NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Bailey, J. C., Gwozdz, R., Rose-Hansen, J., & Sørensen, H. (2001). Geochemical overview of the Ilímaussaq alkaline complex, South Greenland. Geology of Greenland Survey Bulletin, 190, 35-53. https://doi.org/10.34194/ggub.v190.5172 _______________ The Ilímaussaq alkaline complex is one of the latest members of the Mesoproterozoic Gardar igneous province. It was emplaced in three phases, (1) augite syenite, (2) alkali acid rocks and (3) the dominant agpaitic nepheline syenites. The immediate parent for the nepheline syenites is the augite syenite whose geochemical features, such as the low Zr/Nb ratio (3.7), match benmoreites from a nearby alkali basalt series. The agpaitic nepheline syenites are characterised by exceptionally high contents of Zr, Hf, Nb, Ta, REE, Th, U, Sn, Li, Be, Rb, Zn, Pb, Sb, W, Mo, As and Ga, and the volatile elements F, Cl, Br, I and S but exceptionally low levels of Ba, Sr, Co, Cu, Ni, Sc, V and Cr. Fractionation of cumulus phases with a distinctive geochemistry, such as sodalite (rich in Cl, Br, I, B), eudialyte (Zr, Hf, Nb, Ta, W, As) and arfvedsonite (Co, Sc, V, Cr), caused exhaustion of these elements in the residual magmas. The agpaitic magmas underwent extreme fractionation with the final lujavrite forming after 99% crystallisation of the augite syenite. Zirconium was apparently soluble in Ilímaussaq melts up to a concentration of c. 9000 ppm. Whole-rock analyses define a number of discrete Zr–U arrays which are restricted to certain intervals of the cumulate stratigraphy and are taken as evidence for liquid layering in the Ilímaussaq magma chamber. The distribution of the less common trace elements (Bi, Cd, Co, Ge, In, I, Hg, Sc, Se, V, W) and of the more abundant trace elements which failed to form minerals (Br, Cs, Ga, Hf, Rb, Sr) is summarised.

Abstract— Precise radiometric age determination of the Kaalijärv meteorite craters on the island of Saaremaa in Estonia have so far proved inconclusive. Here we present trace element analyses of peat cores taken several kilometers away from the Kaalijärv craters that reveal a distinct Ir‐enriched layer produced by the meteorite impact. By radiocarbon dating the peat cores, we have determined for the first time the precise age of the impact that generated the Kaalijärv craters. The calibrated date of the impact is 400–370 B.C. at ± 1σ.

Abstract-We have measured excess Ir and depletion of 14C, two independent indicator:; of cosmic material, in peat cores from the central Tunguska impact site. Both Ir and 14C show pronounced anomalies in the same stratigraphical depth interval. We have estimated an integral deposition of nonradioactive cosmogenic C of 6.8 f 1.0 mg C cm-2, and an integrated Ir deposition of 5.9 & 1.2 pg Ir cm-2. The veiy high C/Ir ratio and a deduced d13C value of +55 t 10%0 relative to V Pee Dee Belemnite (VPDB) of the imr'actor material found in this study points towards a cometary type impactor, rather than a chondritic or achondritic asteroidal type impactor.

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As recent research has shown that lime-production and pyrotechnic predates ceramics in the Levant and Anatolia, samples of relevant material from Hama M dated to the earliest ceramic phase in the area has been examined. By means of x-ray diffraction we have shown that lime was utilized in two variations, a fine ware for vessel and textile plastering, and a coarse ware for floor and wall-plaster. Some of the implicit technological perspectives are represented.