Providing a temporal framework for every ore system.
Geochronology is crucial for the understanding of mineral systems. In brownfields exploration, it can constrain the timing of nearby mineralising events, as well as the ages of faulting or metasomatic overprinting, providing critical context for deposit evolution. In greenfields exploration, it supports the refinement of regional metallogenic models by linking mineralisation to broader geological processes such as magmatism, metamorphism, and orogenesis. Using the facilities present at Adelaide Microscopy, Ore Grade Petrology offers a range of geochronology solutions through the various decay systems outlined below. If you’re unsure which option fits best, feel free to reach out. We’re happy to create a solution that works for you.
Uranium-lead is seen as the gold standard of geochronological techniques as it uses both the 238U --> 206Pb and 235U --> 207Pb decay schemes simultaneously. As U-Pb geochronology has been completed using laser ablation techniques since the early 2000's, the method is seen as robust with a wide variety of analytical standards available depending on the mineral to be dated. Minerals that can be dated using this technique include zircon, monazite, apatite, titanite, rutile, hematite, xenotime, cassiterite, calcite, scheelite, uraninite, garnet and baddeleyite.
In-situ Lu-Hf geochronology method uses the single 176Lu --> 176Hf decay scheme. As the parent and daughter product of this technique are the same mass, a reaction gas is required to separate two isotopes. This method is relatively new, only being developed in 2021. Because of this, the method is undergoing constant development. This technique can be used on apatite, calcite, garnet, fluorite, xenotime and monazite.
Geochronology via the Rb-Sr system has been around since the 1950's and uses the 87Rb --> 87Sr decay scheme. Much like Lu-Hf geochronology, as the parent and daughter product of this technique are the same mass, a reaction gas is required to separate two isotopes. The availability to perform this method in-situ was developed in 2017, and is undergoing constant development. Minerals that can be dated using this technique include muscovite, biotite, K-feldspar, illite, glauconite, and fine-grained whole-rock shale. An advantage of this technique is that multiple minerals from the same paragenetic stage can be plotted together to constrain the age of mineralisation.
Re-Os geochronology has been used to constrain the age of ore deposits since the early 1980's and uses the single decay scheme 187Re --> 187Os. As the parent and daughter product of this technique are the same mass, a reaction gas is required to separate two isotopes. The in-situ Re-Os technique is undergoing constant development, but has been used to successfully constrain the age of molybdenite, high-Re pyrite and black shales. We can facilitate the use of this technique at Adelaide Microscopy.
Geochronology analyses are available from $3,850 per sample per technique applied. This cost covers:
Fifty spot analyses (additional analyses available at $50 per spot); and
A detailed interpretive report outlining the data and its petrogenetic significance.
MLA mapping is available on 1-inch mounts starting from $1,500 per sample and when required, may include SEM imaging of individual analysed grains.
For further information or a personalised quote, please contact: oregradepetrology@gmail.com