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Beiträge, die mit zircon getaggt sind
This story has us diving into the Adriatic Sea to look at some very small creatures called foraminifera. Foraminifera are these amazing single-celled organisms that feed with strands of ectoplasm from their cell wall and often build a small shell around themselves from various materials. The microscopic shells can be important markers in the sedimentary record for time and environmental conditions. (I still fondly remember a University undergrad assignment being amazed by the diversity of shell types while spending hours picking through a collection of foraminifera shells under a microscope. It was also a very Zen exercise and pretty everyone in the class spent extra time doing it…).
Somewhere, right now, in the Adriatic Sea there is a species of benthic foraminifera called Psammophaga zirconia that are literally surrounding themselves with #zircon grains. P. zirconia’s specialty is picking zircon grains in the sediment to make it’s shell (see the Sabbatini et al 2016 paper at https://www.researchgate.net/publication/299381635_Selective_zircon_accumulation_in_a_new_benthic_foraminifer_Psammophaga_zircona_sp_nov). Not quite sure why, perhaps it’s a buoyancy thing to pick denser minerals stay anchored on the sea floor, but P. zirconia is going to a lot of trouble to select #zircon in particular which isn’t common in the surrounding sediment.
It also has interesting implications for the microfossil record because foraminifera like P. zirconia may have been here since the Precambrian and may have left little accumulations of zircon in ancient sedimentary rocks if we know to look for them. I also think there may be some interesting implications in understanding *how* a single-celled organism is able to differentiate minerals…
So, if Psammophaga zirconia is working hard to pick #zircon, so can you! Vote #zircon in the #MinCup23 final
https://www.mineralcup.org/2023/campaigns/round-5-match-1
Vote in the Finals
You’ve narrowed the list down from 32 minerals to just these finalists. It’s a study of contrasts between a pair of powerhouse minerals as you select which one will join the elite list of Mineral Cup champions.Mika McKinnon (Mineral Cup)
32 minerals have battled for your hearts, but only one can claim the Championship. Will it be #Zircon, the eternal timekeeper, or #Perovskite, the cubical rain on brown dwarf stars?
Vote: https://www.mineralcup.org/2023/campaigns/round-5-match-1
Results: https://www.mineralcup.org/2023/campaigns/round-5-match-1
Vote in the Finals
You’ve narrowed the list down from 32 minerals to just these finalists. It’s a study of contrasts between a pair of powerhouse minerals as you select which one will join the elite list of Mineral Cup champions.Mika McKinnon (Mineral Cup)
It’s a semi-final match for the ages! #Zircon is the undisputed Time Lord of geochronology and #Calcite whispers secrets of ancient climate hidden in the matte part of seashells. Which will it be?
Vote:
https://www.mineralcup.org/2023/campaigns/campaigns/round-4-match-1
Results:
https://www.mineralcup.org/results/round-4-match-1
Every #zircon fan knows it has remarkable resilience. It forms as molten magma cools to form igneous rocks and can survive the subsequent exhumation and erosion of that rock to become sand grains to be carried thousands of kilometres down streams and rivers to the oceans.
You may have even seen some. Ever noticed a streak of darker sand on a pale beach? Sometimes it can just be a wisp, sometimes a deep and well-defined layer. This is a placer deposit of resistant minerals like #zircon and companions rutile, magnetite, tourmaline and others. Because these minerals have a higher density (‘heavier’) than the bulk quartz and carbonate sand grains with them, in the right wave conditions they become concentrated as lighter minerals are washed away (think of it like a giant naturally occurring gold pan). In parts of Australia these concentrations of minerals are large enough to be mined as a source of zirconium and titanium oxide.
Vote: https://www.mineralcup.org/2023/campaigns/round-3-match-1
Results: https://www.mineralcup.org/results/round-3-match-1
It’s a tale involving bear-driven serendipity and some really old #zircon…
Geological mapping in northern Canada is challenging. There are no roads. No coverage. Only a few summer months free of snow and ice. Lots of lakes. 𝙇𝙤𝙩𝙨 of bugs. And bears. They need to fatten up quickly to get through the winter so are always looking for food.
This is a problem for geologists because…
📷 Apatite: Didier Descouens
It’s shiny shark teeth vs the Time Lord. You have 24 hours.
Vote: https://www.mineralcup.org/2023/campaigns/round-1-match-3
Check results: https://www.mineralcup.org/results/round-1-match-3