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At last, origin of Mt Kinabalu made clear
Published on: Sunday, April 11, 2021
By: Kan Yaw Chong
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Groves on the West plateau rockface prove glacial erosion
WHERE exactly did Sabah come from? And where exactly did Mt Kinabalu come from?

Maybe 99 per cent Sabahans cannot answer, though they all feel proud of Sabah, especially the fantastic Mt Kinabalu.

We cannot blame the average folks.

Geology being so complex, its language so colourless, sombre and unenterprising.     

But here at the Daily Express, our minds were opened for the first time last week exactly where the land of Sabah we are standing on came from, starting with all the geological actions that happened deep under the oceans 130 million years ago.

This week, we try our best to come to grips with the “mother of all geological questions”: Where exactly did Mt Kinabalu come from? 

I feel satisfied that at last, that a hitherto nebulous picture is becoming clear. 

In the beginning 

Remember one point we made in last Sunday’s report:

In the beginning, there was no “mountains high”, only oceans deep.

That is, there was no such thing called territorial Sabah maybe even 20 million years ago, definitely 85 million to 130 million years ago – just a sea of oceans.   

Remember also one point if we want to get to understand geology easier.

That is, everything under your feet is actually moving, driven by a red hot 25,000 degree-F temperature still trapped in planet’s interior hot from collision friction of rocks flying through space when earth was formed 5 billion years ago and decay of radioactive elements. 

Last Sunday, we looked at tectonics:

That is, Earth’s solid land crusts plus also everything under the sharks and turtles in the oceans are moving, though so slowly or imperceptibly that most of the time, we are not aware of it, except when a big tremor from a collision surprise you, and unfortunately killed 15 in the 6 magnitude quake centred in Mt Kinabalu on June 5, 2015!

On where exactly did Sabah come from, Prof Dr Felix Tongkul already unveiled his phenomenal understanding to us last week.

If repetition is central to learning, basically, Prof Tongkul explained territorial Sabah is largely (not entirely) made of gargantuan of sediments that were scrapped off (plain language for geology jargon accreted) from the surface of the 130 million year old proto-South China Sea Oceanic Crust which started to move or forced under (subduct) the Sulu Sea Oceanic Crust 85 million years ago, starting at the convergent boundaries somewhere in the Lahad Datu area and this sediment scrapping action moved gradually backwards towards Kota Kinabalu!  

So if you are driving over land from Kota Kinabalu to Lahad Datu, you are basically driving over this carpet of ancient sediments.

Collision, not subduction, fathered Mt Kinabalu: Prof Tongkul

But now this is the question:

If you are climbing Mt Kinabalu, what fathered this singular granite massif which the whole world admire so much, is a totally different story. 

For a long time, based on what was told me by the late American geologist Dale Brunote, a lecturer at Universiti Kebangsaan Sabah branch in the 80s, I thought this youngest pluton in the world came from a micro plate which subducted into very hot condition deep in the gooey mantle where super heated steam melted a huge amount of rocks at the head of the micro plate and sent a ball of molten magma rushing into the Kinabalu area 15 million years ago, where it crystallised or hardened underground nine million years and later uplifted above ground and punched through a fault in the northern end of Crocker Range.

In the 1980s I did not know Tongkul last then.

So I asked Prof Tongkul Friday whether he agreed with Brunote’s version of Mt Kinabalu’s origins, Tongkul said: “I don’t agree.”

Tongkul proceeded to tell me his understanding, which is clearly different from that of Brunote.  

His version goes like this:

Actually what happened was at the tail end of the proto-South China Sea Oceanic crust (which averages 5-7km thick) there was a “rifted continental crust” (which averages much thicker at 10-70km).

So, 85 million years ago, when the proto-South China Sea Oceanic Crust started to move eastward and subducted or dived below the Sulu Sea Oceanic Crust, it did so with little or no obstruction for 65 million years.

But when the thick eastward moving “rifted continental Crust” located at the tail end of the proto South China Sea Oceanic Crust finally caught up with the westward moving scrapped (accreted) sediments about 20 million years ago, it’s collision big time.

“This was the collision which was responsible for the formation of Mt Kinabalu,” Prof Tongkul said. 

“This collision created enough pressure and heat which melted a huge ball of molten magma from the lower density rocks in the rifted continental crust,” he said (see graphics). 

The molten magma which was trapped underground eventually crystallised or hardened 5 to 7 million years ago below ground and later uplifted to become mt kinabalu that we see today,” Prof Tongkul said.

Ongoing collision explains earthquake in Sabah

Remember also that It was also this collision between the “rifted continental crust” and the scrapped off sediments of the proton South China Sea Crust which lifted Sabah and entire Borneo Island above the sea.

“This collision is still on going. That is the reason we have earthquakes and the fact that Mt Kinabalu and whole of Sabah is still rising by a few millimetres per year,” Prof Tongkul cautions all.

Knowledge is a treasure and practice is the key to get it. That’s where value is. 

Daily Express is clear in wanting to help Sabah in that direction. 

Thanks to the proposed 4,750sq km Kinabalu Geopark for 2022 which covers three districts, four townships and 472 villages, bandied about by experts at the 25 March International Seminar, Prof Tongkul has really come out to educate Sabahans in plain language the centre-piece of this aspiration – where exactly did Mt Kinabalu come from, with splendid graphics and tips to a key media, to cement general understanding.

These are Prof Tongkul’s invaluable works. Under the subheading ‘Geological Setting’, Prof Tongkul says: “A large part of Sabah is underlain by ancient oceanic crust of about 130 million years (referring to the proton- South China Sea Oceanic Crust) old and deep water sediments (green and orange colour) of about 25 to 85 million years ago.’

Geology of Kinabalu Geopark 

Under another sub-heading ‘Geology of Kinabalu Geopark’, he says: 

“The Kinabalu Geopark is comprised of sub-vertical slabs of oceanic crust (ophiolites) and deep water sediments of the Trusmadi and Crocker Formations. These vertical slabs are separated by faults. Granitic pluton occur at the southern end (of the proposed Global Geopark) forming Mt Kinabalu.”

Under another similar subheading on the ‘Geology of Kinabalu Geopark’, he writes: “The exposed granitic pluton is made up of three sheets, biotite granite (8Ma) , Hornblende granite ( (7.5 Ma) and porphyritic granite (7Ma). Glacial deposit (10,000 years old) occurred at the Pinousuk Plain.” 

Under the subheading ‘Geology of Kinabalu Geopark’, Prof Tongkul believes that that Mt Kinabalu was under a cover of snow probably hundreds of metres deep. 

As a result, he says: “Numerous glacial erosional landforms and features occur on top of Mt Kinabalu on the West and east Plateau, such as residual peaks, cirques, glacial deposits and grooves showing the direction of ice movement.”

Graphics on the birth of Mt Kinabalu 

Finally, on the Geological Evolution of Kinabalu Geopark, he provided the splendid graphics on where Mt Kinabalu came from and explained with brevity: 

“Magma intrusion around 7-8 million years ago further uplifting the surrounding area. 

“Erosion of sedimentary cover exposed Mt Kinabalu granite and Mt Tambuyukon’s ultrabasic rocks.

“Glaciers formed on top of Mt Kinabalu around 100,000 years ago which melted around 10,000 years ago.”

Before Mt Kinabalu was Trusmadi, Crocker, Tambuyukon

But aeons before Mt Kinabalu hit the roof only relatively recently in geological time (maybe just one million years ago).

As noted earlier, the land that we stand on today is largely made up of a vast carpet of deep sea sediments scrapped off from the top of proto South China Sea Oceanic Crust as it started to subduct or dived below the Sulu Sea Oceanic Crust beginning at the convergent boundary in the Lahad Datu area from 85 million years ago. 

The huge carpet of sediments covered from Lahad Datu all the way across to Kota Kinabalu but remained underwater until the landmark collision 15 million years between the scrapped carpet of sediments and the ‘rifted continental crust’ at the tail end of the proto South China Sea Oceanic Crust.

This was the collision 15 million years ago that uplifted landed Sabah (and Borneo for that matter).

Mt Trusmadi and Crocker Range are familiar to Sabahans. It looks like these big landscape too came from scraped sediments.

Prof Tongkul’s graphics clearly indicate that Trusmadi and East Crocker sediments were deposited on the proto-South China Sea Oceanic Crust 55 to 65 million years ago, the West Crocker sediments deposited 30-45 million years ago while the almost unheard of Wariu sediments deposited 18-25 million years ago and all the uplifted to the surface as dry land Sabah by the tectonic collision 15 million years ago.

So dry land Sabah is largely composed of these ancient scrapped sediments uplifted from the deep while Mt Kinabalu.

But now we know the exactly where Mt Kinabalu came from: From hell to a towering centre piece in the coming Global Kinabalu Geopark 16 times bigger than the 754sq km Kinabalu World Heritage Site, thanks to Prof Tongkul.

 

Note that it was when this eastward moving rifted continental crust which collided with the westward moving scrapped sediments 15 million years ago which ‘fathered’ mount kinabalu. Note Mount Kinabalu magma originating from the rifted continental crust.

Prof Felix Tongkul making a point. 

Graphic used by Prof Tongkul to illustrate how tectonic collision between a rifted continetal crust and scrapped sediments ‘fathered’ Mount Kinabalu. 

Prof Tongkul’s graphic illustrating how a huge ball of molten magma formed after a tectonic collision and formed Kinabalu. 

Geological evolution of Kinabalu Geopark. 

Kinabalu geology cross-section.





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