The geometry of a dyke swarm as a result of dyke interaction with each other and with external stresses

Resumo

In the framework of plane elastic problem we use a numerical approach to study the forms of opening and paths of growth of three parallel magma fractures as a model of dyke swarm formation and development. As expected, the internal dynamic mechanism of dyke interaction distorts their shapes in comparison with a single dyke shape, and curves their paths combining them into a divergent or a convergent system. The external dynamic mechanism of regional stress tends to align the growing dyke paths in parallel to the axis of the maximum compressive stress. The external and internal mechanisms compete with each other. The impact of the internal mechanism is stronger when the ratio of the distance between dykes to their length is less, the initial parallel dyke shift in relation to each other is larger, and the differential regional stress is less. Under the opposite conditions, the external mechanism prevails.