All really good stuff. The regional picture is becoming clear thanks to your research and images.
If you are interested in going boots and all deep into understanding the geology, geochronology and mineralization of pegmatites I found this free paper published in the journal of Economic Geology in 1995 that discusses all these aspects for the Greenbushes pegmatite.
You might be able to get something out of it, I'm not even going to give it a try.
My philosophy when it comes to investing in these lithium plays is keep it simple.
Lithium exploration is pretty much like any other mineral exploration, at least at its initial stage (it gets more complicated after you've found your deposit and you're trying to figure out how to make money out of it).
The first thing you need is some ground. The second thing you need is some ground that is relevant to the mineral you are trying to explore but the best thing to have is an actual significant occurrence of the mineral you are exploring for.
You are probably right to assume that based on the "set up" as you put it in one of your diagrams MCR's ground looks superior to ESR's but that green circle/oval you've drawn has an area of about of about 300km2 whereas the area of an HQ diamond drill hole is about 3,000mm2. Do you know how many times 300km2 can be divided into 3,000mm2? I won't calculate it but I hope you get my point.
ESR have two 3,000mm2 holes that have already hit their target and uncovered thick intersections of pegmatite believed to contain spodumene. The core is already at the assay lab getting its grade determined. They also have a third hole where they know they have another thick intersection but they can't locate the drill core yet.
If MRC find some core or drill a hole identifying thick intersections of spodumene baring pegmatite I'd put them on the same level as ESR but up until then they only have a damn good looking set up as you say and some less advanced targets.
It's a bit like shear hosted gold around Kalgoorlie. Take the Zuleika Shear Zone which runs in NW direction on the southern margin of the Kurrawang syncline. People have traced this structure for at least 200km and when you look at the "set up" along the syncline many places look prospective and many people have tried. The point however is that the gold only occurs at certain locations where the chemistry and structures are optimal. The place to have started looking on this structure is where a mineral occurrence already exists and that's exactly where they started, near shafts (Bakers Find) that were worked as early as 1895 at "21 mile", later to be called Kundana, now one of NST's best gold assets.
Exploration for lithium is no different. We start looking first where the "old timers" found it, but in this case the old timers are the people who were drilling deep for nickel and gold. I'm sure that the Mincor ground also has plenty of drilling but so far no "drill core gems" have surfaced from this old drilling. Mt Edwards contains nickel exploration data starting with WMC and going back to 1967. When I checked the WAMEX records I found reports going back to 1986 so gave up looking straight away as the data base is that deep.
All that stands between ESR and a good pegmatite find are some assays and some further drilling. I don't know if you've seen my video of the proposed holes to be drilled at the Axis and Kingmaker prospects at Mt Edwards yet (see below) but according to ESR's interpretations as to the dip of the pegmatites in their two core holes the surface projection of the pegmatite is only about between 300 and 400m NW of the original holes. I don't know how they have managed to interpret the dip or if the pegmatite will come nearer to the surface but I know they have a valid pre-existing occurrence (pending assays) that can be quickly developed to the next stage (a resource). I suspect MRC will ride on ERS's coat tails if the grades from those holes come back strong, not the other way around.
I do agree that regionally the pegmatites seem to be intruding the ultramafics preferentially and it seems to me also that they intrude where the ultramafics are more tightly folded at the "pointy" ends of the granite intrusions, but I don't know if there is any scientific basis behind this observation. Maybe that first link I gave you about the geology at Greenbushes might help if you read it carefully. On a quick scan of the that scientific paper I noticed that at Greenbushes they also have ultramafics in the hanging wall of the pegmatite, so a similar association there as well. Sorry for the long post but you did ask!!!
MCR Price at posting:
25.0¢ Sentiment: None Disclosure: Not Held