Monosaccharide compositions were determined for a sediment core (RD-1) collected from a tropical wetland, Rawa Danau, West Java, Indonesia (location 6°11′ S and 105°59′ E) to assess the sources and diagenetic fate of carbohydrates in a tropical wetland based on the acid-hydrolysis monosaccharide compositions. Total monosaccharides (TCHO; normalized to organic carbon) and individual monosaccharide abundances were variable and mostly dominated by glucose through out all depths. The high TCHO, uneqimolar monosaccharide compositions and relatively low deoxysugars/pentoses ratio indicated that carbohydrates were preserved under reducing conditions. The monosaccharide compositional data and diagnostic parameters show that sources of sedimentary carbohydrates changes due to changes in terrigenous plant material which predominantly comprised of angiosperm plants. There are also few transitions between terrestrial and aquatic sources as the most dominant source of sedimentary carbohydrates. Principal component analysis (PCA) of the monosaccharide composition of potential source organisms and RD-1 samples revealed that sources of carbohydrates can be distinguished from the factor loading values. A cross plot of principal component one (PC1) and two (PC2) clearly separated terrestrial and aquatic sources since PC2 has positive values for terrestrial sources and negative values for aquatic sources. Vertical profile of PC2 indicated few major changes in sources of carbohydrates in Rawa Danau wetland associated to changes in local environment. Therefore, combination of monosaccharides composition to PCA is applicable for investigating the sources and fate of carbohydrates in natural environments.

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The ornithogenic sediments in the maritime Antarctic are good archives for studying the changes of historical penguin population. Rare earth elements (REEs) along with biological and lithophile elements in two lacustrine sediment cores (Y2 and Y4) influenced by penguin droppings were analyzed with the aim of evaluating their potential as a new palaeoecological proxy. The relative concentrations of REEs in the two cores show dramatic changes, and the average REE contents are 71.21 ± 11.56 (n = 37) and 37.18 ± 10.64 (n = 18) for Y2 and Y4, respectively. The REE light/heavy content ratios (L/H) are 4.48 ± 0.59 for Y2 and 4.70 ± 0.62 for Y4, very close to the mean ratio of four pure guano samples. The chondrite-normalized REE patterns in the Y2 and Y4 sediments significantly influenced by penguin droppings are characteristic of more fractionation, obviously negative Ce anomalies and positive Er anomalies, likely imprinting the REE signal of guano input. The total REE concentration has a statistically significant negative correlation with the levels of guano-derived bio-elements and a positive correlation with the levels of Sc and Al mainly originated from weathered soils. The calculated proportion of guano-derived REE based on two-member mixing equation has a change pattern consistent with that of the historical penguin population size, previously reconstructed from bio-element concentrations in the sediments. These results suggest that the non-crustal signature of REE in the ornithogenic sediments may provide a new palaeoecological proxy for studying the palaeoecological processes of Antarctic penguins on a large time scale.

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The isotopic variation of industrially produced antimony was estimated using multiple-collector inductively coupled plasma mass spectrometry. A reproducible ¹²³Sb/¹²¹Sb ratio of ±0.004% (2 standard deviations) was routinely obtained using a Sn doping mass discrimination correction technique. Only a small isotopic variation of about 0.05% was observed among industrially important Sb materials (five commercially available reagents and two ore minerals). The degree of Sb isotopic variation to determine the uncertainty in Sb atomic weight can be reduced by this new analytical technique to 0.00025 compared to the currently accepted IUPAC isotopic variation determined by conventional mass spectrometry of ±0.001. Heavy isotope enrichment of Sb in a drainage water sample from a stibnite mining area was found. This heavy isotope enrichment tendency in an aqueous environment may be useful in detecting anthropogenic Sb input from industrial emission by the smelting process via air because Sb of anthropogenic origin will have lighter isotope enrichment features.

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Major, trace element and Sr-Nd isotopic compositions of Cenozoic sedimentary rocks from the Dongying Sag and the Zhanhua Sag, Jiyang Depression, provide evidence for provenance evolution and paleogeographic reconstruction. Compared with the average composition of post-Archean Australian shales (PAAS), the Paleogene sedimentary rocks of Shahejie formation (Es) from the Dongying Sag have similar SiO₂, Al₂O₃ contents, lower K₂O, Na₂O contents with K₂O/Na₂O ranging from 0.18 to 4.58, relatively lower contents of V, Cr, Co, Ni, Nb, Ta, Y, Rb, and Cs, and higher contents of Sr, Ba, Zr and Hf. All samples show chondrite-normalized REE patterns similar to that of PAAS, with significant light REE enrichment, flat heavy REE and negative Eu anomalies (Eu/Eu* = 0.71-0.99, average of 0.80). The Sr-Nd isotopic compositions of the Paleogene sedimentary rocks are different from those of the Neogene sedimentary rocks which generally have higher ⁸⁷Sr/⁸⁶Sr and lower ¹⁴³Nd/¹⁴⁴Nd. In the geochemical discrimination diagrams (e.g., La/Th-Hf, La-Th-Sc, and Th-Hf-Co), the studied samples were plotted in the area of felsic rocks rather than mafic rocks, which indicated that the source rocks are mainly composed of post-Archean felsic igneous rocks and recycled sedimentary rocks. This is also supported by interelement ratios such as La/Co, La/Th, Th/Co, and Th/Cr. The Sr-Nd isotopic compositions vary from the Paleogene to Neogene sedimentary rocks further suggesting a change in provenance, during which contemporaneous volcanic lava supplied some clasts with higher ¹⁴³Nd/¹⁴⁴Nd and lower ⁸⁷Sr/⁸⁶Sr ratios for deposition of Paleogene Es sedimentary rocks, whereas the contribution of volcanic detritus became much less during the Neogene time. The geochemistry of sedimentary rocks from the Jiyang depression possibly implies that the Paleozoic sedimentary rocks covering the old metamorphic crystalline basement rocks may not be totally denuded at the surrounding uplifts and highs during the Paleogene time.

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The Western Cordillera of Ecuador consists of Cretaceous crustal fragments of oceanic plateaux and superimposed insular arcs, which were accreted to the northwestern South American margin during the Late Cretaceous and Paleocene. Slices of high-grade metabasites, ultramafic rocks, gabbros and basalts, unmetamorphosed radiolarian cherts and scarce garnet-bearing metasediments were randomly exhumed along Miocene to Recent transcurrent faults crosscutting the Western Cordillera. The basalts show geochemical characteristics of oceanic plateau basalts (flat REE patterns, La/Nb = 0.85). The gabbros differ from the basalts in having lower REE levels, positive Eu anomalies, and negative Nb and Ta anomalies; they are interpreted as resulting from arc magmatism. The amphibolites and banded amphibolites have major and trace element chemistry similar to that of oceanic plateau basalts (flat REE patterns, La/Nb = 0.86) or to cumulate gabbros. The granulite shares with oceanic plateaus similar trace element chemistry (flat REE patterns, La/Nb < 1) and ε_Ndi values (+7.6). Continent-derived metasediments are depleted in heavy REE (La/Y = 4.8) and have a negative Eu anomaly. Foliated lherzolites, melagabbronorites and pyroxenites consist of serpentinized olivine + cpx + opx ± Ca-plagioclase. Lherzolites, melagabbronorites and pyroxenites are LREE depleted with positive Eu anomalies, while the harzburgite displays a U-shaped REE pattern. The trace element abundances of the ultramafic rocks are very low (0.1 to 1 times the chondritic and primitive mantle values). The ultramafic rocks represent fragments of depleted mantle, deformed cpx-rich cumulate, and continental lithospheric mantle or mantle contaminated by subduction-fluid. Except the scarce quartz-rich metasediments, all these rocks likely represent remnants of accreted oceanic crustal fragments and associated depleted mantle. Since these samples were randomly sampled at depth by the fault, we propose that the Western Cordillera and its crustal root are mainly of oceanic nature.

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Diamond prospectivity of Mesoproterozoic lamproites in the Krishna valley at the northern and north-eastern margin of the Cuddapah Basin, southern India, is a matter of significance since several historically world-famous alluvial diamonds were recovered from their near vicinity. As the Krishna lamproites presently expose their root zones the possibility of diamond occurrence in their now-eroded uppermost portions remains an open question and renders assessment of their diamond prospectivity a challenging task. Based on newly developed models from a global data base, that predict diamond potential of hypabyssal facies lamproite/kimberlite from whole-rock geochemistry, we infer the Krishna lamproites to be non-diamondiferous. The non-prospective nature of Krishna lamproites is also additionally corroborated by the (i) non-recovery of macro diamond from bulk processing of samples to date, (ii) relatively larger degree melting of their source regions compared to those of diamondiferous kimberlites from Wajrakarur kimberlite field (Dharwar craton) and also the poorly diamondiferous lamproites from Chelima and Zangamarajupalle (Cuddapah basin) and (iii) their relatively highly fractionated nature. If our proposal is correct, then the primary source(s) for the historically renowned diamonds recovered from the Krishna valley may lie elsewhere or be from host rocks yet to be discovered.

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