TENDENCY AND FRACTAL PATTERN OF MIGRATION OF TRACE-ELEMENTS IN-SOURCEROCKS DURING THERMAL EVENT

The reactivation of trace elements in source rocks is fundamental in t he formation of many economic deposits. Although transport by fluid fl ow and infiltration is very effective along visible fractures, the mig ration of trace elements from the inner part of solid cells to the wea knesses is much less efficient, and so becomes the bottleneck in the m igration of these elements from their initial positions in the source rock to the final deposition site in an ore body. Diffusion may play a key role in the reactivation of trace elements. The overall migration pattern of trace elements in source rocks is characterized by an embe dded sink mosaic structure, which possesses the self-similarity of a f ractal. There are two general migration tendencies of trace elements. One is from within solid cells, such as mineral grains, toward the sin k, consisting of weaknesses in the source rock. The other is from high -temperature fields toward low-temperature ones. High temperature favo rs the realization of these two tendencies. Conjugate geochemical anom alies are the inevitable result of a closed system.