Signal propagation in sediment routing systems: an application for granulates prediction (location, grain-size)

Mapping Intimacies ◽

10.5194/egusphere-egu2020-12866 ◽

2020 ◽

Author(s):

Francois Guillocheau ◽

Cécile Robin

Keyword(s):

Sedimentary Basins ◽

Signal Propagation ◽

Transfer Of Knowledge ◽

Base Level ◽

Erosion Processes ◽

Sediment Routing ◽

Source To Sink ◽

Solute Fluxes ◽

Working Together ◽

Armorican Massif

The consideration of entire &#8220;Source to Sink" systems is one of the most recent and challenging advances in earth surface dynamics and sedimentary geology. To understand S2S systems it is necessary to enhance sharing of knowledge and concepts between (1) geomorphology, which focuses on the understanding of erosion processes driving landform evolution and sediment fluxes, (2) stratigraphy/sedimentology, which focuses on the nature of sedimentary deposits and their distribution in time and space, and (3) tectonics and structural geology, which set the dimensions, geometry and dynamics of source/transfer areas and sedimentary basins (the sink). Understanding S2S systems also involves other Geosciences disciplines such as paleoclimatology and geochemistry, because they allow quantifying the factors controlling S2S systems dynamics (climatic controls on erosion, solid vs. solute fluxes, etc.).The main challenges are (1) to get all the above mentioned disciplines working together on geological or numerical approaches of the whole S2S system, in different tectonic and climatic settings and (2) to convince some industries of the merits of this approach, e.g. industries dealing with geothermy or granulates.We here present one example of academia &#8211; industry transfer of knowledge for granulates: the low accommodation alluvial system of the Armorican Massif of Messinian to Pliocene age, major source of granulates for the development of the Brittany Province (western France). The understanding of the base level fluctuations sensuWheeler (1964), joined to an knowledge of the uplift history, the climate variations, and the source of sediments (Eocene laterite profiles) gave tools for a better prediction on the location and quality of the granulates.

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Rapid Climatic Signal Propagation from Source to Sink in a Southern California Sediment‐Routing System

The Journal of Geology ◽

10.1086/651539 ◽

2010 ◽

Vol 118 (3) ◽

pp. 247-259 ◽

Cited By ~ 54

Author(s):

Jacob A. Covault ◽

Brian W. Romans ◽

Andrea Fildani ◽

Mary McGann ◽

Stephan A. Graham

Keyword(s):

Southern California ◽

Signal Propagation ◽

Sediment Routing ◽

Climatic Signal ◽

Source To Sink

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A Source to Sink Approach to the North Sea Fan Pleistocene Glacial Sediments

10.5194/egusphere-egu21-12600 ◽

2021 ◽

Author(s):

Aurora Machado Garcia ◽

Ivar Midtkandal ◽

Benjamin Bellwald ◽

Ingrid Margareta Anell

Keyword(s):

Sediment Transport ◽

North Sea ◽

Signal Propagation ◽

Sedimentation Rates ◽

The North ◽

Sediment Routing ◽

Source To Sink ◽

Essential Components ◽

The North Sea ◽

Sea Fan

Trough mouth fans are large depocentres forming the ultimate sinks in glacial source-to-sink systems. Their architecture, sedimentological aspects (origin and processes) and their role as paleoclimatic archives are essential components in improving our understanding of Pleistocene and ongoing climate changes. For many years, these depocentres were thought to be dominated by debris flows accumulated in front of ice streams located at the shelf break. However, recent studies have shown that meltwater plays a major role in bringing sediment to the most distal parts of these fans, especially in lower latitudes. The North Sea Trough Mouth Fan encompasses ~110,000&#8201;km2 with water depths of up to 3500 m. It has received sediments throughout the Quaternary, with increased sedimentation rates in the last 1.1 Ma when the Norwegian Channel Ice Stream was active. Recent insight of the fan shows that meltwater turbidites play a major role in sediment delivery to the continental slope and deep-sea basin. The results could entail distinct morphologies for mid-latitude and high-latitude fans. As a result of glacial erosion and the absence of clear imprints of ice sheets on the paleo-shelves, studying trough mouth fan deposits becomes paramount in understanding glacial-interglacial cycles. This project will assess the source-to-sink parameters of the last glaciation (Weichselian) at the North Sea Fan, elucidating the dominant marine and terrestrial processes that led to the studied sedimentary sequences. High-resolution 2D and 3D seismic data, core, volumetric and numerical modeling data will be assimilated to establish a source-to-sink model for the target interval. These results will contribute to the knowledge of how glaciations affect surface mass redistribution, directly affecting the landscape dynamics and sediment routing from Fennoscandia via the North Sea to the slopes and deep basin. Sediment production will be evaluated, assessing whether it increases during the glaciation or if observed higher sedimentation rates are a result of enhanced sediment transport. This project is a part of the Marie Sklodowska-Curie Innovative Training Networks &#8220;S2S &#8211; Future: Signal propagation in source to sink for the future of the Earth resources and energy&#8221; and will further advance how trough mouth flans are highly dynamic areas where sediment transport, dispersal, remobilization and deposition take place, and serve as excellent proxies to the dynamics of glacial pulses in the hinterland.

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Example of the interplay of Tectonics, Eustasy and Surface Processes on the North Slope of Alaska Since the Jurassic

10.5194/egusphere-egu2020-20674 ◽

2020 ◽

Author(s):

Cian Clinton-Gray ◽

Sabin Zahirovic ◽

Claire Mallard ◽

Tristan Salles ◽

Daniela Garrad

Keyword(s):

Landscape Evolution ◽

Sedimentary Basins ◽

North Slope ◽

Mantle Flow ◽

Dynamic Topography ◽

The North ◽

Sediment Routing ◽

Source To Sink ◽

North Slope Of Alaska ◽

Shelf Margin

The North Slope of Alaska has experienced a complex tectonic and geodynamic history. Although regional paleogeographic reconstructions for the North Slope of Alaska have been interpreted from the geological record, a process-based understanding of the source-to-sink system accounting for both the landscape and sedimentary basin evolution of the region has not been undertaken. Additionally, the interaction of the complex tectonic and climatic forces and their influence on the development of sedimentary basins is not well understood.&#160;We investigate the influence of tectonics (including deep mantle flow), eustasy and isostasy (including flexure) on the source to sink system on the North Slope to better understand its evolution since the Jurassic.We use a quantitative forward modelling approach with the open-source surface evolution code Badlands () which incorporate time-dependent dynamic topography estimates from mantle convection models linking plate motions and mantle flow. We present a new method to implement 3D tectonic displacements (including dynamic topography) in landscape evolution models.&#160;&#160;The models capture the North Slope&#8217;s complex tectonic history and reproduce the sediment depositional trends as observed from the sedimentological record. The spatial variation in dynamic topography through time results in tilting of the basin which influenced sediment routing directions. Sea-level fluctuations significantly slow the depositional system, trapping more sediment in the proximal basin. Cross-sections of the modelled deposition are used to more closely analyse the shelf margin evolution. They reveal that the models reproduce the large-scale stratal geometries observed from the seismic record, as well as the shelf margin trajectory shifts since the Jurassic.&#160;This study demonstrates the importance of linking deep Earth processes to landscape evolution models to gain a better understanding of the long-term evolution of sedimentary basins.

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Experimental migration of knickpoints: influence of style of base-level fall and bed lithology

Earth Surface Dynamics ◽

10.5194/esurf-4-11-2016 ◽

2016 ◽

Vol 4 (1) ◽

pp. 11-23 ◽

Cited By ~ 19

Author(s):

J.-L. Grimaud ◽

C. Paola ◽

V. Voller

Keyword(s):

Fall Rate ◽

Pool Depth ◽

Similar Shape ◽

Base Level ◽

Self Organized ◽

Plunge Pool ◽

Source To Sink ◽

Constant Rate ◽

Geomorphic Features ◽

River Profiles

Abstract. Knickpoints are fascinating and common geomorphic features whose dynamics influence the development of landscapes and source-to-sink systems – in particular the upstream propagation of erosion. Here, we study river profiles and associated knickpoints experimentally in a microflume filled with a cohesive substrate made of silica, water and kaolinite. We focus on the effect on knickpoint dynamics of varying the distribution of base-level fall (rate, increment, and period) and substrate strength, i.e., kaolinite content. Such simple cases are directly comparable to both bedrock and alluvial river systems. Under a constant rate of base-level fall, knickpoints of similar shape are periodically generated, highlighting self-organized dynamics in which steady forcing leads to multiple knickpoint events. Temporary shielding of the bed by alluvium controls the spacing between these unit knickpoints. Shielding is, however, not effective when base-level drops exceed alluvium thickness. While the base-level fall rate controls the overall slope of experiments, it is not instrumental in dictating the major characteristics of unit knickpoints. Instead the velocity, face slope and associated plunge pool depth of these knickpoints are all strongly influenced by lithology. The period between knickpoints is set by both alluvium thickness and base-level fall rate, allowing use of knickpoint spacing along rivers as an indicator of base-level fall rate.

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Geomorphic variability and sediment dynamics in small catchments of dryland environments: Application into sand mining

10.5194/egusphere-egu21-2426 ◽

2021 ◽

Author(s):

Abhishek kumar Singh ◽

Nishith Bhatt

Keyword(s):

Time Series ◽

Time Series Data ◽

Mining Activity ◽

Series Data ◽

Western India ◽

Natural Sand ◽

Small Catchment ◽

Sediment Routing ◽

Source To Sink ◽

Small Catchments

The understanding of the sediment routing system and source-to-sink dynamics in a catchment is vital as it helps to assess areas undergoing erosion and deposition. This is significant in catchments which undergo active mining activities especially natural sand materials. The role of climate and natural erosional processes is vital in this as mining of sand is also affected by natural replenishment. In present study, we take a case study of a small catchment of 30km length ~ Chharri, situated in arid landscape of Kachchh of western India. Using geomorphic assemblage mapped using remote sensing and field investigation, we identified natural sub-sinks (depocenters) in the Chharri river valley. The investigation was validated by studying sediment profiles of the depocentral landforms in seasonal time series (pre-monsoon and post monsoon sessions). The changes in morphology, sediments accumulations were integrated to assess the natural sand replenishment in areas which had been undergoing mining activity. Based on time series data it was deduced that the small catchments in dry-land environments, the sand production and dynamics is modulated by type of vegetation, pattern in precipitation and human intervention. The results of such source-to-sink study have long-term implications on sand replenishment, mining activity and landscape evolution of such river basins.

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Diachronous exhumation of the Carpathians from low-temperature thermochronology

10.5194/egusphere-egu21-2648 ◽

2021 ◽

Author(s):

Marion Roger ◽

Peter van der Beek ◽

Arjan de Leeuw ◽

Laurent Husson

Keyword(s):

Low Temperature ◽

Foreland Basin ◽

The Black Sea ◽

Oblique Collision ◽

The Carpathians ◽

Sediment Routing ◽

Source To Sink ◽

Zircon Fission Track ◽

Eastern Carpathians ◽

Exhumation Rates

The Carpathians fold-and-thrust belt results from oblique collision of ALCAPA and Tisza-Dacia plates with the eastern European margin. It formed during the Oligocene and Miocene, propagating laterally from NW to SE as clearly demonstrated by balanced-cross sections (Nakapelyukh et al., 2017; Castellucio et al., 2016; Merten et al., 2010). The coeval development of the foreland basin (Roure et al., 1993) is revealed by an axial transport system that prograded from NW to SE, ultimately supplying sediments to the Black Sea (de Leeuw et al., 2020). However, lacking a regional synthesis and integration of thermochronology data, lateral propagation of exhumation in the orogen has not been demonstrated yet.&#160;We reconstruct the exhumation history of the entire Carpathians from the Oligocene onwards and link it with the development of the Carpathians foreland basin (CFB) using a source-to-sink approach. We compiled more than 500 apatite and zircon fission-track and (U-Th)/He ages from the literature. This comprehensive database was separated by region (Western, Eastern, and South-Eastern Carpathians) and by tectonic domain (as defined in Schmid et al., 2008). This partitioning allows for the inversion of large datasets, reflects the tectonic complexity of the belt, and avoids spurious spatial correlations (Schildgen et al., 2018). The thermochronology data was inverted using Pecube (Braun et al., 2012) to constrain exhumation rates in a Bayesian approach. We thus obtain estimates of exhumation rates through time along the belt (with their uncertainty) and convert these into bulk &#160;sediment fluxes over time, permitting tracking of sediment routing from the eroding belt to the CFB. Ultimately, these data will be used to unravel deeper geodynamics, including the possible effects of slab detachment on the evolution of the belt and its foreland basin.&#160;Key words: Low-temperature thermochronology, Carpathians, exhumation, source to sink, Pecube inversions.

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THE POTENTIAL FOR GEOLOGICAL SEQUESTRATION OF CO2 IN AUSTRALIA: PRELIMINARY FINDINGS AND IMPLICATIONS FOR NEW GAS FIELD DEVELOPMENT

The APPEA Journal ◽

10.1071/aj01002 ◽

2002 ◽

Vol 42 (1) ◽

pp. 25 ◽

Cited By ~ 19

Author(s):

J. Bradshaw ◽

B.E. Bradshaw ◽

G. Allinson ◽

A.J. Rigg ◽

V. Nguyen ◽

...

Keyword(s):

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Greenhouse Gas Emission ◽

Sedimentary Basins ◽

Cooperative Research ◽

Geological Sequestration ◽

Gas Field ◽

Gas Emissions ◽

Field Development ◽

Source To Sink

Many industries and researchers have been examining ways of substantially reducing greenhouse gas emissions. No single method is likely to be a panacea, although some options do show considerable promise. Geological sequestration is one option that utilises mature technology and has the potential to sequester large volumes of CO2. This technology may have particular relevance to some of Australia’s major gas resources that are relatively high in CO2. In Australia, geological sequestration has been the subject of research within the Australian Petroleum Cooperative Research Centre’s GEODISC program. A portfolio of potential geological sequestration sites (sinks) has been identified across all sedimentary basins in Australia, and these have been compared with nearby known or potential CO2 emission sources, including natural gas resources. These sources have been identified by incorporating detailed analysis of the national greenhouse gas emission databases with other publicly available data, a process that resulted in recognition of eight regional emission nodes. An earlier generic economic model for geological sequestration in Australia has been updated to accommodate the changes arising from this process of source to sink matching. Preliminary findings have established the relative attractiveness of potential injection sites through a ranking approach. It includes the ability to accommodate the volumes of sequesterable greenhouse gas emissions predicted for the adjacent region, the costs involved in transport, sequestration and ongoing operations, and a variety of technical geological risks. Some nodes with high volumes of emissions and low sequestration costs clearly appear to be suitable, whilst others with technical and economic issues appear to be problematic. This assessment may require further refinement once findings are completed from the GEODISC site-specific research currently underway.

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Halokinetic modulation of sedimentary systems: an integrated approach

10.5194/egusphere-egu2020-10099 ◽

2020 ◽

Author(s):

Zoe Cumberpatch ◽

Emma Finch ◽

Ian Kane ◽

Christopher Jackson ◽

David Hodgson ◽

...

Keyword(s):

Sedimentation Rate ◽

Carbon Capture ◽

Carbon Capture And Storage ◽

Sedimentary Basins ◽

Integrated Approach ◽

Discrete Element Modelling ◽

Sedimentation Rates ◽

Sediment Routing ◽

And Storage ◽

Sediment Interface

Complicated structural-stratigraphic traps at the salt-sediment interface have historically hosted large hydrocarbon discoveries. Understanding sediment-routing around active salt bodies, is now vital for carbon capture and storage projects due to salt being a &#8216;near-perfect&#8217; seal. Despite advances in subsurface visualisation, the salt-sediment interface remains difficult to image due to steep-bedding, bed-thickness changes and lithological contrasts. Outcropping examples provide depositional facies understanding, but are limited, largely due to the dissolution of associated halites. Studied analogues represent specific sedimentation rates and salt rise rates, which are difficult to accurately constrain and decipher.Discrete Element Modelling (DEM) provides an efficient and inexpensive tool to analyse how depositional architectures around salt structures vary with sedimentation rate. Model input parameters are taken from the Bakio diapir, Basque Cantabrian Basin and the Pierce diapirs, eastern Central Graben and their adjacent, halokinetically influenced stratigraphic successions.Six experiments were run, lasting for a total of 4.6 Myr. After a 2.2 Myr calibration period sediment was added to the model over three 800,000 year stages: 1) 2.2-3 Myr, 2) 3-3.8 Myr 3) 3.8-4.6 Myr. Sedimentation rate was varied to study the effects of sedimentation on mini-basin individualisation and extent of halokinetic modulation. The six experiments represent: no sedimentation, slow, intermediate and fast sediment input, increasing sedimentation and decreasing sedimentation. Outputs are validated by comparison to subsurface and outcropping examples globally.Results show that: 1) Diapir growth is increased with some sedimentation, compared to no sedimentation, in agreement with models of passive diapirism by sediment loading, however growth is inhibited by increasing sedimentation rate. 2) Salt withdrawal mini-basins of 4-5 diapir-widths are formed and are controlled by the width of the diapir; outside of this, the overburden is undeformed. 3) Strata, at least initially, onlap and thin towards the topographic high created by the diapir. 4) Slow aggradation results in rotation of onlaps and sedimentation being restricted to mini-basins, making individualisation more probable, while sedimentation on the diapir roof eventually occurs in all other experiments.5) Under high sedimentation rates, halokinetic influences on stratigraphy are &#8216;buried&#8217; quicker, which could make the upper part of the syn-kinematic sequence difficult to decipher from the post-kinematic sequence.The increasing sedimentation scenario simulates progradation, and is integrated with findings from the halokinetically-influenced successions around the Bakio (N.Spain) and Pierce (UK North Sea) diapirs. At Bakio, stratigraphy deposited above the diapir was removed by Pyrenean inversion. Incorporating outcrop-based sedimentary facies analysis with numerical modelling indicates that deposits experience facies changes towards stratigraphic pinch outs, mass failures could be common closest to diapirs and allows for the development of &#8216;zones&#8217; of variably severe halokinetic influence. Combining Pierce core data and model results highlights a trade-off between reservoir quality and stratigraphic trap integrity that may aid development of hydrocarbon fields and carbon capture and storage sites in salt-bearing sedimentary basins.Our innovative, iterative, integrated approach is capable of improving understanding of the variables influencing sediment-routing and stratigraphic trap configuration around extensional-passive diapirs, and can be applied to a multitude of depositional settings.

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Why do shelf-incising submarine canyons form? - Insights from global topographic analyses and regression trees

10.5194/egusphere-egu2020-8811 ◽

2020 ◽

Author(s):

Anne Bernhardt ◽

Wolfgang Schwanghart

Keyword(s):

Continental Slope ◽

Regression Trees ◽

Signal Propagation ◽

Sediment Supply ◽

Sediment Flux ◽

Slope Gradient ◽

Submarine Canyons ◽

Data Set ◽

Sediment Routing ◽

River Mouths

The efficiency of environmental signal propagation from terrestrial sources to marine sinks highly depends on the connectivity of the sediment-routing system. Submarine canyons that couple river outlets with marine depocenters are particularly crucial links in the routing network as they convey terrestrial sediment, associated pollutants and organic carbon to the deep ocean. However, why and where submarine canyons incise into shelves is still poorly understood. Several factors were proposed, including narrow shelves along active continental margins, onshore sediment flux, more proximal sediment supply during sea-level lowstands, mass wasting along high-gradient continental slopes, and the occurrence of durable bedrock in adjacent catchments. In this study, we test whether we can predict shelf incision of submarine canyons from onshore and offshore parameters. We used maps of global elevation and bathymetry and analyzed them together with a global compilation of 5900 submarine canyon heads. The analysis relies on bagged regression trees that predict the distance of each canyon head from the shelf edge as a function of numerous candidate predictor variables. These variables describe spatial relations of river mouths and canyons, shelf geometry, continental slope gradient, as well as numerous terrestrial catchment properties. Moreover, we added 120 m to the elevation of the present-day topography to simulate a coastal landscape during the Last Glacial Maximum (LGM) and recalculated the topographic terrestrial parameters and the shelf width. The trained model explains 66% (R2) of the variance within the data set with a root mean square error (RMSE) of 31 km and a mean absolute error (MAE, less sensitive to outliers) of 17 km. The highest predictor importance is consistently reported for the weighted distance from canyon heads to the adjacent river mouths during the LGM and the present-day catchment gradient. We find no significant influence of shelf width, continental slope gradient and sediment load, and the moderate fit of the model indicates that we are still missing one or more important controls on the spatial location of canyon heads. Our predictions may be refined by including a more detailed assessment of catchment lithologies, locations of submarine groundwater discharge, locations of tectonic faults, and longshore current directions. Notwithstanding, we conclude that our model identifies important controls on the spatial occurrence and shelf incision of submarine canyons and sorts out much debated but seemingly unimportant variables. &#160;

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