Welcome to Xiaoliuqiu — An Island of Geological Wonder! (CHEMICAL WEATHERING )
In this Earth Cache, you will learn about chemical weathering — in particular, the forces of Mother Nature (such as carbonation, oxidation, and acidification) that contributed to a phenomenon called "Limestone Pavement" that can be found here all around "Secret Beach". Upon learning all about chemical weathering, you will be ready to put on your Earth Science Caps and get geological on location here on Xiaoliuqiu Island. And after you answer the task questions and complete all your Chemical Weathering Studies and Observations (which can all be found at the bottom of this page), you can log a “Found It!” for this Earth Cache. I hope you enjoy! Are you ready? Let's begin . . .
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What is Chemical Weathering Exactly and How did it make Limestone Pavement?
As you can see from the picture at the top of this Earth Cache page, "Secret Beach" is home to an awesome phenomenon known as "Limestone Pavement" — a chemically weathered landscape that causes the rock here to look just like pavement, hence its name. So what is chemical weathering exactly? Basically chemically weathering is when rocks and minerals react to acids, oxygen, carbon, and water as in the case here along Limestone Pavement. And because of chemical weathering, no two rocks ever look exactly the same, which makes for one awesome looking landscape or in the case of limestone pavement, seascape. To truly understand chemical weathering and how it worked to form limestone pavement, we need to look at examples of the different types of chemical weathering that caused such a phenomenon:
⇒ Carbonation —This is when rainwater turns into acid by "grabbing" carbon dioxide on its way down, thus forming a "magical" substance called "carbonic acid". And this "magic medicine" reacts with the calcium carbonate in the limestone here to form cracks, thus creating the "cracky" nature of limestone pavement.
⇒ Oxidation — This is basically like "rust" on a car. When oxidation happens, the rocks will take on a reddish color because of their iron content, like in a few cases of the limestone here along the Limestone Pavement.
⇒ Acidification — This is when acids either from rain or from organisms cause the rocks to wear and the composition to soften as in the case of limestone here among the Limestone Pavement.
And that is the "magic" of chemical weathering upon this entire area around Secret Beach, where you can see lots and lots of sections of Limestone Pavement — with the result being "LEGO" -shaped "blocks" of pavement with the top part being called a clint and the grooves being called a gryke. Below is a diagram showing the different parts of the Limestone Pavement.
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Logging Requirements:
Xiaoliuqiu is an island of Geological Wonder with so many unique landforms and hidden geological treasures, with one in particular — Limestone Beach — which is a landform carved from the "magic" of chemical weathering.
In order to log a Found It! for this Earth Cache, please go to the Posted Coordinates (and the referenced Waypoint if you'd like) to complete the following tasks:
1. Based on what you have learned about Chemical Weathering and based on your observations of this area, find and take photo(s) of Carbonation, Oxidation, and Acidification, and send those photos to me via the Geocaching Messenging Center. How did you come to your conclusions that these were examples of such Chemical Weathering phenomena?
2. Based on what you have learned about the parts of Limestone Pavement, and based on your observations here, what were the approximately "depths" of the grykes? What do these depths tell you about the kind(s) of Chemical Weathering that occurred here? How did you come to your conclusions?
3. Based on what you have learned about the shapes of clints, and based on your observations here of the Limestone Pavement, why do you think the clints here do not follow the "standard" cubic shape that clints usually follow? How did you come to your conclusions?
4. Based on everything you have learned and based on your observations of the Limestone Pavement, which chemical weathering phenomenon was the most present here? Why do you think this is so? What does this tell you about the limestone here and its future?
5. Optional — Post a photo of yourself or a "Geocaching" item identifying yourself here upon the Limestone Pavement.
You may log a Found It! on this cache after you have completed the tasks and emailed me the answers. If there are any issues with your answers, I will contact you. And as a friendly reminder, please do not post any of the answers in your logs. Thank you for visiting this Earth Cache. I hope you enjoy your time here upon the Limestone Pavement.