He proposed a new method for the mineral exploration, so called correlation refraction method, and the deep sounding method for monitoring the Earth crust.

The abundance of lutetium in the Earth crust is only about 0.5 mg/kg.

Synthesis of fermium from naturally occurring actinides uranium and thorium in the Earth crust requires multiple neutron capture, which is an extremely unlikely event.

Its abundance in the Earth crust is 0.5 mg/kg by weight and 50 parts per billion by mols.

The concept of Earth crust and mantle.

In geology, eduction is a process in which the Earth crust spreads sideways, exposing deep-seated rocks.

The earliest Earth crust probably forms similarly out of similar material.

Its abundance in the Earth crust is about 38 mg/kg, which is the second highest among rare-earth elements, following cerium.

A generalized approach to the recognition of the precursory signals of earthquakes preparation process when structural changes and anomalies occur in the Earth crust was proposed.

The concentration of erbium in the Earth crust is about 2.8 mg/kg and in the sea water 0.9 ng/L.