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PostPosted: Dec 3, 2013 12:27 am
by DirtDoc
Tienkengs and the National Geographic: Mystery Caves Of Guangxi ... 93238.html

A production of the National Geographic Channel in conjunction with Chinese television CCTV-9.

For additional maps, cross-sections, and photographs of Mawangdong Cave, Bandong Tienkeng, and the through-cave photographed in this movie, see page 3 of the Leye-Fengshan Geopark, Sanmenhai Karst Tourguide: ... kChina.pdf

NOTE: National Geographic Channel (NGC) is jointly owned by Fox Cable Networks and National Geographic Television & Film. They are acknowledged as producing documentaries with factual content and "pseudo-scientific entertainment programming" on NGC (Wikipedia). This film appears to be a documentary enhanced with exaggerated mystery and danger.

I have been asked to provide some clarification for the US caving community about the use of the term "tiankeng". This is pronounced "Tee-ann Kung" in Mandarin. As many of you know, I have been leading karst-focused tours for geologists and cavers and have first-hand knowledge of Chinese karst since 1993. The cavers staring in the film have clearly had a wonderful time in a spectacular area courtesy of National Geographic. The film does a good job of explaining the area to the general public, and conveying the wonder and excitement of exploring the karst of SW China.

This is a spectacular and interesting film of the huge collapse dolines and high-relief karst near Leye, SW China. It is also contains some unnecessary (in my opinion) exaggeration and self-promotion from Fox Cable and the National Geographic Channel. Anyone in the caving community who has been to the spectacular karst areas of China recognizes the hyperbole. The writers/producers seem either to have done a poor research job (unlikely) or made a deliberate decision to add additional "mystery" and danger to some of the most spectacular karst on Earth. These are clearly world-class caves.

Cave scientists have understood how these huge pits are created for over a hundred years. First described from the Dinaric Karst (Škocjanske jame) in the Balkans, known in China since 1992, explored in China by the Cave Research Foundation Expedition in 1993 (that was before the Funny Word "tienkeng" had been coined), and explored extensively in China by the Hong Meigui Cave Exploration Society (Erin Lynch) since 2001, the British Cave Research Association, and others. Large limestone pits like these are not common, but have been found in many places. At the time of this writing approximately 50 are known to exist in China (which is a VERY big country) and over 35 in other countries.

Simply, they are unusually large collapse dolines. That is the term I prefer to use to describe these features, not the funny Chinese word "tiankeng". The huge volume of limestone that has been removed must have gone somewhere. In most cases there is obviously a good-sized underground river beneath the collapsing doline which keeps removing the breakdown blocks as they fall underground. In this part of China there is stratigraphically over 7 1/2 miles (total thickness) of soluble limestone, high topographic relief, and it rains a whole lot to produce the groundwater that dissolves the limestone. Fracture traces in the limestone likely relate to the specific location of these pits, just as they do for millions of other cave passages around the world.

The public perception and misunderstanding about tienkengs has been caused by a prominent Chinese geologist who arbitrarily made up the word "tienkeng" (Sky Hole or Heavenly Pit) for exceptionally large collapse dolines. He defined them as collapse dolines that are more than 100 meters wide and deep. This is a completely arbitrary term. It is just like using the word "skyscraper" for tall buildings and "megabuilding" for the very tallest one. Then you can claim that your city has the only megabuilding in the world. It has allowed the Chinese to make a Big Deal out of the fact that they do, indeed, have a lot of impressively gigantic collapse dolines in their country. Applying the term to a specific collapse doine has encountered problems about whether a specific feature is really a "tiankeng" of "just" a large collapse doline. They are ALL just collapse dolines! Some of which are unusually big.

Note that the Chinese typically measure the size of the pits at their maximum dimensions and depth (from the highest point around the rim), where western cavers usually measure the depth from the lowest spot on the rim (shortest distance from top to bottom if you were actually going to rappel in). This further confuses the "depth" and "size" issues.

There are numerous references to these large pits in China that have been written over the last 20 years, some accurate, some with included hyperbole. Here is where to start:

Tiankengs: Definition and Description, 2006, Zhu Xuewen and Tony Waltham ... df9541.pdf
This is a summary paper that that defines the features. In regards to the proposed concept of a "tiankeng karst":
The concept of tiankeng karst has been considered within China as a term to describe an extremely mature type of karst landscape that has matured beyond normal fengcong karst with high relief. The term could be used to describe the Leye karst in Guangxi, China, and perhaps the Nakanai karst in New Britain, Papua New Guinea, both of which are distinguished by unusually large numbers of tiankengs. However, some mature karst terrains contain just a few tiankengs, notably just two in each of the karsts of Xingwen, Croatia and Mexico, and these question the applicability of the term. Tiankeng karst may be purely descriptive of the Leye and Nakanai terrains, but the term has not yet been shown to have any geomorphological status with reference to karst evolution.

Figure 1 of this 2006 report shows EXACTLY the "mystery cave" in the Leye Karst that this film is all about. Maoqui Dong is the "incipient tienkeng" that they first rappelled into. - There are all sorts of problems trying to translate Chinese language or idiograms into English, and then trying to figure out by reading the English translations if you are talking about the same place (are the names really the same in Chinese). The names "Bandong" and "Baidong" are likely the same when you read the Chinese characters or pronounce them in Mandarin. It would have not taken much research for the National Geographic explorers to have had a very good idea what they would find when they got to these collapse dolines China and to know how the features had formed.


For a list of 33 "tienkengs" and comparable features known to exist outside China in 2004 (including El Sotano and Golindrinas in Mexico): ... df9540.pdf

Special Issue: Tiankengs Transactions of the British Cave Research Association: Cave and Karst Science: V. 32, n. 2&3 (in one volume). Descriptions of the giant collapse dolines in China and the Wulong Karst World Heritage site.

The Mother Of All collapse Dolines is Xiaozhai, close to the Yangtzee River, just south of the first of the Three Gorges. Down-cutting by the Yangtze has created the great relief found in the area. Xiaozhai is 662 meters deep (measured by the Chinese to obtain maximum depth) and has a trail (with many steps) to the bottom, where a diversion tunnel for hydroelectric power has been constructed. See The Yangtze Gorges Expedition: China caves project 1994 - Guest Editorial by Andy Eavis, BCRA Cave and Karst Science Vol 22 (2) 1995. Description of the Xiaozhai area south of Fungjie and the Yangtze Gorges. ... %20065.pdf

The Yangtze Gorges Expedition: China caves project 1994 - Guest Editorial by Andy Eavis
BCRA Cave and Karst Science Vol 22 (2) 1995: 51

The Yangtze Gorges Expedition: China caves project 1994 - Expedition Report by Kev Senior (Ed.)
BCRA Cave and Karst Science Vol 22 (2) 1995: 53-90
Report of the China Caves Project 1994 expedition to Xinglong. Includes surveys, maps and photos.

So: It appears to me that the term "tienkeng" is proving itself to be a very effective public relations term for the Chinese, similar to the effectiveness of the term "spelunker" introduced by Clay Perry in 1939 and subsequently used widely by newspaper reporters. Both terms are likely to be around for quite some time to come. The geologist and expedition leader in this movie does an excellent job of explaining karst hydrology, even with the inclusion of enhanced mystery, and explaining the previously well-known understanding of how these giant pits develop. The whole tone of the movie (with enhanced mystery and danger) is similar to the one National Geographic produced a couple of years ago on what they claim to be the Biggest Cave in the World (Hang Son Doong in Vietnam: ), where he was also the team geologist.

That said, this film is about some of the most spectacular karst in the world and is worth watching.

My colleagues in China point out that the video is providing lots of publicity for the Leye-Fengshan Geopark, which is likely to make it easier for future expeditions to get permission to cave in those areas.


Re: Tienkengs

PostPosted: Jan 1, 2014 11:56 pm
by CaverCSE
If you count a massive 1/2 mile across and 500ft deep sinkhole developed via passage collapse as a Tienkeng, then I believe Turkey Cot Cover (near Spencer, Tennessee) is a Tienkeng created by Rumbling Falls Cave. In the cave, there are huge terminal breakdown chokes that line up perfectly with Turkey Cot Cove and Rumbling's river passage on the downstream side of the collapse is a massive 300ft wide and 200ft tall borehole.

This area around Spencer, Tennessee forms unusually large volume caves with far less water than what's usually required due to the large number of bedding plain slip faults present. ... 1&t=p&z=15

Re: Tienkengs

PostPosted: Jan 2, 2014 11:04 am
by gindling
The trip to the terminal breakdown in Rumbling Falls is a trip worth taking! Maybe someone will find the way through some day, we didn't. Though seeing that spring in Turkey Cot Cove in flood is an impressive sight and just teases you to try, try again.

Re: Tienkengs

PostPosted: Jan 2, 2014 1:09 pm
by DirtDoc

You can call it that if you want to, but I would not. The whole point I am trying to make (other than telling you how the word originated) is that the funny Chinese tourist-promotional "get us into the Guinness Book because China is Special" word "tienkeng" has, in my opinion, no scientific validity. Features like those in China have been found and recognized around the world for over 100 years, and the descriptive term "large collapse doline" is quite correct. Attempting to put an arbitrary size (100 meters wide and deep) and making up a new word for the very biggest ones does not work very well, especially since there is so much disagreement on how to measure the things.

For Turkey Cot Cover, "Massive Sinkhole" seems to be Just Fine!!

Another point is that however odd that funny word is, it is going to be with us for a long time. Just like the funny word "spelunker". We will have to live with it, but we don't have to use it except to point out how inappropriate it is.


Re: Tienkengs

PostPosted: Jan 2, 2014 6:16 pm
by GroundquestMSA
This is an interesting topic. So many aspects of language are arbitrary (I'm reminded of the definition of "cave," which changes from state to state) ... I wonder why there is a need to discredit the term. Is it because the Chinese geologist made up a set of rules that he felt could only apply to Chinese caves in an attempt to get more publicity? Or did he simply feel that these caves were so fantastic that they deserved a descriptive term?

The comparison to the word "spelunker" is also interesting, as I have yet to understand its fall from grace.

Re: Tienkengs

PostPosted: Jan 4, 2014 2:38 pm
by DirtDoc
Thanks Jonah:

That is a perceptive and very good question. It makes me realize that I was writing for karst scientists and experienced big-pit cavers. There are many reading Cave Chat who are neither.

It is important to understand that I am not discrediting the term "tiankeng" for casual use in the Chinese karst, only saying that using it as a descriptive, precise, scientific term world-wide is not appropriate. That is a significant difference in the use of the word.

We are free to use any word that we wish to refer to something. But it helps if that word or words make some sense to those reading or hearing it.

Language exists so that we can communicate to another. I can describe a physical feature by any name I want, but unless the other person understands what I mean by the words that I choose, they may not form a picture in their mind that is close to the actual physical feature (or idea) I am talking about.

If I tell you that the rose is "red", you and I agree (in general terms) what that means and you form a picture in your mind. Whether your imagined image is close to the real color and shape of the rose that I am describing depends on a number of things, most importantly what "red" means to me and what "red" means to you. Now, I happen to be slightly color blind, so I am not sure I am perceiving the same color that you would perceive should you look at the actual object. Think about the additional problem of verbally communicating to a blind person. Now consider verbally communicating the physical shape of the rose itself.

The key to understanding my answer to your question is in your correct statement "So many aspects of language are arbitrary".

Scientists attempt to establish a less arbitrary language to describe things. If I say "sandstone" to another geologist, he sees in his mind a sedimentary rock composed of small rounded particles that are between 0.0625 mm to 2 mm in size. This is a very precise definition that is agreed to by all geologists. "Sand" does not refer to the material is that makes up the sand grains. Only the size of the fragments matters. The equally precise definition of "sedimentary" means that he sees in his mind a layered rock composed of fragments of pre-existing rocks. Most importantly scientific terminology should be so well defined that if the other geologist visits the outcrop that I am describing, he will use exactly the same terms that I have used to describe the rock.

The general public uses the words "sand" and "stone" in a more casual and arbitrary fashion, as you have noted.

Scientific terminology is intended to improve and enhance communication. Occasionally it is wrongly used to obscure ignorance or to promote a personal, and perhaps a political or other purpose.

Case in point. One of many screwy words in the geologic literature is the word "cactolith" defined as:
"A cactolith is a quasihorizontal chonolith composed of anastomosing ductoliths whose distal ends curl like a harpolith, thin like a sphenolith, or bulge discordantly like an akmolith or ethmolith."

Does that enhance communication? I don't think it does, even to other geologists. It would be better to use more words and say "a cactus-shaped igneous body".

There is a similar problem with the word "tiankeng" when you try to use it in an English-language document.

My complaint is that is does not do any better job of describing these features than saying "A Gigantic Hole in the Ground with Very Steep Walls". AND - there is already an established internationally-accepted scientific term for these features: "large collapse doline".

SO - my objections came when Prof Zhu wanted to insert the word "tiankeng" into the formal geological literature to apply world-wide. Not stated in his definition paper is the fact that he is a strong proponent of karst tourism in China and has deliberately used this term to make the exceptional karst landscapes of China seem even more special for non-scientific reasons. There is a real problem in defining "tiankeng" in practical and unique terms. Exactly what is one of these features? See the confusion of whether Turkey Cot Cover is or is not a "tiankeng".

A part of the definition problem is that the Chinese measure the depth much differently than do western cavers. I anticipate only confusion from the use of the word, not enhancement of communication.

I think that using the word "tiankeng" is not good science. It is certainly confusing for Western cavers to try to apply "tiankeng" to some features they have long-known as "large collapse dolines". My argument is that they do not need to do so.

. I won't get far into that discussion, which has been run into the ground (no pun, of course, intended) in other places and has been overly discussed and well understood in most caving circles. Briefly, the word was used by Clay Perry in 1939 in his book [i]["Underground New England"/i]. Clay encouraged the use of this term by some of his newspaper friends, and it was picked up and spread by the press (and then by the general English-speaking US population) who loved the funny word.

You are incorrect to say that it has fallen from grace. It has not. First of all, its use was never really in grace by cavers in the United States, so it had nowhere to fall from. And it has never fallen from grace in the eyes of newspaper people and other folks who continue to like to use strange-sounding words that others don't understand, presumably in order to make them feel more important or better educated. Now they can also use "tienkeng".

"Spelunker", more recently, has emerged as a term describing someone engaged in various kinds of sexual behavior, including an especially deep-tongued technique of French kissing and by the gay community referring to the act of sodomy. None of this especially enamors the term to most of us in the caving community. If you use the word "spelunker" to describe your caving activities, you need to be careful how you phase it.


Re: Tienkengs

PostPosted: Jan 4, 2014 6:53 pm
by GroundquestMSA
DirtDoc wrote:SO - my objections came when Prof Zhu wanted to insert the word "tiankeng" into the formal geological literature to apply world-wide. Not stated in his definition paper is the fact that he is a strong proponent of karst tourism in China and has deliberately used this term to make the exceptional karst landscapes of China seem even more special for non-scientific reasons.

Very good, I understand.

I suppose that I have assumed too much about the word "spelunker" based on its frequent use in NSS publications. It seems that this use was most common in advertisements, such as the "Smart Spelunkers Wear Levi's" ads on the back of most copies of NEWS through the 50's and 60's. Now that I've read through the articles themselves, I see that cave explorers mostly referred to themselves as cavers. Clearly, there is a stronger prejudice (among cavers) against the word now than there was decades ago, but, as you said, that's another topic.

Re: Tienkengs

PostPosted: Jan 5, 2014 10:53 am
by DirtDoc
To further clarify: I have no problem using "tiankeng" when I am in the karst of China because everyone knows I am looking for a "A Gigantic Hole in the Ground with Very Steep Walls". Just as I use "sótano" (which literally means "basement") when I am in the big pit country north of Mexico City. It is trying to formalize the word to have a very specific meaning that I think is both confusing and unwarranted. Arguing about whether a particular feature is or is not big enough or has the other characteristics proposed by Prof. Zhu to be a "tiankeng" does not seem to be fruitful.