Earth's copper resources estimated from tectonic diffusion of porphyry copper deposits
Earth's copper resources estimated from tectonic diffusion of porphyry copper deposits
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DOI：
10.1130/g24317a.1
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发表时间：
2008-03-01
期刊：
影响因子：
5.8
通讯作者：
Wilkinson, Bruce H.
中科院分区：
文献类型：
--
作者：
Kesler, Stephen E.;Wilkinson, Bruce H.
改进对全球矿产资源的估计与从战略规划到全球地球化学循环等问题有关。本文采用斑岩铜矿垂直地壳构造迁移的时空模型，计算了地球对铜的赋矿能力。该模型仅依赖于地球上最广泛和最重要的铜来源斑岩铜矿的数量和年龄的知识，以估计地壳中侵蚀和保存的矿床数量。模型结果表明，大约125，895个斑岩铜矿床形成于中生代，其中只有大约47，789个保留在不同的地壳深度，这些矿床含有大约1.7 × 10（11）吨铜。假设其他类型的铜矿床在地壳中的表现类似，其丰度与其目前的全球产量成比例，则估计地壳各级的全球铜资源总量为3x10（11）吨。因此，地壳中大约0.25%的铜在中生代被浓缩成矿床，其中约三分之二通过抬升和侵蚀被回收。超过3.3 km的矿床中的铜含量可能是未来开采的极限，可以为目前的世界矿山生产提供5500年，从而量化了矿床的高度不寻常和不可再生性。
Improved estimates of global mineral endowments are relevant to issues ranging from strategic planning to global geochemical cycling. We have used a time-space model for the tectonic migration of porphyry copper deposits vertically through the crust to calculate Earth's endowment of copper in mineral deposits. The model relies only on knowledge of numbers and ages of porphyry copper deposits, Earth's most widespread and important source of copper, in order to estimate numbers of eroded and preserved deposits in the crust. Model results indicate that similar to 125,895 porphyry copper deposits were formed during Phanerozoic time, that only similar to 47,789 of these remain at various crustal depths, and that these contain similar to 1.7 x 10(11) tonnes (t) of copper. Assuming that other types of copper deposits behave similarly in the crust and have abundances proportional to their current global production yields an estimate of 3 x 10(11) t for total global copper resources at all levels in Earth's crust. Thus, similar to 0.25% of the copper in the crust has been concentrated into deposits through Phanerozoic time, and about two-thirds of this has been recycled by uplift and erosion. The amount of copper in deposits above 3.3 km, a likely limit of future mining, could supply current world mine production for 5500 yr, thus quantifying the highly unusual and nonrenewable nature of mineral deposits.