Apatite dating

apatite dating

How is the age of apatite determined?

U-Pb Dating of Apatite The age of apatite grains can be calculated by plotting their U-Pb isotopic composition to form a discordia line. Apatite has a lower closure temperature than zircon, i.e., ~400 - 500°C, and so are more easily ‘reset’ by heating than zircons.

Can LA-ICPMS be used for apatite dating?

Combining U–Th–Pb apatite dating by LA-ICPMS with the apatite (U–Th)/He thermochronometer is slightly more challenging as (U–Th)/He dating is performed on whole crystals, not polished grain mounts.

Is apatite a first cycle detritus?

U–Pb and Th–Pb dating of apatite has potential application in sedimentary provenance studies, as it likely represents first cycle detritus compared to the polycyclic behavior of zircon.

Which Apatite samples have the best age constraints?

Three of the apatite samples (Durango, Emerald Lake and Kovdor carbonatite apatite) have robust independent age constraints and simple post-crystallization histories (rapid thermal relaxation following magmatic emplacement).

How common is apatite in rocks?

Apatite is very common as an accessory mineral in igneous and metamorphic rocks, where it is the most common phosphate mineral. However, occurrences are usually as small grains which are often visible only in thin section.

When was apatite first discovered?

Apatite. The mineral was named apatite by the German geologist Abraham Gottlob Werner in 1786, although the specific mineral he had described was reclassified as fluorapatite in 1860 by the German mineralogist Karl Friedrich August Rammelsberg. Apatite is often mistaken for other minerals.

What is the chemical formula for apatite?

Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ions, respectively, in the crystal. The formula of the admixture of the three most common endmembers is written as Ca10 ( PO4) 6 (OH,F,Cl) 2,...

What is the difference between apatite-and chlorapatite?

- Individual member mineral of the Apatite group with chlorine being dominant in its structure. For a short period of time, it was renamed by the IMA as Apatite- (CaCl), but is now again favored again as Chlorapatite. - Microcrystalline variety of botryoidal white Apatite.

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