<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "https://jats.nlm.nih.gov/nlm-dtd/publishing/3.0/journalpublishing3.dtd">
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" article-type="research-article" dtd-version="3.0" xml:lang="en">
<front>
<journal-meta>
<journal-id journal-id-type="publisher">SE</journal-id>
<journal-title-group>
<journal-title>Solid Earth</journal-title>
<abbrev-journal-title abbrev-type="publisher">SE</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">Solid Earth</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1869-9529</issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/se-3-213-2012</article-id>
<title-group>
<article-title>Heat-flow and subsurface temperature history at the site of Saraya (eastern Senegal)</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Lucazeau</surname>
<given-names>F.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Rolandone</surname>
<given-names>F.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Dynamique des Fluides Géologiques, Institut de Physique du Globe de Paris/Sorbonne Paris Cité, UMR CNRS 7154, 1 rue Jussieu, 75238, Paris cedex 05, France</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>iSTeP, Université Pierre et Marie Curie, 4 place Jussieu, 75252, Paris cedex 05, France</addr-line>
</aff>
<pub-date pub-type="epub">
<day>20</day>
<month>08</month>
<year>2012</year>
</pub-date>
<volume>3</volume>
<issue>2</issue>
<fpage>213</fpage>
<lpage>224</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2012 F. Lucazeau</copyright-statement>
<copyright-year>2012</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/3.0/">https://creativecommons.org/licenses/by/3.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://se.copernicus.org/articles/3/213/2012/se-3-213-2012.html">This article is available from https://se.copernicus.org/articles/3/213/2012/se-3-213-2012.html</self-uri>
<self-uri xlink:href="https://se.copernicus.org/articles/3/213/2012/se-3-213-2012.pdf">The full text article is available as a PDF file from https://se.copernicus.org/articles/3/213/2012/se-3-213-2012.pdf</self-uri>
<abstract>
<p>New temperature measurements from eight boreholes in the West African Craton
(WAC) reveal superficial perturbations down to 100 m below the
alteration zone. These perturbations are both related to a recent increase in
the surface air temperature (SAT) and to the site effects caused by fluid
circulations and/or the lower conduction in the alterites. The ground surface
temperature (GST), inverted from the boreholes temperatures, increased slowly
in the past (~0.4 °C from 1700 to 1940) and then, more
importantly, in recent years (~1.5 °C from 1940 to 2010).
This recent trend is consistent with the increase of the SAT recorded at two
nearby meteorological stations (Tambacounda and Kedougou), and more generally
in the Sahel with a coeval rainfall decrease. Site effects are superimposed
to the climatic effect and interpreted by advective (circulation of fluids)
or conductive (lower conductivity of laterite and of high-porosity sand)
perturbations. We used a 1-D finite differences thermal model and a
Monte-Carlo procedure to find the best estimates of these site
perturbations: all the eight borehole temperature logs can be interpreted
with the same basal heat-flow and the same surface temperature history, but
with some realistic changes of thermal conductivity and/or fluid velocity.
The GST trend observed in Senegal can be confirmed by two previous borehole
measurements made in 1983 in other locations of West Africa, the first one in
an arid zone of northern Mali and the second one in a sub-humid zone in
southern Mali. Finally, the background heat-flow is low
(31±2 mW m&lt;sup&gt;−2&lt;/sup&gt;), which makes this part of the WAC more similar
with the observations in the southern part (33±8 mW m&lt;sup&gt;−2&lt;/sup&gt;) rather
than with those in the northern part and in the Pan-African domains where the
surface heat-flow is 15–20 mW m&lt;sup&gt;−2&lt;/sup&gt; higher.</p>
</abstract>
<counts><page-count count="12"/></counts>
</article-meta>
</front>
<body/>
<back>
<ref-list>
<title>References</title>
<ref id="ref1">
<label>1</label><mixed-citation publication-type="other" xlink:type="simple">Beck, A.&amp;nbsp;E. and Mustonen, E.: Preliminary Heat Flow data from Ghana, Nature Physical Science, 235, 172–174, &lt;a href=&quot;http://dx.doi.org/10.1038/physci235172a0&quot;&gt;https://doi.org/10.1038/physci235172a0&lt;/a&gt;, 1972.</mixed-citation>
</ref>
<ref id="ref2">
<label>2</label><mixed-citation publication-type="other" xlink:type="simple">Birch, A.&amp;nbsp;F.: The effects of Pleistocene climatic variations upon geothermal gradients, American Journal of Science, 246, 729–760, 1948.</mixed-citation>
</ref>
<ref id="ref3">
<label>3</label><mixed-citation publication-type="other" xlink:type="simple">Brigaud, F., Lucazeau, F., Ly, S., and Sauvage, J.&amp;nbsp;F.: Heat flow from the West African Shield, Geophys. Res. Lett., 12, 549–552, &lt;a href=&quot;http://dx.doi.org/10.1029/GL012i009p00549&quot;&gt;https://doi.org/10.1029/GL012i009p00549&lt;/a&gt;, 1985.</mixed-citation>
</ref>
<ref id="ref4">
<label>4</label><mixed-citation publication-type="other" xlink:type="simple">Chapman, D.&amp;nbsp;S. and Pollack, H.&amp;nbsp;N.: Cold spot in West Africa – anchoring the African plate, Nature, 250, 477–478, &lt;a href=&quot;http://dx.doi.org/10.1038/250477a0&quot;&gt;https://doi.org/10.1038/250477a0&lt;/a&gt;, 1974.</mixed-citation>
</ref>
<ref id="ref5">
<label>5</label><mixed-citation publication-type="other" xlink:type="simple">Christensen, J., Hewitson, B., Busuioc, A., Chen, A., Gao, X., Held, I., Jones, R., Kolli, R., Kwon, W.-T., Laprise, R., Rueda, V.&amp;nbsp;M., Mearns, L., Menéndez, C., Räisänen, J., Rinke, A., Sarr, A., and Whetton, P.: Regional Climate Projections. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, chap.&amp;nbsp;11, pp. 847–940, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2007.</mixed-citation>
</ref>
<ref id="ref6">
<label>6</label><mixed-citation publication-type="other" xlink:type="simple">deMenocal, P., Ortiz, J., Guilderson, T., Adkins, J., Sarnthein, M., Baker, L., and Yarusinsky, M.: Abrupt onset and termination of the African Humid Period:: rapid climate responses to gradual insolation forcing, Quat. Sci. Rev., 19, 347–361, &lt;a href=&quot;http://dx.doi.org/10.1016/S0277-3791(99)00081-5&quot;&gt;https://doi.org/10.1016/S0277-3791(99)00081-5&lt;/a&gt;, 2000.</mixed-citation>
</ref>
<ref id="ref7">
<label>7</label><mixed-citation publication-type="other" xlink:type="simple">Diouf, S.: Hydrogéologie en zône cristalline et cristallophyllienne du Sénégal Oriental. Application de la méthode électrique 1D et 2D à la localisation et à la caractérisation des aquifères du batholithe de Saraya et ses environs, Ph.D. thesis, Cheikh Anta Diop, Dakar, 1999.</mixed-citation>
</ref>
<ref id="ref8">
<label>8</label><mixed-citation publication-type="other" xlink:type="simple">Fall, S., Niyogi, D., and Semazzi, F. H.&amp;nbsp;M.: Analysis of Mean Climate Conditions in Senegal (1971–98), Earth Interactions, 10, 1–40, 2006.</mixed-citation>
</ref>
<ref id="ref9">
<label>9</label><mixed-citation publication-type="other" xlink:type="simple">Gasse, F.: Hydrological changes in the African tropics since the Last Glacial Maximum, Quat. Sci. Rev., 19, 189–211, &lt;a href=&quot;http://dx.doi.org/10.1016/S0277-3791(99)00061-X&quot;&gt;https://doi.org/10.1016/S0277-3791(99)00061-X&lt;/a&gt;, 2000.</mixed-citation>
</ref>
<ref id="ref10">
<label>10</label><mixed-citation publication-type="other" xlink:type="simple">Gasse, F., Chalié, F., Vincens, A., Williams, M.&amp;nbsp;A., and Williamson, D.: Climatic patterns in equatorial and southern Africa from 30,000 to 10,000 years ago reconstructed from terrestrial and near-shore proxy data, Quat. Sci. Rev., 27, 2316–2340, &lt;a href=&quot;http://dx.doi.org/10.1016/j.quascirev.2008.08.027&quot;&gt;https://doi.org/10.1016/j.quascirev.2008.08.027&lt;/a&gt;, 2008.</mixed-citation>
</ref>
<ref id="ref11">
<label>11</label><mixed-citation publication-type="other" xlink:type="simple">Giannini, A., Saravanan, R., and Chang, P.: Oceanic Forcing of Sahel Rainfall on Interannual to Interdecadal Time Scales, Science, 302, 1027–1030, &lt;a href=&quot;http://dx.doi.org/10.1126/science.1089357&quot;&gt;https://doi.org/10.1126/science.1089357&lt;/a&gt;, 2003.</mixed-citation>
</ref>
<ref id="ref12">
<label>12</label><mixed-citation publication-type="other" xlink:type="simple">Goutorbe, B., Poort, J., Lucazeau, F., and Raillard, S.: Global heat flow trends resolved from multiple geological and geophysical proxies, Geophys. J. Int., 187, 1405–1419, &lt;a href=&quot;http://dx.doi.org/10.1111/j.1365-246X.2011.05228.x&quot;&gt;https://doi.org/10.1111/j.1365-246X.2011.05228.x&lt;/a&gt;, 2011.</mixed-citation>
</ref>
<ref id="ref13">
<label>13</label><mixed-citation publication-type="other" xlink:type="simple">Gueye, M., Siegesmund, S., Wemmer, K., Pawlig, S., Drobe, M., Nolte, N., and Layer, P.: New evidences for an early Birimian evolution in the West African Craton: An example from the Kedougou-Kenieba inlier, southeast Senegal, South African J. Geology, 110, 511–534, &lt;a href=&quot;http://dx.doi.org/10.2113/gssajg.110.4.511&quot;&gt;https://doi.org/10.2113/gssajg.110.4.511&lt;/a&gt;, 2007.</mixed-citation>
</ref>
<ref id="ref14">
<label>14</label><mixed-citation publication-type="other" xlink:type="simple">Harcouët, V., Guillou-Frottier, L., Bonneville, A., Bouchot, V., and Milesi, J.-P.: Geological and thermal conditions before the major Palaeoproterozoic gold-mineralization event at Ashanti, Ghana, as inferred from improved thermal modelling, Precambrian Res., 154, 71–87, &lt;a href=&quot;http://dx.doi.org/10.1016/j.precamres.2006.11.014&quot;&gt;https://doi.org/10.1016/j.precamres.2006.11.014&lt;/a&gt;, 2007.</mixed-citation>
</ref>
<ref id="ref15">
<label>15</label><mixed-citation publication-type="other" xlink:type="simple">Hartmann, A. and Rath, V.: Uncertainties and shortcomings of ground surface temperature histories derived from inversion of temperature logs, J. Geophys. Eng., 2, 299–311, &lt;a href=&quot;http://dx.doi.org/10.1088/1742-2132/2/4/S02&quot;&gt;https://doi.org/10.1088/1742-2132/2/4/S02&lt;/a&gt;, 2005.</mixed-citation>
</ref>
<ref id="ref16">
<label>16</label><mixed-citation publication-type="other" xlink:type="simple">Huang, S.&amp;nbsp;P., Pollack, H.&amp;nbsp;N., and Shen, P.&amp;nbsp;Y.: Temperature trends over the past five centuries reconstructed from borehole temperatures, Nature, 403, 756–758, 2000.</mixed-citation>
</ref>
<ref id="ref17">
<label>17</label><mixed-citation publication-type="other" xlink:type="simple">Hulme, M., Doherty, R.&amp;nbsp;M., Doherty, T., New, M.&amp;nbsp;G., and Lister, D.: African climate change: 1900–2100, Climate Research, 17, 145–168, 2001.</mixed-citation>
</ref>
<ref id="ref18">
<label>18</label><mixed-citation publication-type="other" xlink:type="simple">Jaupart, C. and Mareschal, J.&amp;nbsp;C.: Heat flow and thermal structure of the lithosphere, in: Treatise on Geophysics, vol.&amp;nbsp;6, pp. 217–251, G. Schubert, Oxford, 2007.</mixed-citation>
</ref>
<ref id="ref19">
<label>19</label><mixed-citation publication-type="other" xlink:type="simple">Kandji, S.&amp;nbsp;T., Verchot, L., and Mackensen, J.: Climate Change and Variability in the Sahel Region: Impacts and Adaptation Strategies in the Agricultural Sector, Tech. rep., United Nations Environment Programme and World Agroforestry Centre, \urlprefix&lt;a href=&quot;http://www.unep.org/Themes/Freshwater/Documents/pdf/ClimateChangeSahelCombine.pdf&quot;&gt;http://www.unep.org/Themes/Freshwater/Documents/pdf/ClimateChangeSahelCombine.pdf&lt;/a&gt;, 2006.</mixed-citation>
</ref>
<ref id="ref20">
<label>20</label><mixed-citation publication-type="other" xlink:type="simple">Kooi, H.: Spatial variability in subsurface warming over the last three decades; insight from repeated borehole temperature measurements in The Netherlands, Earth Planet. Sci. Lett., 270, 86–94, &lt;a href=&quot;http://dx.doi.org/10.1016/j.epsl.2008.03.015&quot;&gt;https://doi.org/10.1016/j.epsl.2008.03.015&lt;/a&gt;, 2008.</mixed-citation>
</ref>
<ref id="ref21">
<label>21</label><mixed-citation publication-type="other" xlink:type="simple">Latil-Brun, M.&amp;nbsp;V. and Lucazeau, F.: Subsidence, extension and thermal history of the West African margin in Senegal, Earth Planet. Sci. Lett., 90, 204–220, &lt;a href=&quot;http://dx.doi.org/10.1016/0012-821X(88)90101-X&quot;&gt;https://doi.org/10.1016/0012-821X(88)90101-X&lt;/a&gt;, 1988.</mixed-citation>
</ref>
<ref id="ref22">
<label>22</label><mixed-citation publication-type="other" xlink:type="simple">Lebel, T. and Ali, A.: Recent trends in the Central and Western Sahel rainfall regime (1990–2007), J. Hydrol., 375, 52–64, &lt;a href=&quot;http://dx.doi.org/10.1016/j.jhydrol.2008.11.030&quot;&gt;https://doi.org/10.1016/j.jhydrol.2008.11.030&lt;/a&gt;, 2009.</mixed-citation>
</ref>
<ref id="ref23">
<label>23</label><mixed-citation publication-type="other" xlink:type="simple">Lesquer, A. and Vasseur, G.: Heat-flow constraints on the West African lithosphere structure, Geophys. Res. Lett., 19, 561–564, &lt;a href=&quot;http://dx.doi.org/10.1029/92GL00263&quot;&gt;https://doi.org/10.1029/92GL00263&lt;/a&gt;, 1992.</mixed-citation>
</ref>
<ref id="ref24">
<label>24</label><mixed-citation publication-type="other" xlink:type="simple">Lesquer, A., Bourmatte, A., Ly, S., and Dautria, J.&amp;nbsp;M.: First heat flow determination from the central Sahara: relationship with the Pan-African belt and Hoggar domal uplift, J. African Earth Sciences, 9, 41–48, &lt;a href=&quot;http://dx.doi.org/10.1016/0899-5362(89)90006-7&quot;&gt;https://doi.org/10.1016/0899-5362(89)90006-7&lt;/a&gt;, 1989.</mixed-citation>
</ref>
<ref id="ref25">
<label>25</label><mixed-citation publication-type="other" xlink:type="simple">Lesquer, A., Villeneuve, J., and Bronner, G.: Heat flow data from the western margin of the West African craton (Mauritania), Physics of the Earth and Planetary Interiors, 66, 320–329, &lt;a href=&quot;http://dx.doi.org/10.1016/0031-9201(91)90087-X&quot;&gt;https://doi.org/10.1016/0031-9201(91)90087-X&lt;/a&gt;, 1991.</mixed-citation>
</ref>
<ref id="ref26">
<label>26</label><mixed-citation publication-type="other" xlink:type="simple">Lézine, A.-M., Hély, C., Grenier, C., Braconnot, P., and Krinner, G.: Sahara and Sahel vulnerability to climate changes, lessons from Holocene hydrological data, Quat. Sci. Rev., 30, 3001–3012, &lt;a href=&quot;http://dx.doi.org/10.1016/j.quascirev.2011.07.006&quot;&gt;https://doi.org/10.1016/j.quascirev.2011.07.006&lt;/a&gt;, 2011.</mixed-citation>
</ref>
<ref id="ref27">
<label>27</label><mixed-citation publication-type="other" xlink:type="simple">Mareschal, J.-C. and Beltrami, H.: Evidence for recent warming from perturbed geothermal gradients: examples from eastern Canada, Clim. Dynam., 6, 135–143, &lt;a href=&quot;http://dx.doi.org/10.1007/BF00193525&quot;&gt;https://doi.org/10.1007/BF00193525&lt;/a&gt;, 1992.</mixed-citation>
</ref>
<ref id="ref28">
<label>28</label><mixed-citation publication-type="other" xlink:type="simple">Mareschal, J.&amp;nbsp;C., Poirer, A., Rolandone, F., Bienfait, G., Gariepy, C., Lapointe, R., and Jaupart, C.: Low mantle heat flow at the edge of the North American continent, Voisey Bay, Labrador, Geophys. Res. Lett., 27, 823–826, 2000.</mixed-citation>
</ref>
<ref id="ref29">
<label>29</label><mixed-citation publication-type="other" xlink:type="simple">Mareschal, J.&amp;nbsp;C., Jaupart, C., Rolandone, F., Gariépy, C., Fowler, C. M.&amp;nbsp;R., Bienfait, G., Carbonne, C., and LaPointe, P.&amp;nbsp;R.: Heat flow, thermal regime, and elastic thickness of the lithosphere in the Trans-Hudson Orogen, Canadian J. Earth Sciences, 42, 517–532, &lt;a href=&quot;http://dx.doi.org/10.1139/e04-088&quot;&gt;https://doi.org/10.1139/e04-088&lt;/a&gt;, 2005.</mixed-citation>
</ref>
<ref id="ref30">
<label>30</label><mixed-citation publication-type="other" xlink:type="simple">Meukam, P., Jannot, Y., Noumowe, A., and Kofane, T.: Thermo physical characteristics of economical building materials, Construction and Building Materials, 18, 437–443, &lt;a href=&quot;http://dx.doi.org/10.1016/j.conbuildmat.2004.03.010&quot;&gt;https://doi.org/10.1016/j.conbuildmat.2004.03.010&lt;/a&gt;, 2004.</mixed-citation>
</ref>
<ref id="ref31">
<label>31</label><mixed-citation publication-type="other" xlink:type="simple">Michel, J.: La province kimberlitique et diamantifère de Kéniéba, Mali, Africa Geoscience Review, 3, 231–246, 1996.</mixed-citation>
</ref>
<ref id="ref32">
<label>32</label><mixed-citation publication-type="other" xlink:type="simple">Misener, A. and Beck, A.&amp;nbsp;E.: The measurement of heat flow over land, in: Methods and Techniques in Geophysics, pp. 10–61, S.K. Runcorn, New York, 1960.</mixed-citation>
</ref>
<ref id="ref33">
<label>33</label><mixed-citation publication-type="other" xlink:type="simple">Moberg, A., Sonechkin, D.&amp;nbsp;M., Holmgren, K., Datsenko, N.&amp;nbsp;M., and Karlèn, W.: Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data, Nature, 433, 613–617, &lt;a href=&quot;http://dx.doi.org/10.1038/nature03298&quot;&gt;https://doi.org/10.1038/nature03298&lt;/a&gt;, 2005.</mixed-citation>
</ref>
<ref id="ref34">
<label>34</label><mixed-citation publication-type="other" xlink:type="simple">Morgan, P.: Diamond exploration from the bottom up: regional geophysical signatures of lithosphere conditions favorable for diamond exploration, Journal of Geochemical Exploration, 53, 145–165, 1995.</mixed-citation>
</ref>
<ref id="ref35">
<label>35</label><mixed-citation publication-type="other" xlink:type="simple">Naba, S., Lompo, M., Debat, P., Bouchez, J.&amp;nbsp;L., and Béziat, D.: Structure and emplacement model for late-orogenic Paleoproterozoic granitoids: the Tenkodogo – Yamba elongate pluton (Eastern Burkina Faso), Journal of African Earth Sciences, 38, 41–57, &lt;a href=&quot;http://dx.doi.org/10.1016/j.jafrearsci.2003.09.004&quot;&gt;https://doi.org/10.1016/j.jafrearsci.2003.09.004&lt;/a&gt;, 2004.</mixed-citation>
</ref>
<ref id="ref36">
<label>36</label><mixed-citation publication-type="other" xlink:type="simple">Ndiaye, P.&amp;nbsp;M.: Evolution au Proterozoique Inférieur de la Région Est – Saraya (craton de L&apos;Afrique de L&apos;Ouest, Sénégal-Mali). Tourmalinisations, Altérations Hydrothermales et Minéralisations Associées, Ph.D. thesis, Université C.A.Diop, Dakar, 1994.</mixed-citation>
</ref>
<ref id="ref37">
<label>37</label><mixed-citation publication-type="other" xlink:type="simple">Ndiaye, P., Dia, A., Vialette, Y., Diallo, D., Ngom, P., Sylla, M., Wade, S., and Dioh, E.: Données pétrographiques, geochimiques et géochronologiques nouvelles sur les granitodes du Paléoprotérozoïque du Supergroupe de Dialé-Daléma (Senégal Oriental): Implications pétrogénétiques et géodynamiques, J. African Earth Sciences, 25, 193–208, &lt;a href=&quot;http://dx.doi.org/10.1016/S0899-5362(97)00098-5&quot;&gt;https://doi.org/10.1016/S0899-5362(97)00098-5&lt;/a&gt;, 1997.</mixed-citation>
</ref>
<ref id="ref38">
<label>38</label><mixed-citation publication-type="other" xlink:type="simple">Pasyanos, M.&amp;nbsp;E. and Nyblade, A.&amp;nbsp;A.: A top to bottom lithospheric study of Africa and Arabia, Tectonophysics, 444, 27–44, &lt;a href=&quot;http://dx.doi.org/10.1016/j.tecto.2007.07.008&quot;&gt;https://doi.org/10.1016/j.tecto.2007.07.008&lt;/a&gt;, 2007.</mixed-citation>
</ref>
<ref id="ref39">
<label>39</label><mixed-citation publication-type="other" xlink:type="simple">Patricola, C. and Cook, K.: Dynamics of the West African monsoon under mid-Holocene precessional forcing: Regional climate model simulations, J. Climate, 20, 694–716, &lt;a href=&quot;http://dx.doi.org/10.1175/JCLI4013.1&quot;&gt;https://doi.org/10.1175/JCLI4013.1&lt;/a&gt;, 2007.</mixed-citation>
</ref>
<ref id="ref40">
<label>40</label><mixed-citation publication-type="other" xlink:type="simple">Pawlig, S., Gueye, M., Klischies, R., Schwarz, S., Wemmer, K., and Siegesmund, S.: Geochemical and Sr-Nd isotopic data on the Birimian of the Kedougou-Kenieba Inlier (Eastern Senegal): Implications on the Palaeoproterozoic evolution of the West African Craton, South African Journal of Geology, 109, 411–427, &lt;a href=&quot;http://dx.doi.org/10.2113/gssajg.109.3.411&quot;&gt;https://doi.org/10.2113/gssajg.109.3.411&lt;/a&gt;, 2006.</mixed-citation>
</ref>
<ref id="ref41">
<label>41</label><mixed-citation publication-type="other" xlink:type="simple">Priestley, K., McKenzie, D., Debayle, E., and Pilidou, S.: The African upper mantle and its relationship to tectonics and surface geology, Geophys. J. Int., 175, 1108–1126, &lt;a href=&quot;http://dx.doi.org/10.1111/j.1365-246X.2008.03951.x&quot;&gt;https://doi.org/10.1111/j.1365-246X.2008.03951.x&lt;/a&gt;, 2008.</mixed-citation>
</ref>
<ref id="ref42">
<label>42</label><mixed-citation publication-type="other" xlink:type="simple">Rath, V., González Rouco, J. F., and Goosse, H.: Impact of postglacial warming on borehole reconstructions of last millennium temperatures, Clim. Past, 8, 1059–1066, &lt;a href=&quot;http://dx.doi.org/10.5194/cp-8-1059-2012&quot;&gt;https://doi.org/10.5194/cp-8-1059-2012&lt;/a&gt;, 2012.</mixed-citation>
</ref>
<ref id="ref43">
<label>43</label><mixed-citation publication-type="other" xlink:type="simple">Rimi, A. and Lucazeau, F.: Heat flow density measurements in northern Morocco, J. African Earth Sciences, 6, 835–843, 1987.</mixed-citation>
</ref>
<ref id="ref44">
<label>44</label><mixed-citation publication-type="other" xlink:type="simple">Ritsema, J. and van Heijst, H.: New seismic model of the upper mantle beneath Africa, Geology, 28, 63–68, 2000.</mixed-citation>
</ref>
<ref id="ref45">
<label>45</label><mixed-citation publication-type="other" xlink:type="simple">Sass, J.&amp;nbsp;H. and Behrendt, J.&amp;nbsp;C.: Heat Flow from the Liberian Precambrian Shield, J. Geophys. Res., 85, 3159–3162, 1980.</mixed-citation>
</ref>
<ref id="ref46">
<label>46</label><mixed-citation publication-type="other" xlink:type="simple">Sebagenzi, M.&amp;nbsp;N., Vasseur, G., and Louis, P.: Recent warming in southeastern Zaire (Central Africa) inferred from disturbed geothermal gradients, Palaeogeography, Palaeoclimatology, Palaeoecology, 98, 209–217, &lt;a href=&quot;http://dx.doi.org/10.1016/0031-0182(92)90199-F&quot;&gt;https://doi.org/10.1016/0031-0182(92)90199-F&lt;/a&gt;, 1992.</mixed-citation>
</ref>
<ref id="ref47">
<label>47</label><mixed-citation publication-type="other" xlink:type="simple">Sebai, A., Stutzmann, E., Montagner, J.-P., Sicilia, D., and Beucler, E.: Anisotropic structure of the African upper mantle from Rayleigh and Love wave tomography, Physics of the Earth and Planetary Interiors, 155, 48–62, &lt;a href=&quot;http://dx.doi.org/10.1016/j.pepi.2005.09.009&quot;&gt;https://doi.org/10.1016/j.pepi.2005.09.009&lt;/a&gt;, 2006.</mixed-citation>
</ref>
<ref id="ref48">
<label>48</label><mixed-citation publication-type="other" xlink:type="simple">Takherist, D. and Lesquer, A.: Detection of Significant Regional Variations in Heat-Flow in Algeria, Canadian J. Earth Sciences, 26, 615–626, &lt;a href=&quot;http://dx.doi.org/10.1139/e89-053&quot;&gt;https://doi.org/10.1139/e89-053&lt;/a&gt;, 1989.</mixed-citation>
</ref>
<ref id="ref49">
<label>49</label><mixed-citation publication-type="other" xlink:type="simple">Vasseur, G. and Lucazeau, F.: Bounds on paleotemperatures and paleoclimatic corrections, Zbl. Geol. Paleontol., 1, 17–24, 1983.</mixed-citation>
</ref>
<ref id="ref50">
<label>50</label><mixed-citation publication-type="other" xlink:type="simple">Zeng, N.: Drought in the Sahel, Science, 302, 999–1000, &lt;a href=&quot;http://dx.doi.org/10.1126/science.1090849&quot;&gt;https://doi.org/10.1126/science.1090849&lt;/a&gt;, 2003.</mixed-citation>
</ref>
</ref-list>
</back>
</article>