Geologists don’t always agree about how the earth’s surface was formed. One debate concerns whether the surface of the earth was hot and molten, or stable and cold, as it was formed.

Scientists do agree that the middle layer of our planet, which melted and rose from the mantle and then hardened, eventually formed earth’s crust.

But a recent study, conducted by geochemists Stephen Parman and Graham Pearson of Durham University in England, provides new clues to how earth’s crust was formed.

These scientists examined bits of metal that were thrust onto the earth’s surface by the ongoing process of plate tectonics. The researchers believe these fragments appear to indicate that the metal was molten. 

The team of geochemists discovered earth’s interior had melted in large quantities, and at a few key points in time. Parman says these measurements correlate to other, similar discoveries. This new evidence supports the theory that the continental crust came into being through a few distinct bursts.

A recent discovery in western Australia even provides a new timeline for when this process began.

Researchers led by Martina Menneken of Weatfälische Willheims-Universität in Germany found tiny diamonds in this remote desert area. Zircon crystals, dating between 3.1 billion and 4.3 billion years old, surrounded these diamonds.  Because the powerful pressure of the crust is what forms diamonds, researchers suspect some crust may have formed very early in earth’s 4.5 billion-year history.

These two studies help answer important scientific questions about our planet’s interior and its history. Until recently geologists knew very little about the process that formed earth’s surface.

[Source: Discover]