SHRIMP U–Pb zircon geochronology and geochemistry of metavolcanic and metasedimentary rocks in Northwestern Fujian, Cathaysia block, China: Tectonic implications and the need to redefine lithostratigraphic units

Geochronological, geochemical and Nd–Hf–Os isotopic fingerprinting of an early Neoproterozoic arc–back-arc system in South China and its accretionary assembly along the margin of Rodinia

“…Li et al, 2010c;Wang et al, 2012b,c). Recent geochronological data have shown that the Neoproterozoic and even Paleozoic units are additionally presented within the previously mapped basement succession (e.g., Li et al, 1998;Wang et al, 2007cWang et al, , 2010bWang et al, , 2011bWang et al, , 2012cWan et al, 2007Wan et al, , 2010Yu et al, 2009Yu et al, , 2010Li et al, 2010aLi et al, ,c, 2011. Within the Cathaysia basement, there are small amounts of mafic and ultramafic rocks (e.g., amphibolite, metagabbro, metadiabase, metabasite, peridotite and pyroxenite), which occur mainly as lens, pods and fragments (e.g., Fujian BGMR, 1985;Guangxi BGMR, 1985;Guangdong BGMR, 1988;Zhejiang BGMR, 1989;Zhang et al, 2012a).…”

“…Inset (b) shows the age-spectra of detrital zircons for the Neoproterozoic sedimentary rocks from the Yunkai-Nanling and Jiangnan domains. Data in (b) from Wang et al (2007bWang et al ( , 2008aWang et al ( , 2010a, Zhang et al (2012a), Yu et al (2007Yu et al ( , 2008Yu et al ( , 2010, Wan et al (2007Wan et al ( , 2010, Li et al (2011);Zhao et al (2011) and Zhou et al (2009). An overall northwestward propagation of orogenic assembly of units is supported by the age-spectra of detrital zircons for the Neoproterozoic sedimentary rocks and their derivation from the southeast (inset (b) of Fig. 16, e.g., Wang et al, 2008aWang et al, , 2010aYu et al, 2005Yu et al, , 2010Zhang et al, 2012a).…”

“…The strongly peraluminous Tiantangshan and Longtang (Yunkai) and Masha (Wuyi) granites were dated at 906 ± 24 Ma (SHRIMP), 901 ± 16 Ma (LA-ICPMS) and 913 ± 11 Ma (SIMS) (e.g., Qin et al, 2006;authors' unpublished data), probably representing the time of crustal anatexis during the closure of the Wuyi-Yunkai intracontinental arc-back-arc basin. Detrital zircons with U-Pb ages of ∼1.0-0.90 Ga (peak age being ∼970 Ma) likely related to the development of the arc-back arc system are abundant in the Neoproterozoic sedimentary rocks along the Wuyi (e.g., Jianning), Nanling (e.g., Zengcheng) and Yunkai (e.g., Xinyi) domains (e.g., Yu et al, 2005Yu et al, , 2007Yu et al, , 2010Wan et al, 2007Wan et al, , 2010Wang et al, 2007cWang et al, , 2008bWang et al, ,c, 2010bLi et al, 2011). Earliest Neoproterozoic (∼1000-900 Ma) inherited grains are commonly identified in the Kwangsian granitic gneiss and Neoproterozoic gneiss with some showing positive ε Hf (t) values (inset of Fig.…”

“…16, e.g., Wang et al, 2008aWang et al, , 2010aYu et al, 2005Yu et al, , 2010Zhang et al, 2012a). The Neoproterozoic successions along the Wuyi-Yunkai domain by equigranular and rounded or subhedral, indicating detritus transported from the orogen to south or southeast (e.g., Wan et al, 2007Wan et al, , 2010Yu et al, 2007Yu et al, , 2008Yu et al, , 2010Wang et al, 2008aWang et al, , 2010bLi et al, 2011). Further to the west, along the Jiangnan domain, ∼1.0 Ga detrital zircons are poorly identified and the age-spectra are characterized by ∼0.86 Ga grains (inset (b) of Fig.…”

Discovery of Paleoproterozoic rapakivi granite on the northern margin of the Yangtze block and its geological significance

“…The discovery of 1.85 Ga Huashanguan rapakivi granites provides important evidence for the formation and cratonization of the Yangtze block in the Paleoproterozoic, and for its later tectonic transformation from collision to extension. Recently, there have been reports on orogenic events of 1.89-1.83 Ga [84], and breakup events of 1.80-1.76 Ga [85][86][87] in the Cathaysian block. These events took place a little later than those in the Yangtze block, which indicates that the two blocks may have been located in different positions in the supercontinent system.…”