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“Did You Know? #005— Earthquake Facts Explained

It sounds like something out of a science fiction movie, but it’s true.

Palawan wasn’t originally part of the Philippines.

Unlike most of the Philippine archipelago—which formed from volcanic activity and oceanic crust—Palawan is a fragment of the Asian continent. Millions of years ago, a massive piece of continental crust broke away from what is now southeastern China, drifted southward across the ocean, and eventually collided with the growing Philippine archipelago.

In geological terms, this drifting landmass is known as the Palawan Microcontinental Block or North Palawan Block.

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The Science

How do scientists know Palawan really came from mainland Asia?

The evidence is remarkably compelling.

Ancient Fossils

Northern Palawan contains fossils of Permian fusulinids and Jurassic ammonites that are between 150 and more than 250 million years old.

These fossils closely match those found in southeastern China—but are absent from most of the volcanic islands that make up the rest of the Philippines.

Tiny Time Capsules

Scientists also studied microscopic zircon crystals trapped inside Palawan’s rocks.

These minerals preserve a geological “birth certificate.” Their ages point directly to ancient mountain-building and volcanic events that occurred in mainland Asia hundreds of millions of years ago.

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Find out if your Barangay is located near the West Valley Fault:
List of Barangays

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Continental Crust

Geophysical studies reveal that the crust beneath Northern Palawan is thick and buoyant—characteristics of continental crust.

This contrasts sharply with the thinner oceanic crust beneath much of the Philippine Mobile Belt.

The Journey

Around 33 million years ago, the opening of the South China Sea caused part of the Asian continental margin to split away.

Over millions of years, this continental fragment drifted southeast.

Between 20 and 16 million years ago, it finally collided with the volcanic islands that would eventually become part of the modern Philippines.

The collision helped shape mountain ranges, altered regional geology, and permanently attached the Palawan block to the Philippine archipelago.

Interestingly, not all of Palawan shares this origin. Northern Palawan belongs to the continental block, while Southern Palawan is composed largely of oceanic rocks separated by the Ulugan Bay Fault.

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Why It Matters

Palawan’s unique geological history explains many of the things that make it different today.

Its famous limestone cliffs in El Nido and Coron originated as ancient coral reefs formed hundreds of millions of years ago. Its wildlife also shares stronger evolutionary links with Borneo and mainland Asia than with much of the rest of the Philippines.

This continental origin also helps explain why Palawan experiences relatively few earthquakes compared with regions crossed by major active faults such as the West Valley Fault.

🛡️ Preparedness Tip

While Palawan is generally less seismically active than many parts of the Philippines, no place is completely earthquake-free. Preparedness remains essential wherever you live.

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⚡ Quick Facts

• 🗺️ Palawan is a fragment of the Asian continent—not a volcanic island like much of the Philippines.
• 🦠 Fossils found in Northern Palawan are over 250 million years old.
• 💎 Zircon crystals in Palawan’s rocks preserve geological evidence linking the island to mainland Asia.
• 🌏 The continental block drifted for millions of years before colliding with the Philippine Mobile Belt.
• 🏞️ El Nido and Coron’s iconic limestone cliffs were once ancient tropical reefs.
• 📍 Only Northern Palawan belongs to the Palawan Microcontinental Block.

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🤔 Myth vs. Fact

Myth: Every island in the Philippines formed from volcanic eruptions.

Fact: While much of the Philippine archipelago has volcanic origins, Northern Palawan is a fragment of continental crust that separated from mainland Asia millions of years ago.

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📚 Learn More

• Palawan Was Never Earthquake-Free
• The Big One Is Not the Biggest Threat—Our Buildings Are
• The Philippines’ Web of Major Fault Systems
• Discover the Safest Places in the Philippines: Earthquake-Free Zones?

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👉 Coming Next

Did You Know?

The Philippines is still growing—and mountains are still rising today.

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Did You Know? is a continuing educational series by WestValleyFault.com, sharing quick, evidence-based facts about earthquakes, geology, and disaster preparedness in the Philippines.