Mount Arafat, in the heart of Makkah, is closely associated with the annual gathering of thousands of pilgrims standing upon it in one of the most profound spiritual scenes in Islam. Yet behind this sacred image lies a story far older than human history itself, one tied to the geological formation of the mountain.
Although the origins of this story date back millions of years, its traces remain preserved within the mountain’s rocks to this day. These formations have effectively become a silent geological archive documenting the ancient history of the region.
A study published in the Journal of Radioanalytical and Nuclear Chemistry sought to uncover that history. Researchers from the Radiation Physics Laboratory at the Department of Physics, COMSATS Institute of Information Technology in Pakistan, examined the mountain’s geological structure and reached several significant findings, most notably that the formation of Mount Arafat was part of a larger tectonic process connected to the emergence of the Red Sea.
The investigation began with the mountain’s surface rocks, which may appear simple and motionless to pilgrims, yet scientific analysis revealed that they belong to a rock type known as granodiorite. This is a deep igneous rock formed when magma cools slowly beneath the Earth’s surface, creating a dense and durable rock filled with mineral crystals.
Researchers found that these rocks contain familiar minerals such as quartz, feldspar, and mica.
Fission Track Dating Reveals the Mountain’s Age
The next step for scientists was determining the age of Mount Arafat itself. To achieve this, they used a precise technique known as fission track dating.
This method is based on the presence of tiny amounts of uranium hidden inside mineral crystals within rocks. Uranium is an unstable element, and over time some of its atoms split spontaneously, releasing microscopic atomic fragments that move at extremely high speeds through the crystal structure.
These fragments leave behind microscopic trails or scratches invisible to the naked eye, yet preserved within the minerals for millions of years.
To observe these traces, scientists polish and chemically treat mineral samples before examining them under a microscope. This reveals a network of fine lines resembling etched marks inside glass. Each trail represents a radioactive event that occurred in the distant past. The older the rock, the greater the number of accumulated tracks inside it.
By counting these tracks and measuring the amount of uranium present in the mineral, researchers can calculate the amount of time that has passed since the rock cooled and became geologically stable.
What makes this technique particularly important is that it does not determine the moment magma was first formed. Instead, it identifies the point at which the rocks cooled sufficiently to preserve these microscopic traces. For this reason, it is considered a valuable tool for documenting the history of mountains, volcanic activity, and movements within the Earth’s crust.
In the case of Mount Arafat, scientists applied this technique to minerals found within the granodiorite rocks and discovered that these formations developed over millions of years during the Late Miocene epoch. This means the mountain is not a relatively recent formation, but part of a much deeper geological history dating back approximately 9 million years.
At that distant time, the Earth looked entirely different. Tectonic forces were actively reshaping the region as the Red Sea began to open and the continental landscape transformed. The mountain’s rocks still preserve evidence from that tectonic phase, which witnessed the separation of the Arabian Peninsula from Africa and the formation of the Red Sea itself, making Mount Arafat part of the geological record documenting the birth of one of the world’s most significant seas.
From Ancient History to the Present Day
After uncovering the tectonic history written within the rocks, the study shifted toward a more immediate question: whether the mountain’s rocks pose any danger to humans.
Like many mountains around the world, Mount Arafat naturally contains elements such as uranium, thorium, and radioactive potassium. However, researchers analysed the rocks and measured the levels of naturally occurring radioactive elements before comparing the results with international safety standards. The study concluded that radiation levels at the mountain are entirely safe and pose no health risk to humans.
This conclusion did not surprise Dr Hassan Bakhit, Vice President of the Arab Geologists Union, who explained that the presence of natural radiation within Mount Arafat’s rocks is entirely normal.
Speaking to Al Jazeera Net, he said: “The presence of natural radiation does not necessarily indicate any health danger. Most igneous rocks on Earth naturally contain small amounts of radioactive elements such as uranium, thorium, and potassium. Scientifically, what matters most is the actual level of radiation exposure.”
He added that the findings reflect the geological nature of deep rocks connected to the Arabian Shield, which are igneous formations created deep within the Earth’s crust and naturally contain radioactive activity within their minerals. He stressed that this is a normal geological phenomenon rather than evidence of any exceptional radioactive threat.
