Geochemical evaluation of mineralization potential of the Somie-Ntem area within the Tikar plain, Ca

• 作者: Mero Yannah Yaya Fodoué Maurice Kwékam Benoit Joseph Mbassa Juliana Amboh Tifang Armand Dongmo Kagou Samuel Ndonwi Ayonghe
• 来源期刊: 地球化学学报(英文）
• 学科: 地球科学
• 关键词: Geochemistry Mineralization Somie-Ntem Tikar plain Cameroon
• 年，卷（期）: 2023,（5）
• 页码范围: 861-886
• 页数: 25页
• 语种: 英文
• DOI: 10.1007/s11631-022-00552-z

摘要

Somie-Ntem area of the Tikar plain belongs to the western Cameroon Domain. The lithology of the plain has been characterized, and the mineral potential is stillunclear despite previous reports on Sn deposit within one of the magmatic complexes. Our results show two groups of granitic rocks displaying oxidized and reduced character; (1) mesocratic (oxidized) granites including biotite-bearing, hornblende-biotite-bearing, hornblende-epidote-bearing and pyroxene-bearing; (2) leucogranites (reduced) that are generally amphibole-pyroxene bearing. These granitoids are hosted by gneisses and metasedimentary rocks partially covered by rhyolites. Major element composition shows high-K calc-alkaline to shoshonite affinity, metaluminous to weakly peraluminous I-type granites. Mesocratic granites show moderately negative Eu anomaly, depleted in Nb, P, Ti, and are related to syn-collisional setting. Leucogranites are post-orogenic with strong negative Eu anomaly, depleted in Ba and Sr and enriched in Hf, Nb and Ta. They are fertile in Sn and Zn, enriched through postmagmatic metasomatism and greisenization. Cr-Cu-Ni-V mineralization occurs in hornblende-bearing gneisses and their enrichment suggests a possible Ni-Cu-type PGEs mineralization in this area. Meanwhile, their trace element shows high Ni/Cu, very low Rb/Sr, low LILE and LREE which indicates mantle fractionation at subduction. The absence of olivine and pyroxene, and increased SiO2 and Al2O3 in the Cr-Cu-Ni-V-bearing rocks show that the parent magma experienced fractional crystallization and crustal contamination during evolution. Notwithstanding, the high Zr/Rb and K/Rb ratios show that hydrothermal activity was not intense to enhance mineralization in the area. Variation in the direction of stress during shear deformation inhibited an effective hydrothermal activity and ore deposition in the region.