To understand how abundant materials change under pressure, A Florida State University geology researcher studied Feldspar, an important mineral in the crust. Usually, any material becomes stiffer when under pressure. However, the researcher observed that Feldspar became softer under pressure. The reason why Feldspar becomes softer is because Feldspar denses into pyroxene and quartz. This densification is also relatable to the seismic discontinuity, which is the area between the crust and the mantle. In 1909, The seismic discontinuity was located when a seismograph found a wave on the crust and the other wave on the upper mantle. Scientists wanted to learn more about the seismic discontinuity by drilling holes, but the project fell short.
