Three-dimensional inversion of airborne time-domain electromagnetic data with applications to a porphyry deposit
Three-dimensional inversion of airborne time-domain electromagnetic data with applications to a porphyry deposit
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DOI：
10.1190/geo2011-0194.1
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发表时间：
2012-02
期刊：
影响因子：
3.3
通讯作者：
Dikun Yang;D. Oldenburg
中科院分区：
文献类型：
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作者：
Dikun Yang;D. Oldenburg
我们反演了加拿大不列颠哥伦比亚省中部一个斑岩存款上空的航空时域电磁（ATEM）数据，并恢复了三维电导率结构。由于存款的圆形几何形状，需要全三维反演。典型的分析，假设一个均匀或分层的地球，产生导电文物，是相反的地质预期。一个合成的例子表明，这些误导性的文物产生的假设是一个一维分层地球和三维反演可以成功地解决这个问题。由于解决航空测量的多个发射器的三维反演的计算挑战，我们介绍了一个工作流程，使用多网格策略来处理现场数据。在我们的反演中，首先使用粗网格和少量的探测来快速重建大尺度的电导率分布。然后对网格进行细化，并纳入更多的探测数据，以更好地解决小规模的特征。这一战略意义重大…
We inverted airborne time-domain electromagnetic (ATEM) data over a porphyry deposit in central British Columbia, Canada and recovered the 3D electrical conductivity structure. Full 3D inversion was required because of the circular geometry of the deposit. Typical analysis, which assumes a homogeneous or layered earth, produces conductive artifacts that are contrary to geologic expectations. A synthetic example showed that those misleading artifacts arise by assuming a 1D layered earth and that a 3D inversion can successfully solve the problem. Because of the computational challenges of solving the 3D inversion with many transmitters of airborne survey, we introduced a work flow that uses a multimesh strategy to handle the field data. In our inversion, a coarse mesh and a small number of soundings are first used to rapidly reconstruct a large-scale distribution of conductivity. The mesh is then refined and more soundings are incorporated to better resolve small-scale features. This strategy significantly ...