Download Analysis of features and natural heritage values of Dashiwei karst in

Analysis of features and natural heritage values of Dashiwei karst in Leye-Fengshan Global Geopark,
China
ZHANG Yuanhai, CHEN Weihai, LIU Wen
(Institute of Karst Geology, Chinese Academy of Geological Sciences, 50 Qixing Road, 541004, Guilin,
Guangxi, China)
ABSTRACT
Dashiwei karst is a part of Leye-Fengshan Global Geopark in the southwestern China, and National 4A
Scenic Area, and it is also the potential natural heritage site of Southern China Karst. It is mainly
featured by tiankengs (great dolines), which is the biggest group in the world, as well as the specific
forest and wild orchid population at the bottom and around tiankeng group. In this paper, with a
geological and comparative analysis, the genesis and features of the Dashiwei karst are analyzed
systematically according to the criteria to be included on the World Natural Heritage List. It is
concluded that Dashiwei karst has outstanding universal values in geosciences, biology and aesthetics,
and meets the criteria vii, viii and x for designation as World Natural Heritage through comparison with
other World Natural Heritage sites of karst.
Key words: Dashiwei, karst, fengcong, tiankeng, orchid, natural heritage value
1. INTRODUCTION
Carbonate rocks are widespread in China, with an outcrop area of 910,000km2, including the areas
concealed by a cover of insoluble rocks, carbonate rocks extend beneath more than 3,400,000km2 and
total thickness of carbonates is more than 10,000m (Li and Luo, 1983). Many types of karst landforms
are developed in these carbonate rocks, especially the colorful and representative karst landforms
within an almost continuous carbonate outcrop of 500,000km2 (Yuan, 1993) that lies in the provinces of
Guizhou and Guangxi and also extends into Yunnan, Sichuan, Chongqing, western Hunan, western
Hubei and northern Guangdong, it is called South China Karst (Fig.1).
Fig.1 The karst distribution of South China Karst (editing from Li and Luo, 1983)
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South China karst is proved to be the best developed karst region, comprehensively reflecting the earth
history in South China and unique characters of physical geography. It extensively embodies the
special karst types, karst ecosystems, biodiversity, natural landscape beauty and evolutionary process,
with world significances. Therefore, South China Karst, as a trans-provincial area in China and
composed of 12 sites, was listed in World Natural Heritage for three sites in 2007 and will be listed for
9 sites in potential phase by phase in the future. The three sites listed in World Heritage areShilin
karst (Yunnan), Lipo karst (Guizhou) and Wulong karst (Chongqing), the potential karst sites are
①Guilin karst (Guangxi), ②Dashiwei karst (Guangxi), ③Xingyi karst (Guizhou), ④Jinfoshan Karst
(Chongqing), ⑤Mulun Karst (Guangxi); ⑥Zhijin Cave (Guizhou), ⑦Fengjie Karst (Chongqing), ⑧
Xingwen Karst (Sichuan), ⑨Longgang Karst (Guangxi) (Fig.1, Fig.2).
Fig.2 The location and area of Dashiwei Karst
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Dashiwei karst in Leye-Fengshan Global Geopark is one of the potential site (②) of South China Karst
and is located in southwestern China in Guangxi Zhuang Autonomous Region, and in the transition
area between the Yunnan–Guizhou plateau and the Guangxi basin, it covers an area of 122.6 km2 in the
center of an “S”-shaped karst area (Fig.2). Dashiwei karst is typical of massive inlier fengcong karst
(cone karst); with a continuous sequence of hard carbonate rocks more than 3000 m thick which are
surrounded by regions of very thick clastic rocks. It is featured by an “S”-shaped geological structure,
and there are prominent NNE, NWW and SE striking joint sets and fissures (Yi, 1983) throughout the
Dashiwei karst area, creating a favorable environment for the development of Bailang subterranean
river system. The river played an important role in the formation of Dashiwei karst.
2. THE FEATURES OF NATURAL HERITAGES IN DASHIWEI KARST
Dashiwei karst has numerous natural heritages including karst landforms and tiankeng flora and fauna.
The karst landforms can be subdivided into two major classes: exokarst, endokarst. Exokarst includes
landscape dominating landforms such as fengcongs, karst valleys and poljes and other easily observed
features such as tiankengs, skylights, through caves. Major endokarst landforms include large
subterranean river, karst caves, cave chambers and speleothems.
2.1 EXOKARST
Dashiwei Exokarst is characterized by high Fengcong (cone karst), large plojies and particularly by
tiankengs. High fengcong is distinctive for its high, steep peaks with elevations often more than 1000 m;
while the associated depressions are 150~500 m lower. Poljes is dominant for marginal poljes, this kind
of negative karst landform is often cultivated or inhabited, particularly in areas of continuous fengcong
karst. Tongle polje is an example, containing Leye county town and several villages.
Fig.3 Dashiwei Tiankeng (photo by Lee Jin)
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A tiankeng is defined as a distinctive type of very large collapse doline that is more than 100 m wide
and deep, with a depth to width ratio close to unity, and vertical cliffs round most of its perimeter. They
are massive negative karst landforms with huge volumes and dramatic enclosing cliffs(Zhu & Waltham,
2005). Developed in a great thickness of carbonate rock in the unsaturated zone, the tiankengs range in
depth and width from 100 m up to several hundred meters, some connecting to subterranean rivers. So
far 28 tiankengs have been discovered in the “S” shaped karst area, 24 of which are in Dashiwei karst.
Generally they are 100-300 m deep, 200-400 m wide at the rim, 1-10 million cubic meters of volume;
Dashiwei tiankeng has the largest scale and the greatest depth (613 m, the second deepest in the world).
At the rim, Dashiwei tiankeng is 600 m wide from east to west and 420 m wide from north to south,
with a total volume of 67.1×106 m3. The area at the rim is 16.6 ha (Fig.3), while the area of the virgin
forest at the bottom is 10.5 ha, the largest in the world (Campion,2002, Huang,2004).
In sequence from the contact between the limestone and sandstone to the center of Dashiwei karst the
following landforms are found: marginal poljes, fengcong valleys and fengcong depressions (Fig.4),
and positive landform increases and negative decreases in elevations (Zhang, 2009. Fig.5).
Fig.4 Polje-Fengcong karst landform profile
Fig.5 The profile of Dashiwei karst (editing from Liu,2003)
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2.2 ENDOKARST
Dashiwei Endokarst is characterized by Large Subterranean River System, karst caves and speleothems.
Bailang subterranean river follows the “S”-shaped course flowing from south to north for 162 km with
a flow rate of 3.48~121 m3/s (Yi, 1983. Fig.2). Large allogenic inputs to the subterranean river have
played a significant role in the formation of huge and complex systems. The upper and middle reaches
of the Bailang river are good for tiankeng development.
There are 13 levels of cave passages distributed at 880-1425m asl, and those above about 1000m asl
formed in Neogene according to the pollen analysis of some caves and those below this level formed in
Quaternary period (Liu,2003). 21 caves in Dashiwei were surveyed, of them the longest cave is Dacao
with 9.46 km long and the deepest is Dashiwei river cave with 837m deep; Dacao cave has
Hongmeigui cave chamber of 50700 m2 (Campionm,2002. Fig.6). More than 50 shafts and vertical
caves have been found in Dashiwei. Their entrance diameters range from several meters to several tens
of meters, and their depths from several tens of meters to several hundreds of meters. They are located
above and near the paths of the subterranean rivers. Fengyan is the deepest one with 369m deep; four
skylights are discovered, the highest one is Maoqidong with 410m high (Campion, 2002), it is
connected with Baidong tiankeng underground (Fig.7). It formed rich formations inside caves,
particularly in Luomei cave, 296 lotus rimstones are located throughout the upper passage, the lotus
rimstones are 0.1~9.2 m in diameter and 5~70 cm high. The 9.2 m-diameter lotus, called “The King of
Cave Lotuses”, is the largest in the world (Huang, 2004).
Fig.6 The profile of Dacao tiankeng-Hongmeigui cave chamber (from Campion,2004)
Fig.7 The profile of Baidong tiankeng-Maoqidong skylight (from Campion,2004)
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In addition, A 33 m-long Neogene stratigraphic section has been found in Mafeng cave on the rim of
Dashiwei tiankeng at 1289~1372 m a.s.l. The primary lithology of the section is fine conglomerate,
gravel-bearing sandstones and mudstone with a thickness of 14.1 m. Pollen analysis confirms that the
deposition occurred during the Neogene (Liu,2004).
2.3 BIODIVERSITY
The forest at the bottom of Dashiwei tiankeng forms an independent ecosystem. It is subtropical
evergreen broadleaf quasi-primeval forest. The tree canopy is mainly composed of rare adult species
such as Manglietia aromatica, whose height can reach 30 m with a circumference of about 2 m. The
shrub layer is mainly composed of Rhapisis and herbaceous ferns dominates the scree slope at the
bottom of the tiankeng (Xue,1996). The cliffs in Dashiwei are a habitat for numerous animals,
including the giant flying squirrel (aka flying cat) Petaurista alborufus .
Orchid Nature Reserve in Dashiwei karst contains more than 100,000 plants. It is a 13 ha ‘gene garden’
for orchids, with 44 genera and 130 species (including 16 new species, 15 of which are only found in
Guangxi, and one of which is only found in China) of wild Orchidaceae (He,2007a). The largest wild
monophyllos and vanilla populations have been found in this nature reserve, with the wild monophyllos
population covering ~0.6 ha and containing 12,000 plants, while the wild vanilla population covers 0.5
ha and contains. 2,000 plants. In addition, a unique and rare wild Paphiopedilum population has also
been discovered in this nature reserve (He,2007a, 2007b).
3. ANALYSIS AND DISCUSSION OF NATURAL HERITAGES
3.1 THE GENESIS OF THE KARST LANDSCAPE
The development of Dashiwei karst landscape is related with its superior geological and geographical
conditions including carbonate rocks, tectonic features, new tectonic movement and topography,
allogenic water, surface water and groundwater circulation and climate.
The carbonate rocks in Dashiwei karst are distributed in succession with an area of 600km2, a thickness
of more than 3000m, and featured by pure and hard, thick-bedded limestone, dolomite and dolomitic
limestone, which are favorable for the erosion and dissolution of karst, as well as the formation of large
vadose zone, providing a hard frame for fengcong, tiankeng and cave chambers and rich material
source for karst formations.
The carbonate rocks in Dashiwei are broadly surrounded by sandstone and shale, and 400-600 lower
than that, displaying an island distribution of carbonate rocks, and forming a series of faults at the
contact boundary between karst and non-karst (Yi,1983), as well as excellent permeability.
Additionally, “S” type areas are in basin shape, a large number of allogenic water with strong dynamics
flow into the basin karst areas and converge into Bailang Subterranean River system; its main stream
passes through “S” type karst area from south to north, and controls development and distribution
landscapes of karst tiankengs and caves.
The Neogene intermittent rapid tectonic uplift in Dashiwei is an important factor for the development
of big vadose zone, levels of cave passages, high fencong, tiankeng as well as subsurface rivers.
Dashiwei karst is in the transition between Yunnan-Guizhou Plateau to Guangxi Basin, and watershed
region between Hongshui River and You River, it formed big potential energy for karst water
circulation, and surface fengcong and subsurface caves as well as tiankeng developed very well.
Dashiwei karst is dominated by a mid-subtropical monsoon climate with heavy rains and clearly
alternating wet and dry seasons. The annual precipitation is in the range of 1550.7-1356.4 mm. The
average annual temperature is between 16.4 ºC and 19.2 ºC. Humid climate and adequate precipitation
played a great role in surface corrosion and erosion, while the rainy season with high-temperature at the
same time brought a strong chemical corrosion underground. In addition, favorable climatic conditions
provided a good ecological environment for the growth of plants, which strengthen the role of
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biological karstification.
3.2 VALUES OF NATURAL HERITAGES
Dashiwei karst abstracts the outstanding characters from karst geomorphology, karst geological
evolution, karst tiankeng ecosystem, biodiversities and karst landscapes and so on, and represents the
unique values in geosciences, aesthetics and biodiversity.
3.2.1 GEOSCIENTIFIC VALUES
Dashiwei karst covers a complete series of subtropical karst landform types in South China, which
include surface karst fengcong, large polje, karst valley, depression, karst tiankeng, subterranean river,
cave and formations. Karst landforms in the geopark have their unique development conditions: karst
inlier areas with peripheral fault partition and inflow of a large number of allogenic water are typical
representatives of karst inlier fengcong in China; moreover, high fengcong, deep depression, large karst
tiankeng and big subterranean river in the geopark profoundly reflect evolutional features of karst in
China: ancient and hard carbonate rocks, large uplifting in the Cenozoic era, unscour of continental ice
sheet at the last glacial age and hydrothermal-supported monsoonal climate are with extremely
important global significance to confirm world status of China’s karst landforms and comparative study
of karst landforms. its evolution model is karst inlier structure→continuous tectonic uplifting in the
center→valley and depression deepening and enlarging→lots of allogenic water flowing into→
development of subterranean rivers, tiankeng and caves→distribution of different landforms such as
polje, karst valley and high cone karst from marginal karst to central karst (Zhang ,2009. Fig.4 and
Fig.5).
A tiankeng is a process formed from subterranean river and it has three dominant stages, that is,
subterranean river stage, large cave chamber stage and collapse doline stage (Zhu,2001,2003,2005).
Dashiwei karst provides fine examples of three successive stages of tiankeng development (Fig.6 and
Fig.7). Hongmeigui and Maoqidong both represent the second stage of tiankeng evolution, they are
different in exposing to surface; Dacao and Baidong tiankengs represent collapsed doline stage, at the
bottom are the river passage of the first stage of tiankeng process. When Hongmeigui and Maoqidong
collapse, two larger tiankengs will be created.
3.2.2 AESTHETIC VALUES
The aesthetic values of Dashiwei karst depends on unique high fengcong karst, peculiar tiankeng, caves
and large subsurface rivers, as well as special tiankeng forest and orchids population. Dashiwei
tiankeng group has unusual morphology , grandness of body , density of distribution, diversity of
landscapes, uniqueness of ecological environment , aesthetic diversity, juxtaposition of scenic elements;
Around the tiankeng group are wonderful caves and formations, for example, 410 m high Maoqidong
skylight, Hongmeigui cave chamber of more than 50,000 m2, and large size and area of lotus rimstones
are incomparable making a strong impression upon the viewer.
3.2.3 BIODIVERSITY VALUES
The biodiversity in Dashiwei karst is mainly featured by tiankeng forest and wild orchid population.
The age of the tiankeng plant community is more than 200 years, which is characterized by complex
varieties, abundant plants and spatial differentiation of ecological types and high endemism, showing
the rich resources and kinds of flora. Orchid National Natural Reserve preserves the largest wild
monophyllos and vanilla populations, a unique and rare wild Paphiopedilum population. regardless of
species or populations of the number, orchids inside the natural reserve are extremely rare, which have
very high scientific research values and relatively fine primitive ecological appreciation. Rare animals
includes those cave animals as blindfish—Sinocyclocheilus hyalinus, Chinapotamon (new species) and
Belisana zhangi sp.nov, etc (Deuve, 2002); and flying squirrels and pangolins, etc. Thus, it can be seen
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that Dashiwei is an excellent region to study modern tropical and subtropical vegetation as well as
prehistoric relict plants; it is also one of the source regions and conservation sites of numerous rare
species.
3.3 COMPARATIVE ANALYSIS OF NATURAL HERITAGE VALUES
3.3.1 GLOBAL COMPARISON OF TIANKENGS
About 90 tiankengs are known worldwide, more than half of which occur in China (Zhu,2003.
Walthum,2005). To date 28 tiankengs have been discovered within the Dashiwei tiankeng group, 24 of
which are in the 100 km2 area of Dashiwei karst. It has the highest density of tiankengs known in the
world. Worldwide there are only 12 known areas with three or more tiankengs in less than100 km2 area
(Zhang,2009). There are ten tiankengs of more than 25 million cubic meters in volume discovered so
far in the world(Tab.1), Dashiwei is the second largest one.
Tab.1 Comparison of large tiankengs throughout the world (Zhu,2003)
No.
1
2
3
4
5
6
7
8
Tiankeng
Name
Xiaozhai
Dashiwei
Jiaole
Xiaoyanwan
Qinglong
Crveno Jezero
Minyé
Mangily
Volume
(×106
m3)
119
67.1
64
40
31.7
30
26
25
Dimensions at Rim
Length Width Area
(m)
(m)
(ha)
625
535
27.4
600
420
16.66
750
400
22
625
475
20
520
200
19.4
450
400
14
350
350
7.5
700
500
28
Depth
Max
Min
(m)
(m)
662
511
613
510
283
110
248
178
276
195
528
431
510
400
140
100
Region
Chongqing
Guangxi
Guangxi
Sichuan
Chongqing
Itmorski
New Britain
Mangily
Country
China
China
China
China
China
Croatia
Papua New Guinea
Madagascar
3.3.2 COMPARISON WITH OTHER KARST AREAS IN THE WORLD HERITAGE LIST
The number of World Heritage nominated areas inscribed specifically for their cave and karst features
and the reasons with karst account to 50 areas up to 2010. Of them, the number is 12 for World
Heritage areas inscribed specifically for their cave and karst features (Puerto-Princesa Subterranean River
National Park in Philippines, Gunung Mulu in Malaysia, Desembarco del Granma National park and System of
Marine Terraces of Cabo Cruz in Cuba, Carlsbad Caverns National Park and Mammoth Cave National Park in USA,
Plitvice Lakes National Park in Croatia, Caves of Aggtelek and Slovak karst in Hungary/Slovakia, Skocjanske Jame in
Slovenia, Ha Long Bay and Phong Nha Ke Bang in Vietnam, South China Karst in China and the Dolomites in Italy).
Within 12 world heritage sites inscribed specifically for their cave and karst feature, only South China
Karst has tiankengs, but Dashiwei karst is unrivalled not only in the dimension and number, but also in
the density and types of tiankengs, as well as the relation between tiankeng and subterranean river.
Within the sites inscribed for caves, such as like Mammoth Cave National Park and Mammoth Cave
National Park in USA, Caves of Aggtelek and Slovak karst on joint areas of Hungary and Slovakia,
Skocjanske Jame in Slovenia and Gunung Mulu in Malaysia, there is no skylights, no more lotus
rimtones comparable to Maoqidong and Luomei cave; the high fengcong and large poljes are the
supplement to South China Karst. In addition, the specific tiankeng forest is unique in natural heritage
and an indispensable to South China Karst.
4. CONCLUSION
Depending on the discussion and analysis of Dashiwei karst natural heritages and comparison with
other similar world natural heritage sites, it is concluded that Dashiwei karst meets criteria vii, viii and
x of World Natural Heritage, and it is the most important component of South China Karst.
Dashiwei karst contains nearly all the types of subtropical karst landforms including fengcong karst,
poljes, valleys, depressions, tiankengs, subterranean rivers, cave systems and speleothems. The karst
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landforms are incomparable for sightseeing. The area also clearly reflects both the conditions necessary
for fengcong karst development. The area’s carbonate rocks are old and hard, making them ideal for
forming and supporting big cave passages and chambers. Rapid uplift since the Cenozoic combined
with a lack of glaciation in the Quaternary has preserved multiple generations of karst landforms.
Therefore, Dashiwei karst meets the following criterions of World Heritage List.
Criterion vii: sites must “contain superlative natural phenomena or areas of exceptional natural
beauty and aesthetic importance”.
Criterion viii: sites must “be outstanding examples representing major stages of earth's history,
including the record of life, significant on-going geological processes in the development of landforms,
or significant geomorphic or physiographic features”
Because of special ecological environment, Dashiwei karst preserves tiankeng forest at the bottom and
rare wild orchid population around, as well as cave animals inside the large subterranean rivers and
caves. And Dashiwei karst meets the criterion x of World Heritage List.
Criterion x: To be included on the, sites must “contain the most important and significant natural
habitats for in-situ conservation of biological diversity, including those containing threatened species
of outstanding universal value from the point of view of science or conservation”.
Dashiwei karst belongs to the same karst geomorphologic regionalization of humid tropical-subtropical
karst landform region in China, and it is an important part of South China Karst.
BIBLIOGRAPHY
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Research Association.
Deuve, T. 2002. Two new remarkable anophthalmic Trechinae from limestone caves in
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107(5):515–523.
Huang B.J, Cai, W.T, Xue,Y.G, Zhu, X.W. 2004. Research on Tourism Resource Characteristics
of Tiankeng Group in Dashiwei ,Guangxi. Geography and Geo - Information Science. Vol.20 (1).
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He T.P. 2007. Analysis of Orchidaceae zones in Guangxi Yachang Nature Reserve. Guangxi
Agricultural & Biological Sciences 3. 215-221
He T.P. 2007. Research for diversity of orchid in Guangxi Yachang Nature Reserve, Guangxi
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The geomorphologic regionalization and features of karst in China1
CHEN Weihai, ZHANG Yuanhai, LIU Wen, QIN Houren, ZHU Dehao, WANG Xunyi
(Institute of Karst Geology, Chinese Academy of Geological Sciences, 50 Qixing Road, 541004, Guilin,
Guangxi, China)
ABSTRACT
Many geomorphologic types of karst are developed in an outcrop karst area of 910,000km2 in China,
depending on big difference of terrain and climate around China, and they are divided into eight karst
geomorphologic regions in China, i.e., humid tropical karst landform region (I), humid
tropical-subtropical karst landform region (II), arid-humid subtropical-semihumid temperate karst
landform region (III), humid-semihumid temperate karst landform region (IV), arid-semiarid temperate
karst landform region (V), humid tropical-subtropical-humid-semihumid plateau temperate karst
landform region (VI), humid subtropical-semiarid plateau temperate karst landform region (VII) and
plateau-high mountain karst landform region (VIII), whose features are discussed in the paper.
Key words: karst, geomorphologic type, geomorphologic regionalization, China
1. INTRODUCTIONA
The geomorphologic regionalization in China was made as early as 1959, and later provincial
regionalization was made in several provinces. Their geomorphologic classification is too simple,
although including karst landform. Mostly they were divided into four main karst zones, i.e. humid
tropical-subtropical karst region (I), humid-semihumid subtropical-temperate karst region (II),
arid-semiarid karst region (III) and plateau-high mountain karst region (IV) by climatic geographical
boundary (Zhang, 1979 ； Lu, 1986; Yuan, 1993). The regionalization is of karst instead of
geomorphologic karst, they contain several elements of karst landform, but more importantly, their
regionalization depends on the difference of karst hydrogeology instead of climatic geomorphology.
Carbonate rocks are widespread in China, with an outcrop area of 910,000 km2 (Li and Luo, 1983,
Fig.1). And because of big difference of geology, terrain and climate around China, the karst landforms
in China are more than complicated than karst hydrogeology, and they have so many differences and
similarities that different karst terminology are used in different provinces and autonomous regions. A
geomorphologic regionalization of karst is necessary to promote our understanding of karst in China
and planning of national economy development.
2. REGIONALIZATION APPROACH
Genetic approach and Morphological approach may be used to classify the typological category of
karst geomorphology.
A genetic approach stresses the origin and development of the features, and the processes and
conditions essential for them to form. The lithology may be firstly used to classify karst
geomorphology into three types in the first class, the whole karst, the semikarst and biokarst landforms
depending on the purity of carbonate rocks; then the second class may depend on the zonal factors and
external factors to classify 6 climatic geomorphologic types and 7 karst landforms respectively.
A morphological approach uses characteristics of shape and dimensions as principal criteria for
delineating karst types. And 23 morphological types are classified(Tab.1).
Table. 1 The karst geomorphologic types in China
Whole
1
Geomorphologic type
Genetic type
Morphologic type
Dissolution
Mountain Fengcong doline
Lithology
Pure
The paper is from the project of 1:4,000,000 China karst geomorphological map compilation.
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Formation conditions
Climate
Humid tropical-subtropical
karst
landform
landform
Gentle Fengcong
doline
Hill
Mountain
ErosionDissolution
landform
Fengqiu doline
Fengcong
canyon
Quasi-fengcong
doline
Gentle fengcong
valley
carbonate
rocks
covered by
loose soils
on surface
in doline or
valley
Mountain
dry valley
Semiarid-semihumid temperate
Mian humid, alternative tropical
and subtropical
Alternative humid & arid
subtropical-temperate
Semiarid-semihumid temperate
Fengqiu valley
Hill valley
Hill dry valley
Semikarst
landform
Plain
ErosionDenudation
landform
Erosiondissolutionaccumulation
landform
DissolutionErosion landform
Biokarst
landfrom
Fenglin plain
Erosiondissolutionaccumulation
landform
DissolutionErosion
landform
Dissolusion-erosi
on-denudation-ac
cumulation
landform
Bioaccumulationdissolution-sea
eroding landform
Humid subtropical
Main humid, alternative tropical
and subtropical
Alternative subtropical and
temperate
Mountain valley
Pill
Main humid, alternative tropical
and subtropical
Humid-rainy subtropical
Fengqiu plain
Quasi-fenglin
Plian
Humid subtropical
mountain
Mountain
Arid-semiarid
cold
hill
Peaks hill valley
Cluster hill
valley
Table land
Gentle hill valley
Plain
Gentle hill plain
Mountain
mountain
Hill
hill
Plain
plain
Coral
reefs
Coral reefs
Impure
carbonate
rocks or
carbonate
rocks interlayered with
non-soluble
rocks
Reef
limestone,
beach rock
temperate-high
Humid-semihumid
tropical-subtropical-temperate
Arid-semiarid-temperate-high
cold
Tropical marine climate
The development of karst landform is complex influenced by many factors, and it has a variety of
combinations. The geomorphologic types could be vague, unclear and overlap near the regional
boundary when making geomorphologic regionalization.
So, the following methods are used.
(1) The maximum similarity and the minimum differences of karst landforms are required within the
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each landform region, and it is the contrary in different landform regions.
(2) The combination of karst features and typical formations should be combined to determine the
regional boundary. For example, the combinations of karsts landform in humid tropical region are
fengcong (cone karst), but the typical ones are fenglin (tower karst), and then its boundary is designated
by the distribution of fenglin.
(3) Karst is distributed around China, and karst landforms are mainly controlled by climatic factors, the
regional boundary is determined firstly by different climatic zone, such as tropical, subtropical,
temperate and plateau high-mountain (alpine) zones, as well as humid, semihumid, semiarid and arid
zones, depending on the main climatic index, the temperature, precipitation, evaporation and dryness.
For example, the coral reef is distributed in tropical region; the tower karst is in humid
tropical-subtropical zone. But the karst landforms are also influenced by non-climatic factors, such as
geological structure, lithology and topography, a comprehensive analysis should be considered to
decide the sub-region boundary.
(4) Karst landforms have two important characteristics, one is that the positive and negative landforms
formed together to be a complete topographical structure; the other is that the high-mountain (alpine)
karst landform system has several thousand meters height difference with different climatic zones,
however, it is in the same complete karst system in geomorphology, and the same geomorphologic
region.
According to the methods mentioned above, karst landforms in China are divided into eight karst
geomorphologic regions, humid tropical karst landform region (I), humid tropical-subtropical karst
landform region (II), arid-humid subtropical-semihumid temperate karst landform region (III),
humid-semihumid temperate karst landform region (IV), arid-semiarid temperate karst landform region
(V), humid tropical-subtropical-humid-semihumid plateau temperate karst landform region (VI), humid
subtropical-semiarid plateau temperate karst landform region (VII) and plateau-high mountain karst
landform region (VIII) (Fig.1).
3. THE MAIN FEATURES OF KARST LANDFORM REGION
3.1 HUMID TROPICAL KARST LANDFORM REGION (I)
The region is situated to the south of the line of Leizhou Peninsula - Penghu Islands - southern Taiwan
– Diaoyu & Chiwei Islands. Its average annual temperature is more than 22℃ and its annual
precipitation is more than 1500 mm (EBCPG, 1984, similarly hereinafter).
It belongs to the Caledonian fold zone of circum-Pacific tectonic domains in the north and South Sea
platform in the south (CAGS, 1975, ZHANG, 1983; similarly hereinafter). A few carbonate rocks were
discovered in southern counties of Hainan Province, they are Middle-Upper Carboniferous limestone,
and Cambrian, Ordovician carbonate clastic rocks, with about 560-930 m thick2. It formed a small area
of fengcong, and some karst hills.
The karst landform in this region is mainly distributed in the sea and featured by coral reefs (HUANG,
1980). Many coral islands are all occur within this region and mostly are widely distributed in the sea
around South China Sea islands and near Taiwan. It is the only region in China to form biological
(coral reefs) karst topography.
3.2 HUMID TROPICAL-SUBTROPICAL KARST LANDFORM REGION (II),
Its boundary is Qinling Mountains in the north; it extends from Qinling to Dabie mountain, the
watershed of Yangtze River and Huaihe River, and East China Sea in the east; and it extends from
Qinling to the Eastern Anemaqen Mountain, turning to the south to Yulong Mountain, then to the
2
The carbonate rocks thickness are from National Geological surveys (unpublished for keep secret and no
bibliography, similarly hereinafter).
)
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Eastern Himalayas in the west. It has very different geomorphologic types in this region, and it consists
of Sichuan Basin and Yunnan-Guizhou Plateau as well as middle-high mountains around in the west,
with elevations of 1500-2000m or more (excluding Sichuan Basin); while in the east it is less than
1000m asl.
It is essentially humid subtropical region except the border area in the south. Its average annual
temperature is 15-19℃ and the annual precipitation is 1000-1400 mm.
It is mainly situated in the Yangtze Platform in the east and Himalayan block in the west, and it
deposited carbonates of more than 10,000m in total thickness from the geological periods of Cambrian
to Triassic with an almost continuous carbonate outcrop of 500,000 km2 (Li and Luo, 1983), where
karst landforms are well-developed (GAO,1986; QIN, 1984, ZHU, 1988). More than 90% of fengcong
(cone karst) and all fenglin (tower karst) are distributed in this region, with areas of 134,500 km2 and
101,000 km2 respectively.
Fig.1 The geomorphologic regionalization of karst in China
3.3 ARID-HUMID SUBTROPICAL-SEMIHUMID TEMPERATE KARST LANDFORM REGION
(III)
Its northern boundary is from Shandong Peninsula along the Yellow River to Qinling Mountains, it
borders on region II in the south.
It consists of Huaihe River drainage area and small part of Yellow River Basin, and features higher
topography in the west and hilly area in the east, slightly tilting to Huanghuai plain in the southeast.
It is humid northern subtropical-southern temperate region, its average annual temperature is 12-15℃
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and the annual precipitation is 700-900 mm.
It is located among North China platform and the Yangtze platform and eastern extension of
Kunlun-Qinling-fault and fold belt. It deposited carbonate rocks mainly in the late mid-Proterozoic to
Early Paleozoic, with 927m thick in succession at most.
After Cenozoic period, it formed continental deposit of more than 6000m thick because of tectonic
decrease, and most of the karst was buried by the plain and it formed well buried and covered karst in
this region. At the same time, the areas in central-southern Shandong and western part were uplifted by
fault movement, and about 1000 km2 area of karst exposed and it formed karst mountains and hills,
especially the cap-shaped karst landform with less than 800 m asl (An, 2010).
3.4 HUMID-SEMIHUMID TEMPERATE KARST LANDFORM REGION (IV)
It is located to the north of region III and borders from the Great Xing’anling Mt., to Yan Mt., Daqin
Mt.-Lvliang Mt. and Qinling Mt. in the west. It is humid-semi humid temperate climatic zone with
average annual temperature of 2-12℃ and annual precipitation of 500-700 mm.
It is located in Songliao block and North China platform with Caledonian and Yanshan fold belts. It
deposited various types of carbonate rocks from Archean to the Cenozoic periods, mainly from
Paleozoic Cambrian to Ordovician period and part of the Proterozoic Sinian period, they are featured
by carbonate interlayers rocks, with 2031m in succession at most, but scattered distribution.
It has the most complete and well developed temperate karst types in this region, including bare karst,
covered and buried karst, with an area of 100,651km2 in total. It features ridge hill valley, cluster hill
valley and karst mountain valley (dry valley) in morphology (CHEN, 1988).
3.5 ARID-SEMIARID TEMPERATE KARST LANDFORM REGION (V)
It borders region IV in the east, and its southern boundary is from Qinling Mountains to Qilian
Mountain, Altun Mountain and Western Kunlun mountains. It consists of Inner Mongolia Plateau,
Ordos Plateau, Loess Plateau, Hexi Corridor, Junggar Basin, Turpan Basin, Tarim Basin, and several
large mountain ranges such as eastern Yin, Helan Mountains, central Kitayama, western Tianshan, Altai
Mountains.
It belongs to the middle temperate climatic zone except southern Xinjiang and some part of Shaanxi,
Shanxi and Gansu in southern temperate zone. Its annual precipitation is 100-300 mm (less than 50mm
in Turpan Basin- Alxa plateau region and 300-500mm near region IV in the east), its average annual
temperature is 2-10℃ except western area with 4- 10℃.
It belongs to Tarim platform structural domain in China, Tianshan Hercynian fold region,
Lanzhou-Xining block, and the Junggar block of Siberia-Mongolia continental tectonic domain, as well
as Altai Caledonian fold belt. The carbonate rocks are thick and old in this region, with total thickness
of 16,000 m from Archean to Paleozoic periods, but pure carbonate rocks are about 5000 m thick. The
karstification in this region are very weak because of dry, cold, windy and few rainfall climatic
environment, it formed middle-high karst mountains with an elevations of 1150-3400 m, and whole
karst covers an area of nearly 6000 km2. The semikarst landforms are more widespread, being featured
by karst mountains and hilly mountains with an altitude of 1500-2500m.
3.6 HUMID TROPICAL-SUBTROPICAL-HUMID-SEMIHUMID PLATEAU TEMPERATE KARST
LANDFORM REGION (VI)
It is located in the west of Sichuan and to the east of Qinghai-Xizang Plateau, and it borders with the
region II in the east and in the south, its western boundary is from the northeastern Himalayas to the
eastern Tanglha Mountains, then to the southern Baryanhar Mountain.
It consists of a series of parallel and alternative mountains and canyons, i.e. Hengduan Mountains. The
average elevation of mountains is 4000-5000 m, the highest one is 6884m asl; the canyons are
generally 1500-2000m deep, the lowest one is 1500 m asl.
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It belongs to plateau temperate humid climatic zone, except semihumid features in the central and
northwestern area. Its annual precipitation is 500-700mm except the adjacent area of Sichuan, Yunnan
and Tibet near Jinshajiang River with about 400 mm; its average annual temperature is 2-8℃.
Most of the region is located in the Bayanhar and Nagqu fold belts, being across two ancient blocks of
the Southern (Gondwana) and the Southern China. It deposited more than 24,000 m thick carbonate
rocks from Sinian to Triassic periods, and the main strata is from Silurian to Permian periods, but the
majority are interlayered, impure and metamorphic carbonate rocks.
It mainly features high-mountain karst in this region, such as fengcong deep canyon and gentle
fengcong canyon, with an elevation of 4600-5500 m and a relative height of 2400-3500 m.
3.7 HUMID SUBTROPICAL-SEMIARID PLATEAU TEMPERATE KARST LANDFORM REGION
(VII)
It is situated to the south of Nyainqentanglha- Kailash and to the north of Himalayas, with elevations
from 5000 m to 6000 m, the highest one is the Everest with altitude of 8848.13 m. It is featured by high
mountains with low-middle mountains, hills and small plain in valley, as well as deep canyon of
1000-4000 m in depth.
It basically belongs to semiarid plateau temperate climatic zone, with big different precipitation of
100-500 mm from the west to the east, its annual average temperature is 0-8℃, being decreased from
the east to the west, and it is less than 0℃ above 5000 m asl. The snow line increases from
4500-5000m asl in the east to 6,000 m asl in the west.
It is in the tectonic unit of Himalayan blocks, Brahmaputra folds, Nagqu folds and Gangdise blocks, it
deposited 2580 meters-thick carbonate rocks from Middle Triassic to Paleogene periods in the center
area, and about 1000 meters-thick crystalline limestone before Permian period formed near the
Everest .
Because of specific natural conditions, the karst landforms in this region are undeveloped (ICPCAS,
1983), the erosional phenomenon and negative karst landforms are very few, in particular influenced by
strong frost weathering on the surface, and the karst formations have no difference from non-karst
landscape.
3.8 PLATEAU-HIGH MOUNTAIN (ALPINE) KARST LANDFORM REGION (VIII)
It consists of high mountain areas among Qilian, Altun, Kunlun, Gangdise, Nyainqentanglha and
Tianshan mountains, and features average high elevations more than 4500m. It is cold-arid climate. The
annual average temperature is less than 0℃ (less than -8℃ in plateau hinterland); the annual
precipitation is less than 100mm (less than 50mm in Qaidam Basin and Ali area).
It belongs to the continental tectonic domains of the North (Siberia-Mongolia), the Northern China, the
Southern China and the South (Gondwana). The carbonate rocks are liberally scattered in this region
and characterized by metamorphosed and interlayered carbonates from Proterozoic to Early Tertiary
period. It is generally more than 1400 m thick in Kunlun mountains area and reaches to 4000m thick,
even 7000 m thick in the eastern Kunlun mountains, and 4000 m thick near Baryanhar mountains, 3600
m in total thickness in the southern Tianshan mountains, and 2900 m thick in the western Qilian
mountain area.
There are two basic types of karst landforms, one is the karst high mountains composed of pure
carbonate rocks in the southern Tianshan (XIEGCAS, 1978), with an area of 3353 km2 and elevations
of 4000-4500 m and relative height of 1500-2500 m; the other is karst mountains composed of impure
and metamorphosed carbonated rocks literally scattered in the region except the area of Qaidam Basin
and near Tanglha mountains, with total area of 677626 km2 and average elevation of 4500m (Tianshan
area) to 4900 m (Qinghai-Xizang Plateau area), and relative height from 400-1000 m in low mountains
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to 1500-2000m in high mountains.
4. CONCLUSION
The geomorphologic regionalization of karst is made firstly in China, and it presents a comprehensive
and systematic karst landform development and distribution in China.
Because the karst research in the western China and the eastern China is very unbalanced, for example,
we have to use the 1:1,500,000 karst geological survey as the base map from the western China,
however, the sufficient data is provided in the eastern China, and we can make sub-regions of karst
landform (not discussed here) in the eastern China, but not in the western China.
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