geomorphological and sedimentological comparison of fluvial ... · lution of the unique sandstone...
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ORIGINAL ARTICLE
Geomorphological and sedimentological comparison of fluvialterraces and karst caves in Zhangjiajie, northwest Hunan, China:an archive of sandstone landform development
Guifang Yang • Xujiao Zhang • Mingzhong Tian •
Yamin Ping • Anze Chen • Zhiliang Ge •
Zhiyun Ni • Zhen Yang
Received: 3 January 2010 / Accepted: 27 November 2010 / Published online: 18 December 2010
� Springer-Verlag 2010
Abstract The Zhangjiajie Sandstone Peak Forest Geo-
park (Zhangjiajie World Geopark) of northwest Hunan,
China hosts a well-preserved sequence of fluvial terraces
and karst caves. In this contribution, a comparative study of
fluvial terraces with karst caves along the middle-lower
Suoxi River in Zhangjiajie World Geopark is presented to
improve the understanding of the development of striking
sandstone landscape in the upper Suoxi River. By inte-
grating geomorphological, sedimentological, and geochro-
nological techniques, the possible correlation between
fluvial terraces and karst caves, as well as their climatic
and tectonic implications is investigated. The available
electron spin resonance and thermo-luminescence numeri-
cal ages coupled with morphostratigraphic analysis indi-
cate that aggradation of fluvial terrace levels occurred at
ca. 347 ± 34 ka (T4), 104.45 ± 8.88 to 117.62 ± 9.99 ka
(T3), 60.95 ± 5.18 ka (T2), and Holocene (T1), followed
by the stream incision. Fluvial terrace levels (T4 to T1)
correlate morphologically with the karst cave levels (L1 to
L4), yet the proposed chronology for the fluvial terrace
levels is a bit later than the chronological data obtained
from karst caves. In northwest Hunan, where a unique
sandstone peak forest landscape was extensively developed,
the fluvial terrace sequences as well as the cave systems are the
important archives for studying the evolution of the sandstone
landscape. The beginning of the sandstone landscape devel-
opment must be earlier than the aggradation of the fluvial
terrace T4, allowing this unique landscape to occur in the
Middle Pleistocene.
Keywords Fluvial terrace � Karst cave � Sandstone
landscape � Geomorphic evolution � Zhangjiajie
Introduction
The geomorphic features of the quartz sandstone landscape
in Zhangjiajie Sandstone Peak Forest Geopark (or Zhang-
jiajie World Geopark), northwest Hunan, China, have been
roughly described through the comparative analysis with
adjacent regions aiming to determine their connection with
climatic control and surface uplift (Guo 1982; Chen 1988;
Hunan Geo-environmental Monitoring Center 1988; Deng
1989; Chen 1993; Wu and Zhang 2002; Tang et al. 2005).
Recent studies have been focused on the timing and geo-
morphic evolution of the sandstone landscape in the upper
reach of the Suoxi River in Zhangjiajie World Geopark
through the analysis of fluvial terraces and karst caves with
a wide distribution in the middle and lower reaches of the
Suoxi River (Fig. 1a). However, prior to this study, very
little was known about the chronology of these morpho-
genetic sequences, which could be very useful for the
reconstruction and interpretation of the geomorphic evo-
lution of the unique sandstone landscape in the study
area (Yang et al. 2009). Difficulties arise when dateable
landforms and deposits are poorly preserved or even
unavailable, as it is often the case in many geological
settings, such as the exposed sandstone areas. The stepped
morphostratigraphic sequences in the study area suggest
that integrated geomorphological, sedimentological, and
G. Yang (&) � X. Zhang � M. Tian � Y. Ping � Z. Ge � Z. Ni �Z. Yang
School of Earth Sciences and Resources,
China University of Geosciences, Beijing 100083, China
e-mail: [email protected]
A. Chen
Chinese Academy of Geological Sciences,
Beijing 100037, China
123
Environ Earth Sci (2011) 64:671–683
DOI 10.1007/s12665-010-0887-6
geochronological analyses may provide valuable informa-
tion on the evolution of the sandstone landscape in the
study area.
For a long time it was believed that fluvial terrace
staircases or multileveled karst caves could indicate former
river bed levels that would provide field evidence for long-
term evolution of river catchments (e.g., Bull 1990; Bourne
and Twidale 2000; Bridgland 2000; Maddy et al. 2000;
Piccini et al. 2003). In recent years, there is growing
awareness of the importance of stepped morphogenetic
sequences because of their potential climatic and tectonic
significance (Bridgland et al. 2004; Peulvast and Sales
2004; Gao et al. 2005, 2008; Westaway et al. 2006; Brid-
gland and Westaway 2008; Carcaillet et al. 2009; Claessens
et al. 2009; Robustelli et al. 2009; Strasser et al. 2009;
Westaway 2009, 2010). Chronologically, dating is a key
to link terraces with karst caves. By integrating
geomorphological, sedimentological, and geochronological
techniques, the possible correlation between terraces and
karst caves, as well as their climatic and tectonic impli-
cations can be investigated. These studies allow recon-
structing the evolution of depositional systems and offer
valuable insights into the basin geomorphic changes in
response to allocyclic factors (Maddy et al. 2001; Robus-
telli et al. 2005, 2009).
Given the specific geological and climatic settings of the
study area, the present study reports the results of geo-
morphological and sedimentological investigation analyz-
ing the relationships between fluvial terraces and karst
caves in the Suoxi River basin from Zhangjiajie Sandstone
Peak Forest Geopark to adjacent areas. The aim of this
work is to characterize the fluvial terraces and karst caves,
relating them to the formation and geomorphic evolution of
the unique sandstone landscape of Zhangjiajie. Numerical
Fig. 1 a The satellite image of
Zhangjiajie showing the spatial
distribution of sandstone
landscapes, karst caves and
fluvial terraces in the upper,
middle, and middle-lower
reaches of the Suoxi River;
b geomorphic sketch map of
Zhangjiajie Sandstone Peak
Forest Geopark indicating the
major landform areas in the
study region
672 Environ Earth Sci (2011) 64:671–683
123
age data provide information on the timing of sandstone
landform development in Zhangjiajie World Geopark.
Regional setting
Zhangjiajie Sandstone Peak Forest Geopark (29�1301800–29�2702700N, 110�1800000–110�4101500E) is located in the
northwestern sector of Hunan Province, China, covering a
total area of 398 km2 (Fig. 1). Elevation ranges from
*200 to 300 m a.s.l. in the valley bottom to ca. 1,300 m
a.s.l. in the mountain peaks (Fig. 2). The area is charac-
terized by a plateau-type monsoon climate, receiving an
annual average precipitation of 1,400 mm and with an
annual average temperature of 16�C (Hunan Geo-envi-
ronmental Monitoring Center 1988).
The geopark stands across the Jiangnan Oldland and
Yangtze Platform. The area can be considered as relatively
stable from the tectonic point of view and magmatic
activity is absent (Fig. 2). Physiographically, the study area
is characterized by a slightly undulating terrain with a
general slope of 5� to 8� towards the NE–NNE direction
(Hunan Geo-environmental Monitoring Center 1988).
In the study area, the drainage system is controlled by the
Suoxi River, a second-order tributary of the Lishui River,
which flows eastward through the region. Of the approxi-
mately 70 km long segment of the Suoxi Valley studied
here, the upper 20 km stretch lies in the core part of
Zhangjiajie Geopark whereas the remaining 50 km lies
downstream. It has dissected the quartz sandstone bedrock
forming various sandstone topographies at different heights
varying from 1,000 m a.s.l. to the present-day river bed.
Zhangjiajie Sandstone Peak Forest Geopark is just in the
transition zone between the northeastern Yun-Gui Plateau
and the middle-low mountain area of northwestern Hunan
Province. Stratigraphic deposits range from youngest
Holocene to Silurian and Devonian age that are represen-
tative of the region (Hunan Bureau of Geology and Mineral
Resources 1988; Fig. 2). Strata of the Middle Silurian
occur in the south, north, and west of the geopark and
constitute the bedrock foundation underlying the sand-
stone. The Silurian strata is disconformably overlain by the
approximately 520 m thick Middle Devonian Yuntaiguan
Formation (D2yn), which is dominated by gray-white, fresh
pink, thick or medium-thick fine-grained quartz sandstone
with a series of interbedded thin-layer siltstones and muddy
Fig. 2 Geological map and
cross-section of Zhangjiajie
World Geopark (modified from
Hunan Geo-environmental
Monitoring Center 1988)
Environ Earth Sci (2011) 64:671–683 673
123
siltstones. The overlying Huangjiadeng Formation (D3h) of
the Upper Devonian has a regional thickness of 5.3–40.6 m
and is a fine-grained ferruginous quartz sandstone, with
1–3 layers of oolitic hematite on the top, making the
resistant red hats on some sandstone peaks. The Huangj-
iadeng Formation sandstone is unconformably overlain by
thick Permian limestone, with Carboniferous strata being
normally absent. In the geopark, the sandstone peak forest
landforms are mostly developed in the Upper and Middle
Devonian units (D2?3), whereas limestone karst landforms
appear in the Permian strata in northeast Tianzi Mountain
above the peak forest landforms or in the Triassic strata
along the Suoxi River valley (Fig. 2). The Quaternary
deposits are very limited, usually represented by fluvial
deposits.
Materials and methods
Two field surveys were carried out in October 2008 and
May 2009 to examine the various stepped morphogenetic
sequences developed in the Zhangjiajie World Geopark
and its adjacent terrains (Fig. 1). Multidisciplinary geo-
morphological, sedimentological, and geochronological
approaches have been applied to better understand the
evolutionary history of the striking sandstone landscape.
The thickness and elevation of the terraces above the
present river bed have been measured by means of GPS,
large-scale topographic mapping and field surveys. The
height, length, and structural configuration of the caves
were systemically measured and analyzed in detail during
the investigation. The lithofacies were identified and
broadly grouped into gravel, sand, and clay, which was
further divided into sub-facies based on textural maturity,
stratigraphication, and color. A total of seven bulk samples
was collected from silt-sized deposits of fluvial terraces
and karst caves along the Suoxi River valley, as well as the
adjacent Maoxi River. The geochronology of terrace and
karst cave deposits was established by means of thermo-
luminescence (TL) and electron spin resonance (ESR)
analyses based on previous publications (Forman 1989;
Laurent et al. 1998; Chiavari et al. 2001; Wray et al. 2001;
Tissoux et al. 2008). Two quartz-rich samples were
selected from the highest terrace and karst cave level for
ESR dating, and five quartz-rich samples were collected
from lower terrace levels for TL dating, respectively
(Table 1). The samples were mostly composed of sand and
silt and they were collected from 10–15 cm from the
exposures in the fluvial terraces along the Suoxi and
adjacent Maoxi Rivers and highest level in Huanglong
Cave. Proximity to boulders was avoided of the removing
and a distance of 20 cm was considered sufficient to
minimize possible contamination of the sample material.
During sampling, iron tubes 10-cm in diameter were driven
into the fluvial profiles and sealed immediately after sam-
ple collection. In the dating lab, the laboratory technician
removed both ends of the samples to yield reliable
numerical ages. The TL dating was performed in the
Institute of Geology, China Earthquake Administration
(CEA), whilst the ESR dating was examined in the Institute
of Crustal Dynamics, CEA. The general principles and
experimental protocols of the ESR and TL dating methods
for deposits from fluvial terraces and highest level of Hu-
anglong Cave are based on previous studies (Lu et al. 1987,
1988; Bahain et al. 2007; Yin et al. 2007). According to
prior works, the systematic error of ESR and TL dating was
estimated to be within 10% (Bahain et al. 2007; Yin et al.
2007). In order to compare the chronology of different
terraces with cave levels, the weathering rinds and sedi-
mentary features of the gravels from the highest level of
Huanglong Cave were investigated using the method of
field gravel counts, including determining the weathering
rinds and colors, lithology, orientation, size and roundness
of the clasts in conglomerates (cf., Laming 1966). At least
116 pebbles and cobbles were measured, allowing for the
statistically valid results.
Description of fluvial terraces and karst caves
Fluvial terraces
In the study area, a stepped sequence of fluvial terraces
occurs along the Suoxi River in Zhangjiajie, northwest
Hunan Province, China. By integrating the interpretation of
large-scale topographic maps, chronologic analyses, and
field surveys, we distinguished four terrace levels in the
Suoxi River. These terrace levels are labeled according to
their relative topographic position from the highest (T4) to
the present-day floodplain (Figs. 3, 4).
In the upstream stretch, one terrace level has been
observed on both banks of the Suoxi River. This terrace
level is present from 275 to 280 m a.s.l. and *10–12 m
above the Suoxi River bed, becoming continuous in
downstream areas (Figs. 3a, 4). The fluvial terrace T1 is a
strath cut across the Triassic limestone. Its surface is
covered by some gravel deposits, which occur in patches
on the left/north bank of the Suoxi River and extend in the
downstream direction around Dengjiaping (P01, Fig. 3a).
In the lower reaches of the Suoxi River, the T1 terrace
lies at about 7 m above the present-day river bed (ca.
173 m a.s.l.). At places, this terrace level is predominant by
a simple dual-texture, with 2–3 m thick finer alluvial
deposits resting on the 1–2 m thick gravel layer (Fig. 3d).
The T2 terrace consists of a lower faces of gravel layer
3–5 m in thickness and an overlying faces of alluvial silts
674 Environ Earth Sci (2011) 64:671–683
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Table 1 Age of Huanglong
Cave and fluvial terraces from
the Suoxi, Maoxi, Yangtze,
Yellow, and Weihe rivers
Geomorphic feature Level Elevation/
m a.s.l.
Above river
level/m a.s.l.
Age
Huanglong Cave (by authors) L1 *345 80–90 463 ± 46 ka (ESR)
L2 *300 40–45 Qp2–Qp
3
L3 *280 20–25 Qp3
L4 *262 2–5 Qh
Terraces of middle Suoxi River
(by authors)
T4 238 *35–40
T3 230 *25–30 104.45 ± 8.88 ka (TL)
117.62 ± 9.99 ka (TL)
T2 220 *15–20
T1 207 *4–6
Terraces of lower Maoxi River
(by authors)
T4 256 78–83 347 ± 34 ka (ESR)
T3 235 57–62 151.05 ± 12.84 ka (TL)
201.24 ± 17.11 ka (TL)
T2 206 28–33 60.95 ± 5.18 ka (TL)
T1 188 10–15
Terraces of the middle Yangtze River
(Li et al. 2001)
T4 0.3–0.5 Ma
T3 0.11–0.15 Ma
T2 0.05–0.06 Ma
T1 0.01–0.03 Ma
Terraces of the Weihe River
(Gao et al. 2008)
T4 0.412 Ma
T3 0.128 Ma
T2 0.064 Ma
T1 0.011 Ma
Terraces of the Yellow River
(Li et al. 1997)
T4 0.6 Ma
T3 0.120 Ma
T2 0.055 Ma
T1 0.010 Ma
Fig. 3 Integrated cross-section depicting various terrace levels on both banks of the upper (a) to middle (b) and lower reaches (c) and (d) of the
Suoxi River
Environ Earth Sci (2011) 64:671–683 675
123
0.5–1 m in thickness. This terrace is represented by small
treads ranging from 178 to 183 m a.s.l. Remnants of terrace
T2 are continuous in downstream areas of the Suoxi River
with a tread at 180 m a.s.l. The T3 terrace level is repre-
sented at *22–25 m above the Suoxi River bed in some
reaches of the Suoxi River valley by a 1–1.5 m thick gravel
layer, overlain by 0.2–0.4 m of alluvial silts. The fluvial
succession comprise dominantly well-sorted, weakly
weathered, and moderate imbricated sandstone or siltstone,
which was stuffed by relatively loose and light brown
sands and silts (Fig. 5). Clast size ranges from 10 to 20 cm
(along a axis) but the maximum size measured up to
*50 cm. The matrix is light olive brown, coarse sand and
grit. In the middle reach of the Suoxi River valley, terraces
show similar characteristics in terms of relative height and
sedimentary features, whereas having a higher absolute
height (Fig. 3b, c). These three terrace levels can be traced
downstream and at P06, they occur at *9, 24 and 39 m
above the Suoxi River bed (Figs. 3c, 4). Additionally, some
small relics of fluvial deposits occur at higher elevation in the
peak summits along the middle Suoxi River valley (Figs. 3b,
4). When taking the relative height from the Suoxi River
bed and spatial distribution pattern into consideration,
these deposits might be equivalent to the terrace level T4,
extending laterally for several kilometers (Figs. 3b, 4).
Two samples from the T3 terrace level were collected
for TL dating (Fig. 3b), yielding 104.45 ± 8.88 and
117.62 ± 9.99 ka (Table 1), in agreement with regional
results of 0.1–0.2 Ma from the adjacent Maoxi River
(151.05 ± 12.84 ka and 201.24 ± 17.11 ka, Table 1) and
middle Yangtze River (Xie 1991; Li et al. 2001; Yang
2006).
Typical karst cave: Huanglong Cave
Huanglong Cave is located 10 km east of Jundiping village
and in the northern side of the Suoxi Valley, forming part
of the Zhangjiajie World Geopark (Chen 1987; Ge et al.
2009). The cave network ranges from 260 to 400 m a.s.l.,
with exit standing approximately 5 ± 2 m above the
present Suoxi River. Huanglong Cave is characterized by a
unique configuration and wide variety of stalactites, sta-
lagmites, columns, and flowstones (Cheng 1988; Yang
2007; Ge et al. 2009; Fig. 6). The cave can be divided into
four different east–west trending levels, with a total length
of 13 km and a vertical development of 140 m.
The upper level ranges from 345 to 400 m a.s.l.,
including Dragon King’s Palace and the Stone-flower
Chamber (Fig. 6). A 60-cm thick water-laid deposits
composed of clayey sand and gravels have been recognized
(Figs. 6, 7). The gravel diameter is dominantly 3–5 cm,
reaching up to 18 cm and showing relatively good sorting
and roundness though with poor fabrics and a weak degree
of weathering (Figs. 6, 7). The sedimentary succession
exhibits a characteristic and fairly simple admixture of
resistant sandstone/siltstone clasts floating in reddish-
brown mud matrix. For instance, among the 116 pebbles
and cobbles of water-laid deposits, 31% were milky quartz
siltstone, 29.3% grayish yellow quartz siltstone, 14% light
fresh red Quartz siltstone, 10% grayish white quartz silt-
stone, 9% purple quartz siltstone, and a small amount of
brick-red siltstone, light brown quartz siltstone, and sage
green quartz siltstone (Fig. 6). Infilling fine-grained sand,
silt, and even clay of matrix materials are strongly
cemented and very tough indeed. The ESR dating of the
highest gravel layer found in Huanglong Cave indicate that
the formation of the cave started more than 463 ± 46 ka
ago (Table 1).
Assemble Platform and Immortal Hall, with an
approximate elevation of 300 m a.s.l., constitute the second
level. Water-laid deposits including silt, sand, and pebbles
have been found at the junction of Dragon Ballroom and Ji
Platform. This level is the one that reached the highest
length. The third floor is represented by the Charming
Fig. 4 Longitudinal profile
with west–east direction of
fluvial terraces in the Suoxi
River Basin
676 Environ Earth Sci (2011) 64:671–683
123
Palace situated at 280 m a.s.l. and 20–25 m above the
present river channel (255–260 m). On the west of the cave
corridor, the water-laid deposits, mainly consisting of
sandy clay, sand, and gravels are 1.5–2.0 m thick (Fig. 6).
The detrital sediments from Yanba Grotto to Charming
Palace are dissected by a modern underground river,
becoming the lowest level of the karst cave. The present
underground river, with the same elevation as the T1 ter-
race level in the upper Suoxi River (Chen 1987), maintains
a hydraulic connection with the Suoxi River by supplying
and receiving water in the low-flow and flood seasons,
respectively.
Fig. 5 Simplified vertical
section of terrace level T3 in P05
along the Suoxi River
Fig. 6 Horizontal (a) and vertical (b) distribution of Huanglong Cave (shaded colors used to differentiate different levels; modified from Hunan
Geo-environmental Monitoring Center 1988)
Environ Earth Sci (2011) 64:671–683 677
123
Discussion
Terraces ages and correlation with karst caves
In the study area, the relatively hot and dry Neocene cli-
mate was not favorable for alluviation process and cave
development. During the Quaternary, however, with gla-
cial-interglacial cycles accompanied by tectonic uplift, the
conditions were adequate for developing stepped morpho-
genetic sequences (Cheng 1988; Hunan Geo-environmental
Monitoring Center 1988; Bourne and Twidale 2000; Ge
et al. 2009; Yang et al. 2009). As noted in many other
Fig. 7 Gravel layer and its characteristics in the highest level of
Huanglong Cave (a) and (b) general and close-up views of gravel
layer in the highest level in Huanglong Cave; c Roundness: 1–5
represent the extremely well-, well-rounded, rounded, subangular and
angular geometry of clasts; d weathering degree; 1–4 indicate the
fresh, weak, moderate and complete-weathering, respectively;
(e) Lithologic component: 1, light red quartz siltstone; 2, milky
quartz siltstone; 3, purple quartz siltstone; 4, light brown quartz
siltstone; 5, grayish white quartz siltstone; 6, grayish yellow quartz
siltstone; 7, sage green quartz siltstone; 8, brick-red quartz siltstone
Fig. 8 Major karst caves and
stepped morphogenetic
sequences developed during the
middle Mid-Pleistocene in
China
678 Environ Earth Sci (2011) 64:671–683
123
studies, episodes of karst cave and terrace aggradation can
be associated with periods of interglacial and glacial, while
river incision is more intensive during glacial/interglacial
transitions (Bridgland 2000; Piccini et al. 2003; Bridgland
and Westaway 2008).
The Huanglong Cave initially occurred more than
463 ± 46 ka ago, broadly contemporaneous with MIS 11,
during interglacial conditions dominated by the wettest
climate. The warm and humid climatic conditions during
the Middle Pleistocene would be favorable for cave
development (Lu 1986; Chen 1992). In regional terms, a
large number of caves developed during this time from
southern to northern China (Lu 1986; Chen 1992; Wang
et al. 2002; Ge et al. 2009; Zhang et al. 2009; Fig. 8). This
was followed by the aggradation of terrace level T4 in the
adjacent Maoxi River and middle Yangtze River (0.46 ±
0.046 Ma, 0.347 ± 0.034 Ma, and 0.3-0.5 Ma, respec-
tively; see Li et al. 2001; Xiang et al. 2005; Yang 2006;
Table 1). Four horizontal or slightly inclined cave passages
provide valuable evidence to reconstruct the former
groundwater table and its relation to the regional fluvial
base level, indicating ages of MIS 11, 7e, 5e and 3,
respectively.
In the present study, TL dating of five samples from the
Suoxi and the adjacent Maoxi River valleys offer an
opportunity to develop a chronologically constrained evo-
lutionary history for the Zhangjiajie area during the Late
Quaternary, with terrace levels T3 and T2 formed at ca.
0.1–0.2 Ma and 0.06 Ma, respectively (Table 1). The
positions of T3 and T2 levels above the Suoxi River suggest
that they were most likely developed during the Late
Pleistocene, during MIS 6 and 4, and controlled by the
middle Yangtze River (Yang and Chen 1988; Xie 1990,
1991; Tian et al. 1996; Li et al. 2001; Xiang et al. 2005;
Yang 2006).
The good correlation between terrace level T4 and the
upper cave level indicate that karst cave was formed in the
middle Middle Pleistocene or even earlier. A significant
base-level standstill is likely to have occurred during this
period, at which time a new karst feature emerged at an
elevation approximately 80–90 m above the contemporary
river level in Zhangjiajie, followed by the aggradation of
terrace level T4 during a cold period (Table 1).
Geomorphological and sedimentological comparison
of fluvial terraces and karst caves
The highest terrace level is not well preserved along the
Suoxi River, because the high relief and climatic condi-
tions (i.e., high temperature excursions and rainfall up to
1,400 mm/year) favor rapid erosion over a longer time
span. Mechanical erosion must have been very active
during the middle Middle Pleistocene, destroying most of
the fluvial terraces. Some remnants of this level have been
identified in the middle reach of this valley during the
investigation, the typical dual stratigraphy and pebble im-
brications, however, cannot be recognized (Fig. 3). Only in
some restricted low-relief areas there are small to medium-
scale remnants of this level (Figs. 3b, 4).
The altitude of the widespread and continuous T3 terrace
level in the adjacent Maoxi River and the most extensive
level 2 of Huanglong Cave (Ge et al. 2009) indicate the
paleoclimatic condition during they were formed. The
climate of MIS 7 during the level 2 of karst cave developed
must be extremely warm and moist in this area. This par-
ticular period of MIS 7e dominated by extremely warm and
humid climate would favour the extensive karstification
development. On the basis of regional correlations, the
well-developed terrace level T3 has been assigned to MIS
6. Given the abundance of surface cobbles and pebbles
observed, the relatively weak weathering rinds of the
gravels (with an average thickness of approximately
\0.6 cm) in terrace level T3 from the Suoxi River and the
adjoining Maoxi River are considered to represent deposits
of MIS 6, during which the dominant cool the dry climate
was likely resulted in the deposition of coarse sedimentary
units. When the finer matrix, mainly slit and clay, enter
simultaneously into the alleviation during interglacial
times, they will aggradate atop the coarser groups, pro-
ducing to the dual stratigraphy. In regional correlations, the
numerical ages, the relative height and sedimentological
features of terrace level T3 indicate that it was formed
during the Late Pleistocene in both Maoxi and Suoxi
Rivers. Similarly, the relative height and geomorphic
configuration of terrace levels T2 and T1 suggest that they
are correlative to the two lower levels of Huanglong Cave,
Late Pleistocene to Holocene in age.
The gravel layer identified in the Huanglong Cave
dominated by siltstone can provide some clues on the
origin of the cave. The completely different lithology
between the gravel layer and the host rock indicates an
allochthonous source for the gravel (Cheng 1988; Huang
et al. 2006). We deemed that the fairly uniform lithology of
water-laid gravels with a good sorting and roundness
should be conveyed by the river flow from the local
Devonian sandstone outcrops, where large amounts of
detritus would have been supplied by mass wasting and
stream erosion (Yang et al. 2009; Fig. 7). This conclusion
is also confirmed by other lithological data (Hunan Bureau
of Geology and Mineral Resources 1988; Huang et al.
2006; Tables 2, 3). The poor fabrics and the lack of a dual
stratigraphy associated with gravel layer give evidence of
the larger water flow and prompt deposition process. It is
probable that rainfall was abundant, perhaps confined to a
short reason, but coming as occasional violent cloudbursts;
these would have been sufficient to cause torrential flow in
Environ Earth Sci (2011) 64:671–683 679
123
valleys. Material of all sizes would be moved and carried
relatively long distances. When transported into the cave,
the pebbles and cobbles were deposited quickly in a rela-
tively closed environment. Due to the lack of exposure to
the surface, weathering process on gravels was limited
(Fig. 7). In this case, the medium to weak weathering rinds
of most gravels (mostly \0.8 cm) indicative of Late
Pleistocene or even in late Middle Pleistocene times may
post-date the deposition (Fig. 7d). The saturated infilled
finer sediments with widespread rubefaction are evidence
of onetime presence of a warm and humid climate during
which they were formed, in consistence with the paleo-
climatic picture of the study area over the middle Middle
Pleistocene (Hunan Bureau of Geology and Mineral
Resources 1988; Liu 2002). From this it may be deduced
that the Huanglong Cave preferably occurred in thus a
subtropical climatic regime in Zhangjiajie during the
middle Middle Pleistocene.
Implication for sandstone landform development
The sandstone landforms concentrate mainly on the
boundary of Tianzi Mountain and areas between Wangjia
village and Heicao Valley in the upper reach of the Suoxi
River (Fig. 1b). Their summits show four distinctive ero-
sional levels varying primarily from 800 to 1,000, 700 to
750, 500 to 550 and 300 to 400 m. a.s.l., respectively
(Fig. 9a). When comparing the typical sandstone land-
scapes with those of fluvial terraces and karst caves, four
distinctive geomorphic levels are evident and correspond to
each other very well since they are commonly controlled
by the Suoxi River (Fig. 9). The top level of Huanglong
Cave corresponds to the highest level (L1) of sandstone
landform and the highest terrace level of the Suoxi River,
while the lowest river water levels of cave and fluvial
systems should represent the current standstill level. The
good correlations in geomorphic pattern among these
stepped morphogenetic sequences suggest that the warm
and moist climate during middle Middle Pleistocene
(*46.3 ka) favored karstification processes, followed by
the aggradation of terrace level T4 during a cold period
(Table 1).
Therefore we assume the beginning of incision is a bit
earlier than the aggradation of terrace level T4
([0.35 Ma) on the scale of the Suoxi River. During an
early stage, the Suoxi River might have begun to develop
its drainage network, with the fluvial dissection of river
into the sandstone bedrock within the Zhangjiajie Sand-
stone Peak Forest Geopark. The regional tectonic move-
ment and associated stress release lead to highly
developed fracture and joint systems in the study area,
which generates the mass wasting and greatly accelerate
the stream incision process (Chen 1987, 1988; Yang et al.
2009). For these reasons, the timing of sandstone land-
form formation, however, should be constrained to Mid-
dle Pleistocene when the long-term tectonic stable period
was finished.
The chronologic data from the karst cave and terrace
sequences in the Suoxi and its adjacent Maoxi rivers also
helps to understand the evolution of sandstone landform.
Table 2 Host rock component of Huanglong Cave (unit: %; revised from Cheng 1988)
Host rock Calcite Clay Ferric ingredient Dolomite Micro-fissure
Fine-grained silty limestone 98 2–3 1 Minority
Dolomitic limestone 86 0.5–1.0 11 1.0–2.0
Table 3 Lithologic components of different Zhangjiajie sandstone landscapes (unit: %; modified from Huang et al. 2006)
Locality Lithology Stratum SiO2 CaO Al2O3 TiO2 Fe2O3 Others
Baofeng Lake White quartz sandstone D2yn 97.20 0.00018 1.84 0.15 0.00076 0.0015
White quartz sandstone D2yn 94.20 0.00039 1.66 0.00063 0.0004 0.0007
Jinbian stream White Quartz sandstone D2yn 95.90 0.71 2.18 0.13 0.14 0.13053
White quartz sandstone D2yn 94.00 0.51 2.94 0.23 1.25 0.00058
Baizhang Valley Red quartz sandstone D2yn 83.60 0.00066 10.60 0.36 2.67 0.00127
Red silty mudstone D2yn 67.20 0.00011 22.00 0.92 2.17 0.00055
Xianyao bay Red quartz sandstone D2yn 79.40 0.12 4.77 0.39 13.20 0.000132
White siltstone D2yn 66.80 0.00021 24.70 1.30 0.27 0.00092
Koho Red quartz sandstone D3h 92.20 0.00097 5.26 0.21 0.46 0.33
Peak forest Red quartz sandstone D3h 93.50 0.00062 0.88 0.21 3.96 0.24019
D2yn Yuntaiguan Formation of Middle Devonian, D3h Huangjiadeng Formation of Upper Devonian
680 Environ Earth Sci (2011) 64:671–683
123
The geochronology of the stepped morphogenetic sequen-
ces of the Suoxi River that formed during the middle period
of the Middle Pleistocene has been constrained dating
terraces and karst cave systems. The integration of a geo-
morphological analysis and the available data may allow us
to propose some inferences on the age of the sandstone
landscape. Consequently, the earliest possible time of
stream incision of Suoxi should be earlier than the age of
the oldest terrace level T4 (approximately [347 ± 34 ka;
Fig. 9). They are also supported by the additional evidence
from sedimentary features and geomorphic pattern in the
study region. The strongly cemented gravel layer and
red infilled deposit features in highest level of Huanglong
Cave should be dated as middle Middle Pleistocene
when warm and humid climate was predominant. Based on
these comparable evidences from geomorphological,
sedimentological and geochronological features, we thus
propose that the Suoxi River began to incise the sandstone
landform in the Middle Pleistocene, accompanied by the
later mass wasting owing to the well-developed fracture
and joint systems in the region.
Conclusions
In this paper, we present the results of an integrated geo-
morphological, sedimentological and geochronological
study carried out along the Suoxi River of northwest Hunan
Province, China. This area is characterized by the occur-
rence of four distinct erosional levels in the sandstone
landscape, karst caves and fluvial terraces in the upper,
middle, and middle-lower reaches of the Suoxi River. This
Fig. 9 Geomorphic correlation
of the sandstone peak forest
landscapes (a), karst caves
(b) and fluvial terraces (c) in the
upper, middle, and middle-
lower Suoxi catchment from
Zhangjiajie
Environ Earth Sci (2011) 64:671–683 681
123
present study indicates that fluvial terraces and karst caves
from the Suoxi River basin with comparable ages help to
understand the evolution of the sandstone landscape.
Sandstone landscape development occurred probably in the
middle Middle Pleistocene due primarily to the surface
uplift and stream incision. These also can be generally
correlated with each other both temporally and spatially
based on weathering rinds and sedimentary features
through the Suoxi River valley and adjacent Maoxi River
valley. Pebble and cobble roundness in the highest cave
level reflects relatively long transport distance or repeated
transport processes and thus is mostly rounded but uniform
in lithology, showing an origin from Devonian rock
exposures. Due to the lack of exposure to the surface, the
medium to weak weathering rinds of most gravels and the
matrix of fine-grained particles with widespread rubefac-
tion in the highest cave level provide evidence of a warm
and humid climate picture in the study area. A significant
base-level standstill is likely to have occurred during this
period, followed by aggradation of terrace level T4 during a
cold period. From this it may be deduced that the timing of
sandstone formation must be earlier than the aggradation of
highest terrace level T4 in Zhangjiajie during the Middle
Pleistocene.
Acknowledgments This work is within the scope of the specific
funding ‘‘Formation age of sandstone peak forest landform and crustal
stability of Zhangjiajie World Geopark’’ from Zhangjiajie Geopark
Management Department. We are extremely thankful to the anony-
mous reviewer(s) for fruitful comments and suggestions. We
acknowledge with gratitude the advice of Professors Zhijiu Cui,
Naigong Deng and Keyi Guo in our research group. Special thanks
should be given to the cooperation of the staff at Zhangjiajie Geopark
Management Department, and the Bureau of Land Resource Man-
agement office in Zhangjiajie, who made much of this work possible.
Professor Chuanlun Zhang provides some helpful reviews and edi-
torial suggestions.
References
Bahain J-J, Falgueres C, Laurent M, Voinchet P, Dolo J-M, Antoine
P, Tuffreau A (2007) ESR chronology of the Somme River
terrace system and first human settlements in northern France.
Quat Geochronol 2:356–362
Bourne JA, Twidale CR (2000) Stepped landscapes and their
significance for general theories of landscape development.
South Afr J Geol 103:105–119
Bridgland DR (2000) River terrace systems in north-west Europe: an
archive of environmental change, uplift and early human
occupation. Quat Sci Rev 19:1293–1303
Bridgland D, Westaway R (2008) Climatically controlled river terrace
staircases: a worldwide Quaternary phenomenon. Geomorphol-
ogy 98:285–315
Bridgland D, Maddy D, Bates M (2004) River terrace sequences:
templates for Quaternary geochronology and marine-terrestrial
correlation. J Quat Sci 19:203–218
Bull WB (1990) Stream-terrace genesis: implications for soil
development. Geomorphology 3:351–367
Carcaillet J, Mugnier JL, Koci R, Jouanne F (2009) Uplift and active
tectonics of southern Albania inferred from incision of alluvial
terraces. Quat Res 71:465–476
Chen CM (1987) The geology-factor of the development of the karst
geotto on the borderland of northwest Hunan. Nat Sci J Hunan
Norm Univ 10(1):97–104 (in Chinese)
Chen CM (1988) On the new tectogenesis of northwestern Hunan.
Hunan Geol 7(2):64–72 (in Chinese)
Chen CM (1992) Karst cave in diwas (geodepressions), China. Geol
Rev 38(3):215–223 (in Chinese)
Chen GD (1993) Geotectonic conditions of formation of the
Wulingyuan peak-forest landform, China. Geotectonic Metall
17(2):103–112 (in Chinese)
Cheng WM (1988) Researches on the development and cavern
landscape of Huanglongdong in Wulingyuan. Nat Sci J Hunan
Norm Univ 11(4):355–360 (in Chinese)
Chiavari C, Martini M, Sibilia E, Vandini M (2001) Thermolumi-
nescence (TL) characterisation and dating feasibility of ancient
glass mosaic. Quat Sci Rev 20:967–972
Claessens L, Veldkamp A, ten Broeke EM, Vloemans H (2009) A
Quaternary uplift record for the Auckland region, North Island,
New Zealand, based on marine and fluvial terraces. Global
Planet Change 68:383–394
Deng MC (1989) On characteristics origin and evolution of Suoxi
topography. Nat Sci J Hunan Norm Univ 12(8):262–268 (in
Chinese)
Forman SL (1989) Applications and limitations of thermolumines-
cence to date Quaternary sediments. Quat Int 1:47–59
Gao HS, Pan BT, Li JJ, Wu GJ, Li BY, Ye YG (2005) Age and
genesis of the stepped geomorphic surfaces in Jinta River Basin
of the Eastern Qilian Mountains. J Mt Sci 23(3):129–135 (in
Chinese)
Gao HS, Liu XF, Pan BT, Wang Y, Yu YT, Li JJ (2008) Stream
response to Quaternary tectonic and climatic change: evidence
from the upper Weihe River, central China. Quat Int 186:123–
131
Ge ZL, Yang GF, Zhang XJ, Tian MZ, Yang Z, Ping YM, Ni ZY
(2009) Development characteristics and controlling factors of
karst caves in Wulinguan. In: Proceedings of the third interna-
tional symposium on development within Geoparks, pp 316–322
(in Chinese)
Guo KY (1982) Sandstone peak forest landform in NW Hunan. Nat
Mag 5(5):375–376 (in Chinese)
Huang LY, Zhu C, Kong QY (2006) The contribution of lithological
component to sandstone forest landform genesis in Zhangjiajie,
Hunan Province. J Anhui Norm Univ 29(5):484–489 (in
Chinese)
Hunan Bureau of Geology and Mineral Resources (1988) Hunan
regional geology. Geological Publishing House, Beijing,
pp 1–718 (in Chinese)
Hunan Geo-environmental Monitoring Center (1988) Scientific
investigation report of Wulingyuan Sandstone Peak Forest
Geopark, pp 1–206 (in Chinese)
Laming DJC (1966) Imbrication, paleocurrents and other sedimenr-
tary features in the lower New Red Sandstone, Devonshire,
England. J Sediment Res 36:940–959
Laurent M, Falgueres C, Bahain JJ, Rousseau L, Van Vliet Lanoe B
(1998) ESR dating of quartz extracted from Quaternary and
Neogene sediments: method, potential and actual limits. Quat
Sci Rev 17(11):1057–1062
Li JJ, Xie SY, Kuang MS (2001) Geomorphic evolution of the
Yangtze Gorges and the time of their formation. Geomorphology
41(2–3):125–135
Li JJ, Fang XM, der Voo RV, Zhu JJ, Niocaill CM, Ono Y, Pan BT,
Zhong W, Wang JL, Sasaki T, Zhang YT, Cao JX, Kang SC,
Wang JM (1997) Magnetostratigraphic dating of river terraces:
682 Environ Earth Sci (2011) 64:671–683
123
rapid and intermittent incision by the Yellow River of the
northeastern margin of the Tibetan Plateau during the Quater-
nary. J Geophys Res 102:10121–10132
Liu TS (2002) Quaternary environment. Science Press, Beijing,
pp 1–304 (in Chinese)
Lu YR (1986) Carsologica Sinica. Geological Publishing House,
Beijing, pp 63–260 (in Chinese)
Lu YC, Prescott JR, Robertson GB, Hutton JT (1987) Thermolumi-
nescence dating of the Malan loess at Zhaitang, China. Geology
15:603–605
Lu YC, Prescott JR, Hutton JT (1988) Sunlight bleaching of the
thermoluminescence of Chinese loess. Quat Sci Rev 7:335–338
Maddy D, Bridgland DR, Green CP (2000) Crustal uplift in southern
England: evidence from the river terrace records. Geomorphol-
ogy 33:167–181
Maddy D, Bridgland D, Westaway R (2001) Uplift-driven valley
incision and climate-controlled river terrace development in the
Thames Valley, UK. Quat Int 79:23–36
Peulvast J-P, Sales VC (2004) Stepped surfaces and palaeolandforms
in the northern Brazilian «Nordeste»: constraints on models of
morphotectonic evolution. Geomorphology 62:89–122
Piccini L, Drysdale R, Heijnis H (2003) Karst morphology and cave
sediments as indicators of the uplift history in the Alpi Apuane
(Tuscany, Italy). Quat Int 101–102:219–227
Robustelli G, Muto F, Scarciglia F, Spina V, Critelli S (2005) Eustatic
and tectonic control on Late Quaternary alluvial fans along the
Tyrrhenian Sea coast of Calabria (south Italy). Quat Sci Rev
24(18–19):2101–2119
Robustelli G, Luca F, Corbi F, Pelle T, Dramis F, Fubelli G,
Scarciglia F, Muto F, Cugliari D (2009) Alluvial terraces on the
Lonian coast of northern Calabria, southern Italy: implications
for tectonic and sea level controls. Geomorphology 106:165–179
Strasser M, Strasser A, Pelz K, Seyfried H (2009) A mid Miocene to
early Pleistocene multi-level cave as a gauge for tectonic uplift
of the Swabian Alb (Southwest Germany). Geomorphology
106:130–141
Tang YS, Chen WG, Zhu C (2005) A study on Zhangjiajie quartz
sandstone landform genesis. J Mt Sci 23(3):308–312 (in
Chinese)
Tian LJ, Li PZ, Luo Y (1996) Evolution history of three Gorge valley
of Yangtze River. Southwest Jiaotong University Press, Chen-
gdu, pp 1–73 (in Chinese)
Tissoux H, Toyoda S, Falgueres C, Voinchet P, Takada M, Bahain J-
J, Despriee J (2008) ESR dating of sedimentary quartz from two
Pleistocene deposits using Al and Ti-centers. Geochronometria
30:23–31
Wang F, Li HC, Zhu RX, Hu YT (2002) Downcutting and uplifting in
the middle part of Qinling Orogenic belt during the Late
Quaternary. Chin Sci Bull 47:1556–1560
Westaway R (2009) Quaternary uplift of northern England. Global
Planet Change 68:357–382
Westaway R (2010) Cenozoic uplift of southwest England. J Quat Sci
25:419–432
Westaway R, Bridgland D, White M (2006) The Quaternary uplift
history of central southern England: evidence from the terraces
of the Solent River system and nearby raised beaches. Quat Sci
Rev 25:2212–2250
Wray RAL, Price DM, Young RW (2001) Thermoluminescence
dating of alluvial sequences in coastal valleys of southern New
South Wales: problems and potential. Aust Geogr 32(2):201–220
Wu C, Zhang C (2002) The form and evolvement of the physiognomy
of the beauty spot in Zhangjiajie. Geogr Territ Res 18(2):52–55
(in Chinese)
Xiang F, Zhi LD, Wang CS, Li YZ, Yang WG (2005) Terrace age
correlation and its significance in research of Yangtze Three
Gorges, China. J Chengdu Univ Technol (Sci Technol Ed)
32:162–166 (in Chinese)
Xie M (1990) Neotectonic uplift velocity and type along the
Changjiang River during Quaternary. Quat Sci (4):308–315 (in
Chinese)
Xie M (1991) Water level change amplitude-a key factor influence
terrace differentiation and neotectonic analysis. Acta Geogr
Sinica 46(3):353–359 (in Chinese)
Yang DY (2006) Yangtze geomorphological processes. Science Press,
Beijing, pp 1–219 (in Chinese)
Yang XT (2007) Characteristics of karst tourism geology resources of
Hunan Province and its exploitation and protection research.
J Cent South Univ For Technol (Social Sci) 1(2):92–96 (In
Chinese)
Yang DY, Chen BC (1988) The study of terraces within the Yangtze
Gorges. J Nanjing Univ (Geography) 9:32–43 (in Chinese)
Yang GF, Chen AZ, Tian MZ, Zhang XJ (2009) Sandstone peak
landform of Zhangjiajie National Geopark: characteristics and
formation. In: Proceedings of the third international symposium
on development within Geoparks, pp 306–315 (in Chinese)
Yin GM, Lin M, Lu YC, Li JP, Han F (2007) Preliminary ESR dating
results on loess samples from the loess-paleosol sequence at
Luochuan, Central Loess Plateau, China. Quat Geochronol
2:381–385
Zhang XJ, Li ZM, Chen J, Zhang JZ (2009) Correlation of neotectonic
movement and landscape geomorphology in Yuntai Mountain
Area. Internal report in Chinese, unpublished, pp 1–107
Environ Earth Sci (2011) 64:671–683 683
123