Novo Resources and its supporters are claiming that the Pilbara conglomerates in Western Australia may host the largest gold deposit in the world, even bigger than the Witswatersrand. As a result, a new gold rush is taking place that is every bit as fervent, if not desperate, as the 1849 California Gold Rush. The "17ers" might end up being badly disappointed, however, just like many of the 49ers were. The reason is simple. Geology 101. The following is an assemblage of points being made by an alleged geologist "Blythefan" (who supposedly lives and works in Western Australia) on the Australian bulletin board "Hotcopper". I am only including selected and relevant quotes and quips. My own comments are appended at the end of each paragraph or section. While everything stated here is highly speculative theorizing, it's enough to give major pause. This post will continue to be updated as long as relevant geological points are being raised in this particular forum.
UPDATE 12/11/17: I will not add any more comments to this post as it has now been determined with a relatively high level of confidence that the claims of the "Hotcopper geologist" as further pontificated upon by me in the below sections are in fact correct. The Purdy's Reward and Comet Wells areas of Pilbara gold-bearing conglomerates are not a direct Witwatersrand analogy with gold precipitated from acidic seawater but rather simple paleoplacers within an alluvial setting and a possible shallow marine platform ("beach") similar to Nome, Alaska. This is confirmed as per the latest Novo corporate presentation, which to the company's and Quinton Hennigh's credit, has been honestly disclosed in a timely manner. The implication is that Novo's share price is still probably too high. Perhaps they can mine the conglomerates, as Nome is still being dredged today, but it may never be at a scale to interest the majors. A billion dollar valuation certainly seems excessive. Keith Barron of Aurelian/Fruta del Norte fame has posted his thoughts in agreement with this geological interpretation although he like a few others such as Bob Moriarty seem to think you can just mine these conglomerates at a great profit (Barron claims mining costs might be as low as $100/ounce) so possibly a big valuation can still arise. The low cost, however, is unlikely to be realized because placers are not evenly distributed even with a major offshore marine component. A lot of waste material will have to be sorted through in order to find the rich paystreaks. I don't see any large mining company dredging offshore at Nome. It's not likely to happen in the Pilbara conglomerates either. The Novo share price is still high at $5 Canadian per share (about US$500 million market cap). At half that we might start to approach value, assuming the marine platform is a major component of the deposit. If it's simply an alluvial valley fill type conglomerates, forget it. Too much time would pass in between finding where the gold was concentrated as paystreaks in such a depositional environment. A placer miner may not see production for months and then could produce thousands of ounces over the course of a few weeks. Maybe a small operation could work that way, but not a big mining company.
11/23/17 16:32:17: - "So your guess is as good as mine as to the latitude of the Pilbara 3 billion years ago, and therefore there's absolutely no evidence to suggest that there were large tides driving the production of conglomerates at the shoreline." [TS: A previous comment had suggested the Pilbara craton was at a higher latitude during gold deposition which would have meant large tides generating a lot of conglomerates, but not sure how this would work or why it would be important for the amount of gold deposited. Shoreline conglomerates, if that is what they have at Purdy's Reward where all the current excitement is focused, tend to be limited in both thickness and lateral extent especially if clastic. The larger accumulations would be pounded down over time into finer particles due to cycles of marine transgression and progradation. The presence of shoreline conglomerates at all would indicate rapid geological change and as previously stated, any type of violent meteoric, hydraulic, tectonic or igneous activity would be anathema to the sustained well-being of the cyanobacteria that supposedly fixed the oxygen locally in order to precipitate the Pilbara gold nuggets out of acidic pools of water. The cyanobacteria would have preferred relatively shallow and calm waters, not violent tidal shorelines featuring cliffs crumbling down atop rocky paleobeaches that are then quickly buried, exhumed and re-buried.
11/23/17 16:32:17: - "The presence of gold in sediments does not necessarily carry any relationship to the saturation of gold in the waters overlying them. There are placer deposits in, say, the mountain streams of Alaska. Are the waters in those streams saturated in gold and causing the precipitation of the nuggets? No. The same holds true for the Pilbara. There's absolutely no evidence at all that gold in sea water caused the accumulation of these nuggets." [TS: Here I think a mistake is made in that the Hennigh theory assumes an acidic rain and seawater that theoretically can hold more gold in solution compared to meteoric water today. So we can't really compare to the relatively pure mountain streams of Alaska, which have almost zero ability to dissolve and carry gold in solution. That said, it remains to be shown in actual lab experiments how much gold that acidic water can hold in solution at atmospheric pressures and sub-boiling temperatures. Planetary science studies point to a 6.0 pH for Archean seawater and a 4.0 pH for rain. That compares to values today of 8.2 pH and 5.6 pH, respectively. Moreover, modern "acid rain" has a similar pH of around 4.0. Yet we don't have massive chemical erosion taking place these days. Most of it is the normal physical variety. The pH differences between the Archean and now are simply not likely to be sufficient to account for billions of ounces of gold being remobilized due to the chemical erosion of gold-bearing crustal rocks. And we are still talking about just the Witwatersrand gold being possibly precipitated, where the gold grain size could at least theoretically be accounted for by chemical dissolution and accretion. In the Pilbara, the gold found so far is in nugget form and this points to mechanical erosion of a lode deposit.]
11/20/17 21:16:31: - "So, no, the 2.0Ga ocean had <1:10,000th as much Au dissolved in it as the 2.9Ga ocean. In theory. In reality, the atmosphere at even 2.55 Ga was so oxygenated that BIF was precipitating out...but, uh, why was BIF precipitating out of the sea at 3.4 and 3.44 Ga in the Cleaverville Formation? Was this because the ocean was saturated in iron, or because of oxygenation? I dunno, you tell me." [TS: Questioning the idea that oxygenation of the atmosphere resulted in gold that was dissolved in water being precipitated out into the Witwatersrand conglomerates and perhaps the Pilbara conglomerates. The oxygenation-precipitation theory has some problems including the extensive period of time over which BIF (Banded Iron Formation) was formed. Precipitation of BIF and other dissolved minerals was not a single worldwide event related to atmospheric oxygenation but localized based on the chemical condition and composition of surface waters. "Algae" mats may have played a role by locally providing oxygen which would have fixed some minerals dissolved in water. What's more probable is that it may have been actually the carbon provided by these early microbes that concentrated the gold, at least in the Witwatersrand, and this process occurred post-deposition during metamorphism (including diagenesis and Vredefort asteroid impact). In other words, the gold may have been deposited at the same time and in the same places as microbes thrived, but not necessarily because these microbes were oxidizing the anoxic gold-bearing waters. Rather the conditions where microbes thrived (low energy, shallow water flow) would also be ideal for fine alluvial gold settling out.]
11/20/17 21:16:31: - "Was the acid rain falling on the mountains in the Pilbara at 2.77 Ga eating away the rocks? I guess it must have been, because magic science gnomes from the Google said so! The evidence for deep aggressive weathering in the uplands, though, is nil. Zip. Zilch. Go to Marble Bar and look for yourself. There's no palaeosols, there's no deeply weathered flow tops in the Mt Roe. The best you've got is calcite alteration and amgydales in the Tumbiana. ANd by the time you get to the Pyradie you have extensive stromatolite beds forming, and if you know anything about carbonate and acid rain, its that acid rain destroys stromatolites, so the atmosphere at the onset of the Fortescue was doubtless so oxygenated that widespread shallow oceanic stromatolites were growing. The Pyradie o laid down within 20 ma of the Mt Roe, so I guess it happens in a flash amirite?" [TS: Pilbara rocks don't indicate a lot of upland erosion like the Witwatersrand. So the question is, where did the gold supposedly dissolved in the seawater come from? If acidic water was responsible, then why are stromatolites (a formation of calcium carbonate that would dissolve in acid) preserved in the same geological layer?]
11/20/17 21:16:31: - "Sorry. You can't accept part of the science and then ignore the rest. Like, the hardey Formation, Lyre Creek Member, is unaltered felsic volcanics with pyrite in the tuff. I guess that the oxygen fugacity of the everything was low, and the sulfur fugacity was so high, that to get buckshot pyrite you needed no oxygen. But that also means no acid rain. Bit of a pickle, eh? Can't get acid rain (H2SO4-) without free oxygen!" - [TS: The following abstract from "Detrital pyrite in Witwatersrand gold reefs: X-ray diffraction evidence and implications for atmospheric evolution {November 1998}" should help shed some light: "Pyrite is easily oxidized, and therefore unambiguous evidence of detrital pyrite grains in metasediments is a significant constraint on when an oxygenated atmosphere developed. Compact rounded pyrite in the Witwatersrand gold reefs of South Africa has a detrital habit and is texturally equivalent to and spatially associated with detrital zircon and chromite. X-ray precession photography reveals that petrographically featureless As-poor grains are untwinned single crystals of high diffraction quality. This new evidence from crystallography is consistent with mechanically abraded pyrite from primary lode gold deposits, and excludes an origin by replacement of a pre-existing detrital phase. Further evidence of a detrital origin for the compact rounded pyrite is afforded by isolated grains of arsenian pyrite displaying truncated As-rich growth bands. The geographically extensive Witwatersrand fluvial conglomerates evidently had a matrix of quartz and pyrite sand and pyritic mud in their unconsolidated state and, thus, the late Archean atmosphere of Earth was likely essentially anoxic." Let's throw aside the idea that free oxygen may have been required to make Archean acid rain (it's possible that hydrogen sulfide and sulfur dioxide degassed from sub-aerial volcanic eruptions could substitute). Let's also throw aside the idea that the acid rain was probably not much more acidic than 4.0 pH (essentially similar to the acidity of today's acid rain). That still leaves the observation that Witwatersrand pyrite is claimed to be consistent with erosion from a primary lode gold deposit. So, if pyrite was eroded instead of being dissolved by acid rain, what made such a big difference for the gold?]
UPDATE 12/11/17: I will not add any more comments to this post as it has now been determined with a relatively high level of confidence that the claims of the "Hotcopper geologist" as further pontificated upon by me in the below sections are in fact correct. The Purdy's Reward and Comet Wells areas of Pilbara gold-bearing conglomerates are not a direct Witwatersrand analogy with gold precipitated from acidic seawater but rather simple paleoplacers within an alluvial setting and a possible shallow marine platform ("beach") similar to Nome, Alaska. This is confirmed as per the latest Novo corporate presentation, which to the company's and Quinton Hennigh's credit, has been honestly disclosed in a timely manner. The implication is that Novo's share price is still probably too high. Perhaps they can mine the conglomerates, as Nome is still being dredged today, but it may never be at a scale to interest the majors. A billion dollar valuation certainly seems excessive. Keith Barron of Aurelian/Fruta del Norte fame has posted his thoughts in agreement with this geological interpretation although he like a few others such as Bob Moriarty seem to think you can just mine these conglomerates at a great profit (Barron claims mining costs might be as low as $100/ounce) so possibly a big valuation can still arise. The low cost, however, is unlikely to be realized because placers are not evenly distributed even with a major offshore marine component. A lot of waste material will have to be sorted through in order to find the rich paystreaks. I don't see any large mining company dredging offshore at Nome. It's not likely to happen in the Pilbara conglomerates either. The Novo share price is still high at $5 Canadian per share (about US$500 million market cap). At half that we might start to approach value, assuming the marine platform is a major component of the deposit. If it's simply an alluvial valley fill type conglomerates, forget it. Too much time would pass in between finding where the gold was concentrated as paystreaks in such a depositional environment. A placer miner may not see production for months and then could produce thousands of ounces over the course of a few weeks. Maybe a small operation could work that way, but not a big mining company.
11/23/17 16:32:17: - "So your guess is as good as mine as to the latitude of the Pilbara 3 billion years ago, and therefore there's absolutely no evidence to suggest that there were large tides driving the production of conglomerates at the shoreline." [TS: A previous comment had suggested the Pilbara craton was at a higher latitude during gold deposition which would have meant large tides generating a lot of conglomerates, but not sure how this would work or why it would be important for the amount of gold deposited. Shoreline conglomerates, if that is what they have at Purdy's Reward where all the current excitement is focused, tend to be limited in both thickness and lateral extent especially if clastic. The larger accumulations would be pounded down over time into finer particles due to cycles of marine transgression and progradation. The presence of shoreline conglomerates at all would indicate rapid geological change and as previously stated, any type of violent meteoric, hydraulic, tectonic or igneous activity would be anathema to the sustained well-being of the cyanobacteria that supposedly fixed the oxygen locally in order to precipitate the Pilbara gold nuggets out of acidic pools of water. The cyanobacteria would have preferred relatively shallow and calm waters, not violent tidal shorelines featuring cliffs crumbling down atop rocky paleobeaches that are then quickly buried, exhumed and re-buried.
11/23/17 16:32:17: - "The presence of gold in sediments does not necessarily carry any relationship to the saturation of gold in the waters overlying them. There are placer deposits in, say, the mountain streams of Alaska. Are the waters in those streams saturated in gold and causing the precipitation of the nuggets? No. The same holds true for the Pilbara. There's absolutely no evidence at all that gold in sea water caused the accumulation of these nuggets." [TS: Here I think a mistake is made in that the Hennigh theory assumes an acidic rain and seawater that theoretically can hold more gold in solution compared to meteoric water today. So we can't really compare to the relatively pure mountain streams of Alaska, which have almost zero ability to dissolve and carry gold in solution. That said, it remains to be shown in actual lab experiments how much gold that acidic water can hold in solution at atmospheric pressures and sub-boiling temperatures. Planetary science studies point to a 6.0 pH for Archean seawater and a 4.0 pH for rain. That compares to values today of 8.2 pH and 5.6 pH, respectively. Moreover, modern "acid rain" has a similar pH of around 4.0. Yet we don't have massive chemical erosion taking place these days. Most of it is the normal physical variety. The pH differences between the Archean and now are simply not likely to be sufficient to account for billions of ounces of gold being remobilized due to the chemical erosion of gold-bearing crustal rocks. And we are still talking about just the Witwatersrand gold being possibly precipitated, where the gold grain size could at least theoretically be accounted for by chemical dissolution and accretion. In the Pilbara, the gold found so far is in nugget form and this points to mechanical erosion of a lode deposit.]
11/20/17 21:16:31: - "So, no, the 2.0Ga ocean had <1:10,000th as much Au dissolved in it as the 2.9Ga ocean. In theory. In reality, the atmosphere at even 2.55 Ga was so oxygenated that BIF was precipitating out...but, uh, why was BIF precipitating out of the sea at 3.4 and 3.44 Ga in the Cleaverville Formation? Was this because the ocean was saturated in iron, or because of oxygenation? I dunno, you tell me." [TS: Questioning the idea that oxygenation of the atmosphere resulted in gold that was dissolved in water being precipitated out into the Witwatersrand conglomerates and perhaps the Pilbara conglomerates. The oxygenation-precipitation theory has some problems including the extensive period of time over which BIF (Banded Iron Formation) was formed. Precipitation of BIF and other dissolved minerals was not a single worldwide event related to atmospheric oxygenation but localized based on the chemical condition and composition of surface waters. "Algae" mats may have played a role by locally providing oxygen which would have fixed some minerals dissolved in water. What's more probable is that it may have been actually the carbon provided by these early microbes that concentrated the gold, at least in the Witwatersrand, and this process occurred post-deposition during metamorphism (including diagenesis and Vredefort asteroid impact). In other words, the gold may have been deposited at the same time and in the same places as microbes thrived, but not necessarily because these microbes were oxidizing the anoxic gold-bearing waters. Rather the conditions where microbes thrived (low energy, shallow water flow) would also be ideal for fine alluvial gold settling out.]
11/20/17 21:16:31: - "Was the acid rain falling on the mountains in the Pilbara at 2.77 Ga eating away the rocks? I guess it must have been, because magic science gnomes from the Google said so! The evidence for deep aggressive weathering in the uplands, though, is nil. Zip. Zilch. Go to Marble Bar and look for yourself. There's no palaeosols, there's no deeply weathered flow tops in the Mt Roe. The best you've got is calcite alteration and amgydales in the Tumbiana. ANd by the time you get to the Pyradie you have extensive stromatolite beds forming, and if you know anything about carbonate and acid rain, its that acid rain destroys stromatolites, so the atmosphere at the onset of the Fortescue was doubtless so oxygenated that widespread shallow oceanic stromatolites were growing. The Pyradie o laid down within 20 ma of the Mt Roe, so I guess it happens in a flash amirite?" [TS: Pilbara rocks don't indicate a lot of upland erosion like the Witwatersrand. So the question is, where did the gold supposedly dissolved in the seawater come from? If acidic water was responsible, then why are stromatolites (a formation of calcium carbonate that would dissolve in acid) preserved in the same geological layer?]
11/20/17 21:16:31: - "Sorry. You can't accept part of the science and then ignore the rest. Like, the hardey Formation, Lyre Creek Member, is unaltered felsic volcanics with pyrite in the tuff. I guess that the oxygen fugacity of the everything was low, and the sulfur fugacity was so high, that to get buckshot pyrite you needed no oxygen. But that also means no acid rain. Bit of a pickle, eh? Can't get acid rain (H2SO4-) without free oxygen!" - [TS: The following abstract from "Detrital pyrite in Witwatersrand gold reefs: X-ray diffraction evidence and implications for atmospheric evolution {November 1998}" should help shed some light: "Pyrite is easily oxidized, and therefore unambiguous evidence of detrital pyrite grains in metasediments is a significant constraint on when an oxygenated atmosphere developed. Compact rounded pyrite in the Witwatersrand gold reefs of South Africa has a detrital habit and is texturally equivalent to and spatially associated with detrital zircon and chromite. X-ray precession photography reveals that petrographically featureless As-poor grains are untwinned single crystals of high diffraction quality. This new evidence from crystallography is consistent with mechanically abraded pyrite from primary lode gold deposits, and excludes an origin by replacement of a pre-existing detrital phase. Further evidence of a detrital origin for the compact rounded pyrite is afforded by isolated grains of arsenian pyrite displaying truncated As-rich growth bands. The geographically extensive Witwatersrand fluvial conglomerates evidently had a matrix of quartz and pyrite sand and pyritic mud in their unconsolidated state and, thus, the late Archean atmosphere of Earth was likely essentially anoxic." Let's throw aside the idea that free oxygen may have been required to make Archean acid rain (it's possible that hydrogen sulfide and sulfur dioxide degassed from sub-aerial volcanic eruptions could substitute). Let's also throw aside the idea that the acid rain was probably not much more acidic than 4.0 pH (essentially similar to the acidity of today's acid rain). That still leaves the observation that Witwatersrand pyrite is claimed to be consistent with erosion from a primary lode gold deposit. So, if pyrite was eroded instead of being dissolved by acid rain, what made such a big difference for the gold?]
11/20/17 21:16:31: - "So, yeah, by the time you get to the mass balance equations, you're saying there's not enough gold in literally a whole craton of rock. Mate, the background level of gold is ~1ppb. If you have 30 billion grams of gold in the Wits (roughly) that's 30 billion tones of rock." [TS: This bit is funny given he royally screws up the maths in criticizing another bulletin board comment's math. In fact, he is off by a factor of 1000 so that's 30 TRILLION tonnes of rock. It's a lot, but not really that much on a cratonic scale. And just a drop in the bucket at the mantle scale. It's in the mantle-crust mixing boundary where differentiated melts had gold concentrations, and then these melts erupted during discrete periods to bring the gold to surface.]
11/20/17 21:16:31: - "That's barely a small mountain range; a thousand cubic kilometres. Or, to put it in perspective, a metre of mud atop a thousand square kilometres. Which is nothing. The Cleaverville was buried 8 kilometres deep before 2900 Ma, and then came to surface by 2770 Ma." [TS: Ummm not quite. It's a million cubic kilometers, or 1 kilometer of mud atop a thousand square kilometers. That's a lot of rock but still just a fraction of the Archean craton. The gold concentration was probably very high in a portion of the craton that was intruded by komatiites (a type of high temperature and low viscosity magma that can have a large partial melt gradient especially when saturated by sulfur). The komatiites and similar mantle melts probably scavanged gold and were responsible for providing heat energy and pathways for transporting huge quantities of gold (and other metals) from the mantle toward the surface. The gold probably separated from the high temperature melts into felsic/granitic fractions near the surface explaining why komatiites are often barren and the gold is mainly associated with quartz near the surface.]
11/14/17 12:21:29: - "Someone post the inevitable stratigraphic column of the Fortescue vs Wits. And point out to me where in the Fortescue Group there are BIFs. Then come and tell me whether the BIF which encloses this Mt Oscar conglomerate is part of the Fortescue Group or not. Big hint for you lot: this is not the Mt Roe. It's in the older Whim Creek Group, and as such, it's not this magical mystical Wits 2.0 stuff." [TS: He is conflating a couple things here but the point is still valid. The relevant slice of Fortescue sediment is younger (2.7 billion years or ~2.7 Ga) than the Witwatersrand (~2.8 Ga), suggesting that the gold deposition in the two basins was different. BIF or Banded Iron Formation can be used as a marker to stratigraphically place and establish the age of rock layers. In the Pilbara, the Mt. Roe Formation directly overlies the gold-bearing conglomerates that have been the source of all the recent hooplah. Yet the Mt. Oscar conglomerates where some nuggets were found by Artemis (Novo's main partner in the Pilbara) is not even part of the same stratigraphy. In other words, the Fortescue and Witwatersrand are different ages, and the Mt. Oscar is yet older. So comparing any of the three without a lot of caveats, much less understanding, is not good geology.]
11/9/17 11:37:05: - "See, you CAN determine if there's a few ppm Au in surface material with a pan, and release this material to the ASX (assays pending), in 2 weeks. So what's the big issue with all these explorers faffing about? Get out there, check the outcrops (you can drive if you must, not everyone needs to hire a chopper), pan the soils, take some soil samples (10kg is probably a good size) and put them in for Leachwell." [TS: He is saying that other companies are easily able to do some gold panning, separate out any nuggets and then check to see how much in fine gold remains. Fine gold is important because you are not going to build multiple-million ounce deposits (in terms of compliant resource statements) out of nuggets. In fact, the entirety of the Witwatersrand (Novo's favorite "comparable" to the Pilbara) is contained in fine gold. Novo for some reason has not done this type of panning where the gold-bearing conglomerates outcrop, and that reason may have to do with stretching out the "magic" story as long as possible.]
11/7/17 19:15:31: - It's interesting you mention Frimmel; he would say that the Fortescue is too young by 150Ma for a truly good Au deposit formed by this 'Wits 2.0' theory as you describe it inaccurately. Frimmel and hennigh's theory is that algal mats fixed the Au in place; this requires a magical combination of oxygen-creating pond scum living in rivers and lagoons at river mouths, to fix Au from acidic weathering of uplands. To form stromatolites, being very blunt here, requires very little tectonism. this is not the case for shoreline facies with conglomerates, which at best are re-working the pond scum lagoonal facies into a placer deposit (hence, Purdy's). [TS: The Witwatersrand is older than the Fortescue Formation that contains the target gold-bearing conglomerates in the Pilbara. The ideal age for a Witwatersrand-style deposit would be the same age as the Witwatersrand. A difference of 150 million years might not seem huge, but the early landmass on Earth was undergoing massive and radical changes so in fact 150 million years is pretty darn major. The Witwatersrand gold has some association with stromatolites, which are cemented formations left behind by cyanobacteria. The stromatolites in the Witwatersrand are intact and found in a setting that suggests shallow water and gradual erosion. Meanwhile the target gold-bearing conglomerates in the Pilbara are "immature" in the sense they are not well sorted, sized or rounded. This suggests a tectonic setting of a rapidly-rising continental margin or river valley into which cliffs have crumbled with relatively fast burial afterwards. Again, a different geological model compared to the Witwatersrand.]
11/7/17 19:15:31: - This all comes back around to whether you can extrapolate the Purdy's mineralisation across the basin. As shown in the WAMEX reports relating to Munni Munni, the Lyre Creek felsic porphyry shows that this is not the case. Go to GSWA Bulletin 144 and look at the palaeoenvironment of the Hardey Formation; there are hundreds of square kilometres of the Hardey FM basal unconformity which is dominated by felsic pyroclastics. Where's your Wits 2.0 play if your bugs are cooked to death by hot lava? [TS: The gold-bearing conglomerates most likely do not persist in the Pilbara as a continuous sheet as they do in portions of the Witwatersrand. Large parts of the Pilbara are covered by felsic volcanics of the same age as the conglomerates. Volcanoes would have erupted violently and frequently, during the supposed time of gold deposition, causing havoc and destroying the relatively laconic setting required for a Witwatersrand gold setting, at least as hypothesized by Novo's Quinton Hennigh.]
11/7/17 19:15:31: - At the risk of repeating myself, go read more stuff about the nature of the unconformity around Marble Bar, most of which has no conglomerate, which is in palaeovalleys. Again, every klick of unconformity that lacks sediment is about ten million ounces sterilised according to Sproot and Kaiser's spurious wibbly-wobbly fantasty maths. [TS: No further comment necessary.]
11/7/17 19:15:31: - Meakins also lays out the geochemistry of soils and streams in mineralised Hardey Formation. ARV's own geochemistry from Mt Oscar is actually the most comprehensive dataset on soils and rocks yet. It's not pretty, with only 10-20ppb in soils, and 80-100ppb in rocks, when you discount the nuggets. [TS: He points out that previous studies of Pilbara rocks in nugget-bearing formations reveal low fine gold content.]
11/7/17 19:15:31: - At Purdy's there is not soil data publically available because Novo has gone straight in to trenching and bulk samples and hype. I doubt we would ever see it published, but you never know; ARV has a duty to disclose material information and I would have thought that if they lefted the skirts on Mt Oscar they'd want to show Purdy's was at least as good if not better. [TS: Again a question as to why simple soil analysis even if just using a gold pan has not been conducted. The soils enveloping the gold-bearing conglomerates should have fine gold assuming the conglomerates themselves have fine gold.]
11/7/17 19:15:31: - This leads into the crux of the issue to my mind. ARV has shown that Mt Oscar has nothing special; spotty soils with micro-nuggets and rocks with micro-nuggets. This matches the endowment of the Marble bar sub-basin (a structural graben). Soils done by Hunter Ltd and Platina and others around Munni Munni showed absolutely no enrichment except at the ppb levels. [TS: Other parts of the Pilbara have been explored and reveal no special Witwatersrand-style gold endowment.]
11/7/17 19:15:31: - This is not the footprint of a billion ounce deposit. I made this point on the DEG threads last week about their 6 mini-nugget find; if that area was as rich as Purdy's (aka the Wits 2.0 theory of a uniform sheet of unbelievable riches) then DEG ought by now have found a shedload of slugs of gold dripping out of the rocks. Seams, literal seams, of gold. These are absent and you have a couple of random nuggets. [TS: No further comment necessary.]
11/7/17 19:15:31: - "So, what's the argument against this line of reasoning?
"It's unique!" - OK, stop calling it Wits 2.0
"There's no geochemical signature!" - OK, so what about the Au in the fines? Surely that's dispersing downstream and forming a giant alluvial trail like Womerina
"All the gold is in the nuggets like it is in the goldfields" - Nope, provably not true, see the photo of the nugget sweating gold into the matrix, see the fine gold in matrix, etc
"It totally is contiguous across the basin!" - uh, no, see the actual GSWA maps, read the GSWA papers.
"The hardey has mineralisation!" - sure it does, crappy stuff at Beatons Creek. Novo itself knows its not a sheet of billions of ounces because otherwise Beatons Creek would be a ripper, not a 500K Oz maybe-ran. Meakins shows that it's mineralised, but no more than Mt Oscar, and it doesn't have a massive soil anomaly. Also, see above re: the felsic volcanics stoping out the conglomerates. [TS: Highlighting the idea that any fine gold might be due to "sweating" or breaking/eroding off the sharp edges of gold aggregations ("nuggets"). Apparently there is a photo of a nugget in matrix showing some smaller gold particles immediately nearby in the same matrix. If this "sweating" is the source of the fine gold, it may also mean the original gold nuggets were possibly of the standard variety that form as leaf, wire, dendrites and crystals in a lode deposit. Not at all the same or even similar to the Witwatersrand. In a lode deposit, the gold is carried along by the intrusive as part of the magma melt and precipitates under permissive conditions at a late stage as the magma cools near surface with or without the assistance of hydrothermal fluids. One reasonable theory is that lode deposits with large gold endowment are derived from mantle melts that contain elements from early meteorite impacts including heavy metals such as gold, nickel and the platinum group (otherwise we wouldn't have these elements in the crust since the heavy metals present in the original planet-forming material that accreted to form the Earth would have sunk into the core). Moreover, a special type of high temperate and low viscosity magma called a komatiite may be involved in the transport of gold from the deeper mantle toward surface where it is concentrated in host rocks by various geological processes. The Witwatersrand has komatiites as well as platinum-group metals. Komatiites do exist in the Pilbara but there association with gold has not been investigated, although it should be.]
11/7/17 01:23:34 - "Lets see what WAMEX says.
A75368: soils taken south of Munni Munni in Fortescue Group;
Rock chips on unconformity; 2ppb max, Ave <1ppb. Yep, ripper!" [TS: Low background gold grades.]
11/7/17 01:23:34 - "A28380
Au-PGE anomalies were greater in streams sourced from the Fortescue Group unconformity. However, the unconformity in the west of the Munni munni intrusion is blanketed by a tuff unit - so no conglomerate there. Guess that's $4.5B in-ground value sterilised! The Hardey Formation is described uniformly as 'sandstone and shale with minor tuffs', so no conglomerate there. The Bellary Formation is described as discontinuous, so maybe you have something on the eastern edge." [TS: Even with the presence of gold from an unknown source, there is a lack of conglomerates in this particular area of the Pilbara and this precludes a Witwatersrand type of deposit. The insinuation is that the Piblara isn't a vast sheet of gold similar to portions of the Witwatersrand but rather pockets of smaller deposits here and there.]
11/7/17 01:23:34 - "Like, hey, the MMD61 hole log reads
0-40 Fortescue Group; 0-35m Felsic Tuff interalated with mudstone and siltstone. 35-40m black carbonaceous shae with interlayered siltstone, trace sulphides. Yep boiz, that's shoreline conglomerate facies! Not! it's deep water so you're SOL. oh, wait, it's got carbon, so I must be wrong, and this must be the carbon leader! Wasn't sampled, so we'll see!" [TS: Quinton Hennigh's theory relies on a near-shore shallow environment for precipitating gold. One such environment would be a "shoreline conglomerate facies" where a shoreline platform or shelf creates the shallow water conditions for cyanobacteria to thrive. That's not the case in this portion of the Pilbara. But there is carbon, which is associated with Witwatersrand gold deposition, so perhaps there is hope?
11/7/17 01:23:34 - "MMD62, 89m of Fortescue described as black aphanitic tuff. Whoopsie, no conglomerate, no carbon leader. " [TS: Another portion of the Pilbara that doesn't contain conglomerates or carbon. Again indicating the Pilbara isn't an extensive gold-bearing, or at least highly fertile, sedimentary package like the Witwatersrand.]
Disclaimer: This is not investment advice, just an opinion. Consult your own expert. I have no position in shares of Novo directly or indirectly and have no relationship with the company or any of its affiliates.
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