The Xing'an Block (XB) is located between the Erguna
Block (EB) and the Songnen Block (SB), which
topographically occupies the northeastern half of the Great
Xing'an Range (Liu et al., 2017). The XB was
tr...The Xing'an Block (XB) is located between the Erguna
Block (EB) and the Songnen Block (SB), which
topographically occupies the northeastern half of the Great
Xing'an Range (Liu et al., 2017). The XB was
traditionally considered to be composed of a Precambrian
metamorphic basement and post-Cambrian cover.
However, the recent geochronological studies show that
the so-called "Precambrian metamorphic rocks^^ are much
younger in age and considered to be formed in the Early
Paleozoic, indicating no existence of the Precambrian
metamorphic basement.展开更多
To better understand the Paleo-to Mesoproterozoic tectonic evolution of the Dabie Orogen in the northern margin of Yangtze Block,we present geochronological data for metasedimentary and metavolcanic rocks in the Huwan...To better understand the Paleo-to Mesoproterozoic tectonic evolution of the Dabie Orogen in the northern margin of Yangtze Block,we present geochronological data for metasedimentary and metavolcanic rocks in the Huwan complex.A total of 385 detrital zircon LA-ICP-MS analyses for metasedimentary rocks yielded three^(207)Pb/^(206)Pb age populations:1.50-1.80 Ga,1.81-1.87 Ga and 1.93-2.0 Ga,providing a maximum depositional timing of ca.1.50 Ga;while metafelsic volcanic gneisses yielded protolith U-Pb ages of 1893±54 Ma.The peak ages are remarkably consistent with the tectonothermal events that occurred in the northern Yangtze Block,indicating the presence of Paleo-to Mesoproterozoic magmatism in the Dabie Orogen.The age range of 1.93-2.0 Ga correlates with the Paleoproterozoic collision;the age range of 1.81-1.87 Ga coincides with the period of the post-orogenic extension;and the age range of 1.50-1.80 Ga is interpreted to associate with an extensional regime.Zircon cores with age of 1732-1965 Ma haveε_(Hf)(t)values ranging from-11.70 to-2.47,indicating that juvenile crust involved in their magma sources.Owing to the similar age spectra,we proposed that the nucleus of the Dabie Orogen was close to the Yangtze Block since the Paleoproterozoic.The Huwan complex has an intimate affiliation to the Yangtze Block,and implies multiple orogenic cycles.It was not only experienced the Paleo-Tethys ocean subduction and collision,but also recorded Paleo-to Mesoproterozoic tectono-magmatic events in the Dabie Orogen.展开更多
基金supported by the China Geological Survey (grant No. DD20160047-02)the Young Scientists Fund of Shandong Province (grant No. ZR2016DB08)the Financial Fund of Shandong Province (grant No. 2017CXGC1604)
文摘The Xing'an Block (XB) is located between the Erguna
Block (EB) and the Songnen Block (SB), which
topographically occupies the northeastern half of the Great
Xing'an Range (Liu et al., 2017). The XB was
traditionally considered to be composed of a Precambrian
metamorphic basement and post-Cambrian cover.
However, the recent geochronological studies show that
the so-called "Precambrian metamorphic rocks^^ are much
younger in age and considered to be formed in the Early
Paleozoic, indicating no existence of the Precambrian
metamorphic basement.
基金granted by National Natural Science Foundation of China(Grant No.42172103)China Geological Survey(DD20221645)Hubei Geological Bureau(KJ2023-11,KCDZ2022-06,KCDZ2023-01)。
文摘To better understand the Paleo-to Mesoproterozoic tectonic evolution of the Dabie Orogen in the northern margin of Yangtze Block,we present geochronological data for metasedimentary and metavolcanic rocks in the Huwan complex.A total of 385 detrital zircon LA-ICP-MS analyses for metasedimentary rocks yielded three^(207)Pb/^(206)Pb age populations:1.50-1.80 Ga,1.81-1.87 Ga and 1.93-2.0 Ga,providing a maximum depositional timing of ca.1.50 Ga;while metafelsic volcanic gneisses yielded protolith U-Pb ages of 1893±54 Ma.The peak ages are remarkably consistent with the tectonothermal events that occurred in the northern Yangtze Block,indicating the presence of Paleo-to Mesoproterozoic magmatism in the Dabie Orogen.The age range of 1.93-2.0 Ga correlates with the Paleoproterozoic collision;the age range of 1.81-1.87 Ga coincides with the period of the post-orogenic extension;and the age range of 1.50-1.80 Ga is interpreted to associate with an extensional regime.Zircon cores with age of 1732-1965 Ma haveε_(Hf)(t)values ranging from-11.70 to-2.47,indicating that juvenile crust involved in their magma sources.Owing to the similar age spectra,we proposed that the nucleus of the Dabie Orogen was close to the Yangtze Block since the Paleoproterozoic.The Huwan complex has an intimate affiliation to the Yangtze Block,and implies multiple orogenic cycles.It was not only experienced the Paleo-Tethys ocean subduction and collision,but also recorded Paleo-to Mesoproterozoic tectono-magmatic events in the Dabie Orogen.
