TY - JOUR

T1 - A refined late-Cryogenian – Ediacaran Earth history of South China:

T2 - phosphorous-rich marbles of the Dabie and Sulu orogens

AU - Prave, A. R.

AU - Meng, F.

AU - Lepland, A.

AU - Kirsmäe, K.

AU - Kreitsmann, T.

AU - Jiang, C. Z.

N1 - This research was supported by the National Natural Science Foundation of China Grant Numbers 41473039 and 4151101015, and by the Estonian Science Agency project PUT0696.

PY - 2018/2

Y1 - 2018/2

N2 - The late-Cryogenian – Ediacaran geological framework for South China is constructed principally from sedimentary successions preserved in the central and western regions of the Yangtze Block. New stratigraphic and carbonate-carbon isotope data allow us to extend that framework into the exhumed HP-UHP subduction complexes of the eastern Dabie and Sulu orogens that separate the South and North China cratons. Those data show that marble and phosphorous-rich (P-rich) units in those complexes were originally part of an Ediacaran shallow-marine shelf-carbonate platform. The basal pebbly schist (metadiamictite) and lowermost P-rich marble of the Jinping Formation (Haizhou Group) in the Sulu Orogen matches in both facies character and C-isotope profile that of the Marinoan-equivalent glacial-cap carbonate couplet of the Nantuo and Doushantuo formations. The Daxinwu Formation (Susong Group) in the eastern Dabie Orogen contains a marble unit that has, for several hundreds of metres, a strikingly uniform C-isotope profile of low δ13C positive values and is overlain by a P-rich graphitic schist; these features match those of the late Ediacaran to early Cambrian Dengying Formation. These correlations establish that the HP-UHP metasedimentary rocks, many of which were once considered to be Palaeo- to Mesoproterozoic in age, are a Neoproterozoic-age cover sequence of the continental margin of the Yangtze Block. Further, their widespread development limits their utility as indicators of offset across the Tan-Lu fault zone and, instead, favours tectonic models that interpret that feature as a continental-scale tear fault formed during the Mesozoic collision and suturing of the North and South China cratons.

AB - The late-Cryogenian – Ediacaran geological framework for South China is constructed principally from sedimentary successions preserved in the central and western regions of the Yangtze Block. New stratigraphic and carbonate-carbon isotope data allow us to extend that framework into the exhumed HP-UHP subduction complexes of the eastern Dabie and Sulu orogens that separate the South and North China cratons. Those data show that marble and phosphorous-rich (P-rich) units in those complexes were originally part of an Ediacaran shallow-marine shelf-carbonate platform. The basal pebbly schist (metadiamictite) and lowermost P-rich marble of the Jinping Formation (Haizhou Group) in the Sulu Orogen matches in both facies character and C-isotope profile that of the Marinoan-equivalent glacial-cap carbonate couplet of the Nantuo and Doushantuo formations. The Daxinwu Formation (Susong Group) in the eastern Dabie Orogen contains a marble unit that has, for several hundreds of metres, a strikingly uniform C-isotope profile of low δ13C positive values and is overlain by a P-rich graphitic schist; these features match those of the late Ediacaran to early Cambrian Dengying Formation. These correlations establish that the HP-UHP metasedimentary rocks, many of which were once considered to be Palaeo- to Mesoproterozoic in age, are a Neoproterozoic-age cover sequence of the continental margin of the Yangtze Block. Further, their widespread development limits their utility as indicators of offset across the Tan-Lu fault zone and, instead, favours tectonic models that interpret that feature as a continental-scale tear fault formed during the Mesozoic collision and suturing of the North and South China cratons.

KW - Dabie Orogen

KW - Sulu Orogen

KW - Haizhou group

KW - Susong group

KW - Ediacaran

KW - Marinoan glaciation

KW - Phosphorite

U2 - 10.1016/j.precamres.2017.11.022

DO - 10.1016/j.precamres.2017.11.022

M3 - Article

VL - 305

SP - 166

EP - 176

JO - Precambrian Research

JF - Precambrian Research

SN - 0301-9268

ER -