Respective roles of the weathering profile and the tectonic fractures in the structure and functioning of crystalline thermo-mineral carbo-gaseous aquifers

Dewandel, Benoı̂t; Alazard, Marina; Lachassagne, Patrick; Bailly-Comte, Vincent; Couëffé, Renaud; Grataloup, Sandrine; Ladouche, Bernard; Lanini, Sandra; Maréchal, Jean-Christophe; Wyns, Robert

doi:10.1016/j.jhydrol.2017.02.028

Cited by 22 publications

(16 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, it is only in the last 15 years that the creation of the fractured layer was demonstrated to be also linked to the same weathering processes (Dewandel et al 2006(Dewandel et al , 2011Lachassagne et al 2011). This was demonstrated from observations performed by these authors all over the world: France (Dewandel et al 2017a;Lachassagne et al 2001cLachassagne et al , 2014bMaréchal et al 2014;Wyns et al 2004), South Korea (Cho et al 2002(Cho et al , 2003, Burkina Faso (Courtois et al 2010), and India (Dewandel et al 2006(Dewandel et al , 2010(Dewandel et al , 2012(Dewandel et al , 2017bMaréchal et al 2004Maréchal et al , 2006, and also from several other observations performed in various regions of France (Brittany, Massif Central, Vosges, Corsica, Pyrénées), other African countries, French Guiana, Madagascar, etc., mostly reported within BRGM reports. The role of weathering in creation of the fractured layer is also directly or indirectly confirmed by the data sets of most of the authors working on HRA.…”

Section: Introductionmentioning

confidence: 92%

Review: Hydrogeology of weathered crystalline/hard-rock aquifers—guidelines for the operational survey and management of their groundwater resources

2021

View full text Add to dashboard Cite

Hard rocks or crystalline rocks (i.e., plutonic and metamorphic rocks) constitute the basement of all continents, and are particularly exposed at the surface in the large shields of Africa, India, North and South America, Australia and Europe. They were, and are still in some cases, exposed to deep weathering processes. The storativity and hydraulic conductivity of hard rocks, and thus their groundwater resources, are controlled by these weathering processes, which created weathering profiles. Hard-rock aquifers then develop mainly within the first 100 m below ground surface, within these weathering profiles. Where partially or noneroded, these weathering profiles comprise: (1) a capacitive but generally low-permeability unconsolidated layer (the saprolite), located immediately above (2) the permeable stratiform fractured layer (SFL). The development of the SFL’s fracture network is the consequence of the stress induced by the swelling of some minerals, notably biotite. To a much lesser extent, further weathering, and thus hydraulic conductivity, also develops deeper below the SFL, at the periphery of or within preexisting geological discontinuities (joints, dykes, veins, lithological contacts, etc.). The demonstration and recognition of this conceptual model have enabled understanding of the functioning of such aquifers. Moreover, this conceptual model has facilitated a comprehensive corpus of applied methodologies in hydrogeology and geology, which are described in this review paper such as water-well siting, mapping hydrogeological potentialities from local to country scale, quantitative management, hydrodynamical modeling, protection of hard-rock groundwater resources (even in thermal and mineral aquifers), computing the drainage discharge of tunnels, quarrying, etc.

show abstract

Section: Introductionmentioning

confidence: 92%

Review: Hydrogeology of weathered crystalline/hard-rock aquifers—guidelines for the operational survey and management of their groundwater resources

2021

View full text Add to dashboard Cite

show abstract

“…Naturally sparkling mineral waters or CO 2 -rich mineral waters occur in many places around the world, in various geological context most often associated to volcanic or mantellic activity. In Europe, CO 2 -rich groundwater are observed in many regions of France [1,2], Germany [3], Poland [4], Italy [5], Portugal [6], for instance, but also overseas in Morocco [7], Australia [8] and South Korea [9], among others. Although they often trigger an intense economic and touristic activity (bottling, balneotherapy, spa and wellness), the detailed 'plumbery' of the system, the gas origin and its interactions with groundwater often remain unclear and constitute an active research topic.…”

Section: Introductionmentioning

confidence: 99%

Induced Polarization as a Proxy for CO2-Rich Groundwater Detection—Evidences from the Ardennes, South-East of Belgium

Defourny

Nguyen

Collignon³

et al. 2020

Water

View full text Add to dashboard Cite

CO 2 -rich mineral groundwaters are of great economic and touristic interest but their origin and circulation paths in the underground are often poorly understood. A deeper understanding of the system plumbery and the development of non—to minimally—invasive near-surface geophysical methods for the prospection of potential productive areas is therefore of great interest to manage future supply. The objective of this contribution is to assess the ability of the time-domain induced polarization (TDIP) method, combined with the electrical resistivity tomography (ERT) method, to make the distinction between CO 2 -rich groundwater from non-gaseous groundwater. Three combined ERT/TDIP tomographies were performed above known uplift zones in the south-east of Belgium where thousands of CO 2 -rich groundwater springs exist. On all profiles, important contrasts in both electrical resistivity and chargeability distributions were observed in the vicinity of the upflow zone, also reflected in the normalized chargeability sections computed from the measured data. Low resistivity vertical anomalies extending in depth were interpreted as a saturated fracture network enabling the upflow of deep groundwater to the surface. High chargeability anomalies appearing directly close to the CO 2 -rich groundwater springs were inferred to metallic oxides and hydroxides precipitation in the upper part of the aquifer, linked to pressure decrease and changing redox conditions in the up-flowing groundwater approaching the land surface. The combined interpretation of electrical resistivity and induced polarization datasets provides a very promising method for a robust prospection of CO 2 -rich groundwater.

show abstract

“…Such a complexity naturally associates a rapid decrease in groundwater yield and storage with depth [11] [12]. Many studies have investigated fractured basement aquifers to appraise groundwater structure and functionality [13] [14] [15] [16], understand groundwater recharge [17] [18], evaluate the hydrogeochemical evolution of groundwater [19] [20], and place production water wells [21]. Regional scale hydraulic properties are preferably interpreted using numerical simulation of long-term groundwater fluxes and records of hydraulic heads distributed throughout the aquifer [22] [23].…”

Section: Introductionmentioning

confidence: 99%

Subsurface Characterization for Groundwater Management nearby the Unfinished Obelisk Archeological Site, Aswan Governorate, Egypt

Abdulaziz¹

2019

OJG

View full text Add to dashboard Cite

Recently, the area located within the Unfinished Obelisk (UO) archeological site showed numerous seepages and accumulations of groundwater in a small pond located a few meters from the Unfinished Obelisk. The Supreme Council of Antiques sponsored integrated geological, geophysical, and hydrogeological studies to identify the possible sources of groundwater and the optimum technique to manage the groundwater flow system that may jeopardize this invaluable sculpture. The geological units and the prevailing structure have been studied in detail using Landsat imagery and field work over two consecutive seasons. The field studies indicated the development of several fault/joint systems oriented mainly ENE-WSW with clear indications of mineralization and intensive weathering effects along these fabrics. Several resistivity (vertical seismic profile and resistivity imaging) measurements extending down to at least 20 m depth and Radar imaging down to 10 m depth are gathered to investigate the extension of outcrop units and the dominant structures prevailing the near subsurface. Geophysical data indicated the development of at least three hydrostratigraphic units arranged from top to bottom as valley fill, fractured/weathered granite, and slightly fractured to massive granitic unit. In addition, the major faults mapped by resistivity images helped to locate several observation wells and a production well to test the transmissivity across the groundwater system. The results of a pumping test indicated very low aquifer conductivity and the development of an aquitard with preferential vertical flow at the study area. This enforces a local interference through a shallow underground drainage system with sump and pump to maintain low groundwater level at the UO-archeological site.

show abstract

Respective roles of the weathering profile and the tectonic fractures in the structure and functioning of crystalline thermo-mineral carbo-gaseous aquifers

Cited by 22 publications

References 35 publications

Review: Hydrogeology of weathered crystalline/hard-rock aquifers—guidelines for the operational survey and management of their groundwater resources

Review: Hydrogeology of weathered crystalline/hard-rock aquifers—guidelines for the operational survey and management of their groundwater resources

Induced Polarization as a Proxy for CO2-Rich Groundwater Detection—Evidences from the Ardennes, South-East of Belgium

Subsurface Characterization for Groundwater Management nearby the Unfinished Obelisk Archeological Site, Aswan Governorate, Egypt

Contact Info

Product

Resources

About