@article {Huang202007982,
	title = {The niobium and tantalum concentration in the mantle constrains the composition of Earth{\textquoteright}s primordial magma ocean},
	journal = {Proceedings of the National Academy of Sciences},
	volume = {117},
	number = {45},
	year = {2020},
	month = {nov},
	pages = {27893{\textendash}27898},
	publisher = {National Academy of Sciences},
	abstract = {Silicate Earth is widely considered identical to chondrites in its refractory lithophile element ratios. However, its subchondritic Nb/Ta signature deviates from the chondritic paradigm. To resolve this Nb deficit, its sequestration in Earth\&$\#$039;s core under very reducing core-forming conditions has been proposed based on low-pressure data. Here, we show that under conditions relevant to core formation Nb is siderophile at high pressures under all redox conditions, corroborating Nb inventory in Earth\&$\#$039;s core. Further core formation modeling shows that Earth\&$\#$039;s core could have formed under moderately reducing or oxidizing conditions, whereas highly reducing conditions mismatch the geochemical observables; although Earth may have sampled a variety of reservoirs, it is problematic to accrete primarily from materials as reduced as enstatite chondrites.},
	issn = {0027-8424},
	doi = {10.1073/pnas.2007982117},
	url = {https://www.pnas.org/content/early/2020/10/22/2007982117 https://pnas.org/doi/full/10.1073/pnas.2007982117},
	author = {Huang, Dongyang and Badro, James and Siebert, Julien}
}
