The Dabie-Sulu orogeny also termed Qinling-Dabie-Sulu or Dabie Shan-Sulu was a
mountain building
Mountain formation refers to the geological processes that underlie the formation of mountains. These processes are associated with large-scale movements of the Earth's crust (tectonic plates). Folding, faulting, volcanic activity, igneous intr ...
event in the
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...
from 240 to 220 million years ago caused by the collision of the North China and South China
cratons
A craton (, , or ; from grc-gre, κράτος "strength") is an old and stable part of the continental lithosphere, which consists of Earth's two topmost layers, the crust and the uppermost mantle. Having often survived cycles of merging and ...
. It extends 2000 kilometers (1250 miles) from the Tanlu fault zone between
Shanghai
Shanghai (; , , Standard Mandarin pronunciation: ) is one of the four direct-administered municipalities of the People's Republic of China (PRC). The city is located on the southern estuary of the Yangtze River, with the Huangpu River flow ...
and
Wuhan
Wuhan (, ; ; ) is the capital of Hubei, Hubei Province in the China, People's Republic of China. It is the largest city in Hubei and the most populous city in Central China, with a population of over eleven million, the List of cities in China ...
in modern-day China to the Qaidam basin north of the Tibetan Plateau.
Description
Typically 50 to 100 kilometers wide the orogeny contains the small South Qinling terrane. In fact, the Dabie-Sulu orogen is part of the larger Central China orogeny, extending through the Kunlun Range, Qinling Range, Tongbai-Dabie Range. Although it is offset by the
Tan-Lu fault The Tancheng-Lujiang Fault (referred to as the Tan-Lu Fault) is a large fault in the east China. It was named after it was initially discovered that it starts from Tancheng, Shandong Province in the north and reaches the Lujiang County in Anhui Pro ...
zone, it stretches through the Sulu region of the
Shandong Peninsula
The Shandong (Shantung) Peninsula or Jiaodong (Chiaotung) Peninsula is a peninsula in Shandong Province in eastern China, between the Bohai Sea to the north and the Yellow Sea to the south. The latter name refers to the east and Jiaozhou.
G ...
and reaches South Korea.
The orogeny is the largest area ultrahigh pressure metamorphic belt in the world. Low-temperature, but high-pressure conditions led rocks to reach
eclogite
Eclogite () is a metamorphic rock containing garnet (almandine-pyrope) hosted in a matrix of sodium-rich pyroxene (omphacite). Accessory minerals include kyanite, rutile, quartz, lawsonite, coesite, amphibole, phengite, paragonite, zoisite, dol ...
-grade on the sequence of
metamorphic facies
A metamorphic facies is a set of mineral assemblages in metamorphic rocks formed under similar pressures and temperatures.Essentials of Geology, 3rd Edition, Stephen Marshak The assemblage is typical of what is formed in conditions corresponding ...
. The added presence of diamonds and
felsic
In geology, felsic is a modifier describing igneous rocks that are relatively rich in elements that form feldspar and quartz.Marshak, Stephen, 2009, ''Essentials of Geology,'' W. W. Norton & Company, 3rd ed. It is contrasted with mafic rocks, whi ...
gneiss
Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures an ...
indicates deep burial up to 100 kilometers below the surface.
The China Continental Scientific Drilling Project was approved in China's ninth Five-Year Plan in 1997, with the CCSD-1 well inaugurated on 25 June 2001 drilling into the Dabie-Sulu orogen at Lianyungang City, Jiangsu Province. The goal of the project throughout the 2000s was to collect data about
rheology
Rheology (; ) is the study of the flow of matter, primarily in a fluid ( liquid or gas) state, but also as "soft solids" or solids under conditions in which they respond with plastic flow rather than deforming elastically in response to an appl ...
and mantle mineralogy, as well as study processes similar to those in the center of the Himalayas, but at lower cost.
See also
*
List of orogenies
The following is a list of known orogenies organised by continent, starting with the oldest at the top. The organization of this article is along present-day continents that do not necessarily reflect the geography contemporary to the orogenies. ...
*
Geology of China
The geology of China (or the geological structure of the People's Republic of China) consists of three Precambrian cratons surrounded by a number of orogenic belts. The modern tectonic environment is dominated by the continued collision of India ...
References
Orogenies of Asia
Triassic orogenies
{{Orogeny-stub