Danopolonian migmatization of Mesoproterozoic sedimentary rocks in southernmost Sweden: a SIMS zircon study

To assess the age and origin of the metasedimentary migmatites in southernmost Sweden and their relationships with the Mesoproterozoic granitoid magmatism in the area, we have dated migmatite zircon using the secondary ion mass spectrometry U-Pb method. The studied metasedimentary migmatites, here called the Noteboda migmatites, occur along the southwestern boundary of the 1442 Ma Taghusa granitoid intrusion in southeastern Skane. They contain the mineral assemblage garnet + biotite +/- muscovite + cordierite + sillimanite + quartz + plagioclase + K-feldspar and were formed during a retrograde evolution from c. 750-720 degrees C and 6 kbar (peak conditions) to c. 675 degrees C and 4 kbar. Zircon is characterized by detrital cores surrounded by U-rich rims and overgrowths. Separate rounded metamorphic grains also exist. The age probability-density distribution peaks for detrital zircon are at c. 1700, 1670, 1650, 1610, 1570 and 1530 Ma. These ages suggest Gothian orogenic rocks in the present west as the most probable principal source. Sedimentation occurred after c. 1530 Ma, the age of the youngest detrital zircon, indicating the existence of a previously unknown period of Mesoproterozoic sedimentation in southernmost Sweden. A homogeneous zircon overgrowth yielded a concordant Pb-207/Pb-206 age of 1439 +/- 5 Ma, which dates the migmatization and is close to the age of the Taghusa intrusion. We conclude that the burial of the sediments down to c. 20 km, their metamorphism and progressive migmatization took place concurrently with granitic magmatism, NE-SW compression, folding and shearing of the crust between 1460 and 1440Ma during the Danopolonian orogeny

Thermal Conversion of Alkali Lignin of Aspen Wood in Ethanol in the Presence of Sulfated Catalysts Based on Zirconium Dioxide

Исследовано влияние сульфатированных катализаторов ZrO 2 и ZrO 2 –Al 2 O 3 на термическую конверсию щелочного лигнина древесины осины в этаноле при 400 °С и состав образующихся продуктов. Установлено, что сульфатированные ZrO 2 -содержащие катализаторы увеличивают в 1,4–1,5 раза степень превращения лигнина в жидкие и газообразные продукты. При этом резко возрастает выход этанолрастворимой фракции жидких продуктов, выкипающей выше 180 °С, увеличивается содержание в жидких продуктах 1,1-диэтоксиэтана при существенном снижении содержания фенола и его производных.The influence of sulfated catalysts ZrO 2 and ZrO 2 –Al 2 O 3 on thermal conversion of alkaline lignin from aspen wood and on composition of obtained products was studied. Sulfated ZrO 2 -containing catalysts increase by 1.4–1.5 times the degree of lignin conversion to liquid and gaseous products. At the same time they increase dramatically the yield of ethanol-soluble fraction with b.p. higher 180 °С and the content of 1,1 diethoxyethane along with significant reducing the content of phenol and its derivatives in this liquid fraction

Thermal Conversion of Alkali Lignin of Aspen Wood in Ethanol in the Presence of Sulfated Catalysts Based on Zirconium Dioxide

Исследовано влияние сульфатированных катализаторов ZrO 2 и ZrO 2 –Al 2 O 3 на термическую конверсию щелочного лигнина древесины осины в этаноле при 400 °С и состав образующихся продуктов. Установлено, что сульфатированные ZrO 2 -содержащие катализаторы увеличивают в 1,4–1,5 раза степень превращения лигнина в жидкие и газообразные продукты. При этом резко возрастает выход этанолрастворимой фракции жидких продуктов, выкипающей выше 180 °С, увеличивается содержание в жидких продуктах 1,1-диэтоксиэтана при существенном снижении содержания фенола и его производных.The influence of sulfated catalysts ZrO 2 and ZrO 2 –Al 2 O 3 on thermal conversion of alkaline lignin from aspen wood and on composition of obtained products was studied. Sulfated ZrO 2 -containing catalysts increase by 1.4–1.5 times the degree of lignin conversion to liquid and gaseous products. At the same time they increase dramatically the yield of ethanol-soluble fraction with b.p. higher 180 °С and the content of 1,1 diethoxyethane along with significant reducing the content of phenol and its derivatives in this liquid fraction