Petrogenesis of high-K, calc-alkaline and shoshonitic intrusive rocks in the Tongling area, Anhui Province (eastern China), and their tectonic implications

2013 ◽  
Vol 126 (1-2) ◽  
pp. 78-102 ◽  
Author(s):  
C. Wu ◽  
S. Dong ◽  
P. T. Robinson ◽  
B. R. Frost ◽  
Y. Gao ◽  
...  
2014 ◽  
Vol 1010-1012 ◽  
pp. 1372-1375
Author(s):  
Zi Long Yue ◽  
Yan Li Gao ◽  
Zhao Ge Zeng

The intermediate-acidic intrusive rocks in Tongling area of Anhui province can be divided into two magmatic series, namely the shoshonitic series and the high-potassium(K) calc-alkaline series. The shoshonitic series is characterized by an association of pyroxene monzodiorites + monzodiorites + quartz monzonites, and high Rittmann indices. This series has common association with gold deposits. The high-potassium(K) calc-alkaline series is characterized by an association of diorite + quartz monzodiorites + granodiorites. It has lower Rittmann indices and REEs than the shoshonitic series and is associated with copper deposits. Results obtained from the studies show that the former is derived from the differentiation of the alkaline basic magma in mantle and the later is mixture between the differentiated mantle magma and crustal magma. The chronology of intermediate-acidic intrusive rocks is about 140Ma.


2017 ◽  
Vol 34 (1) ◽  
pp. 45 ◽  
Author(s):  
Elizard González-Becuar ◽  
Efrén Pérez-Segura ◽  
Ricardo Vega-Granillo ◽  
Luigi Solari ◽  
Carlos Manuel González-León ◽  
...  

Plutonic rocks of the Puerta del Sol area, in central Sonora, represent the extension to the south of the El Jaralito batholith, and are part of the footwall of the Sierra Mazatán metamorphic core complex, whose low-angle detachment fault bounds the outcrops of plutonic rocks to the west. Plutons in the area record the magmatic evolution of the Laramide arc and the Oligo-Miocene syn-extensional plutonism in Sonora. The basement of the area is composed by the ca. 1.68 Ga El Palofierral orthogneiss that is part of the Caborca block. The Laramide plutons include the El Gato diorite (71.29 ± 0.45 Ma, U-Pb), the El Pajarito granite (67.9 ± 0.43 Ma, U-Pb), and the Puerta del Sol granodiorite (49.1 ± 0.46 Ma, U-Pb). The younger El Oquimonis granite (41.78 ± 0.32 Ma, U-Pb) is considered part of the scarce magmatism that in Sonora records a transition to the Sierra Madre Occidental magmatic event. The syn-extensional plutons are the El Garambullo gabbro (19.83 ± 0.18 Ma, U-Pb) and the Las Mayitas granodiorite (19.2 ± 1.2 Ma, K-Ar). A migmatitic event that affected the El Palofierral orthogneiss, El Gato diorite, and El Pajarito granite between ca. 68 and 59 Ma might be related to the emplacement of the El Pajarito granite. The plutons are metaluminous to slightly peraluminous, with the exception of El Oquimonis granite, which is a peraluminous two-mica, garnet-bearing granite. They are mostly high-K calc-alkaline with nearly uniform chondrite-normalized REE and primitive-mantle normalized multielemental patterns that are characteristic of continental margin arcs and resemble patterns reported for other Laramide granites of Sonora. The Laramide and syn-extensional plutons also have Sr, Nd and Pb isotopic ratios that plot within the fields reported for Laramide granites emplaced in the Caborca terrane in northwestern and central Sonora. Nevertheless, and despite their geochemical affinity to continental magmatic arcs, the El Garambullo gabbro and Las Mayitas granodiorite are syn-extensional plutons that were emplaced at ca. 20 Ma during development of the Sierra Mazatán metamorphic core complex. The 40Ar/39Ar and K-Ar ages obtained for the El Palofierral orthogneiss, the Puerta del Sol granodiorite, the El Oquimonis granite, and the El Garambullo gabbro range from 26.3 ± 0.6 to 17.4 ± 1.0 Ma and are considered cooling ages associated with the exhumation of the metamorphic core complex.


2021 ◽  
pp. 1-22
Author(s):  
Jia-Hao Jing ◽  
Hao Yang ◽  
Wen-Chun Ge ◽  
Yu Dong ◽  
Zheng Ji ◽  
...  

Abstract Late Mesozoic igneous rocks are important for deciphering the Mesozoic tectonic setting of NE China. In this paper, we present whole-rock geochemical data, zircon U–Pb ages and Lu–Hf isotope data for Early Cretaceous volcanic rocks from the Tulihe area of the northern Great Xing’an Range (GXR), with the aim of evaluating the petrogenesis and genetic relationships of these rocks, inferring crust–mantle interactions and better constraining extension-related geodynamic processes in the GXR. Zircon U–Pb ages indicate that the rhyolites and trachytic volcanic rocks formed during late Early Cretaceous time (c. 130–126 Ma). Geochemically, the highly fractionated I-type rhyolites exhibit high-K calc-alkaline, metaluminous to weakly peraluminous characteristics. They are enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs) but depleted in high-field-strength elements (HFSEs), with their magmatic zircons ϵHf(t) values ranging from +4.1 to +9.0. These features suggest that the rhyolites were derived from the partial melting of a dominantly juvenile, K-rich basaltic lower crust. The trachytic volcanic rocks are high-K calc-alkaline series and exhibit metaluminous characteristics. They have a wide range of zircon ϵHf(t) values (−17.8 to +12.9), indicating that these trachytic volcanic rocks originated from a dominantly lithospheric-mantle source with the involvement of asthenospheric mantle materials, and subsequently underwent extensive assimilation and fractional crystallization processes. Combining our results and the spatiotemporal migration of the late Early Cretaceous magmatic events, we propose that intense Early Cretaceous crust–mantle interaction took place within the northern GXR, and possibly the whole of NE China, and that it was related to the upwelling of asthenospheric mantle induced by rollback of the Palaeo-Pacific flat-subducting slab.


2012 ◽  
Vol 610-613 ◽  
pp. 2904-2907
Author(s):  
Song Chen

The limestone soils and its source rock samples had been collected from Suzhou area for the testing about major and trace elements. The concentration value have been compared with the background and the migration coefficient(K) of element form source rock to soil have been calculated, the result showed: the elements Ca and Th are enrichment, the Al is loss seriously, the Ti, V, Cr, Mn, Zn, Rb, Sr., Zr, and Pb are basic fairly with the background value; the K, Cu, Fe and As are slightly higher than the soil background values; The elements Si, Ti, Mn, Zr, Pb and Th have high K in subsoil layer; the element Fe, Cr, As and Rb have the least K in subsoil layer; the element Al, V, Cu and Zn can be showed disorder with the more high migration coefficient in topsoil.


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