Welcome to Xiaoliuqiu — An Island of Geological Wonder! (KARST TOPOGRAPHY )
In this Earth Cache, you will learn about a unique kind of erosion known as karst topography — an area with an abundance of geological, geomorphological, and hydrological features — and the forces of Mother Nature behind such a phenomenon. And this special kind of karst topography can all be seen here in one location — Shanzhugou (山豬溝)! So upon learning all there is to know about karst topography and the forces of Mother Nature that sculpted "Shanzhugou! (山豬溝)", you will be ready to put on your Earth Science Caps and get geological on location here at Xiaoliuqiu Island. And after you answer the task questions and complete all your Coastal Erosion 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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So what is Karst Topography Exactly and Why is Shanzhugou Full of such a Phenomenon?
Karst topography simply describes a place where there is a lot of geological, geomorphological, and hydrological features, meaning, there are lots of caves, sinkholes, fissures, and underground streams, for example, as is the case here at Shanzhugou! Such a phenomenon occurs because of the dissolution of soluble rocks such as limestone, which is in abundance here at Shanzhugou. In other words, because of the limestone here and its susceptibility to "disappear" in water, the rocks will "lose" some of their parts and piece and you'll end up with some pretty awesome geological, geomorphological, and hydrological features! How cool is that? So, how did all this karst topography happen at one location here? Well, the limestone here is thinly bedded and highly fractured meaning the "beds" or "piles" of limestone are quite thin — less than 30 cm each — and this limestone is cracked everywhere. And because this area is prone to constant rainfall that downward movement of water upon the limestone accelerates the dissolution of the bedrock. So how does something as simple as rainfall act as a catalyst in dissolving the rock here at Shangzhugou? Well, this rain isn't just any kind of rain but a "special" kind of rain that carries carbonic acid — a combination of carbon dioxide and water. And this acidic rain is the culprit behind the dissolution of calcium carbonate — the chemical makeup of limestone. So this acid rain is what is behind the "destruction" of the limestone all around Shanzhugou, which results in the eroding of the land and thus creating its karst topography.
So what Kinds of Karst Topography caused by Erosion can be seen here at Shanzhugou?
1) Solution Flutes — The falling rainwater, which contains carbon dioxide and acts as an acid and as it falls down the limestone it carves grooves into the rockface. These parallel vertical grooves are known by their German name, Rillenkarren, and are located right here in Shanzhugou.
2) Solution dolines — The rainwater weakens the limestone and the soil and causes it to collapse underneath it into a shallow "void" or a sinkhole type formation. One such solution doline can be found here at Shanzhugou.
3) Solution Caves/Foibas — The acidic rainwater dissolves the limestone along the joints, bedding planes, and fractures to form caves or a deep natural sinkhole known as a foiba here at Shanzhugou.
4) Karst Fenster — The magic of the rainwater causes a "window" to be formed where a river or other water source can be viewed through a doline or sinkhole, and if you look closely enough you will find one such feature here at Shanzhugou.
5) Scowle — This particular feature is basically the windy, labyrinth, forest-like path that Shanzhugou is all about. These scowles were once a natural underground cave system that formed among the limestone due to the rainwater dissolving areas around the rock and thus forming natural paths to walk on.
6) Calanque — This particular landform is basically a rugged, sharp-edged cliff of limestone, formed from the "carving" power of the acidic rainwater, and with an abundance of such features present here at Shanzhugou, it could easily be argued that calanques exist.
So as you can see, the magic of the acidic rainwater has been responsible for a plethora of karst landscapes to exist right here at Shanzhugou as the limestone here is more susceptible to erosion than in other places. And Shanzhugou is the only place in Xiaoliuqie where you can see up close and personal such geological, geomorphological, and hydrological features!
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Logging Requirements:
Xiaoliuqiu is an island of Geological Wonder with so many unique landforms and hidden geological treasures, with a group of karst landforms concentrated right here at Shanzhugou!
Please note that this area is open from 7:00 a.m. ~ 5:00 p.m. daily
In order to log a Found It! for this Earth Cache, please go to the Posted Coordinates and follow the path to go around in a loop around Shanzhugou to all six referenced Waypoints and complete the following tasks.
1. As you travel in a loop around Shanzhugou:
Based on what you have learned about karst topography and the geological, geomorphological, and hydrological features of such a landscape:
⇒ Identify which karst landscape is at each of the Waypoints.
⇒ Estimate the size (length, width, depth) of the respective landscape
⇒ Classify the landscape as either geological, geomorphological, or hydrological
How did you come to your conclusions about identifying and classifying each of the landscapes? Which one(s) were a little difficult to identify/classify? Why? Also, which group had the most kind of landscape — geological, geomorphological, or hydrological? How did you come to your conclusion and why do you think there is an abundance of a certain kind of landscape here?
2. After visiting ALL Waypoints including the Posted Coordinates, and based on your conclusions and observations with identifying each of the karst landscapes, which landscape(s) appeared to be the most affected by the rainwater? What does this tell you about the rainwater and the limestone itself? What "future" do these landscapes have?
3. As you traveled in a loop around Shanzhugou, what other factors did you see that could have contributed to the "erosion" or the "change in shape" of these landscapes?
4. Optional — Post a photo of yourself or a "Geocaching" item identifying yourself here at "Shanzhugou!"
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 at Shanzhugou.