The 401–409 Ma Xiaodonggou granitic intrusion: implications for understanding the Devonian Tectonics of the Northwest China Altai orogen

<p>Palaeozoic granitoids in the Chinese Altai are important for understanding the evolution of the Central Asian Orogenic Belt (CAOB). The Xiaodonggou granitic intrusion, situated in the Chinese Altai (southern CAOB), is composed of two intrusive phases, medium-grained granite intruded by porphyritic granite. Zircon LA-ICP-MS U–Pb analyses of medium-grained granite and porphyritic granite yield ages of 409 ± 2 Ma and 400 ± 1 Ma, respectively, indicating that these formed in Early Devonian time. Medium-grained granite and porphyritic granite have similar geochemical features and Nd–Hf isotopic compositions. Arc-like geochemical characteristics (e.g. enrichment of LILEs and negative anomalies of Nb, Ta, Ti, and P) show that both phases are volcanic arc granites (VAGs). Geochemical and isotopic characteristics suggest that these magmas originated from melting older crust. Based on their near-zero or negative <i>ε</i>_Nd(<i>t</i>) values (−1.4to 0) and positive <i>ε</i>_Hf(<i>t</i>) values (+1.4 to +7.8), together with Nd model ages of 1.15–1.26 Ga and zircon Hf model ages of 0.90–1.30 Ga, we suggest that the Xiaodonggou granites were derived from a mixture of juvenile and old crustal components. Some other Devonian granitic intrusions were recently identified in the Chinese Altai with ages between 416 and 375 Ma. These Devonian granites have similar geochemical characteristics and petrogenesis as Xiaodonggou granites. The formation of these Devonian granites was in response to subduction processes, suggesting that Chinese Altai was an active continental margin in Early Devonian time.</p

Devonian porphyry Cu deposits in NW China: the Xiaotuergen example

<p>The Nuoerte Basin in northern Altay contains numerous mineral discoveries, including the Xiaotuergen porphyry Cu, Kumasu VMS Pb–Zn, and Hongshanzui orogenic Au deposits. This deposit, newly discovered by the 4th Geological Team of XJBGMR – the Xiaotuergen porphyry Cu deposit – is mainly hosted along the contact zone between the granodiorite porphyry and the Nuoerte Formation volcanic-sedimentary rocks. Disseminated, veinlet, veinlet-disseminated, and stockwork Cu mineralization occur in the granodiorite porphyry. Wall-rock alteration styles include mainly potassic (K-feldspar and biotite), silicic, carbonate, sericite, pyrite, chlorite, and epidote alterations. In this study, we used LA-ICP-MS zircon dating for the various rock types in the Xiaotuergen Cu ore district. The tuff at the periphery of the ore district has been newly dated to be ca. 411 Ma. This, together with stratigraphic correlation, suggests that the local stratigraphy is the Lower Devonian Nuoerte Formation, rather than the Lower Carboniferous Hongshanzui Formation as previously assumed. The ore-hosting granodiorite porphyry, quartz porphyry, biotite monzogranite, and granite porphyry are dated to be ca. 405 Ma, 400 Ma, 398 Ma, and 397 Ma, respectively. This constrains the Cu mineralization to be slightly younger than 405 Ma, and indicates that they may have belonged to the same Early Devonian intrusive event. Magmatism at Xiaotuergen had recommenced in the Late Devonian, as represented by minor granite porphyry dikes (ca. 370 Ma) intruding the ore-hosting granodiorite porphyry.</p

Geochemistry and Sr–Nd–Hf isotopes of Middle Devonian igneous rocks of the Sarsuk polymetallic Au deposit: implications for understanding the tectonic evolution of the south Altay Orogenic Belt, Northwest China

<p>The medium-tonnage Sarsuk polymetallic Au deposit is located in the Devonian volcanic–sedimentary Ashele Basin of the south Altay Orogenic Belt (AOB), Northwest China. Within the deposit, the rhyolite porphyries and diabases are widespread, emplaced into strata. The orebodies are hosted by the rhyolite porphyries. We studied the petrography, geochemistry, and Sr–Nd–Hf isotopes of the rhyolite porphyries and diabases, in order to understand the petrogenesis of these rocks and their tectonic significance. They display typical bimodality in geochemistry compositions. The diabases are characterized by SiO₂ contents of 44.84–59.77 wt.%, high Mg# values (43–69), enrichment in large ion lithophile elements (LILE) and light rare earth elements (LREE), depletion in Nb and Ta, low (⁸⁷Sr/⁸⁶Sr)<i>_i</i> (0.706687–0.707613) values, positive <i>ε</i>_Nd(<i>t</i>) (4.8–6.8) values, and positive and high <i>ε</i>_Hf(<i>t</i>) (7.15–15.19) values, suggesting a depleted lithosphere mantle source that might have been metasomatized by subduction-related components. The rhyolite porphyries show affinity to sanukitoid magmas contents [high SiO₂ (78.6–81.82 wt.%) and MgO (3.38–5.94 wt.%, one sample at 0.61 wt.%), and enrichments in LILE and LREE], they were derived from the equilibrium reactions between a mantle source and subducted oceanic crust materials. Those characteristics together with the positive <i>ε</i>_Nd(<i>t</i>) (4.1–8.4) and <i>ε</i>_Hf(<i>t</i>) (2.88–15.17) values indicate that the diabases and rhyolite porphyries were generated from the same mantle peridotite source. But the rhyolite porphyries underwent fractional crystallization of Fe–Ti oxides, plagioclase, and apatite due to their negative Eu (<i>δ</i>Eu = 0.21–0.28) and P anomalies. According to the geochemical and isotopic data, the Sarsuk Middle Devonian igneous rocks are considered to be the products of the juvenile crustal growth in an island arc setting. The Sarsuk polymetallic Au deposit formed slightly later than the Ashele Cu–Zn deposit in the Ashele Basin, but they have the same tectonic setting, belonging to the trench–arc–basin system during extensional process in the south AOB.</p

Geology, genesis, and geodynamic setting of Cihai: an Early Permian diabase-hosted skarn iron deposit in the eastern Tianshan, Northwest China

<p>Extensive Permian mafic–ultramafic intrusions crop out within the eastern Tianshan, southern part of Central Asian Orogenic Belt (CAOB). Most of these mafic–ultramafic complexes are associated with Cu-Ni-Co deposits. However, Cihai, located in the southern part of the eastern Tianshan, is a large Fe deposit hosted in the Early Permian mafic rocks. The mafic to intermediate rocks are composed of gabbro, diabase, and monzodiorite. Geological and geochemical characteristics suggest that their parental magmas might have been generated by interaction between the depleted asthenospheric mantle and the metasomatized lithospheric mantle. Iron ores of the Cihai iron deposit are hosted in the diabase, and all Fe–Ti oxides in the ore-hosted diabase are ilmenite, instead of magnetite as previously reported. Chondrite-normalized REE patterns show that the magnetite separates from disseminated, banded, and massive iron ores, which are distinct from those in magmatic Fe-Ti deposits. Geological and chemical features suggest that the main ore bodies in the Cihai iron deposit are of hydrothermal origin, rather than magmatic as previously suggested. Numerous other Early Permian mafic rocks were recently identified in the Tarim basin and the eastern Tianshan with ages between 301 and 269 Ma. The mafic rocks in the Tarim basin exhibit characteristics of Oceanic Island Basalt (OIB), whereas the mafic rocks in the eastern Tianshan show island arc basalt (IAB) affinity. In addition, the presence of skarn iron deposit instead of Fe–Ti oxide deposit in the eastern Tianshan during the Early Permian time also lends little support for a plume-related environment. These features, together with a lack of verified anomalous high-temperature magmas in the eastern Tianshan, suggest that the Permian Tarim mantle plume may not account for the formation of the mafic rocks in the eastern Tianshan area, and that the Tarim LIP does not extend to the eastern Tianshan area.</p

Notes on mineralogical genera

For the identification of peptides with tandem mass spectrometry (MS/MS), many software tools rely on the comparison between an experimental spectrum and a theoretically predicted spectrum. Consequently, the accurate prediction of the theoretical spectrum from a peptide sequence can potentially improve the peptide identification performance and is an important problem for mass spectrometry based proteomics. In this study a new approach, called MS-Simulator, is presented for predicting the <i>y</i>-ion intensities in the spectrum of a given peptide. The new approach focuses on the accurate prediction of the relative intensity ratio between every two adjacent <i>y</i>-ions. The theoretical spectrum can then be derived from these ratios. The prediction of a ratio is a closed-form equation that involves up to five consecutive amino acids nearby the two <i>y</i>-ions and the two peptide termini. Compared with another existing spectrum prediction tool MassAnalyzer, the new approach not only simplifies the computation, but also improves the prediction accuracy

MS-Simulator: Predicting <i>Y</i>‑Ion Intensities for Peptides with Two Charges Based on the Intensity Ratio of Neighboring Ions

For the identification of peptides with tandem mass spectrometry (MS/MS), many software tools rely on the comparison between an experimental spectrum and a theoretically predicted spectrum. Consequently, the accurate prediction of the theoretical spectrum from a peptide sequence can potentially improve the peptide identification performance and is an important problem for mass spectrometry based proteomics. In this study a new approach, called MS-Simulator, is presented for predicting the <i>y</i>-ion intensities in the spectrum of a given peptide. The new approach focuses on the accurate prediction of the relative intensity ratio between every two adjacent <i>y</i>-ions. The theoretical spectrum can then be derived from these ratios. The prediction of a ratio is a closed-form equation that involves up to five consecutive amino acids nearby the two <i>y</i>-ions and the two peptide termini. Compared with another existing spectrum prediction tool MassAnalyzer, the new approach not only simplifies the computation, but also improves the prediction accuracy

HSP70/HSP70-PCs affect the protein levels of E-cadherin , α-SMA (A), total-p38, phosphor-p38 (C) and mRNA (B) expression of E-cadherin and α-SMA.

<p>24h after induction, cells were harvested for western blotting and real-time RT-PCR. Data are presented as means ± SD from three independent experiments (normalized to GADPH expression).</p

The mRNA and protein expression of E-cadherin, p-p38, HSP70 and α-SMA in tumors and the correlation between tumor-free survival and expression of HSP70, α-SMA and p-p38.

<p>(A) The mRNA expressions of E-cadherin, α-SMA and HSP70 and p38 (normalized to GADPH expression). (B) Photomicrographs of well-differentiated hepatic cancer (top panel) and poorly differentiated hepatic cancer. p-p38, HSP70 and α-SMA were detected in the cytoplasm; E-cadherin was detected in the plasmalemma. Original magnification, 200´. (C) The protein expressions of α-SMA, HSP70, p38 and p-p38 (normalized to GAPDH expression). Kaplan-Meier tumor-free survival curves for hepatic cancer patients showing that the median tumor-free survival time of patients correlated with HSP70 (D), α-SMA (E) and p-p38 (F) expression.</p

Expression of E-cadherin (red) and α-SMA (green) in Huh-7 cells observed by immunofluorescence.

<p>α-SMA was detected in the cytoplasm; E-cadherin was found in the plasmalemma and the cytoplasm. HSP70/HSP70-PCs treatment reduced the expressions of E-cadherin and promoted the expression of α-SMA.</p

Reductase activity of hPDI and its mutants.

<p>The mutants were designed to interfere with inter-domain interactions. The activity was determined according to insulin reduction as described in the text. The activity of WT PDI was taken as 100%. Date were expressed as mean ± S.D. (n = 3). Statistical significance was analyzed by using two-tailed <i>t</i>-test, ^*** and ^* represent P<0.001 and P<0.05, respectively.</p