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The Early Cretaceous Jehol Biota evolution has remarkable spatiotemporal correlation with the destruction of the North China craton though the coupling mechanism remains enigmatic. The craton destruction was accompanied by intense magmatic activity and the released volatiles and nutrients might have had climatic and environmental impacts on the biotic evolution. In this study, we investigated the mentioned hypothetical causal link by determining concentrations and total emissions of volatile elements (S, F, Cl) and bulk‐rock P contents of volcanic rocks that were erupted during the pre‐flourishing, flourishing and post‐flourishing stages of the Jehol Biota. Our results show that the volcanism near the flourishing stage has lower S (1,083–2,370 ppm), Cl (1,277–5,608 ppm) and higher P2O5 contents (0.48–0.84 wt.%) than that in the non‐flourishing stages with S of 1,991–3,288 ppm, Cl of 7,915–12,315 ppm and P2O5 of 0.17–0.23 wt.%. Fluorine contents in the three stages vary from 893 to 3,746 ppm. The total volatile emissions are minor in the flourishing stage (1–14 Gt S, 0.6–10 Gt Cl, 0.6–9 Gt F) but elevated in the non‐flourishing stages (2–766 Gt S, 4–1,168 Gt Cl, 1–175 Gt F). Our data suggest that regional climatic and environmental impacts of volcanism in the non‐flourishing stages probably hindered the species diversification. The high P flux released from lithospheric mantle‐derived lavas during the peak time of craton destruction might have enhanced primary productivity and contributed to the flourishing of the Jehol Biota. Our study provides insights into the relationship between the biosphere and deep geodynamic processes driven by volcanism. Plain Language Summary: It is generally believed that volatiles, such as S, Cl, and F, released by massive volcanic events may have strong ecological pressures both at the local and global scales. However, it is puzzling that the flourishing of the Jehol Biota, an Early Cretaceous terrestrial lagerstätte recording the origin and early evolution of feathered dinosaurs, birds, mammals, and angiosperms, occurred simultaneously with extensive volcanic activities in the northeastern China. To find the possible influence of volcanism on the biotic evolution, we determined the contents and total emissions of S, Cl, and F (toxic gases) and bulk‐rock P (nutrient) contents of volcanic rocks that were erupted during the pre‐flourishing, flourishing, and post‐flourishing stages of the Jehol Biota. Our results show that the volcanism at the flourishing period of the Jehol Biota was dominated by intermediate‐mafic magmas, with the total S, Cl, and F emissions having limited impacts on the local climate and environment, while the high P flux released from lavas might have enhanced primary productivity. On the contrary, the intermediate‐felsic volcanic rocks in the non‐flourishing stage released abundant toxic gases and the P flux was limited, which probably hindered the species diversification. Key Points: Volcanic gases (S, Cl, and F) had limited climatic effects in the flourishing stage of the Jehol BiotaHigh P flux from lithospheric mantle‐derived lavas facilitated the flourishing of the Jehol BiotaVolcanism associated with the North China craton destruction affected terrestrial biota evolution [ABSTRACT FROM AUTHOR]

To investigate the effects of melt-rock interaction on Li isotope fractionation, we report in situ Li concentrations and δ7Li of olivine (Ol), orthopyroxene (Opx), and clinopyroxene (Cpx) for six peridotite xenoliths from the eastern North China Craton. These xenoliths contain two lherzolites, two Cpx-rich lherzolites, and two wehrlites and are variably metasomatized. Lithium isotope zonation is observed in most peridotite minerals. The majority of Cpx grains display isotopically light cores with lower Li concentrations than the heavy rims. However, the Opx grains show a different style of zonation from Cpx, where higher Li concentrations in the cores are associated with much lighter δ7Li. Olivines in most peridotites have a restricted range of Li concentration and δ7Li within individual grains, whereas the olivines in a lherzolite show isotopically light cores (210.3) with high Li concentrations (2.3 ppm) and heavy rims (5.5) with low Li concentrations (1.7 ppm). These Li isotopic variations in mineral phases may reflect the combined effects of diffusion driven kinetic fractionation of Li isotopes during melt/fluid-peridotite interactions and slow cooling. Intersample heterogeneity of Li isotopes is also apparent. Olivine with forsterite (Fo) content of 91.3 in one lherzolite sample has "normal" mantle-like Li concentrations (1.1~2.4 ppm) and light δ7Li (210.3~5.5), while Ol with Fo content of 89.7 in another lherzolite has slightly high Li concentrations (2.0~3.0 ppm) but similar δ7Li (1.6~6.4) relative to normal mantle. Olivines in Cpx-rich lherzolites have lower Fo contents (83.8-87.5), higher Li concentrations (1.4~4.5 ppm), and heavier δ7Li (5.0~22.0) than those in lherzolites and normal mantle. The δ7LiOl value correlates positively with Li concentration and negatively with Fo from lherzolites to Cpx-rich lherzolites, indicating a reaction between lherzolites and melts with isotopically heavy Li- and Fe-rich signatures. By contrast, olivines in wehrlites have extremely lower Fo contents (82.2~83.2) and higher Li concentrations (2.4~4.2 ppm) than those in normal mantle, while their δ7Li values are within the range of normal mantle, reflecting metasomatism of the peridotites by asthenospheric melt. Overall, the large intragrain and intersample variations in Li concentrations and isotopic compositions reflect kinetic isotope fractionation during multiple metasomatisms. [ABSTRACT FROM AUTHOR]

Li contents and its isotopes of minerals in mantle peridotite xenoliths from late Cretaceous mafic dikes, analyzed in situ by Cameca IMS-1280, reveal the existence of melt/rock interaction in remains of refertilized Archean lithospheric mantle in Qingdao, Jiaodong Peninsula, North China Craton. Two groups of peridotites exist, i.e., low-Mg# lherzolite and high-Mg# harzburgites. The low-Mg# lherzolite has a relatively homogeneous Li concentration (ol: 2.01–2.11 ppm; opx: 1.77–1.88 ppm; cpx: 1.75–1.93 ppm) and Li isotopic composition (δ7Li in ol: 4.2–7.6‰; in opx: 6.0–8.3‰; in cpx: 5.3–8.4‰). The similarity in δ7Li value to the fresh MORB provides further evidence for the argument that the low-Mg# lherzolite could be the fragment of the newly accreted lithospheric mantle. The high-Mg# harzburgites have heterogeneous Li abundances (ol: 0.83–2.09 ppm; opx: 0.92–1.94 ppm; cpx: 1.12–4.89 ppm) and Li isotopic compositions (δ7Li in ol: −0.5 to +11.5‰; in opx: −6.2 to +11.1‰; in cpx: −34.3 to +10.1‰), showing strong disequilibrium in Li partitioning and Li isotope fractionation between samples. The cores of most minerals in these high-Mg# harzburgites have relatively homogeneous δ7Li values, which are higher than those of fresh MORB, but similar to those previously reported for arc lavas. These harzburgites have enriched trace elemental and Sr–Nd isotopic compositions. These observations indicate that in the early Mesozoic the lithospheric mantle beneath the southeastern North China Craton was similar to that in arc settings, which is metasomatized by subducted crustal materials. Extremely low δ7Li preserved in cpxs requires diffusive fractionation of Li isotopes from later-stage melt into the minerals. Thus, the Li data provide further evidence that the Archean refractory lithospheric mantle represented by the high-Mg# harzburgites was refertilized through melt/rock interaction and transformed to the Mesozoic less refractory and incompatible element and Sr–Nd isotopes enriched lithospheric mantle. [ABSTRACT FROM AUTHOR]

Presents the in situ analysis of oxygen isotopes carried out by ion microprobe for zircons from localities of HP-UHP metamorphic rocks including eclogites in the Dabie-Sulu terrane. Significance of zircon isotopes in archeological dating; Possibility to trace zircon value with a particular geological time or event for complicated evolution of given rocks; Interest from international geoscientists of the Dabie-Sulu terrain for its coesite and diamond-bearing eclogites.

Abstract: In-situ lithium (Li) concentrations and δ7Li of olivine, orthopyroxene (opx) and clinopyroxene (cpx) in mantle xenoliths from the Quaternary Longgang maar provide insights into the nature and evolution of the lithospheric mantle beneath the easterly part of the North China Craton. SIMS analyses show Li partitioning of olivine>opx≥cpx and Li isotopic disequilibrium in each sample. Olivines in harzburgite are generally homogeneous, with Li abundances in the range of normal mantle, but their δ7Li (−0.9 to −4.0) are lower than normal mantle olivine δ7Li values of ~+4±2. Olivines in cpx-rich lherzolite and pyroxenite have higher Li contents and normal mantle-like δ7Li values. The olivine δ7Li values in the harzburgite and cpx-poor lherzolites are much lower than those published for worldwide peridotites, showing the peculiarity of these peridotites. The Li abundances and δ7Li in the olivines show a positive correlation, indicating mixing between a low-δ7Li melt and normal mantle. Collectively, Li elemental and isotopic compositions of the xenoliths suggest that low δ7Li in olivines reflect a slab-derived Li isotopic signature in the lithospheric mantle. These observations, coupled with geochemical and geophysical evidence, suggest that the lithospheric mantle has been modified three times by (1) low-δ7Li melt likely derived from the subducted Pacific plate (leading to the low δ7Li of olivines), (2) high-degree partial melting (decreasing Li abundances of harzburgite and cpx-poor lherzolites close to the normal mantle), and (3) refertilization by melts mainly from the asthenosphere (producing the normal mantle-like δ7Li and high Li contents in cpx-rich lherzolite and pyroxenite). The melts/fluids derived from the subducted Pacific plate could play a crucial role in the destruction of the craton. [Copyright &y& Elsevier]

Abstract: Water contents of clinopyroxene, orthopyroxene and olivine in mantle peridotite xenoliths from the Hannuoba and Nushan basaltic volcanoes (North China Craton) were determined by Fourier transform infrared spectroscopy (FTIR). Results show that contents vary from 50 to 155 ppm (H2O wt.) for clinopyroxene and from 20 to 55 ppm for orthopyroxene in Hannuoba peridotites, and from 5 to 355 ppm for clinopyroxene and from 5 to 140 ppm for orthopyroxene in Nushan peridotites. Water contents in clinopyroxene and orthopyroxene define a good positive correlation with a ratio of ~2.1. This, together with the roughly homogeneous distribution of hydrogen from core to rim region in pyroxene grains, suggests that they have preserved the initial water content of the mantle source. By contrast, olivine in these peridotites contain very little, if any, water, which were probably caused by significant loss of H during their ascent due to the faster H diffusion in olivine relative to pyroxenes and by the relatively lower water content in the mantle source of Hannuoba and Nushan. Previous studies [Xia, Q.K., Yang, X.Z., Deloule, E., Sheng, Y.M., Hao, Y.T., 2006. Water in the lower crustal granulite xenoliths from Nushan, eastern China. Journal of Geophysical Research, 111(B11202) doi:10.1029/2006JB004296; Yang, X.Z., Deloule, E., Xia, Q.K., Fan, Q.C., Feng, M., in press. Water contrast between Precambrian and Phanerozoic continental lower crust of eastern China. Journal of Geophysical Research doi:10.1029/2007JB005541] have shown that the water content ranges from 275 to 720 ppm for clinopyroxene, from 60 to 185 ppm for orthopyroxene and from 65 to 205 ppm for plagioclase in Hannuoba mafic granulite xenoliths, and from 200 to 2330 ppm for clinopyroxene, from 140 to 1270 ppm for orthopyroxene and from 145 to 900 ppm in plagioclase in Nushan mafic granulite xenoliths. The significant difference between the water content of peridotite and that of coexisting mafic granulite xenoliths, e.g. 0–100 ppm (mostly <50 ppm) vs. 100–1000 ppm (mostly >200 ppm) for the estimated bulk concentration, demonstrates that the distribution of water in the deep continental lithosphere is vertically heterogeneous. This may be due to the different genesis of peridotites and granulites (the residue of partial melting vs. the product of melt crystallization). Based on these water data, we define the rheological structure of the lowermost crust and uppermost mantle below the Hannuoba and Nushan regions. The viscosity (strength) of the underlying shallow mantle is similar, whereas the deep crust is relatively stronger at Hannuoba and weaker at Nushan. Difference in the viscosity structure may further influence the dynamical processes between different zones in this craton. [Copyright &y& Elsevier]