Genesis of magmatic ilmenite ores associated with the Mazua ultramafic intrusion, NE Mozambique

The Mazua ultramafic intrusion is among the most promising intrusions hosting Fe-Ti oxide ores in Mozambique. Fe-Ti oxide ores are mainly composed of ilmenite occurring as lenses, veins and layers, either massive or disseminated in hornblende pyroxenite. This study discusses the nature and origin of the intrusion and related ilmenite ore body on the basis of whole-rock and mineral chemistry. Textural and structural evidences support a cumulate origin for these rocks, including the occurrence of relict cumulate textures, layering of alternating oxides and silicate-rich rocks, and size-grading of silicate-rich layers. Primary magmatic features have, however, largely been overprinted by subsolidus processes. The occurrence of the cumulate assemblage (Fe-Ti oxides and clinopyroxene), without plagioclase and olivine, suggests that the magma underwent differentiation before its emplacement. The evolved magmatic nature of the intrusion is consistent with the calculated Mg-number of approximately 50 for the melt in equilibrium with clinopyroxene crystals. The high TiO2 concentrations (>4 wt%) of the evolved magma, by differentiation, are interpreted as the main factors controlling the crystallization of Fe-Ti oxides. We propose that the ores formed from crystallization and settling of Fe-Ti oxide minerals from an evolved basaltic magma. This model is consistent with (1) the occurrence of Fe-Ti oxides and clinopyroxene as cumulates in relation to the coexisting amphibole, (2) the layering structures of alternating oxides and silicate matrix, (3) the scarcity of apatite supported by the extremely low whole-rock P2O5 concentrations and (4) the restricted occurrence of ore veins, excluding the formation from immiscible oxide melts

Herbig Ae/Be Stars in the Magellanic Bridge

We have found Herbig Ae/Be star candidates in the western region of the Magellanic Bridge. Using the near infrared camera SIRIUS and the 1.4 m telescope IRSF, we surveyed about 3.0 deg x 1.3 deg (24 deg < RA < 36 deg, -75 deg < Dec. < -73.7 deg) in the J, H, and Ks bands. On the basis of colors and magnitudes, about 200 Herbig Ae/Be star candidates are selected. Considering the contaminations by miscellaneous sources such as foreground stars and early-type dwarfs in the Magellanic Bridge, we estimate that about 80 (about 40%) of the candidates are likely to be Herbig Ae/Be stars. We also found one concentration of the candidates at the young star cluster NGC 796, strongly suggesting the existence of pre-main-sequence (PMS) stars in the Magellanic Bridge. This is the first detection of PMS star candidates in the Magellanic Bridge, and if they are genuine PMS stars, this could be direct evidence of recent star formation. However, the estimate of the number of Herbig Ae/Be stars depends on the fraction of classical Be stars, and thus a more precise determination of the Be star fraction or observations to differentiate between the Herbig Ae/Be stars and classical Be stars are required.Comment: 22 pages, 6 figures. Accepted for publication in Ap

A qualitative case study on the Swedish Midsummer event in Tobetsu, Japan : An exploratory approach of the perception of the event in regards to the local community and the organizers

The Swedish Midsummer event has been organized and celebrated for several years in Tobetsu inJ apan, especially since the establishment of a sister city relationship with Leksand in Sweden. Yet, there is little to no data or literature on the event as to why Japanese residents chooses to involve the culture of Sweden by organizing such an event annually and what the residents actually perceive of the event This research explores the Swedish Midsummer event in Tobetsu more closely in the formof a case study which involves the organizers and residents. By conducting semi-structured interviews it was clear that the organizers want to highlight the relationship with Sweden, to enable cultural interaction as well as attracting more people to the town due to its decreasing and aging residents. However, some of the residents find the event disturbing while others enjoy it to some degree. As a case study on Tobetsu, this research demonstrates the utilization of a sister city relationship in order to differentiate the town and to nurture the relationship with the other town, in this case being Leksand, on a local level by contextualizing it in a yearly cultural event. The findings of this case study along with the theoretical framework highlights the importance of involving the residents in the organization of the event in order to succeed and reach the goals of Midsummer. In the future, there exists an interesting notion of following up this research, in order to investigate whether the goals of organizing Midsummer in Tobetsu have been fulfilled or not and if and/or how the residents have been involved in the organization process

A qualitative case study on the Swedish Midsummer event in Tobetsu, Japan : An exploratory approach of the perception of the event in regards to the local community and the organizers

The Swedish Midsummer event has been organized and celebrated for several years in Tobetsu inJ apan, especially since the establishment of a sister city relationship with Leksand in Sweden. Yet, there is little to no data or literature on the event as to why Japanese residents chooses to involve the culture of Sweden by organizing such an event annually and what the residents actually perceive of the event This research explores the Swedish Midsummer event in Tobetsu more closely in the formof a case study which involves the organizers and residents. By conducting semi-structured interviews it was clear that the organizers want to highlight the relationship with Sweden, to enable cultural interaction as well as attracting more people to the town due to its decreasing and aging residents. However, some of the residents find the event disturbing while others enjoy it to some degree. As a case study on Tobetsu, this research demonstrates the utilization of a sister city relationship in order to differentiate the town and to nurture the relationship with the other town, in this case being Leksand, on a local level by contextualizing it in a yearly cultural event. The findings of this case study along with the theoretical framework highlights the importance of involving the residents in the organization of the event in order to succeed and reach the goals of Midsummer. In the future, there exists an interesting notion of following up this research, in order to investigate whether the goals of organizing Midsummer in Tobetsu have been fulfilled or not and if and/or how the residents have been involved in the organization process

Intercultural Understanding through Communication Activities: Comparing Authorized Textbooks for Japanese Elementary School EFL

The Course of Study for Elementary School asserts that it is necessary to understand the culture behind the communication, focusing on its relationship with society, the world, and others. In this study, the researcher analyzed the content of communication activities included in authorized textbooks for elementary school foreign language study from a cultural perspective, considering the characteristics of the culture therein. The results revealed differences among textbooks, with social culture as social topics and individual culture in the exchange of individual information the main cultural focus of interactive language activities. The paper closes by discussing the implications of these aspects of culture and the prospects for future research on deepening understanding of different cultures through communication

Primary source of placer gold in the Luk Ulo Metamorphic Complex, Central Java, Indonesia

The Luk Ulo Metamorphic Complex, Central Java is a product of the Cretaceous subduction and accretion, and includes diverse types of protoliths. Two-types of primary mineralization have been recognized in this area, namely, (1) seafloor basalt-hosted massive sulfide mineralization and (2) low-grade metamorphic rocks-hosted vein type mineralization. Later erosion of these types of primary mineralization formed placer gold deposits along rivers. However, the source has never been identified. Thus, this study aims at understanding the source of placer gold, the characteristics of the primary mineralization, and the tectonic evolution of the study area on the basis of mineralogy, mineral chemistry, whole-rock geochemistry, and sulfur isotope analyses. Volcanogenic massive sulfide (VMS)-type mineralization was identified in the seafloor basalt and few deep-sea sedimentary rocks, and both the ores and host rocks preserved pre-metamorphic textures and minerals. The characteristics of this VMS-type mineralization include (1) crustiform quartz veins with pyrite cutting the host rocks, (2) zonation of local silicification to interlayered chlorite/smectite-chlorite-laumontite-calcite-epidote alteration from central to outer zone, (3) pyrite-dominated ores with minor amounts of arsenian pyrite, chalcopyrite, and marcasite, (4) unmetamorphosed host rocks and ores, and (5) sulfur isotope signature with a median δ34S of +3.1‰ suggesting sulfur derived from magmatic source and/or sulfur extracted from basaltic rocks with a small contribution of biogenic sulfur. On the other hand, low-grade metamorphic rocks-hosted vein type mineralization was identified as orogenic-type gold mineralization, and the mineralized veins formed after the peak of metamorphism. It is characterized by (1) pyrite-arsenian pyrite ores with minor amounts of arsenopyrite, galena, tetrahedrite, chalcopyrite, and sphalerite, (2) quartz-illite-graphite alteration assemblage, (3) mineralized veins cross-cutting the foliation of metamorphic host rocks, (4) high antimony contents of pyrite (up to 1.7 wt) and rutile (up to 160 ppm), (5) relatively high ore-forming temperature (423 ± 9°C, calculated from arsenopyrite and graphite geothermometers), and (6) remobilized-sedimentary sulfur signature of the ores with a median δ34S of −9.8‰. Several lines of evidence suggest that placer gold was likely derived from the erosion of orogenic-type gold ores in the surrounding areas. This evidence includes the presence of gold-bearing ores hosted by low-grade metapelites and metagranitoid with characteristics of orogenic-type gold mineralization, whereas the VMS-type ores are barren in gold. The occurrence of the mid-oceanic ridge- and accretion zone-related mineralization in this area reflects the subduction and amalgamation of oceanic and continental crustal blocks during the Cretaceous period. Discovery of gold mineralization hosted in the Cretaceous basement rocks of the Sunda arc indicates the importance to broaden the gold exploration targets to include not only young volcanic rocks, but also relatively old metamorphic basement rocks. © 2022 Society of Resource Geology