Fourteen fission track apatite ages and thirteen zircon ages are measured for the Osuzuyama volcanoplutonic complex (OVPC) and the surrounding Hyuga unit in Kyushu, Southwest Japan. The average apatite OVPC age is 12.6 ± 0.9 (±1σ) Ma, slightly younger than the average zircon age of 15.2 ± 0.5 (±1σ) Ma which is consistent with K-Ar ages reported before. Apatite ages of the nearby Hyuga unit are more or less older than the average apatite OVPC age, suggesting that the OVPC age would represent time of slow cooling after intrusion rather than the time of exhumation. Compared to the previously reported apatite data from the Shimanto accretionary complex at the north of the studied area, the age here is older and indicates less exhumation of the studied region. Given reasonable assumptions, the difference in the amount of exhumation since Miocene is estimated being larger than ∼1 km, probably controlled by the material to be exhumed and local geological setting.

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Abundant tourmaline occurs in the Lavicky leucogranite, Czech Republic as spherical to ovoid quartz-tourmaline orbicules, typically 5 to 7 cm in diameter. The tourmalines also occur as fine-grained quartz-tourmaline veins (<1 cm thick) that cut the orbicule-rich granite. Electron microprobe analyses reveal that tourmaline from the quartz-tourmaline orbicules is Fe-rich schorl with a range of Fe/(Fe + Mg) ratio 0.62 to 0.77 and Na/(Na + Ca) ratio 0.82 to 0.95. In contrast, tourmaline from quartz-tourmaline veins is Mg-rich dravite with a range of Fe/(Fe + Mg) ratio 0.23 to 0.45 and Na/(Na + Ca) ratio 0.67 to 0.90. Very low δ¹¹B values of −37.3 to −32.1‰ are found in the tourmalines from the orbicules, whereas tourmalines from the veins display relatively higher δ¹¹B values of −28.2 to −21.3‰. The overall large δ¹¹B variation is suggested to reflect mixing of different boron sources and boron isotope fractionation during magmatic degassing and magmatic-hydrothermal evolution at late solidus to early subsolidus stages of granite crystallization. Only non-marine evaporites show very negative δ¹¹B values (<−20‰) in all natural boron reservoirs, hence, the very low δ¹¹B values of the quartz-tourmaline orbicules likely indicate a major contribution of boron from non-marine evaporites that probably exist in the magma source regions or assimilated into the magma during its ascent. Quartz-tourmaline orbicules may have formed during a transition from magmatic to hydrothermal processes, whereas the vein tourmalines formed by mixing of the exsolved magmatic-hydrothermal fluids with an external fluid rich in Ca and Mg and having higher δ¹¹B than the exsolved magmatic fluids.

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A method is proposed for the determination of Pt, Pd, Ru and Ir in geological samples by isotope dilution-inductively coupled plasma mass spectrometry (ICP-MS). Mono-isotopic elements Rh and Au are determined by external calibration using Lu as the internal standard. Sodium peroxide fusion in corundum crucibles (instead of glassy carbon or zirconium crucibles) is used to decompose the samples. After dissolution of the fused cake in water, the solution is spiked with enriched stable isotopes of Pt, Pd, Ru and Ir, and then acidified with HCl. This solution is then evaporated to dryness promoting the formation of anhydrous silicate from colloidal material. PGEs and Au are then pre-concentrated by Te co-precipitation. The reagents HCl and SnCl₂ are purified by Te co-precipitation. PGE blank levels are thus only derived from the Na₂O₂ which has PGE concentrations of <0.02 ng/g. Lutetium is added as the internal standard to correct for instrument drift and matrix suppression effects for the determination of the mono-isotopic elements. Method detection limits range from 0.02 to 0.3 ng/g. The results obtained for the CCRMP (CANMET, Ottawa, Canada) certified reference materials WGB-1 (gabbro), TDB-1 (diabase), UMT-1 (ultramafic ore tailings), WPR-1 (altered peridotite), WMG-1 (mineralized gabbro), and WMS-1 (massive sulphide) are in good agreement with certified values.

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The Liaodong gold province, along the eastern margin of the North China craton, is a large productive base of gold in China. The Wulong gold deposit hosted in granitoid is a famous Au-bearing quartz vein gold deposit in this region, and located at the northern side of Sanguliu granite. The ages of Sanguliu granite determined by the conventional Rb-Sr isochron and U-Pb zircon methods are 131 ± 4.5 Ma and 129 ± 2.9 Ma respectively, thus the comprehensive isotopic age of Sanguliu granite is 130 Ma. Lode gold deposits commonly consist of pyrite and lesser amounts of galena and sphalerit sulfides accompanied by quartz and calcite. Here we use direct Rb-Sr dating of pyrite from Wulong gold deposit, and determined the age of Wulong gold deposit. A positive correlation between present-day ⁸⁷Sr/⁸⁶Sr and ⁸⁷Rr/⁸⁶Sr ratios of pyrite from the Wulong gold deposit corresponds to an age of 120 ± 3 Ma, which dates the age of gold mineralization. The Sr initial ratios (0.714816 to 0.7148927 of Sanguliu granite and 0.715280 to 0.715504 of pyrites in Au-bearing quartz veins) and Pb isotopic compositions in pyrites and Sanguliu granite indicates that lead was derived partially from the similar magmatic source, and the liner array of Pb isotope composition in pyrite show a incorporation of two end members (may be incorporation of basic and acid wall rocks). The studies of H and O isotopes of fluid inclusions in auriferous quartz veins demonstrate that the magmatic water predominates in ore fluids, and also reflect a little formation waters.

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The oxidation of pyrite in acid sulfate soils (ASS) produces high concentration of strong acid (H₂SO₄) in the soil. The acid reacts with soil minerals and dissolves aluminum and other acid-soluble metals. During rainfall, they are flushed and discharged into terrestrial and aquatic environments. The authors examined the chemical characteristics of the runoffs from ASS in Arashiyama and in Ooshitai, which are located in the northern part of Okinawa Island and evaluated their potential effects on surrounding environments. The results show that the runoffs were very acidic with pH range of 2.87 to 4.29, and minimum values were close to the pH values of the soils. The dominant species were SO₄^2-, Al³⁺, and Fe²⁺ and they were well correlated with pH. The acidity of the runoffs caused dissolution of metals in the following order: Mn > Zn > Cu = Cd. The quality of runoffs was found to be poor and was mainly governed by the interaction of rain and soil. A comparison between the stream waters collected during rain event and on fine day showed a marked changes in stream water chemistry during rainfall as follows: alkalinity was reduced by 3.7 times, sulfate concentration was increased by 3 times whereas pH was decreased by 0.18 units. These changes are attributed to the contamination by runoff from ASS. Moreover brown flocky sediments were observed to have covered entire streambed at the discharging point. The chemical composition of the sediments shows that as those of runoffs, they were dominated by Fe, Al, and SO₄. These results indicate that the sediments were mainly formed as the results of mixing runoffs and stream water.

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Al, K, Sc and Ti concentrations of the terrestrial material-dominant sediments from ODP site 1144 were reported. Comparison between the bulk and the acid-leached sediments indicates that about 20∼30% of the Al, K and Sc in the bulk sediments are not hosted in terrestrial detritus, rather they are of authigenic origin. However, authigenic Ti is negligible. The results indicate that Ti rather than Al is the best proxy for terrestrial materials. Significant climate controls are displayed in the Al/Ti, K/Ti and Sc/Ti variation patterns both for the bulk and the acid leached sediments. Such variation patterns can be mainly accounted for in terms of climate change in their provenance areas in South China. Elevated Al/Ti, K/Ti and Sc/Ti ratios during interglacial periods indicate that chemical weathering then was stronger than during glacial periods, which might be related to a more humid climate in interglacial periods.

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The Middle Miaoershan batholith in South China is one of the best examples of a composite granitic complex, comprising coarse-grained, porphyritic, biotite monzogranites, quartz monzonites, and medium- and fine-grained two-mica granites, formed respectively during the Caledonian, Hercynian, Indosinian and Yanshanian tectonic activity. This is confirmed by radiometric (Rb-Sr, U-Pb, and K-Ar) isotopic ages of 368, 296, 214, and 120 Ma, respectively. The majority of the granitic rocks are peraluminous with aluminum saturation indices [ASI, molar Al₂O₃/(CaO + Na₂O + K₂O)] of 1.05–1.48 and high ⁸⁷Sr/⁸⁶Sr initial ratios, i.e., (⁸⁷Sr/⁸⁶Sr)_i (0.71012–0.72935). Chondrite-normalized (N) rare earth element (REE) abundance patterns for the granitoids are heterogeneous with (La/Yb)_N between 5.75 and 14.38, variably negative Eu anomalies (Eu/Eu* = 0.24–0.80), and overall patterns similar to those of the host metasedimentary rocks. With respect to the old intrusive unit (CMG), the three young intrusive units (HXG, IDG and YG) possess generally lower ΣREE and Zr abundances, and larger negative Eu anomalies, indicating that they may be partially derived from re-melting of the CMG; plagioclase, zircon, and LREE-bearing accessory phases remained in the source during this partial re-melting of the CMG. δ¹⁸O values for all of the granitoids are relatively uniform at 10.12 to 12.99, with a mean of 11.36. The lead isotopes for K-feldspar from the granitoids have a limited variation both within and between massifs, and all of the sample points fall near the upper crust growth curve in a ²⁰⁷Pb/²⁰⁴Pb vs. ²⁰⁶Pb/²⁰⁴Pb plot, indicating derivation from supracrustal sources for rock lead and rock-forming material. The Caledonian Miaoershan granitoids (CMG), however, are proposed to have had a supracrustal metasedimentary source mixed with a minor component of infracrustal derivation, resulting in a relatively low initial (⁸⁷Sr/⁸⁶Sr)_i value (0.70761) and ASI (<1.0). The presence of inherited zircon as ancient core relicts within young magmatic zircons in the CMG shows that partial melting of crustal material, dominantly of metasedimentary origin, combined with re-melting of the granitoids formed by previous partial melting episodes, may be the dominant processes in the genesis of the granitoids. Limited variations of their chemical compositions and Sr, Pb isotopes among different massifs are probably related to the provenance of their source materials.

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The Hangam bauxite deposit is located in the Firouzabad region in southwestern Iran. Structurally the deposit located in the Simply Folded Belt of the Zagros Mountains. The Hangam bauxite horizon, which lies between the Sarvak and the Ilam formations, is approximately 30 meters thick and covers an area of about 1 km². According to stratigraphical and sedimentological data a sedimentary hiatus during Cenomanian-Turonian times has exposed the Sarvak Limestone to karst weathering and the layers of carbonate argillaceous debris (Basal Marly Limestone; Ferruginous Carbonate Marl; Red Marly Limestone; White Marly Limestone) accumulated on its surface, which was partly converted to bauxite (Pisolitic Bauxite, Yellow Bauxite and Red Bauxite). Twenty four samples were collected from eight layers of the deposit for laboratorys work. Microscopic studies of thin and polished-thin sections show pelitomorphic, fluidal, and pseudobrecciated textures, all poiting to an authigenic origin for the Hangam bauxite. This study uses the geochemistry of immobile elements to trace the precursor rock of the bauxite deposit and to calculate the mass changes that took place during weathering and bauxitization. Plots of chemical data and calculation of correlation coefficients show that Al and Ti were immobile during the bauxitization process and were used for mass change calculations. Mass changes were calculated from the concentration ratio of immobile elements for the different bauxite rocks and the Sarvak Limestone. As only one linear trend is evident in the Al-Ti binary diagram and the Sarvak Limestone coincides with this trend, we concluded that the source of the Hangam bauxite was the underlying argillaceous limestone (Sarvak Formation).

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