Normally in a Naldrett-type scenario, massive sulphides form at the base of the magma chamber and grade upwards into an interstitial zone followed by a disseminated zone. Hence, from drilling of DE1, one might assume that the "tops are to the east". However, such an interpretation is probably too early to make as the contact relationships between the "peridotite" and the barren country rock have not been made public. We could be looking at one of a number of multiple "pulses" from the lower portion of a very large magma chamber or some other genetically or structurally induced phenonomen. What is still important to remember, is that the volume of sulphides to peridotite, as Prof Mungall has stated, implies that the original volume of magma that produced the mineralization, should be orders of magnitude greater than what has been identified to date.