EXAMPLES OF FRACTURE CONNECTIVITY IN WISCONSIN’S PRECAMBRIAN CRYSTALLINE BEDROCK

2020 ◽  
Author(s):  
David J. Hart ◽  
◽  
Prajukti Bhattacharyya
Keyword(s):  
Crystalline Bedrock

scholarly journals Multidisciplinary Approaches for Assessing a High Temperature Borehole Thermal Energy Storage Facility at Linköping, Sweden

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4379
Author(s):  
Max Hesselbrandt ◽  
Mikael Erlström ◽  
Daniel Sopher ◽  
Jose Acuna
Keyword(s):  
Thermal Properties ◽  
High Temperature ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Thermal Response ◽  
Site Investigation ◽  
Thermal Response Test ◽  
Response Test ◽  
Crystalline Bedrock

Assessing the optimal placement and design of a large-scale high temperature energy storage system in crystalline bedrock is a challenging task. This study applies and evaluates various methods and strategies for pre-site investigation for a potential high temperature borehole thermal energy storage (HT-BTES) system at Linköping in Sweden. The storage is required to shift approximately 70 GWh of excess heat generated from a waste incineration plant during the summer to the winter season. Ideally, the site for the HT-BTES system should be able to accommodate up to 1400 wells to 300 m depth. The presence of major fracture zones, high groundwater flow, anisotropic thermal properties, and thick Quaternary overburden are all factors that play an important role in the performance of an HT-BTES system. Inadequate input data to the modeling and design increases the risk of unsatisfactory performance, unwanted thermal impact on the surroundings, and suboptimal placement of the HT-BTES system, especially in a complex crystalline bedrock setting. Hence, it is crucial that the subsurface geological conditions and associated thermal properties are suitably characterized as part of pre-investigation work. In this study, we utilize a range of methods for pre-site investigation in the greater Distorp area, in the vicinity of Linköping. Ground geophysical methods, including magnetic and Very Low-Frequency (VLF) measurements, are collected across the study area together with outcrop observations and lab analysis on rock samples. Borehole investigations are conducted, including Thermal Response Test (TRT) and Distributed Thermal Response Test (DTRT) measurements, as well as geophysical wireline logging. Drone-based photogrammetry is also applied to characterize the fracture distribution and orientation in outcrops. In the case of the Distorp site, these methods have proven to give useful information to optimize the placement of the HT-BTES system and to inform design and modeling work. Furthermore, many of the methods applied in the study have proven to require only a fraction of the resources required to drill a single well, and hence, can be considered relatively efficient.

scholarly journals Three-dimensional hydrostratigraphy and groundwater flow models in complex Quaternary deposits and weathered/fractured bedrock: evaluating increasing model complexity

2021 ◽  
Author(s):  
Susanne Charlotta Åberg ◽  
Annika Katarina Åberg ◽  
Kirsti Korkka-Niemi
Keyword(s):  
Groundwater Flow ◽  
Three Dimensional ◽  
Model Complexity ◽  
Quaternary Sediments ◽  
Fractured Bedrock ◽  
Flow Models ◽  
Flow Modelling ◽  
Crystalline Bedrock ◽  
Discharge Patterns ◽  
Geological Units

AbstractGreater complexity in three-dimensional (3D) model structures yields more plausible groundwater recharge/discharge patterns, especially in groundwater/surface-water interactions. The construction of a 3D hydrostratigraphic model prior to flow modelling is beneficial when the hydraulic conductivity of geological units varies considerably. A workflow for 3D hydrostratigraphic modelling with Leapfrog Geo and flow modelling with MODFLOW-NWT was developed. It was used to evaluate how the modelling results for groundwater flow and recharge/discharge patterns differ when using simple or more complex hydrostratigraphic models. The workflow was applied to a study site consisting of complex Quaternary sediments underlain by fractured and weathered crystalline bedrock. Increasing the hydrostratigraphic detail appeared to improve the fit between the observed and simulated water table, and created more plausible groundwater flow patterns. Interlayered zones of low and high conductivity disperse the recharge/discharge patterns, increasing the vertical flow component. Groundwater flow was predominantly horizontal in models in which Quaternary sediments and bedrock were simplified as one layer per unit. It appears to be important to define the interlayered low-conductivity units, which can limit groundwater infiltration and also affect groundwater discharge patterns. Explicit modelling with Leapfrog Geo was found to be effective but time-consuming in the generation of scattered and thin-layered strata.

Fracture anisotropy characterization in crystalline bedrock using field-scale azimuthal self potential gradient

2008 ◽  
Vol 358 (1-2) ◽  
pp. 35-45 ◽  
Author(s):  
DeBonne N. Wishart ◽  
Lee D. Slater ◽  
Alexander E. Gates
Keyword(s):  
Potential Gradient ◽  
Field Scale ◽  
Fracture Anisotropy ◽  
Crystalline Bedrock ◽  
Self Potential

scholarly journals Modeling early in situ wetting of a compacted bentonite buffer installed in low permeable crystalline bedrock

2016 ◽  
Vol 52 (8) ◽  
pp. 6207-6221 ◽  
Author(s):  
B. Dessirier ◽  
A. Frampton ◽  
Å. Fransson ◽  
J. Jarsjö
Keyword(s):  
Compacted Bentonite ◽  
Crystalline Bedrock ◽  
Bentonite Buffer

The chemistry of Norwegian groundwaters: III. The distribution of trace elements in 476 crystalline bedrock groundwaters, as analysed by ICP-MS techniques

2000 ◽  
Vol 246 (1) ◽  
pp. 21-40 ◽  
Author(s):  
Bjørn Frengstad ◽  
Aase Kjersti Midtgård Skrede ◽  
David Banks ◽  
Jan Reidar Krog ◽  
Ulrich Siewers
Keyword(s):  
Trace Elements ◽  
Crystalline Bedrock ◽  
Icp Ms ◽  
Distribution Of Trace Elements

scholarly journals The keystone species of Precambrian deep bedrock biosphere belong to <i>Burkholderiales</i> and <i>Clostridiales</i>

2015 ◽  
Vol 12 (21) ◽  
pp. 18103-18150 ◽  
Author(s):  
L. Purkamo ◽  
M. Bomberg ◽  
R. Kietäväinen ◽  
H. Salavirta ◽  
M. Nyyssönen ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Carbon Fixation ◽  
Keystone Species ◽  
Carbon Assimilation ◽  
Sugar Metabolism ◽  
Archaeal Community ◽  
Amino Sugar ◽  
Amplicon Sequencing ◽  
Fracture Zones ◽  
Crystalline Bedrock

Abstract. The bacterial and archaeal community composition and the possible carbon assimilation processes and energy sources of microbial communities in oligotrophic, deep, crystalline bedrock fractures is yet to be resolved. In this study, intrinsic microbial communities from six fracture zones from 180–2300 m depths in Outokumpu bedrock were characterized using high-throughput amplicon sequencing and metagenomic prediction. Comamonadaceae-, Anaerobrancaceae- and Pseudomonadaceae-related OTUs form the core community in deep crystalline bedrock fractures in Outokumpu. Archaeal communities were mainly composed of Methanobacteraceae-affiliating OTUs. The predicted bacterial metagenomes showed that pathways involved in fatty acid and amino sugar metabolism were common. In addition, relative abundance of genes coding the enzymes of autotrophic carbon fixation pathways in predicted metagenomes was low. This indicates that heterotrophic carbon assimilation is more important for microbial communities of the fracture zones. Network analysis based on co-occurrence of OTUs revealed the keystone genera of the microbial communities belonging to Burkholderiales and Clostridiales. Bacterial communities in fractures resemble those found from oligotrophic, hydrogen-enriched environments. Serpentinization reactions of ophiolitic rocks in Outokumpu assemblage may provide a source of energy and organic carbon compounds for the microbial communities in the fractures. Sulfate reducers and methanogens form a minority of the total microbial communities, but OTUs forming these minor groups are similar to those found from other deep Precambrian terrestrial bedrock environments.

scholarly journals Veronico beccabungae-Mimuletum guttati, a new plant community in Slovakia

2018 ◽  
Vol 87 (3) ◽  
Author(s):  
Richard Hrivnák ◽  
Michal Slezák ◽  
Karol Marhold
Keyword(s):  
Floristic Composition ◽  
Mean Annual Precipitation ◽  
Mineral Matter ◽  
Herb Layer ◽  
High Coverage ◽  
Crystalline Bedrock ◽  
Water Ph ◽  
Phytosociological Relevés ◽  
First Time ◽  
Mean Annual Air Temperature

Vegetation with high coverage by the alien species <em>Mimulus guttatus</em> was studied in the hilly regions of central Slovakia in 2015 and 2016. The floristic composition of these stands was recorded in ten phytosociological relevés corresponding to the <em>Veronico beccabungae-Mimuletum guttati</em> (alliance <em>Glycerio-Sparganion</em>) association. This association was reported for the first time in Slovakia in this study. This association was found to be closed or almost closed (mean coverage value of herb layer = 92%) and formed relatively species-rich stands (15 species per relevé), usually in narrow and small patches along the upper parts of streams and their spring areas in uplands at altitudes from 561 to 1,048 m. Localities with the <em>Veronico beccabungae-Mimuletum guttati</em> association were characterized by typical mountain climates, with both relatively low mean annual air temperature (5.5°C) and high mean annual precipitation (885 mm). While water temperature (~13°C) of these habitats varied considerably among streams (7.4–19.9°C), their herbaceous vegetation preferred neutral to slightly alkaline water (pH = 6.1–7.5) with low amounts of soluble mineral matter (~72.6 μS cm<sup>−1</sup>). This kind of vegetation was most often developed on sites with coarser sediments (stone, gravel, and sand) formed from crystalline bedrock. A comparison of vegetation data of the <em>Veronico beccabungae-Mimuletum guttati</em> association across Central Europe demonstrated considerable floristic variability among regions.

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