The first deep heat flow determination in crystalline basement rocks beneath the Western Canadian Sedimentary Basin

Residual aeromagnetic data of parts of Southeastern Nigerian sedimentary basin were reduced to the equator and subjected to magnetic vector inversion and spectral analysis. Average depths of source ensembles from spectral analysis were used to compute depth to magnetic tops (Z), base of the magnetic layer (Curie Point t Depth (CPD)), and estimate geothermal gradient and heat flow required for the evaluation of the geothermal resources of the study area. Results from spectral analysis showed depths to the top of the magnetic source ranging between 0.45 km and 1.90 km; centroid depths of 4 km - 7.87 km and CPD of between 6.15 km and 14.19 km. The CPD were used to estimate geothermal gradients which ranged from 20.3°C/km to 50.0°C/km 2 2 and corresponding heat flow values of 34.9 mW/m to 105 mW/m , utilizing an average thermal conductivity -1 -1 of 2.15 Wm k . Ezzagu (Ogboji), Amanator-Isu, Azuinyaba, Nkalagu, Amagunze, Nta-Nselle, Nnam, Akorfornor environs are situated within regions of high geothermal gradients (>38°C/Km) with models delineated beneath these regions using 3D Magnetic Vector Inversion, having dominant NW-SE and NE-SW trends at shallow and greater depths of <1km to >7 km bsl. Based on VES and 2D imaging models the geothermal system in Alok can be classified as Hot Dry Rock (HDR) type, which may likely have emanated from fracture systems. There is prospect for the development of geothermal energy in the study area. Keywords: Airborne Magnetics, Magnetic Vector Inversion, Geothermal Gradient, Heat Flow, Curie Point Depth, Geothermal Energy.

Download Full-text

VARIABLE FLUID AND HEAT FLOW REGIMES IN THREE DEVONIAN DOLOMITE CONDUIT SYSTEMS, WESTERN CANADA SEDIMENTARY BASIN: ISOTOPIC AND FLUID INCLUSION EVIDENCE/CONSTRAINTS

Basin-Wide Diagenetic Patterns ◽

10.2110/pec.97.57.0119 ◽

1997 ◽

pp. 119-137 ◽

Cited By ~ 4

Author(s):

ERIC MOUNTJOY ◽

STEVE WHITTAKER ◽

ANTHONY WILLIAMS-JONES ◽

HAIRUO QING ◽

EVA DRIVET ◽

...

Keyword(s):

Heat Flow ◽

Fluid Inclusion ◽

Sedimentary Basin ◽

Flow Regimes ◽

Western Canada ◽

Western Canada Sedimentary Basin ◽

Canada Sedimentary Basin

Download Full-text

Influence of basement rocks on fluid evolution during multiphase deformation: the example of the Estamariu thrust in the Pyrenean Axial Zone

10.5194/se-2020-65 ◽

2020 ◽

Author(s):

Daniel Muñoz-López ◽

Gemma Alías ◽

David Cruset ◽

Irene Cantarero ◽

Cédric M. Jonh ◽

...

Keyword(s):

Sedimentary Cover ◽

Crystalline Basement ◽

Normal Faults ◽

Published Data ◽

Fluid Migration ◽

Rock Interaction ◽

Fluid Chemistry ◽

Vein Formation ◽

Basement Rocks ◽

Calcite Veins

Abstract. Calcite veins precipitated in the Estamariu thrust during two tectonic events decipher the temporal and spatial relationships between deformation and fluid migration in a long-lived thrust and determine the influence of basement rocks on the fluid chemistry during deformation. Structural and petrological observations constrain the timing of fluid migration and vein formation, whilst geochemical analyses (δ13C, δ18O, 87Sr/86Sr, clumped isotope thermometry and elemental composition) of the related calcite cements and host rocks indicate the fluid origin, pathways and extent of fluid-rock interaction. The first tectonic event, recorded by calcite cements Cc1a and Cc2, is related to the Alpine reactivation of the Estamariu thrust, and is characterized by the migration of meteoric fluids, heated at depth (temperatures between 56 and 98 °C) and interacted with crystalline basement rocks before upflowing through the thrust zone. During the Neogene extension, the Estamariu thrust was reactivated and normal faults and shear fractures with calcite cements Cc3, Cc4 and Cc5 developed. Cc3 and Cc4 precipitated from hydrothermal fluids (temperatures between 127 and 208 °C and between 102 and 167 °C, respectively) derived from crystalline basement rocks and expelled through fault zones during deformation. Cc5 precipitated from low temperature meteoric waters percolating from the surface through small shear fractures. The comparison between our results and already published data in other structures from the Pyrenees suggests that regardless of the origin of the fluids and the tectonic context, basement rocks have a significant influence on the fluid chemistry, particularly on the 87Sr/86Sr ratio. Accordingly, the cements precipitated from fluids interacted with crystalline basement rocks have significantly higher 87Sr/86Sr ratios (> 0.710) with respect to those precipitated from fluids that have interacted with the sedimentary cover (

Download Full-text

The role of geological structures on groundwater occurrence and flow in crystalline basement aquifers: a status review

Bayero Journal of Pure and Applied Sciences ◽

10.4314/bajopas.v11i1.27 ◽

2018 ◽

Vol 11 (1) ◽

pp. 155-164

Author(s):

M.A. Idris ◽

M.L. Garba ◽

S.A. Kasim ◽

I.M. Madabo ◽

K.A. Dandago

Keyword(s):

Hydrological Cycle ◽

Crystalline Basement ◽

Geological Structures ◽

Secondary Porosity ◽

Groundwater Movement ◽

Remote Sensing Technique ◽

Basement Rocks ◽

Groundwater Occurrence ◽

Basement Aquifers

The paper is review on the role of geological structures on groundwater occurrence and flow in Crystalline Basement aquifers. The aim was to study the existing available literatures in order to evaluate structural/lineaments (faults, joints/fractures, folds, shear zone etc.) their influences and controls of groundwater occurrence and flow of bedrock of crystalline rocks of igneous and/or metamorphic origin. Groundwater in the basement aquifers resides/occurs within the weathered overburden and fractured bedrocks which originate from rainfall through the process of hydrological cycle. Remote sensing technique uses satellite imagery or aerial photograph to identify linear features on the ground and attempts to relate these lines to geologic structures capable of transmitting and storing large quantities of groundwater. Faults, joints/fractures and folds act as conduit and make rocks excellent aquifers. These features also, served as channels for groundwater movement which may results to an increased in secondary porosity, permeability and therefore, can results as a groundwater prospective/promising zones in crystalline basement rocks. Keywords: Basement Terrain, Groundwater, Lineament, Movement, Occurrence

Download Full-text