Dynamic updates of 3D orebody surface models

With a wide range application of 3D geosciences modeling in mineral deposit exploration, dynamic updates of 3D orebody surface models are required to integrate new exploration data like borehole logs. In this paper, we set up a methodology for integrating new exploration data into existing models. General steps of constructing orebody surface models which are expressed as TIN (Triangular Irregular Networks), are described in order to generate closed orebody TIN. Then, we describe our updating process from three aspects, breaking new borehole data into economic mineral segments, updating orebody surface models by mineral segments and postprocessing updated models. Special attention has been given to the second aspect, in which two problems are mainly considered. One problem is called correspondence problem - which orebody TIN should be modified according to a given mineral segment. While the other is called updating problem - how orebodies are updated. To solve the first problem, we define Correspondence Relation (CR) as the relation between a closed orebody TIN and a mineral segment. To solve the second problem, a simple method is adopted by fulfilling some projection principles of mineral segment endpoints. The above methodology is implemented in a mineral assessment system, and a case study is conducted by using the real borehole sample data from an iron ore district located in Liaoning, China. The application shows the capability of our methodology for dynamic updates of 3D orebody surface models. We conclude that our methodology integrates new exploration data available into 3D modeling process and it is a support to updates of existing orebody surface models.