Mongolia: A Beautiful Landlocked Country in East Asia Was Once an Ocean

Mongolia, a vast and stunning landlocked country in East Asia, holds within its borders a fascinating geological secret: it was once the site of a mighty ocean. 

This ancient ocean, born from the upwelling of boiling rock from the Earth's crust, emerged over 400 million years ago and existed for an impressive 115 million years. 

The discovery of this ocean provides invaluable insights into the Earth's geological history and the intricate processes that shape our planet.

A Peek into the Past

The story of Mongolia’s ancient ocean begins with the tearing of the Earth's crust, a dramatic event that led to the formation of a vast body of water. 

This ocean's existence and eventual disappearance are crucial for understanding Wilson cycles, the process through which supercontinents break apart and eventually reassemble. 

These cycles are slow and expansive, progressing at a rate of less than an inch per year, as explained by Daniel Pastor-Galan, a geoscientist at the National Spanish Research Council in Madrid. 

“It's telling us about processes in the Earth that are not very easy to understand and that are also not very easy to see,” he shared in an interview with Live Science.

Reconstructing Ancient Earth

Geoscientists have successfully reconstructed the breakup of the last supercontinent, Pangea, which occurred 250 million years ago. 

However, understanding the interactions between the mantle and the crust before this period has been challenging. 

The recent discovery in Mongolia sheds light on these ancient processes, offering a glimpse into the complex dynamics of our planet’s interior.

During their fieldwork in northwestern Mongolia, researchers uncovered volcanic rocks dating back to the Devonian period (419 million to 359 million years ago). 

This era, known as the "Age of the Fishes," saw the dominance of fish in the oceans and the spread of plants on land. 

At that time, two major continents, Laurentia and Gondwana, existed alongside a series of microcontinents that eventually coalesced to form Asia.

The Mongol-Okhotsk Ocean

The volcanic rocks discovered in Mongolia revealed the existence of the Mongol-Okhotsk Ocean, which opened up in the region between 410 million and 415 million years ago. 

The chemistry of these rocks indicated the presence of a mantle plume, a stream of hot and buoyant mantle rock, which played a crucial role in the ocean's formation. 

Mantle plumes are typically involved in the initial stages of the Wilson cycle, contributing to the breakup of continents and the creation of oceans, much like the Atlantic Ocean.

Professor Mingshuai Zhu, the lead author of the study and a professor of geology and geophysics at the Chinese Academy of Sciences, explained that the ocean formed in the same location where present-day Mongolia exists. 

This phenomenon is consistent with the life cycle of oceans, where hotspots remain relatively stable for millions of years, continuously influencing the Earth's surface. 

“A good thing is that a hotspot is relatively stable so they keep on, for many millions of years, in the same place,” added Pastor-Galan.

From Ocean to Landlocked Beauty

Today, Mongolia's landscape is a far cry from its ancient oceanic past. 

The country is renowned for its stunning natural beauty, from the vast steppes and the Gobi Desert to the towering Altai Mountains. 

This transformation from an ocean to a landlocked nation underscores the dynamic nature of our planet's geology.

The discovery of Mongolia's ancient ocean not only enriches our understanding of Earth's history but also highlights the intricate and slow-moving processes that have shaped our world. 

As researchers continue to study this remarkable geological history, we gain deeper insights into the powerful forces at work beneath our feet.

Mongolia's past as an ocean is a testament to the ever-changing nature of our planet, a reminder that the landscapes we see today are the result of millions of years of geological evolution. 

This beautiful landlocked country, with its rich cultural heritage and breathtaking scenery, carries within it the story of an ancient ocean that once was, offering a unique perspective on the Earth's dynamic history.