Follow-up Research on Terrestrial Iridium Concentrations
Gitreal: You are a bully, especially when it comes to geology and measurements. The man said what he said. The assays and technical reports for the Walla Walla project are available to view online and are in some ways more thorough than the Lucky Ben. Rest assured it was sampled and measured properly, and is more than representative enough of the resource that was sold given the valuation at sale.
The presence of iridium at 8.16% in the sample is highly unusual for terrestrial rocks, including those typically found in geological formations like the Idaho Batholith, where SDRC's sample occurred. Iridium is indeed rare on Earth's crust due to its siderophile (iron-loving) characteristics, which caused most of it to sink into the Earth's core during the planet's formation. However, iridium is notably more abundant in meteorites, particularly in certain types of meteorites known as iron meteorites, but even this does not fully explain SDRC's steeply anomalous sample.
Iron meteorites, which are composed primarily of iron and nickel, can have iridium concentrations that vary significantly but are typically in the range of parts per million (ppm) to 0.5% by mass. However, even in these cases, 8.16% would be extraordinarily high. Stony-iron meteorites (pallasites and mesosiderites) also contain iridium, but again, the concentrations are much lower than what was reported by SDRC.
On Earth, high iridium concentrations are generally associated with layers in the geological record where large meteorite impacts have occurred, such as the K-T boundary, which is marked by a thin layer enriched with iridium, leading to the hypothesis of a massive impact event (such as the one that led to the extinction of the dinosaurs).
In my opinion, the idea that a sample from the Idaho Batholith might exhibit high concentrations of iridium similar to those found at the K-T boundary is a fascinating proposition, not to mention the most geologically sound explanation presented so far, aside from (dare I egg you on) error or fraud. The K-T boundary is primarily known for its high iridium levels, and can be found at various points around the globe, indicating widespread deposition of extraterrestrial material from the impact event. To date, there are no well-documented impact craters associated with the Idaho Batholith, but there are lesser documented ones such as the Beaverhead Impact Structure (crater over 50 km in diameter.) Studies of central Idaho's geology have mainly focused on its magmatic history, mineralization (especially of elements like gold, silver, and lead), and tectonic evolution. There hasn't been widespread reporting or identification of iridium-rich layers akin to the K-T boundary within this region, but just because there's an absence of documented iridium anomalies similar to the K-T boundary here, it does not entirely rule out their existence. Geological anomalies can go undetected until specifically searched for, especially in less thoroughly studied or difficult-to-access areas like these.
SDRC has a monumental undertaking before them, wouldn't you say? Something requiring great care, time, money, perhaps the recruitment of cutting edge technologies like like ICP-MS (Inductively Coupled Plasma Mass Spectrometry) to survey the broader area.... something that could provoke a massive response from the academic world and dramatically change our understanding of the region. Something if found to be of economic value that could provoke renewed commercial interest to the surrounding mining districts....
AI
