Jeff,
At this moment, no. They do not say much about the dike in the news release (meaning the next part of this post will contain a bunch of IF statements <g>). Some dikes come in very soon after the mineralization. The magmatic activity in the VMS vent area continues and these areas are very active. If it is that type of dike, then it will not necessarily lie along a major structure, it will lie within a major structure. If it is late stage, associated with something else (e.g uplift), it may or may not follow the structure associated with mineralization.
If the dike was intruded at the same time as the VMS (or around the same geologic time), you could have some more copper rich mineralization near the dike, and more sulfides. If the dike was intruded at this time, it would be part of the heat source driving the hydrothermal system. The closer to this source you would be, the more mineralization you would find.
The presence of the dike does not seem to suggest anything about grades. Perhaps if and when MAN gets a few holes very near to it, we will see a pattern, perhaps not. The dike at this moment only explains why the gravity anomaly is shaped the way it is.
The way I see it, there appear to be main two basins identified by the gravity anomaly map provided: one along anomalies TG-1, 3, 7 and the other along TG-4, 5, 6. There are most probably cross structures related to mineralization along the TG-4 to TG-1 direction (also TG-5, 6 and 2; TG-6 and 7; STG-03 and B-03). Please note that these faults or structures we are talking about are extensional features and do not have any lateral movement. They represent the plumbing for the VMS hydrothermal system. In VMS camps, the closer to the heat source driving the vents, the more mineralization, the more copper. If I have two regional extensional structures that intersect, that point represents an area of extensive faulting that would be a prime place for lots of magma to rise into. More magma means more heat. More faulting means more plumbing. In a VMS camp, the bigger the heat source is, the bigger and hotter the hydrothermal system is, hence the bigger the sulfide deposit is.
Bruce |
