It’s great to see you digging into this with a critical eye! Let’s break down the situation with Eclipse Metals sending historic drill cores from their Ivittuut project in Greenland to ALS Luleå in Sweden, while noting that labs in Canada are also involved in chemical testing, as per the update in the Greenlandic newspaper Sermitsiaq (dated March 7, 2025, based on your reference and the current date). Your hypothesis about overlimit issues and the geochemical behavior of rare earth elements (REEs) in the Grønnedal carbonatite is intriguing, and I’ll explore it step-by-step, while also considering why multiple labs might be involved.
What’s Happening?
Eclipse Metals has shipped historic drill cores—likely from their Ivittuut and Grønnedal targets within exploration license MEL2007-45—to ALS Luleå in Sweden for scanning and testing. The Sermitsiaq article you linked (in Danish) suggests progress in the Ivittuut rare earths project, with an upcoming public hearing anticipated, indicating advancing exploration efforts. Meanwhile, you’ve noted that labs in Canada are handling chemical testing, and you’re questioning why the protocol splits testing across different labs, potentially for "further confirmation."
Why Multiple Labs?
In mineral exploration, it’s not uncommon to use multiple laboratories for sample analysis, and there are several practical and technical reasons this might be happening here:
Specialization of Facilities
ALS Luleå in Sweden is renowned for advanced analytical techniques like ICP-MS (Inductively Coupled Plasma Mass Spectrometry) and ICP-SFMS, which are ideal for precise trace element analysis, including REEs. "Scanning" could refer to these spectrometry methods or even XRF (X-ray Fluorescence) for elemental mapping. However, Canadian labs—such as those in Vancouver or Ontario (e.g., ALS Canada or SGS)—are global leaders in geochemical assaying for mining projects, particularly for REEs and base metals. Canada’s labs might be handling the bulk chemical testing due to their capacity, proximity to North American expertise, or Eclipse’s operational logistics (as an Australian company, they may have established workflows with Canadian facilities).
Overlimit Protocols
Your thought about an "overlimit issue" is spot-on and aligns with standard assay practices. When initial testing (e.g., at ALS Luleå) detects concentrations of elements like REEs above the detection limit of a given method (say, 10,000 ppm for XRF or ICP-MS), the sample is flagged as "overlimit." A different lab or method is then used for confirmation, often with a higher detection range or a more specialized technique (e.g., fusion ICP or gravimetric analysis). If Canada is doing the chemical testing, it could be because they’re equipped to handle overlimit assays, especially if Grønnedal’s carbonatite yields exceptionally high REE grades—something historical data suggests, with total REEs up to 34,400 ppm reported in surface samples.
Quality Assurance/Quality Control (QA/QC)
Mining companies often split samples between labs for independent verification to ensure data reliability, especially for a project like Ivittuut, which could attract significant investor attention due to its REE potential. ALS Luleå might perform initial scans, while Canadian labs run parallel or confirmatory assays to cross-check results. This is critical for JORC-compliant reporting (Australia’s mineral resource standard), which Eclipse, as an ASX-listed company (EPM), must follow.
Logistical or Contractual Reasons
Eclipse may have existing contracts with Canadian labs from prior projects (e.g., their Australian or earlier Greenland work), or Canada might offer faster turnaround times for bulk assays. Shipping cores from Greenland to Sweden and then redistributing subsamples to Canada could reflect a streamlined workflow, though it’s less likely the physical cores themselves are moving again—more likely pulverized splits or pulps are sent.
Your Hypothesis: Overlimit and Geochemical Behavior
You’ve suggested that the Grønnedal carbonatite’s natural REE concentrations might be so high—potentially due to leaching and precipitation in acidic solutions—that it triggers overlimit issues, necessitating further confirmation. Let’s examine this:
High REE Concentrations
Grønnedal-Ika is a carbonatite complex, a prime REE target, with past assays showing total REE oxides (TREO) up to 22,695 ppm in drill cores and 34,400 ppm in surface samples. These are extraordinarily high values—well above typical economic thresholds (e.g., 1% TREO is ~10,000 ppm). Initial scans at ALS Luleå might hit upper detection limits, requiring a lab like ALS Canada to use alternative methods (e.g., peroxide fusion ICP-MS) to quantify the full extent of mineralization.
Leaching and Precipitation in Acidic Solutions
Your idea about REEs leaching from the carbonatite and precipitating in acidic conditions is geochemically plausible. Carbonatites like Grønnedal often contain REE-bearing minerals (e.g., bastnäsite, monazite) that can mobilize in acidic environments. Historical weathering or supergene enrichment near the surface could concentrate REEs, especially light REEs like lanthanum (La) and cerium (Ce), or magnet-critical ones like neodymium (Nd) and praseodymium (Pr), which Grønnedal is noted for. If acidic groundwater or mine-related fluids (e.g., from past cryolite extraction at Ivittuut) interacted with the carbonatite, REEs could dissolve and re-precipitate as secondary minerals, boosting local concentrations. This could explain why historic cores might exceed expected ranges, triggering overlimit flags.
Second Overlimit?
You mentioned a potential "second overlimit" scenario. This could happen if the first confirmatory assay (say, in Canada) still can’t fully quantify the REEs because concentrations exceed even the adjusted method’s limits. For example, if Nd or Pr hit tens of thousands of ppm, a third technique (e.g., neutron activation analysis) might be needed. However, this is less common—most modern labs can handle high-grade REEs with proper dilution or method tweaks. A second lab might instead reflect a split for specific elements (e.g., heavy REEs vs. light REEs) or mineralogical studies (e.g., XRD to identify REE phases).
Critical Examination
Your thought process holds water: Grønnedal’s geology supports high REE potential, and overlimit issues are a logical reason for lab splitting. However, let’s challenge the assumption that leaching/precipitation is the sole driver. The historic cores, drilled decades ago, might not reflect active supergene processes today—those high grades could stem from primary mineralization (e.g., carbonatite dykes or magnetite-rich zones). Eclipse’s 2022 drilling at Grønnedal confirmed REE enrichment in dolerite dykes and carbonatite, suggesting structural controls rather than just weathering. Still, your acidic solution idea could apply to near-surface samples or tailings, which might be included in the historic dataset.
The Canada-Sweden split might not be purely technical. Cost, lab availability, or regulatory requirements (e.g., Greenlandic oversight favoring European labs for initial scans) could play roles. Without explicit details from Eclipse or Sermitsiaq, we’re piecing this together logically.
Conclusion
The protocol likely involves ALS Luleå for initial scanning (spectrometry or XRF) due to its European proximity and expertise, with Canadian labs handling detailed chemical assays, possibly for overlimit confirmation or QA/QC. Your overlimit hypothesis fits Grønnedal’s high-grade profile, and leaching in acidic conditions could amplify this, though primary geology might suffice. If you’d like, I can search for more specifics (e.g., Eclipse’s latest ASX releases or lab capabilities) to refine this—your call! What do you think of this breakdown?
(20min delay)