Geology Reference
In-Depth Information
Fig. 8 Region VI karst landform
(alpine karst in Western Sichuan
by Zhang Yuanhai)
gentle
fengcong
canyons, with
an
elevation
of
from late Sinian to early Permian periods with the exception
of the Cambrian, late Silurian and early Carboniferous
periods); for example, there is a 1,000 m thick Lower
Ordovician limestone with shale, sandstone and their meta-
morphosed equivalents and 240 m thick Lower Permian
limestone with clastic rocks near Mt Everest.
Because of the climatic conditions in this region, the karst
landforms are undeveloped. Erosional phenomena and neg-
ative karst landforms are very few, and erosion and weath-
ering in particular are in
4,600
5,500 m and a relative height of 2,400
3,500 m
-
-
(Wang 1990 ) (Fig. 8 ). This region contains
ve national
karst geoparks.
3.7
Humid Subtropical-Semiarid Plateau
Temperate Karts Landform Region (VII)
Region VII is situated to the south of Nyainqentanglha-
Kailash and to the north of the Himalayas. It is characterised
by high mountains with low-middle mountains (of eleva-
tions from 5,000
uenced by severe frosts on the
surface, and the karst formations have no difference from
non-karst landscapes. There are no karst geoparks in this
region.
6,000 m, the highest being Mt Everest with
an altitude of 8,848 m), hills and small plains in valleys, as
well as canyons of 1,000
-
4,000 m in depth. This region is
located in a semiarid plateau temperate climatic zone, with a
large difference in precipitation from west (100 mm) to the
east (500 mm); its annual average temperature is 0
-
3.8
Plateau-High Mountain (Alpine) Karst
Landform Region (VIII)
-
8
°
C,
decreasing from the east to the west, and it is less than 0
°
C
This region consists of high mountain areas among Qilian,
Altun, Kunlun, Gangdise, Nyainqentanglha and Tianshan
mountains, and is characterised by an average high eleva-
tions of >3,000 m. It is located in a cold-arid climate. The
annual average temperature <0
above 5,000 m ASL. The snow line increases
from
4,500
5,000 m ASL in the east to 6,000 m ASL in the west.
This region is located in the tectonic unit of Himalayan
blocks, Brahmaputra folds, Nagqu folds and Gangdise
blocks. It is underlain by carbonate rocks some 3,580 m
thick in the central region, being characterised by limestone
interlayered with shale, sandstone and volcanics deposited in
the Middle and Lower Triassic, Middle and Lower Jurassic,
Upper Cretaceous and Palaeogene periods. There are also
carbonate rock deposited before the late Permian period, i.e.,
-
C in the plateau
hinterland); the annual precipitation is <100 mm (<50 mm in
Qaidam Basin and Ali area). This region belongs to the
continental tectonic domains of the North (Siberia-Mongo-
lia), the Northern China, the Southern China and the South
Gondwana. Carbonate rocks are commonly scattered in this
region except for the area of Qaidam Basin, Tanglha-Kailash
°
C(<
8
°
Search WWH ::




Custom Search