Rock and palaeomagnetic evidence for the Plio-Pleistocene palaeoclimatic change recorded in Upper Rhine Graben sediments (Core Ludwigshafen-Parkinsel)

AbstractThis paper summarizes results of magnetostratigraphic and rock magnetic investigations performed on fluvial sediments from the Ludwigshafen-Parkinsel drilling project (Upper Rhine Graben (URG) Germany). The drilling penetrated into Pleistocene gravel, sand, silt and clay, and unconsolidated Pliocene deposits. Its primary objective was the exploration of groundwater resources in the area of Ludwigshafen. Our rock magnetic investigations together with results of heavy mineral analyses (see Hagedorn & Boenigk, 2008) show a clearly structured sediment profile. It was possible to identify the change from mainly locally controlled sedimentation from the Graben margins to a more distinct Alpine controlled sedimentation at a depth of 177 m by magnetic data. Based on lithostratigraphic correlation with other sedimentary records from the URG and also based on palynological evidence, this event happened at the end of Late Pliocene during a time of normal polarity of the Earth's magnetic field (Gauss Chron?). The well-documented characteristic change in magneto-mineralogy from goethite to greigite almost at the same stratigraphic level, we interpret solely as a climatic signal which can be correlated with the global climate change at ∼2.5 Ma that is well documented in a wide range of sedimentary environments (e.g. deep-sea sediments, loess).

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The Pliocene and Pleistocene fluvial evolution in the northern Upper Rhine Graben based on results of the research borehole at Viernheim (Hessen, Germany)

E&G Quaternary Science Journal ◽

10.3285/eg.57.3-4.2 ◽

2009 ◽

Vol 57 (3/4) ◽

pp. 286-314 ◽

Cited By ~ 1

Author(s):

Christian Hoselmann

Keyword(s):

Research Programme ◽

Heavy Mineral ◽

Characteristic Change ◽

Upper Rhine Graben ◽

Sedimentary Sequence ◽

Sedimentary Sequences ◽

Mineral Fraction ◽

Rhine Graben ◽

Minimum Disturbance ◽

Upper Rhine

Abstract. The research borehole drilled in 2006 by the Hessian Agency for the Environment and Geology (HLUG) north of Viernheim (Hessisches Ried) reached a total depth of 350 m, and penetrated high resolution fluviatile and limnic-fluviatile sediments (0 to 225 m) of Pleistocene age, and partially highly pedogenically overprinted limnic-fluviatile sands, clays and silts of Pliocene age (225 to 350 m). The Pliocene sediments tend to be sourced locally. The sediments repeatedly show sourcing from the Odenwald which is characterised by a high percentage of green hornblende in the heavy mineral fraction. As part of the Heidelberg Basin research programme, one of the main purposes of this borehole was to analyse the Pleistocene “Normal Facies” of the northern Upper Rhine Graben, i.e. a sedimentary sequence subject to minimum disturbance, largely unaffected during the Pleistocene by material sourced from the graben margins or smaller tributaries. The Pleistocene sedimentary sequence consists of three units: a thin horizon with reworked Pliocene material is overlain by ten cycles each beginning erosively with gravely sandy sediments and ending with siltyargillaceous to in part peat-like sediments. Internal cycles can also be identified, amongst other features. A characteristic aspect is the green-grey, strongly calcareous, micaceous and well sorted, fi ne to medium sands of the Rhine. These are dominated by the Rhine Group (garnet, epidote, green hornblende and alterite) in the heavy mineral fraction. These sediments are classifi ed as the “Rhenish Facies”. The upper Pleistocene sedimentary sequences at the top of the Viernheim research borehole are dominated by several fi ning-upward and in part coarsening-upward sequences. The deposits in this part of the well are dominated by gravel deposited by the Neckar. The heavy mineral distribution of the sand fraction reveals, however, that there was mixing with Rhenish sediments. Weichselian to Holocene aeolian sands form the topmost part of the well section. The stratigraphic classifi cation of the Pleistocene sedimentary sequences is still uncertain in parts. The Pliocene-Pleistocene boundary is placed at 225 m because of the characteristic change in facies. Due to lithostratigraphic correlations with sediments within the Lower Rhine Embayment, a larger unconformity at the depth of 225 m must be accepted. Research carried out in the area around the well indicates that the youngest fine-clastic section penetrated by the well between 39.76 and 58.55 m is of Cromerian age.

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Integrated 3D geological modelling of the northern Upper Rhine Graben by joint inversion of gravimetry and magnetic data

Tectonophysics ◽

10.1016/j.tecto.2021.228927 ◽

2021 ◽

pp. 228927

Author(s):

Matthis Frey ◽

Sebastian Weinert ◽

Kristian Bär ◽

Jeroen van der Vaart ◽

Chrystel Dezayes ◽

...

Keyword(s):

Joint Inversion ◽

Magnetic Data ◽

Upper Rhine Graben ◽

Geological Modelling ◽

Rhine Graben ◽

Upper Rhine

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3D Modelling of the Northern Upper Rhine Graben Crystalline Basement by Joint Inversion of Gravity and Magnetic Data

10.5194/egusphere-egu21-477 ◽

2021 ◽

Author(s):

Matthis Frey ◽

Sebastian Weinert ◽

Kristian Bär ◽

Jeroen van der Vaart ◽

Chrystel Dezayes ◽

...

Keyword(s):

High Resolution ◽

Heat Transport ◽

Joint Inversion ◽

Transport Processes ◽

Crystalline Basement ◽

Magnetic Data ◽

Moho Depth ◽

Upper Rhine Graben ◽

Rhine Graben ◽

Upper Rhine

<p>The crystalline basement of the Upper Rhine Graben presents an attractive target for deep geothermal projects due to its favourable temperatures and its high potential as a fractured and faulted reservoir system. It is already exploited at several sites, e.g. Soultz-sous-For&#234;ts or Landau, and further projects are currently planned or under development. The crystalline units are furthermore the main source of radiogenic heat production and thus, together with the shallow Moho depth and convective heat transport along large fault zones, significantly contributing to the crustal temperature field. For these reasons, we developed the most detailed 3D geological model of the basement in the northern Upper Rhine Graben to date within the Interreg NWE DGE-ROLLOUT and Hesse 3D 2.0 projects. Due to the small number of very deep boreholes as well as seismic profiles reaching the basement beneath the locally more than 5 km thick sedimentary cover, we additionally used high-resolution magnetic and gravity datasets. In contrast to common deterministic modelling approaches, we performed a stochastic joint inversion of the geophysical data by applying a Monte Carlo Markov Chain algorithm. This method generates a large set of random but valid models, which enables a statistical evaluation of the results, e.g. concerning the model uncertainties. For a realistic attribution of the model, we used existing petrophysical databases of the region and measured the magnetic susceptibility of more than 430 rock samples. As a result of the inversion, high-resolution voxel models of the density and susceptibility distribution were generated, allowing conclusions about the composition and structure of the crystalline crust, which leads to a reduction of uncertainties and risks associated with deep geothermal drillings in the northern Upper Rhine Graben. Furthermore, our model will serve as a basis for realistic simulations of heat transport processes in the fractured basement and a meaningful assessment of the deep geothermal potential in the future.</p>

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Characterization of conditions and fluid flow paths in the Buntsandstein Gp. sandstones reservoirs, Upper Rhine Graben

BSGF - Earth Sciences Bulletin ◽

10.1051/bsgf/2021027 ◽

2021 ◽

Author(s):

Claire Bossennec ◽

Yves Géraud ◽

Johannes Böcker ◽

Bernd Klug ◽

Luca Mattioni ◽

...

Keyword(s):

Fluid Flow ◽

Fracture Network ◽

Fluid Inclusion Study ◽

Upper Rhine Graben ◽

Isotopic Ratios ◽

Rhine Graben ◽

Basin Scale ◽

Wide Range ◽

Upper Rhine

Deeply buried sandstone reservoirs are targeted in the Upper Rhine Graben (URG) for geothermal and hydrocarbon resources. These reservoirs, which are located at the top of the geothermal convective cells, have a complex diagenetic and structural history recorded by paragenesis. Here the focus is made on the characterization of carbonates and barite cementations which trace paleo geothermal circulations within the fracture network affecting the sandstones. These mineralizations are studied with a double approach on geochemistry and structural, faults and associated fracture network, to characterize fluid-flow episodes on different structural positions in the rift basin and its shoulders. Barite sulphur isotopic ratios suggest a common signature and source for all the locations. REE patterns, oxygen isotopic ratios, and fluid inclusion study suggest though two regimes of fluid flow forming barite, depending on their location. On the graben shoulders the barite have a higher content in total REE and contain non-saline fluids inclusions, suggesting that fluid circulations at the graben border faults interact with sulphate rich layers, and precipitate at high temperatures .In -deep-seated sandstones, fluid inclusions in barites show a wide range of salinities, suggesting a higher contribution of sedimentary brines, and precipitation at lower temperatures. These barite mineralizations are associated with carbonates and apatite with a diagenetic origin, according to their REE signature. These data are used to build a model for fluids circulation within the graben: Fast and deep down- and up-flows are taking place along the major border faults, which are leaching evaporitic horizons, and precipitates from geothermal fluid during fault activity. A part of these deep-down meteoric waters is reaching the centre of the basin. In this central part of the basin, fluid circulation is slower and restricted to the bottom of the basin, where fluid-mixing with sedimentary brines occurs. This new understanding of fluid pathways in the targeted reservoir brings new insights on the compartmentalization of geothermal circulations at the basin scale.

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