In February 1971, a meteorite fell on the roof of a barn belonging to Mr. E. Schmitz in Tintigny, a village in southern Belgium. Upon its recovery, its meteoritic origin was confirmed by the schoolteacher, Mr. A. Rossignon who then looked after the sample. In 2017, for the first time, the meteorite was given to specialists for a detailed examina-tion and classification. We used various analytical techniques to characterize its mineralogy, elemental, and isotopic composition. Based on the obtained data, we classified it as a polymict eucrite, a meteorite originating from 4 Vesta, and named it Tintigny [1]. Tintigny is partly covered by shiny black fusion crust. Its interior mainly exhibits a light grey color and shows a brecciated texture composed of a fine-grained matrix, hosting darker crystals and cm-sized dark grey clasts. Under the microscope, a brecciated sub-ophitic basaltic texture mainly composed of plagioclase/maskelynite and clinopy-roxene is dominant. In addition to the dominant sub-ophitic texture, at least three distinct textures exposed in clasts are observable. At least two generations of shock effects (such as fractures), are present in the sample: those limited to clasts and large crystals, and those that crosscut both the large grains and the matrix. The accessory minerals include troilite, ilmenite, chromite, FeNi metal, and silica. Mineral chemistry calculations of pyroxene end-members show ranges from 8.5 to 60.7 mol% for enstatite, 30.1–70.0 mol% for ferrosilite, and 2.6–38.4 mol% for wollastonite. Based on these values, most pyroxenes in Tintigny are pigeonite and augite [2]. The Fe/Mn ratios of pyroxenes range from 27.1 to 39.3, with the highest ratio observed in pyroxene from the symplectitic clast. Fe/Mn and Fe/Mg ratios in low-Ca pyroxene (Wo<10) are 30.2±4.4 and 0.8±0.3, respectively. These ratios in high-Ca pyroxene (n=8) are 34.3±3.7 for Fe/Mn and 2.6±2.4 for Fe/Mg. The average pyroxene Fe/Mn ratio for all pyroxene is 32.5±4.4 (SD, n=14). Fe/Mg ranges from 0.6 to 8.2, with an average value of 1.8±2.0 (SD, n±14). Considering pyroxene Fe/Mn ranges of 40±11, 62±18, 32±6, and 30±2 for basaltic rocks from the Earth, Moon, Mars, and 4 Vesta (eucrites), respectively, and based on our data, particularly those of low-Ca py-roxene, Tintigny falls in the range of basaltic eucrites [3]. The bulk rock Fe/Mn and Fe/Mg ratios of Tintigny are 33.9 and 3.1, respectively. These values overlap with those measured for howardite-eucrite-diogenite (HED) and martian meteorites [4]. With a Ga/Al ratio of 4.17×10-5, Tintigny falls within the range of those of eucrites. Using the CI-normalized elemental concentration, we can see strong simi-larities between Tintigny and noncumulate eucrites, which is also reflected based on the abundance of TiO2 (0.63) and FeO/MgO ratio (2.66) in Tintigny. The bulk oxygen isotopic composition of Tintigny, as determined by laser fluorination, is also consistent with it being an HED (δ17O=1.72±0.04 ‰; δ18O=3.76±0.08‰; Δ17O=-0.25±0.01 ‰ (n=2, errors 2SD)), with a composition that plots close to the Eucrite Fractionation Line [5]. Based on the Meteoritical Bulletin Database, only 70 HED falls have been reported so far. Including Tintigny, only 39 eucrite falls are known to date, 11 of them occurred in Europe, with Tintigny being the only one from Belgium. In addition to the scientific importance of studying a eucrite fall like Tintigny, we emphasize the significance of the discovery of a historical meteorite fall by drawing attention to national scientific heritage that must be properly un-derstood and safeguarded for generations of scientists, scholars, and amateurs to come. Nowadays, together with four other meteorites from Belgium (Hautes Fagnes LL5, Lesves L6, St. Denis Westrem L6, and Tourinnes-la-Grosse L6), the Tintigny achondrite is exhibited in the meteorite gallery of the Institute of Nat-ural Sciences in Brussels and is open to the public for visits.
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RBINS Staff Publications 2024
Almost nothing is known about the evolution of shell colour in invertebrates. This is largely due to the ultra-rarity of fossils in which colour patterns and pigments are preserved and immediately visible, and therefore easy to identify, especially when these are hundreds of millions of years old. This hampers our understanding of the role and function of colour in extinct animals, their ecology, mode of life, interactions, development, and evolution. A good example for this ultra-rarity is the Palaeozoic of Belgium, world-renowned for its exquisitely preserved fossils of the Devonian and Carboniferous, enabling to document major transitions in ecosystem dynamics and the evolution of life on Earth (e.g. nekton revolution, terrestrialisation, major climate changes, anoxic events, biodiversity crises) but from which only a few cephalopod, bivalve and gastropod mollusc and brachiopod shells were historically documented preserving coloured traces (mostly by L.-G. de Koninck and P. de Ryckholt, mid to late 19th century). However, recently, it was discovered that many more specimens preserve these traces, in particular those from Tournaisian–Viséan shallow marine reef environments, allowing to investigate its occurrence in different evolutionary lineages of marine invertebrates exactly during one of the main periods of revolution in geologic history. In Brain project B2/P233/P2 nicknamed COLOURINPALAEO financed by Belspo, after gathering all the specimens available in the main Belgian collections, we will use different techniques (multispectral photogrammetry and spectro-imaging) to better visualise the preserved colour patterns and pigments. Furthermore, advanced spectroscopic techniques, namely Raman micro-probe spectroscopy, synchrotron trace elemental mapping and absorption spectroscopy, will be used to identify the chemical signature of the pigments as well as their mode and pathways of preservation. Some of the first results on this multidisciplinary study on a unique set of Belgian fossils will be presented.
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RBINS Staff Publications 2024