Geophysical investigation using gravity data in Kinigi geothermal field, northwest Rwanda

Jean d.Amour Uwiduhaye; Hideki Mizunaga; Hakim Saibi

doi:10.1016/j.jafrearsci.2017.12.016

Geophysical investigation using gravity data in Kinigi geothermal field, northwest Rwanda

Jean d.Amour Uwiduhaye, Hideki Mizunaga, Hakim Saibi

Department of Geoscience

Research output: Contribution to journal › Article › peer-review

29 Citations (Scopus)

Abstract

A land gravity survey was carried out in the Kinigi geothermal field, Northwest Rwanda using 184 gravity stations during August and September, 2015. The aim of the gravity survey was to understand the subsurface structure and its relation to the observed surface manifestations in the study area. The complete Bouguer Gravity anomaly was produced with a reduction density of 2.4 g/cm³. Bouguer anomalies ranging from −52 to −35 mGals were observed in the study area with relatively high anomalies in the east and northwest zones while low anomalies are observed in the southwest side of the studied area. A decrease of 17 mGals is observed in the southwestern part of the study area and caused by the low-density of the Tertiary rocks. Horizontal gradient, tilt angle and analytical signal methods were applied to the observed gravity data and showed that Mubona, Mpenge and Cyabararika surface springs are structurally controlled while Rubindi spring is not. The integrated results of gravity gradient interpretation methods delineated a dominant geological structure trending in the NW-SE, which is in agreement with the regional geological trend. The results of this gravity study will help aid future geothermal exploration and development in the Kinigi geothermal field.

Original language	English
Pages (from-to)	184-192
Number of pages	9
Journal	Journal of African Earth Sciences
Volume	139
DOIs	https://doi.org/10.1016/j.jafrearsci.2017.12.016
Publication status	Published - Mar 2018

Keywords

Analytic signal
Bouguer anomaly
Horizontal gradient
Kinigi
Rwanda
Tilt angle

ASJC Scopus subject areas

Geology
Earth-Surface Processes

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10.1016/j.jafrearsci.2017.12.016

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@article{012f9e8357334550932627c3ea027996,

title = "Geophysical investigation using gravity data in Kinigi geothermal field, northwest Rwanda",

abstract = "A land gravity survey was carried out in the Kinigi geothermal field, Northwest Rwanda using 184 gravity stations during August and September, 2015. The aim of the gravity survey was to understand the subsurface structure and its relation to the observed surface manifestations in the study area. The complete Bouguer Gravity anomaly was produced with a reduction density of 2.4 g/cm3. Bouguer anomalies ranging from −52 to −35 mGals were observed in the study area with relatively high anomalies in the east and northwest zones while low anomalies are observed in the southwest side of the studied area. A decrease of 17 mGals is observed in the southwestern part of the study area and caused by the low-density of the Tertiary rocks. Horizontal gradient, tilt angle and analytical signal methods were applied to the observed gravity data and showed that Mubona, Mpenge and Cyabararika surface springs are structurally controlled while Rubindi spring is not. The integrated results of gravity gradient interpretation methods delineated a dominant geological structure trending in the NW-SE, which is in agreement with the regional geological trend. The results of this gravity study will help aid future geothermal exploration and development in the Kinigi geothermal field.",

keywords = "Analytic signal, Bouguer anomaly, Horizontal gradient, Kinigi, Rwanda, Tilt angle",

author = "Uwiduhaye, {Jean d.Amour} and Hideki Mizunaga and Hakim Saibi",

note = "Funding Information: Authors express their gratitude to Japan International Cooperation Agency ( JICA ) for financial support for the field work and for KIZUNA-program. The first author expresses his gratitude to Mr. Honda MITSURU, Dr. Saito HIROKI (West Japan Engineering Consultants, Inc.) and Endo SUSUMU (Mitsubishi Material Techno Corporation) for their technical advices during the field work. First author thanks also Rwanda Energy Group Limited for all supports. The authors thank Dr. Joseph Batir for reviewing and enhancing the quality of the paper. Publisher Copyright: {\textcopyright} 2017 Elsevier Ltd",

year = "2018",

month = mar,

doi = "10.1016/j.jafrearsci.2017.12.016",

language = "English",

volume = "139",

pages = "184--192",

journal = "Journal of African Earth Sciences",

issn = "1464-343X",

publisher = "Elsevier Limited",

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AU - Uwiduhaye, Jean d.Amour

AU - Mizunaga, Hideki

AU - Saibi, Hakim

N1 - Funding Information: Authors express their gratitude to Japan International Cooperation Agency ( JICA ) for financial support for the field work and for KIZUNA-program. The first author expresses his gratitude to Mr. Honda MITSURU, Dr. Saito HIROKI (West Japan Engineering Consultants, Inc.) and Endo SUSUMU (Mitsubishi Material Techno Corporation) for their technical advices during the field work. First author thanks also Rwanda Energy Group Limited for all supports. The authors thank Dr. Joseph Batir for reviewing and enhancing the quality of the paper. Publisher Copyright: © 2017 Elsevier Ltd

PY - 2018/3

Y1 - 2018/3

N2 - A land gravity survey was carried out in the Kinigi geothermal field, Northwest Rwanda using 184 gravity stations during August and September, 2015. The aim of the gravity survey was to understand the subsurface structure and its relation to the observed surface manifestations in the study area. The complete Bouguer Gravity anomaly was produced with a reduction density of 2.4 g/cm3. Bouguer anomalies ranging from −52 to −35 mGals were observed in the study area with relatively high anomalies in the east and northwest zones while low anomalies are observed in the southwest side of the studied area. A decrease of 17 mGals is observed in the southwestern part of the study area and caused by the low-density of the Tertiary rocks. Horizontal gradient, tilt angle and analytical signal methods were applied to the observed gravity data and showed that Mubona, Mpenge and Cyabararika surface springs are structurally controlled while Rubindi spring is not. The integrated results of gravity gradient interpretation methods delineated a dominant geological structure trending in the NW-SE, which is in agreement with the regional geological trend. The results of this gravity study will help aid future geothermal exploration and development in the Kinigi geothermal field.

AB - A land gravity survey was carried out in the Kinigi geothermal field, Northwest Rwanda using 184 gravity stations during August and September, 2015. The aim of the gravity survey was to understand the subsurface structure and its relation to the observed surface manifestations in the study area. The complete Bouguer Gravity anomaly was produced with a reduction density of 2.4 g/cm3. Bouguer anomalies ranging from −52 to −35 mGals were observed in the study area with relatively high anomalies in the east and northwest zones while low anomalies are observed in the southwest side of the studied area. A decrease of 17 mGals is observed in the southwestern part of the study area and caused by the low-density of the Tertiary rocks. Horizontal gradient, tilt angle and analytical signal methods were applied to the observed gravity data and showed that Mubona, Mpenge and Cyabararika surface springs are structurally controlled while Rubindi spring is not. The integrated results of gravity gradient interpretation methods delineated a dominant geological structure trending in the NW-SE, which is in agreement with the regional geological trend. The results of this gravity study will help aid future geothermal exploration and development in the Kinigi geothermal field.

KW - Analytic signal

KW - Bouguer anomaly

KW - Horizontal gradient

KW - Kinigi

KW - Rwanda

KW - Tilt angle

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SN - 1464-343X

VL - 139

SP - 184

EP - 192

JO - Journal of African Earth Sciences

JF - Journal of African Earth Sciences

ER -

Geophysical investigation using gravity data in Kinigi geothermal field, northwest Rwanda

Abstract

Keywords

ASJC Scopus subject areas

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