South China Craton

[2] Recent study suggests that the South China Block possibly has one more sub-block which is named the Tolo Terrane.

Third, almost all major known clades of Triassic marine reptiles have been recovered from the South China sedimentary sequences.

On the one hand, the central and eastern part of the South China Block experienced three important Phanerozoic tectonic events.

On the other hand, the Late Paleozoic Emeishan flood basalt magmatism is an important event in the western part of the block.

[2] The igneous rocks are unconformably overlain by weakly metamorphosed Neoproterozoic sequences (e.g., Banxi Group) and unmetamorphosed Sinian units.

However, a late Permian Emeishan large igneous province is reported in the western margin of the Yangtze Block.

This is supported by the preserved ancient crustal remnant (i.e. 3.8 Ga detrital zircon derived from the South China Block).

[9] The U-Pb crystallization age distribution of 7000 detrital zircons is characterized by several peaks over the history of Earth spans.

Despite so, only divergent double subduction system can provide plausible explanation on two key observations in the Jiangnan Orogen.

[21] After the amalgamation, it is widely recognized that continental rifting and widespread 800—760 Ma bimodal magmatism occurred in the South China Block.

[29][32][33] They suggest the head of the mantle plume, which was sited beneath the South China Block, led to rifting and bimodal magmatism since 825 Ma.

On the one hand, the South China Block is proposed to be located between eastern Australia and western Laurentia in the interior of Rodinia (i.e. "Missing-link" hypothesis).

However, there is clear evidence that the final time of the amalgamation of the South China Block is much later than 900 Ma.

The Wuyi-Yunkai Movement (Ordovician-Silurian) represents the first Phanerozoic tectonic event in the South China Block.

The far-field stress associated with distant continental collisions led to crustal thickening and metamorphism (460–445 Ma) in the interior of the South China Block.

[46] The driving force of such internal deformation was attributed to the South China Block-India Craton collision in the Cambrian.

[50] The Emeishan flood basalt magmatism represents the most significant geological feature in Southwest China.

[52][53] The Indosinian (Triassic) and Yanshanian (Jurassic-Cretaceous) Movement represents the Mesozoic deformation and magmatism event.

[18] As the flat slab penetrated beneath the continental crust, the fold and thrust belt migrated inland, resulting in the younging trend towards the continent.

At the same time, it exerted a downward pull on the overlying continental crust to create a broad basin with a lake.

Occurrence of a Permian magmatic arc There are some doubts on the starting time of Pacific plate westward subduction.

Occurrence of Jurassic adakitic rock A conventional way to generate magma is by melting in the mantle wedge which is aided by the fluid release from the subducted slab.

[1] Present-day Southeast Asia is a huge jigsaw puzzle of different continental blocks which are bounded by sutures or orogenic belts.

[59][60] The current configuration of continental blocks is the result of an array of rifting and collision events over more than 400 million years.

[59][60] Simply put, the geological evolution of Southeast Asia is characterized by the Gondwana dispersion and Asian accretion.

[59] As they drifted northward, successive oceanic basins opened between Gondwana and the blocks including the Paleo-Tethys, Meso-Tethys and Ceno-Tethys.

[59] Destruction and closure of those basins resulted in accretion of once isolated Southeast Asia continental blocks.

[59] However, some scientists believed that the collision took place in the Triassic based on the Triassic-aged deformation in the Song Ma suture zone.

[63][64] If the South China Block-Indochina Block collision occurred in the Triassic, it should have led to the development of an orogen (i.e. topographic high) and associated clastic sediment deposition by weathering.

In South China, 75% of these deposits were derived from granitic and volcanic rocks during the Jurassic to the early Cretaceous.

Three Precambrian cratonic bodies in China (i.e. North China Craton, Tarim Block and South China Block). The South China Block occupies the bulk of South China. It is divided into the Yangtze block in the northwest and the Cathaysia Block in the southeast. Modified from Zheng, Xiao & Zhao (2013). [ 1 ]
Distribution of igneous rock in the Cathaysia Block. Modified from Wang et al., (2013).
The supercontinent cycle is divided into three stages. The continental blocks first converge by subduction. Then, They collide to form the supercontinent . Finally, they drift apart from each other, leading to the supercontinent breakup. The interplay between magma generation and preservation potential of the detrital zircon determine the age distribution of the detrital zircon in three stages. Although the volume of magma generated is low during collision, the high preservation potential results in a peak of the number of detrital zircon. Therefore, the age peak is coincident with the assembly of the supercontinent . Blue: Magma volume. Red: Preservation potential. Brown area: Age distribution of the detrital zircon. Modified from Hawkesworth et al. (2009). [ 10 ] [ 11 ]
The divergent double subduction system is characterized by two synchronous arcs and low grade metamorphism. Grey: sediment.
Missing link hypothesis. (Li, 2003)
The South China Block is proposed to be located between eastern Australia and western Laurentia in the interior of Rodinia .
The South China Block may be located in the periphery of the Rodinia .
Generation of the Silurian (440–415 Ma) granitic intrusion.
East-trending thrust- fold structure and northeast-trending strike slip fault in Hefu shear zone. Modified from Li et al., (2016) [ 58 ]
Ichthyosaur fossil at the Natural History Museum, London