Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Yokoyama Tetsuya 0000-0003-2247-7232 Aka Festus T Usui Tomohiro Kuritani Takeshi Wirmvem Mengnjo J Iwamori Hikaru Fozing Eric M Tamen Jules 0000-0002-4302-5035 Mofor Gilbert Z Ohba Takeshi Tanyileke Gregory Hell Joseph Victor 2017 Major elements, trace elements and Sr-Nd-Pb isotopes form lavas of lakes Nyos, Wum, Elum and Oku sampled in the Oku Volcanic Group of the Cameroon Volcanic Line dataset https://doi.org/10.1594/PANGAEA.874334 2017-04-06T12:03:10 Lake Nyos is located at the summit of a stratovolcano in the Oku Volcanic Group (OVG) along the Cameroon Volcanic Line. The sudden release of magmatic CO2 trapped at the bottom of Lake Nyos in August 1986 caused historical casualties of 1750 people and over 3000 cattle. New geochemical data of volcanic rocks from the Nyos volcano and the first available data for volcanic rocks from other maar-bearing volcanoes (Lakes Elum, Wum and Oku) in the OVG are presented and compared. Lavas from the Nyos, Elum and Wum volcanoes show similarities in major and trace elements and Sr?Nd?Pb isotopes, suggestive of a similar mantle source. However, this source is slightly different from that of the Oku volcano. The samples from Lake Oku have lower alkali, higher TiO2 and more depletion and enrichment in most incompatible trace elements than those from the Nyos, Elum and Wum volcanoes. These differences and those observed in the Sr?Nd?Pb results are consistent with a heterogeneous source for lavas in the OVG. Trace element compositions suggested the presence of garnet in the source (< 6% garnet) and modelled melting results indicate < 2% partial melting of the source material. Isotope data plot within the focal zone, extending towards enriched mantle 1 (EM1; e.g. Lakes Oku and Nyos samples). This indicates the involvement of at least three mantle components: depleted mid-ocean ridge basalt mantle, high-µ and EM1 components in the magmatism of the lavas studied. The contributions of these components in different proportions, originating from asthenospheric and subcontinental lithospheric mantle sources, can account for the observed variations in geochemical characteristics. The geochemical characteristics of the studied lavas indicate that the magma source need not necessarily have an abnormal CO2 concentration to pose a potential threat. Degassing of an ordinary magma chamber and the migration of gas to the bottom of the lakes through cracks and faults can lead to the accumulation of CO2 in lake bottoms. This is controlled by tectonic parameters (fractures and faults) that enhance degassing from the magma chamber to the lake bottom and physical parameters of the lake (e.g. size, depth, temperature and solubility) that control CO2 stability. Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Yokoyama Tetsuya 0000-0003-2247-7232 Aka Festus T Usui Tomohiro Kuritani Takeshi Wirmvem Mengnjo J Iwamori Hikaru Fozing Eric M Tamen Jules 0000-0002-4302-5035 Mofor Gilbert Z Ohba Takeshi Tanyileke Gregory Hell Joseph Victor 2015 Geochemistry of lavas from maar-bearing volcanoes in the Oku Volcanic Group of the Cameroon Volcanic Line journal article Chemical Geology 406 https://doi.org/10.1016/j.chemgeo.2015.03.030 55-69 10.2069 10.453889 6.192778 6.44505 10.322673 6.345606 not specified OVG_Lake_Elum 6.333333 10.333333 Cameroon Sampling by hand HAND Position is estimated from map. OVG_Lake_Nyos 6.44505 10.29657 Cameroon Sampling by hand HAND Position is estimated from map. OVG_Lake_Oku 6.192778 10.453889 Cameroon Sampling by hand HAND Position is estimated from map. OVG_Lake_Wum 6.411263 10.2069 Cameroon Sampling by hand HAND Position is estimated from map. 1768 CC-BY-3.0 Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/ Event label Event Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Event Latitude of event Latitude Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Latitude Longitude of event Longitude Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Longitude Sample ID Sample ID Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Sample ID Silicon dioxide SiO2 % https://en.wikipedia.org/wiki/Silicon_dioxide silicon dioxide http://purl.obolibrary.org/obo/CHEBI_30563 Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 SiO2 [%] Titanium dioxide TiO2 % https://en.wikipedia.org/wiki/Titanium_dioxide titanium dioxide http://purl.obolibrary.org/obo/CHEBI_32234 Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 TiO2 [%] Aluminium oxide Al2O3 % aluminium oxide http://purl.obolibrary.org/obo/CHEBI_30187 Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Al2O3 [%] Iron oxide, Fe2O3 Fe2O3 % iron oxide http://purl.obolibrary.org/obo/CHEBI_50816 ferric oxide Fe2O3 Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Fe2O3 [%] Manganese oxide MnO % manganese oxide Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 MnO [%] Magnesium oxide MgO % magnesium oxide http://purl.obolibrary.org/obo/CHEBI_31794 Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 MgO [%] Calcium oxide CaO % https://en.wikipedia.org/wiki/Calcium_oxide calcium oxide http://purl.obolibrary.org/obo/CHEBI_31344 Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 CaO [%] Sodium oxide Na2O % sodium oxide Na2O https://pubchem.ncbi.nlm.nih.gov/compound/73971 Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Na2O [%] Potassium oxide K2O % potassium oxide http://purl.obolibrary.org/obo/CHEBI_88321 Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 K2O [%] Phosphorus pentoxide P2O5 % phosphorus oxide http://purl.obolibrary.org/obo/CHEBI_37349 Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 P2O5 [%] Loss on ignition LOI % http://en.wikipedia.org/wiki/Loss_on_ignition loss Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 LOI [%] Total Total % total https://www.oxforddictionaries.com/definition/american_english/total Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Total [%] Magnesium Mg % magnesium Dimensionless Ratio ψ Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Mg [%] Chromium Cr mg/kg chromium Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Cr [mg/kg] Nickel Ni mg/kg nickel Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Ni [mg/kg] Cobalt Co mg/kg cobalt Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Co [mg/kg] Vanadium V mg/kg vanadium Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 V [mg/kg] Zinc Zn mg/kg zinc Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Zn [mg/kg] Copper Cu mg/kg copper Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Cu [mg/kg] Rubidium Rb mg/kg rubidium Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Rb [mg/kg] Strontium Sr mg/kg strontium Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Sr [mg/kg] Yttrium Y mg/kg yttrium Y Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Y [mg/kg] Zirconium Zr mg/kg zirconium Zr Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Zr [mg/kg] Niobium Nb mg/kg niobium Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Nb [mg/kg] Caesium Cs mg/kg caesium Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Cs [mg/kg] Barium Ba mg/kg barium Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Ba [mg/kg] Lanthanum La mg/kg lanthanum La Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 La [mg/kg] Cerium Ce mg/kg cerium http://purl.obolibrary.org/obo/CHEBI_33369 Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Ce [mg/kg] Praseodymium Pr mg/kg praseodymium Pr Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Pr [mg/kg] Neodymium Nd mg/kg neodymium Nd Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Nd [mg/kg] Samarium Sm mg/kg samarium Sm https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:33374 Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Sm [mg/kg] Europium Eu mg/kg europium Eu https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:32999 Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Eu [mg/kg] Gadolinium Gd mg/kg gadolinium Gd Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Gd [mg/kg] Terbium Tb mg/kg terbium Tb https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:33376 Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Tb [mg/kg] Dysprosium Dy mg/kg dysprosium Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Dy [mg/kg] Holmium Ho mg/kg holmium Ho Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Ho [mg/kg] Erbium Er mg/kg erbium http://purl.obolibrary.org/obo/CHEBI_33379 Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Er [mg/kg] Thulium Tm mg/kg thulium Tm https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:33380 Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Tm [mg/kg] Ytterbium Yb mg/kg ytterbium http://purl.obolibrary.org/obo/CHEBI_33381 Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Yb [mg/kg] Lutetium Lu mg/kg lutetium Lu https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:33382 Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Lu [mg/kg] Hafnium Hf mg/kg Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Hf [mg/kg] Tantalum Ta mg/kg Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Ta [mg/kg] Lead Pb mg/kg lead Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Pb [mg/kg] Thorium Th mg/kg thorium http://purl.obolibrary.org/obo/CHEBI_33385 Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Th [mg/kg] Uranium U mg/kg uranium Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 U [mg/kg] Europium Eu mg/kg europium Eu https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:32999 Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 Eu [mg/kg] Strontium-87/Strontium-86 ratio 87Sr/86Sr strontium-87 87Sr strontium-86 86Sr https://en.wikipedia.org/wiki/Isotopes_of_strontium ratio Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 87Sr/86Sr Neodymium-143/Neodymium-144 ratio 143Nd/144Nd ratio Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 143Nd/144Nd Lead-206/Lead-204 ratio 206Pb/204Pb ratio Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 206Pb/204Pb Lead-207/Lead-204 ratio 207Pb/204Pb ratio Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 207Pb/204Pb Lead-208/Lead-204 ratio 208Pb/204Pb ratio Asaah Asobo N E asoboasaah@gmail.com 0000-0003-4940-6629 208Pb/204Pb citable author50177 author61357 author61358 author61359 author61360 author61361 author61362 author61363 author61364 author61365 author61366 author61367 author61368 event2835385 event2835386 event2835387 event2835388 geocode1600 geocode1601 journal3311 license101 method11566 param1546 param1552 param16065 param1666 param1825 param2208 param2270 param24196 param24198 param5126 param675 param678 param679 param680 param681 param683 param684 param685 param686 param687 param688 param689 param690 param691 param692 param693 param694 param695 param696 param697 param698 param700 param701 param702 param703 param704 param705 param706 param707 param708 param709 param80 param81 param811 param817 param82 param84 param85 param86 param87 param98941 pi61357 ref90384 term1073193 term1073224 term1073359 term1073376 term1073379 term1073388 term1074034 term1074050 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