Hall of Jade Ripples lies at the northern corner of Kunming Lake in the Summer Palace. It is noted as having served as the prison of Emperor Guangxu in the late Qing Dynasty.
THE STONE IN THE PALACE 园中石
In China, viewing stones (scholars rocks and spirit stones known by the Chinese as "Gongshi") have been an art of appreciation for over a thousand years.
This large bluish, glossy stone, known as the Blue Iris Stone, located in the classical gardens at The Summer Palace, Beijing, China, is the largest stone decoration in any Chinese garden. The stone drew the attention of its finders due to it being a large, dark and sleek stone, and was thought to be shaped like a fungus.
THE STONE GEOLOGY 岩石地质学
The Blue Iris Stone is a piece of karst limestone from Beijing’s Fangshan District and was moved to the present location in the garden. The stone is an excellent example of weathered and partially dissolved limestone.
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3). Most limestone is composed of skeletal fragments of marine organisms such as coral, forams and molluscs.
Typically limestone forms by accumulation at the bottom of an ocean or shallow sea. Freshwater limestone can form at the bottom of a lake. After limestone forms the process of weathering occurs. The weathering will mostly occur underground forming caves. Changes in landforms and erosion can bring the limestone to the surface where further Karst weathering can occur.
Karst topography occurs when calcium carbonate in limestone is dissolved by weak acids such as carbonic acid. The mild acids find and dissolve susceptible parts of the rock and the resistant sections remain. Weathering and acid action will follow cracks and separate sections of the rock. The karstification of a landscape may result in a variety of large or small features both on the surface and beneath. Underground spectacular caves are formed. On exposed surfaces, small features may include solution flutes, runnels, clints and grikes, collectively called karren or lapiez.
The Blue Iris Stone shows many of these Karst features. Look along the top of the stone. You can see a cross section of limestone pavement, known as clints and grikes. Look down the sides of the stone and you can see examples of solution flutes and runnels. The stone is a fine specimen of Karst topography. Perhaps those ancient Chinese were looking for an elegant esthetic garden feature but cleverly they selected a worthy scientific sample.
LOGGING REQUIREMENTS FOR THIS EARTHCACHE 记录须知
In order to log this Earth Cache you must visit the Summer Palace in Beijing China, there is an entrance fee of around $30 CNY ($20 CNY in winter) to access this cache. You must find the court yard at the listed coordinates and locate the large stone – (you really cannot miss it). You must then answer the following questions to claim a find:
1) What was the stone popularly named? 这块石头的俗称是什么？
2) Can you see features in the stone that show it is limestone? 你在这块石头上能找到哪些石灰石的特征？
3) How much of the stone has been dissolved by weathering? Does the weathering form a network or is it discrete dissolution? Does the dissolution follow features in the stone structure? 这块石头的风化侵蚀程度如何？风化是呈网状分布还是分散各处的？侵蚀是否依着石灰石的特征进行？
4) What small features did you observe on the surface of the stone? Why do you think these features have formed? 你在石头表面可以观察到哪些微小特征？你认为这些特征是如何形成的？
There is no need to wait for a confirmation email to log your find. I will read each email to confirm your answers and will contact you if there is a problem. Please do not email photos, just upload them with your log – please use caution though when uploading photos that you do not include the details listed on the information board, any logs showing this will be deleted and you will be asked to resubmit.
If an email is not received in a timely manner after logging your cache, the log will be deleted. 如果在你登记后的一段时间内我仍未收到你的答案，你的记录将被删除。