Early diagenetic alterations of organic matter from conifers were simulated at low temperature of 80°C for five and a half years. Their diagenetic products of aliphatic hydrocarbons were identified and quantified. The results reveal that in the early sedimentation of organic matter from conifers, n-alkanes have developed; natural terpenoids have transformed into diagenetic terpenoids, in which some seldom reported evolutionary intermediates—two cadinatetraenes, three norabietatetraenes and one abietatetraene—were detected and identified. The diagenetic pathways for cadalane-type sesquiterpenoids and abietane-type diterpenoids are proposed. The experimental data also show that the diagenesis of aliphatic hydrocarbons is influenced by different inorganic environments. The influences can be concluded as follows: high salinity is propitious to generate and expulse aliphatic hydrocarbons; iron may promote the increase of alkanes, but interrupt the alterations of terpenoids; gypsum, when not coexisting with metal, may slow the degradation from long chain alkanes to short ones; and heavy metal probably delays the early diagenesis of both alkanes and terpenoids. These influences observed under low temperature may enrich studies on early diagenesis of organic matter from higher plants.

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In aragonitic coral skeletons, the Na/Ca molar ratio is clearly higher than any other minor- or trace-element/Ca molar ratio (i.e., Na/Ca > Sr/Ca ≥ S/Ca ≥ F/Ca ≈ Mg/Ca). However, little attention has been paid to the Na/Ca ratio and there is little discussion of its variability and controlling factors. In this paper, we present monthly-to-bimonthly resolved Na/Ca, Sr/Ca and Mg/Ca measurements of four Porites coral skeletal samples: two modern samples from Ishigaki Island in the Ryukyu Islands, one modern sample from Myrmidon Reef in the Great Barrier Reef, and one fossil sample (6750 ± 45 BP) from Okinawa Island in the Ryukyu Islands. The two samples from Ishigaki Island show different annual cycles of the Na/Ca ratio, while the other two samples exhibit irregular fluctuations in the Na/Ca ratio. These observations suggest that the Na/Ca ratio of coral skeletons is controlled by some factor(s) other than temperature, salinity, and seawater Na/Ca ratio. We also present a discussion about modes of Na, S and Mg incorporation into coral skeletons using published data and observations for abiogenic marine aragonites as well as coral skeletons. We suggest that the principal mechanism for the incorporation of Na, S and Mg into biogenic and abiogenic marine aragonites is ion incorporation into lattice defects and distortions and/or ion adsorption (including the adsorption at the aragonite-organic matter interface).

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We report two first U-Pb zircon ages of the felsic rocks in the Ashizuri igneous complex, southwestern Shikoku, using the LA-ICP-MS. Samples are a syenite (ASH54) and a biotite granite (ASH5). Weighted means of the ²³⁸U-²⁰⁶Pb ages of concordant data of ASH54 and ASH5 are 13.12 ± 0.09 Ma (2σ) and 12.95 ± 0.06 Ma (2σ), respectively. It is concluded that the felsic member of the Ashizuri complex was formed almost simultaneously at ca. 13 Ma after the major activity of the Outer Zone Granitic Rocks. Presence of alkali dolerite dike cutting the syenite indicates that the alkali basaltic magma intruded after the subduction of Shikoku Basin of the Philippine Sea plate beneath the southwest Japan arc. Alkali basaltic magma of Ashizuri complex may have been derived from a depth possibly deeper than that of subducted Shikoku Basin of the Philippine Sea Plate.

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New Sr-Nd-O isotopic data are reported for the early Triassic (early Indosinian) Weiya quartz syenite from eastern Central Tianshan, northwestern China, with the aim of documenting its possible source(s), constraining its petrogenesis and discussing its tectonic implications. Whole-rock Rb-Sr isochron of the Weiya quartz syenite rock yielded an age of 246.5 ± 4.8 Ma, which is well consistent with zircon SHRIMP U-Pb age. Additionally, the rock exhibits positive ε_Nd(t) value (+1.36 to +1.66), medium I_sr (0.7088 to 0.7090), “normal” δ¹⁸O value (6.9 to 8.1‰) and young Nd model ages (T_DM = 0.88 to 0.91 Ga). Combined with their petrogaphic and geochemical characters, the Weiya quartz syenite is suggested to have been generated by partial melting of juvenile lower crust rocks at high temperature. The partial melting is attributed to intra-continental subduction, which resulted in thickening of the continental crust, delamination of the lithosphere root, underplating of mantle-derived magma and subsequent regional extension. Heat from underplated mantle magma caused melting of the overlying lower crustal rocks and consequent generattion of the quartz syenitic liquid. It is supposed that the intra-continental subduction was induced by tectonic conversion from the Paleo-Asian subduction-collision system to the Paleo-Thethys regime during the latest Permian or earliest Triassic in the eastern Tianshan.

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The tungsten deposit region of South China is well known as the world's leading tungsten (W) producer. The Piaotang tungsten deposit in the region is such a representative large-scale quartz vein type tungsten polymetallic deposit that is closely associated with granitoids. In the present study we present precise LA-ICP-MS zircon U-Pb dating and LA-MC-ICPMS zircon Hf isotopic data for the samples from exposed quartz diorite body and buried granite stock in the Piaotang tungsten deposit area. Zircon U-Pb dating results indicate that the quartz diorite body was formed in Early Paleozoic time at 439 ± 2 Ma, whereas the granite body was emplaced in Early Yanshanian time at 158 ± 3 Ma. Both the quartz diorite and granite have negative ε_Hf(t) values, with similar two-stage zircon Hf model ages ranging from 1.8 to 2.1 Ga. Through integration of our new data with the isotope data of Precambrian basement rocks in western Cathaysia, we suggest that the Paleoproterozoic Hf model ages (1.8-2.1 Ga) might be an average age which resulted from mixing of continental materials of different ages. Both the Piaotang Early Paleozoic quartz diorite and Early Yanshanian granite are produced by reworking of the heterogeneous Neoproterozoic crust. Our zircon ages, together with the geochemical data and geological features and ore-forming ages of this tungsten deposit, indicate that the buried Early Yanshanian granite, rather than the exposed quartz diorite, is genetically associated with tungsten mineralization. The distinct metallogeny difference between the Piaotang Early Paleozoic quartz diorite and Early Yanshanian granite can be ascribed to the different degrees of magma differentiation. The Early Yanshanian granite is highly differentiated rock and similar to the other W-Sn deposits generating granitoids in South China. The extents of magma differentiation depend on the tectonic setting and the mechanism of magma generation. On the basis of the relationship between two different stages of magmatism and W mineralization in the Piaotang tungsten deposit, and the similarities with other granite related W-Sn deposits in the same region, it is proposed that the regional tectonic setting and lithosphere dynamics are the key factors controlling the metallogenic capacity of granitoids in South China.

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Rare earth elements (REE), Sr, Ba, Fe, Mg, Ca, Na, and K concentrations in three kinds of living foraminiferal tests collected from Iriomote Island, Japan were measured in order to obtain some qualitative aspects of trace element behavior during biogenic CaCO₃ formation. The obtained results were examined using the sample/seawater concentration ratios, which can be considered as a measure of total effect of element incorporation into biogenic CaCO₃ in marine environments. On a sample/seawater concentration ratio vs. ionic radius diagram, the foraminifera/seawater ratios of trivalent REEs and divalent Mg, Ca and Sr fall on their respective curves having peaks near the Ca ionic radius. This is consistent with the most widely accepted theory that solid/liquid partition coefficients are largely controlled by the sizes of the host site in the crystal and the substituting cation, such that a cation that has the most suitable size for the site can enter the crystal most easily. On the other hand, the foraminifera/seawater ratios of Fe and Ba show higher values than those expected from the crystal structure control model, which might be caused by insoluble precipitates such as Fe-hydroxides and barite. It is interesting that the concentrations of REEs in foraminifera are correlated with those of Fe, which suggests coprecipitation of REE with Fe-hydroxide. Such coprecipitation of REE might have occurred in seawater, followed by uptake of Fe-hydroxides by foraminiferal food micro-organisms. After digestion of such food, the dissolved REEs in intracellular fluid might have fractionated as CaCO₃ crystallization proceeds, and the combined crystal structure and ionic radius effect becomes conspicuous forming a peak on the foraminifera/seawater ratio vs. ionic radius diagram.

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Despite increasing processing power of systems, sequential programs have limitations to achieve corresponding performance gains. Parallelization of sequential programs can exploit the computation potential to reduce overall execution expenditures. However, parallelization of a very large legacy program arises great challenges, because 1) former design of the program did not consider parallelization, 2) the large-scale program has been developed for long time even decades, and 3) some developers of the program are no longer available. In the atmospheric science field, there are many such legacy programs and GEOS-Chem model developed in Harvard University is one of examples. In this paper, we suggest simple procedures of the MPI parallelization which can be easily applied to a large legacy program. We applied this method to the GEOS-Chem model which is already parallelized with the OpenMP method alone. Our test results showed that the good performance improvement can be obtained by parallelizing a small portion of the program.

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Aerosol samples were collected at Mangshan in the north of Beijing, China in autumn 2007 and analyzed for α,ω-dicarboxylic acids (C₂-C₁₂), ketoacids (ωC₂-ωC₄, ωC₉, pyruvic acid) and α-dicarbonyls (glyoxal and methylglyoxal). Oxalic (C₂) acid was found as the most abundant species, followed by succinic (C₄) and malonic (C₃) acids. Concentrations of most compounds, except for C₂ and some other species, were higher in daytime than nighttime, indicating that diacids are produced by photochemical oxidation of organic precursors emitted from anthropogenic sources such as fossil-fuel combustion in Beijing, and are transported to Mangshan area by the northerly wind in daytime. Phthalic acid (Ph) was detected as the 4th most abundant diacid both in daytime and nighttime samples, indicating that anthropogenic sources significantly contribute to the organic aerosols. However, lower adipic (C₆)/azelaic (C₉) acid ratios in nighttime than daytime suggest that biogenic source makes more contribution to the aerosols in nighttime. Higher ratios of C₂/total diacids in nighttime than daytime suggest the aging of aerosols proceed more in nighttime, probably due to the aqueous phase oxidation of biogenic precursors. This study demonstrates that water-soluble organic aerosols are secondarily produced in the vicinity of Beijing by the oxidation of both anthropogenic and biogenic precursors.

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