE

Distributed physically based models (DPMs) have become the standard tool for urban drainage modelling. However, high computational demands limit these in applications where fast or multiple simulations are needed. This paper presents simple fit-for-purpose cheaper-to-run surrogate models (SMs) for pipe network simulations which are validated against a DPM. The SMs are set up by lumping the DPM network into compartments in which the volume of water is governed by mass balances. Outgoing discharges to downstream compartment(s) and surcharging are computed from unambiguous volume-discharge curves. The SMs are applied on a 45 km2 catchment, Elster Creek in Melbourne, Australia. The number of simulated states and simulation times are reduced by approximately 3 and 6 orders of magnitude, respectively. Different SM complexities are examined. The simplest SM using steady state training data performed well with NSE of 0.98 for volume in the most upstream compartment. When emulating the aggregated surcharge from that compartment, the SM captured all surcharge events correctly. NSE improved from 0.35 to 0.84 when subdividing the compartment into 17 subcompartments. Uncertainty of SM parameters was examined using the Generalized Likelihood Uncertainty Estimation (GLUE) methodology. Two different sampling methods were applied. Limits of acceptability for real-time control, warning and planning, resulted in many accepted models upstream and few to none in downstream backwater-prone areas. All applications showed SM uncertainty bands within expected uncertainty bands for DPM, supporting the use of a simpler conceptual model in fit-for-purpose modelling in urban water systems when computational demands of DPMs are prohibitive.