Why should rare earth elements be standardized by chondrites?

The distribution pattern of rare earth elements is mainly divided according to the total amount of rare earth elements, the relative content of light and heavy rare earth elements and the abnormal abundance of characteristic elements.

Divided into five types:

1 divided by the total rare earth elements.

2 divided by the ratio of cerium/ytterbium or lanthanum/ytterbium.

3 divided by the anomaly of δEu

4 divided by the abnormal value of δCe

5 according to the fractionation degree of each rare earth element.

Rare earth distribution model can be used to eliminate the "sawtooth" shape of rock sample abundance curve due to odd-even effect, and the accuracy of sample abundance test can be inferred according to whether the normalized value curve is smooth or not. In the study of the origin of igneous rocks, it can be shown that: 1 indicates the degree of magmatic differentiation; ② Distinguish similar rocks; 4 reflecting the degree of partial melting and separation crystallization; 5 indicates the expansion speed of the mid-ocean ridge; 6. Determine the source of magma (for example, see courseware: REE distribution pattern of typical crust, typical island arc volcanic rocks, REE distribution pattern of active continental margin magmatic rocks, REE distribution pattern of continental alkaline magmatic rocks).

Different samples should be standardized: basalt-chondrite; Granite-MORB; ; Mantle rock -C 1 chondrite