Basement Complex aquitard

Aquitard

Version Metadata
f64ad8c6-548f-4f2a-927d-a28f36a47c67
Project
Carboniferous Basin

Datasets

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Basement Complex aquitard unit description

Update:2014-02-04
The basement complex belongs to the hydrogeological Appalachian region. This hydrogeological unit is a basement uplift area along large regional St-Joseph - Dorchester fault. It is characterized by rugged terrain. The basement complex receives the largest annual rainfall, but it has the lowest recharge rates throughout the region. It is considered a major regional aquitard showing a bad aquifer potential. The main discharge is Fundy Bay. The hydrogeological unit is covered with a till layer, extending throughout the region. The till has a poor aquifer potential. Some colluvium also overlay the basement complex. Considering the general characteristics of the till, the basement complex is under semi-confined conditions, reducing the risk of contamination. The unit has a low vulnerability. The water quality is good.
Physiography
Hydrogeological regionMaritime Bassin
Hydrogeological context
ReliefThe basement complex represents the Caledonian Mountains. Elevations range from 100-150 m to over 400 m in the higher sections. The mountains represent the highest elevation of the area. The terrain is steep. The lower elevations have moderate slopes (10-15%) while the mountains are characterized by steep slopes (over 30%).
Area464.00 km2
Lithology
DescriptionThe basement complex belongs to the hydrogeological Appalachian region. They reflect the tectonic evolution and include deformation, fractures and stratification. The basement complex is covered by a till unit. In some places, colluvium overlay the basement complex.
Source
Aquifer
AquifersList of aquifer none

Unit properties

Bedrock aquifer media
Typical value:porous - fractured
Description Groundwater circulates within the bedrock through fractures and interconnected pore spaces between the individual grains. Since fractures have a much higher permeability than the matrix around them, groundwater flows predominantly through fractures.
Source Hydrogeological Atlas of South-Central Area of the Maritimes Carboniferous Basin
Confinement
Typical value:semi confined
Description The system can be considered semi-confined, but confined and unconfined conditions can be found, mainly depending on the till layer composition.
Source Hydrogeological Atlas of South-Central Area of the Maritimes Carboniferous Basin
Surficial sediment thickness
Description In New Brunswick, the till thickness varies between 0-20 m. The average thickness is 8 m for New Brunswick and Nova Scotia.
Source Hydrogeological Atlas of South-Central Area of the Maritimes Carboniferous Basin
Well depth
42.7 m Range: [19.8 to 106.7] m
Source Hydrogeological Atlas of South-Central Area of the Maritimes Carboniferous Basin
Regional precipitation
1204 mm/y Range: [1081 to 1392] mm/y
Source Hydrogeological Atlas of South-Central Area of the Maritimes Carboniferous Basin
Regional evapotranspiration
Range: [345 to 440] mm/y
Source Hydrogeological Atlas of South-Central Area of the Maritimes Carboniferous Basin
Regional recharge
33 mm/y
Description This hydrogeological unit has the weakest recharge rates throughout the area.
Source Hydrogeological Atlas of South-Central Area of the Maritimes Carboniferous Basin
Regional discharge
Description Fundy Bay is a discharge area.
Source Hydrogeological Atlas of South-Central Area of the Maritimes Carboniferous Basin
Hydrogeological unit potential
Typical value:low
Description The hydrogeological unit is considered as an aquitard unit.
Source Hydrogeological Atlas of South-Central Area of the Maritimes Carboniferous Basin
Aquifer vulnerability
Typical value:Low
Groundwater Quality
Typical value:fresh
Description Groundwater shows good quality
Source Hydrogeological Atlas of South-Central Area of the Maritimes Carboniferous Basin