Ann: Lab Results Confirm Kimberlite Target Areas, page-169

I'm now sure the L259 area was a small lake as the transported SRVK (yellow circles) appear as finely bedded lacustrine sediments. The lacustrine sediments in the photo turn up bright yellow (Oct 6, 2015 announcement) which indicates it is weathered kimberlite. The presence of a lake and the consequential weathering effect on the L259 kimberlite is very important.
The weathering of kimberlite means it is being broken down which results in the release of its diamonds and all its indicator minerals (garnets and ilemnites). Don't forget these are scattered all over Block 8 and maintained a coarse nature which shows they have not travelled far according to Dr John Ward (31 Aug, 2015 announcement).

Note that deeply weathered kimberlite also loses its magnetic property. This may explain why L259, unlike the other kimberlites, has a low magnetic signature. Also, having a thick cover of lake sediment would further reduce its magnetic reading.

Lastly, this is potentially good news for the upcoming bulk sampling preparations. Weathering of a kimberlite makes it softer which increases the suitability for processing at the onsite DMS plant.

Theory only, just trying to join the dots, looking forward to the upcoming announcements.