By: Kayan Sayeed 09F
The Chocolate Hills are a geological formation in the Bohol province of the Philippines. There are at least 1,260 hills but there may be as many as 1,776 hills spread over an area of more than 50 square kilometres. They are covered in green grass that turns brown during the dry season, that is where the name “chocolate hills” came from.
The Chocolate hills
This is a picture of the Chocolate Hills during the dry season.
The Chocolate Hills
The Chocolate Hills
A birds eye view of the chocolate hills.
The Chocolate Hills form a terrain of haycock hills – mounds of a generally conical and almost symmetrical shape. This means they are all similarly cone shaped and almost identical to each other. These cone-shaped or dome-shaped hills are made of grass-covered limestone. The domes vary in sizes from 30 to 50 metres high with the largest being 120 metres in height.
Below is a picture of the Bohol Island province where I have depicted the area where the Chocolate Hills are.
This is a map of the island province in Philippines of which the brown parts are the chocolate hills.
The Bohol province in relation to the rest of the Philippine including the location of chocolate hills.
A map of Philippines highlighting the location of Bohol.
How were the Chocolate Hills formed? (Geology and Description)
Arguments surround the formation of The Chocolate Hills however the most scientifically and geographically proven one is that they were formed through weathering.
The Chocolate Hills are unique mounds made of marine limestone, which is a sedimentary rock (also a soluble rock), covered in grass. This grass turns brown in summer thus a look of chocolate kisses. They are conical karsts (landscape underlain by limestone that has been eroded by dissolution (decomposition), producing characteristic landforms) that sits on top of hardened clay. They were formed a long time ago by the uplifts of coral deposits and the action of erosion as well as weathering with rain water and wind. They were fractured by tectonic processes when the piece of land rose from the sea. They were once corals but due to the erosion effects of rain water they were carved. The acid in the rain also played a part in the formation and the wind which eroded the karsts further.