Taiwan: Yehliu Geopark

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View down the cuesta of the Yehliu Promontory. Photographed 12/06/2012 at Yehliu Geopark, Taiwan.

After visiting Yangmingshan National Park, my wife and I continued our Taiwan vacation at Yehliu Geopark. Although there was much to see on this stretch of the northeastern coast, it’s best known for the fascinating rock formations that have been shaped by millions of years of weathering.

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Satellite view of the Yehliu Promontory. Photographed 12/06/2012 at Yehliu Geopark, Taiwan.

The rocks at Yehliu are part of the Taliao Formation, deposited in a shallow sea environment during the Miocene Epoch (between 23 and 5 million years ago). Since then the land has risen relative to the sea, exposing the marine sediments. These rocks are made up of interbedded sandstone and mudstone layers of varying thickness. The sandstone is bioturbated and filled not only with fossils of marine invertebrates, but remnants of their burrows and tracks as well.

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Waves crashing along the coast. Photographed 12/06/2012 at Yehliu Geopark, Taiwan.

Sandstone is relatively resistant to weathering, while mudstone is not. Within the sandstone, the fossil tracks and burrows also create uneven areas of strength and weakness. Over the last few million years waves, wind, rain, and sun have worked away at these rocks of varying hardness, leading to differential weathering.

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Hoodoo rocks photographed 12/06/2012 at Yehliu Geopark, Taiwan.

Hoodoos (“mushroom rocks”) are the most obvious example of this differential weathering. Harder concentrations of rock form the capstones while softer areas are eroded:

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Hoodoo rocks photographed 12/06/2012 at Yehliu Geopark, Taiwan.

The weathered shapes are sometimes more elaborate:

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Marine Bird Rock photographed 12/06/2012 at Yehliu Geopark, Taiwan.

On flat surfaces this weathering leads to potholes. These often harbor crabs and other organisms:

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Potholes photographed 12/06/2012 at Yehliu Geopark, Taiwan.

Seawater also works away at the rock on a smaller scale through salt heaving. The water deposits salt in the pores of the rock, and after drying it crystallizes and breaks apart mineral grains. This can lead to honeycomb weathering:

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Honeycomb weathering photographed 12/06/2012 at Yehliu Geopark, Taiwan. Random hominid for scale.

Weathering rings are also common where iron-rich minerals have oxidized:

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Weathering rings photographed 12/06/2012 at Yehliu Geopark, Taiwan. Lighter for scale.

Although the rocks took center stage at Yehliu, there were also some interesting organisms to be found. This plant featured some sharp serrations along its sword-like leaves:

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Unknown plant photographed 12/06/2012 at Yehliu Geopark, Taiwan.

There were also some beautiful birds…

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Eurasian magpie (Passeriformes: Corvidae: Pica pica) photographed 12/06/2012 at Yehliu Geopark, Taiwan.

…insects…

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Unknown butterfly (Lepidoptera) photographed 12/06/2012 at Yehliu Geopark, Taiwan.

…and birds eating insects:

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Unknown bird feeding on a grasshopper (Orthoptera). Photographed 12/06/2012 at Yehliu Geopark, Taiwan.

As is often the case in Japanese-influenced Taiwan, cartoon characters were to be found even here:

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Cartoon character “mascots” representing some of the rock formations. Photographed 12/06/2012 at Yehliu Geopark, Taiwan.

Yehliu is a great concentration of fascinating geology, plants, wildlife, coastline, mountains, and culture all in one relatively small area. More than any other place we went in northern Taiwan, I strongly recommend this location as a “must-see.”

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View toward the mainland from the Yehliu Promontory. Photographed 12/06/2012 at Yehliu Geopark, Taiwan.

Literature cited:

Hong, E. and E. Huang. 2001. Formation of the Pedestal Rocks in the Taliao Formation, Northern Coast of Taiwan. Western Pacific Earth Sciences 1:99-106.

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About Jeremy Sell

Science and nature nerd.
This entry was posted in Botany, Culture, Ecology, Entomology, Geology, Organism Interactions, Vertebrate Zoology and tagged , , , , , , , , , . Bookmark the permalink.

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