Tag: geology

We Have A Clearer Picture Of Newborn Earth Thanks To A 4 Billion Year-Old Rock

Posted on by Jennifer Spencer

Many scientists paint a picture of the Earth as a pretty nasty place when it was born. A swirling storm of space dust came together in the cosmos, and the resulting planet was thought of as a literal hellscape.

But some recent research puts this grim vision of the early Earth in question. And the answers might be found in costume jewelry.

Most Think The Earth Was Volatile And Inhospitable

Scientific evidence shows that the planet did not develop its vast oceans, majestic mountain ranges, and lush wildlife overnight.

Earth is 4.5 billion years old. It had to take many baby steps first before it became the verdant planet we experience today.

This “primordial stew” eventually hosted life, but the theory was that happened only after a billion year cooling off period.

Rather than seas of water covering the globe, early Earth featured molten lava oceans. The heat and generally destructive power of lava meant that early biological life was practically impossible.

Until recently, many in the scientific community saw this rough developmental stage of our planet as a fairly lengthy period.

The Best Documentation Of The Young Planet Comes From a Crystal

How did scientists develop their concepts of early Earth? Mostly through guesswork.

Since the planet is made of rock, it naturally followed that the heat resulting from the planetary creation would create the massive lava flows. And there was little basis to question these reasonable hypotheses.

It’s not as if we had any way to record what happened. That is, until scientists realized that certain billion-years-old rocks did an excellent job of recording history.

Zircon, which many know as the crystal used in knock-off diamond rings, is one of the oldest things on the planet.

Some samples date to 4.4 billion years ago, only slightly younger than the earth itself.

This practically indestructible rock also records scientific events. Sure, the recordings are only readable by scientists, but the lessons they tell are illuminating about Earth’s early origins.

The Gemstone’s Chemical Fingerprint Tells A Compelling Story

The language of zircon is chemistry. Each sample of this crystal is like a small time capsule.

Scientists recently found a large deposit of this 4 billion-year-old stuff and found evidence of early biochemical reactions that date back to the zircon’s creation.

These biochemical reactions are the fingerprints of early life.

On top of this, the chemical trail of breadcrumbs shows evidence of water (and lots of it) billions of years ago.

So, rather than a fireball planet covered with lava, primordial Earth was wet and full of early life forms.

This finding does not disprove the early lava theory but rather shortens the window of time for this early stage of the planet.

It also opens up new inquiries into other ways to extract data about ancient Earth. Now that we know we can look at chemistry and its traces as a decipherable language, there are practically no limits to what can be explored and discovered.

New Study Reveals Volcanoes Are Fed By ‘Mush Reservoirs’ Rather Than Molten Magma Chambers

Posted on by Jennifer Spencer

All this time, geologists thought a volcanic eruption was a ‘bang’ event, only to find out what is happening is actually more akin to ‘squeezing.’ At least that’s what a new study from Imperial College London and the University of Bristol is proposing.

Our Understanding Of Volcanoes Was Wrong

The magma chamber model has been the dominant and widely taught theory about the inner workings of a volcano. The model states that underneath every volcano is a great big chamber full of liquid magma. Using this model, scientists had come to understand (or so they thought) how and why volcanoes erupt, and why some erupt and some are dormant. The theory aligns well with all the indirect evidence they had gathered based on things like geophysical readings and pre-eruption events which can be seen from the surface only. The only real issue was that they could never seem to find many large magma chambers.

This new study posits that volcanoes are instead fed by what are called ‘mush reservoirs.’ Mush Reservoirs are areas that contain primarily solid crystals, and magma flows in the small pockets between the crystals. With this theory, scientists now need to understand how a mush reservoir could cause an eruption, and why that would happen. Understanding volcanic eruptions is closely tied to public safety, as predicting a volcanic event before it actually happens will allow people to evacuate and minimize the lives lost.

The Inner Workings Of A Volcano

Volcanoes need flowing magma to erupt. In order for magma to flow, scientists always thought very few crystals could be present. That’s why the molten magma chambers seemed to explain volcanic eruptions. Keep in mind that no human has actually ever laid eyes on one of these chambers. It was all speculation. The magma chemistry analyses in the new study have now challenged this theory.

It turns out, such a large magma chamber does not seem to be necessary after all. The small pools of magma formed between gaps in the crystals indicate that the mush reservoir model is more likely. The research team made a digital model of a mush reservoir to test if and how it would function. This is how they think it works. The magma rises through the crevices between the crystals, as the crystals themselves are too dense to pass through. In this process, the magma and crystals form a chemical reaction that starts to melt the crystals, resulting in areas that don’t have very many crystals.

It turns out that magma passing through the crevices between crystals is what leads to eruptions. Molten rock takes formation inside of mostly crystalline hot rocks. Instead of residing in large magma chambers as previously believed, it actually resides in the rocks’ pores. Slowly, the rock melt gets squeezed out, forming pools of melt, and can cause eruption as well as temporary magma chambers.

This New Model Makes More Sense To Geologists

Geogists used to get confused about certain volcanic phenomena, because much of it didn’t fit with the molten magma chamber theory. On the contrary, the mush reservoir theory makes sense with lots of known volcanic phenomena. Take for example the way magma’s chemical composition transforms over time or finding ancient crystals in new magma. That is quite promising in the world of volcanic research.

Only further studies can solidify the mush reservoir theory, but it seems inevitable that it will become the dominant model for understanding how volcanoes function.