Hudyma, MR, Frenette, P & Leslie, I 2010, 'Monitoring open stope caving at Goldex Mine', in Y Potvin (ed.), Caving 2010: Proceedings of the Second International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 133-144, https://doi.org/10.36487/ACG_rep/1002_6_Hudyma (https://papers.acg.uwa.edu.au/p/1002_6_Hudyma/) Abstract: Goldex is a sublevel open stoping mine near Val-d’Or in northwestern Quebec. The orebody will be extracted in stages, using a novel mining method, resulting in a single stope with the dimensions of 450 m on strike, 250 m in height and up to a width of 120 m. A microseismic monitoring system was designed to monitor the profile of the large stopes and the extent of overbreak around the stopes. This paper discusses the design of the seismic system, and the results of the seismic monitoring with regard to observations of stope performance. In particular, the paper discusses how the seismic source parameter Apparent Stress can be used to identify areas of active rock mass fracturing.