Abstract In this paper the main results of the first archaeological dig in Colombia of a pre-Hispanic goldsmith workshop are presented succinctly; this workshop worked over 800 years in the lower ...basin of the Saldaña river (Magdalena Valley). Human groups settled there during the late period (9th-17th c. AD) had technical expertise (hammered-annealing, lost wax casting and emptying), tools (refractory ceramic and lithic industry) and forest resources and minerals needed to produce parts in copper and gold high quality, complexity and size (heartlike pectorals, anthropomorphic and zoomorphic figures with tips on bracket). Ann Arbor: Museum of Anthropology, University of Michigan. "Sicán Metalworkings Furnaces: Excavation, Archaeometric and Experimental Data and Insights into their Operation and Broader Production Context".
We present a detailed petrological, structural and geochronological study of the mylonitic Ryoke metamorphic rocks within the granitic mylonite (Kashio mylonite) and Sanbagawa metamorphic rocks along ...the Median Tectonic Line (MTL), Japan. Located in the Oshika area of the Chubu District, the Kashio mylonite is one of the few geologic units that can be used to determine detailed pressure–temperature–time–deformation (P–T–t–D) paths during mylonitization because it occurs as many small tectonic blocks of mylonitic metasediment. Detailed petrological analysis coupled with conventional thermobarometry and P–T pseudosection modelling give estimated peak P–T conditions (M1a) of 650–790°C at 4.6–5.6 kbar for the Ryoke metamorphic rocks. The gneissose Ryoke granitoids were emplaced subhorizontally at around 685–710°C and 4.6–5.8 kbar, after peak metamorphism. The Kashio shear zone developed immediately after the last igneous activity at ca. 71 Ma, and two stages of mylonitization (stages D1 and D2) can be identified from microstructural observations. The retrograde P–T conditions (M1b) recorded in the Kashio mylonite exhibit a systematic change in temperature from 710°C to 450°C at 5.2–2.6 kbar with decreasing distance from the MTL. By contrast, highly deformed mylonites with zoned garnets demonstrate a striking increase in pressure from 4.0 to 8.3 kbar with decreasing temperature from 590°C to 450°C after low‐P/T‐type metamorphism. Such a temperature range indicating isothermal compression is consistent with deformation temperatures of stage D1 determined from quartz microstructures and quartz c‐axis fabric opening‐angle deformation thermometer. Moreover, the timing of the two mylonitization episodes during retrograde metamorphism are estimated to be 69–67 and 66–64 Ma, respectively, with a high cooling rate of ~34°C/Ma using the revised time–temperature relationship of the host Ryoke granitoids. The rapid change in tectonic setting with strain localization occurred during the brief period between 69 and 64 Ma. Our field and petrological observations imply that a thick D1 mylonite zone was formed by rapid subsidence (≥10 km) with cooling of the hangingwall rocks from the middle crust to the subduction interface. It is considered that the underplating of exhumed high‐P/T‐type metamorphic rocks led to further cooling between hangingwall and footwall rocks and the formation of a narrow D2 mylonite zone, which served as an old plate boundary. Thus, low and high‐P/T‐type metamorphic belts had already been amalgamated as paired metamorphic belts beneath the brittle–ductile transition of the subduction zone before exhumation. The rapid cooling of hangingwall rocks at the subduction interface is proposed to play an essential role in the thermal overprinting of exhumed high‐P/T‐type metamorphic rocks.
Suzuki Izumi's (1949-1986) short story "Onna to onna no yo no naka" (A World of Women and Women) was published in 1976, at the time when the genre of separatist feminist utopia was flourishing in the ...West. Worlds of women in the context of Western literature have been viewed as part and parcel of the feminist movement and debates of the 1970s and 1980s and some attempts have been made to look at Suzuki's story through the same lens. However, this essay claims that "A World of Women and Women" should be examined as an expression of discomfort experienced by women in society rather than as a possible blueprint for a better social order or utopian feminist vision. I contend that Suzuki's work reflects the contemporary cultural atmosphere of disappointment both with the state and with protest movements, with what the philosopher Yoshimoto Takaaki called "communal illusion." The story is a critique of a discursive space near and dear to Suzuki's heart - the world of shōjo narratives (narratives aimed at girls and young women), constructed as an insular space that precludes real engagement with the reality of having to live in a world in which men do exist.
•Weathering of arenite sandstone with sparse calcite cement is a chain reaction.•Important weathering process is pore opening caused by dissolution of calcite.•Calcite is dissolved by sulfuric acid ...generated by pyrite oxidation.•After the dissolution of calcite, pore spaces are connected and become wider.•Mineralogical changes are mostly limited near the ground surface.
We conducted a multifaceted analysis of the weathering zones of arenite, containing a minute amount of calcite cement, based on mineralogical, chemical, and physical properties. The survey targeted sandstone with mudstone interbeds belonging to the Cretaceous Izumi Group. The survey revealed that the weathering mechanism is a chain reaction; the most important process is the pore opening between the grains caused by the dissolution of calcite cement in the initial stage of weathering. Subsequently, the pores between the grains connect and widen, separating the sand grains within the sandstone. This primary weathering action may be a major difference from wacke. During calcite dissolution in the initial stage, sulfuric acid generated by pyrite oxidation in sandstone plays an important role. Chlorite breaks down as calcite dissolves; however, iron resulting from the breakdown disappears only after the pore water has been replaced by acidic water.
Sandstones with advanced diagenesis are dense and hard, and it was previously assumed that thick weathering zones could not develop because they were less susceptible to weathering. However, we discovered that weathering caused arenite with a minute amount of calcite cement to disintegrate into grains down to a depth of 30 m. The surface layer of the weathered arenite lost fine particle fraction and crept to form a fragile soil layer susceptible to landslides.
In this study, a new late Campanian (Late Cretaceous) heteromorph ammonoid, Didymoceras morozumii Misaki and Tsujino sp. nov., from the Hiketa Formation, Izumi Group, southwestern Japan, is ...described. It is characterized by a loose helical post-embryonic early whorl and relatively tight helical middle whorls, followed by a retroversal hook with a highly elevated apertural end, and two rows of irregular tubercles. Didymoceras morozumii sp. nov. occurs in the upper part of the Didymoceras sp. Zone, which is overlain by the Didymoceras awajiense Zone. Didymoceras awajiense-bearing beds of the Hiketa Formation in the study area is correlated to the lower part of that of the Toyajo Formation in the Kii Peninsula on the basis of the shell forms of D. awajiense. Didymoceras morozumii sp. nov. and D. awajiense have similar characteristics, and it is thought that D. awajiense evolved from D. morozumii sp. nov. As indicated in the descendants, some specimens of D. morozumii sp. nov. are also encrusted by anomiid bivalves.
Histories of wartime Japan often focus on the Japanese home islands after Japan's surrender to Allied forces on 15 August 1945. Japanese citizens living in Korea, Manchuria, and elsewhere in the ...far-flung Japanese Empire are usually left out of the historiographical record. In a new book about the evacuees-hikiagesha-from the defunct Empire, Shimokawa Masaharu presents a vivid, harrowing portrait of the suffering of those who had to make their way back to Japan after the end of the Greater East Asia War. In particular, Shimokawa focuses on Izumi Sei'ichi, who established a sanatorium and abortuary in Fukuoka for women who had been raped by enemy soldiers.
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Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Asian hesperornithiforms are extremely rare in contrast to North American records; thus, their diversity in Asia during the Cretaceous is unclear. Maastrichtian hesperornithiform materials have been ...reported from both fluvial and marine deposits in North America but only from fluvial deposits in Asia. Asian hesperornithiforms from Maastrichtian deposits have been considered as freshwater taxa because of their occurrence from fluvial sediments and their histological features. Here, we report the first hesperornithiform record from marine Maastrichtian deposits in Asia. It is represented by an isolated left tibiotarsus from the inter-arc basin deposit of the Kita-ama Formation (lower Maastrichtian), Izumi Group of southwest Japan. It has a shallow tibial incision, fibular crest extending to the mid shaft, and laterally angled lateral articular surface. Although its phylogenetic position within Hesperornithiformes is ambiguous, these characters are similar to non-hesperornithid hesperornithiforms. Unossified proximal and distal epiphyses indicate that this individual was immature. A remarkably thick cortical area of the tibiotarsus suggests that this hesperornithiform was a sea-dwelling bird and that the habitat of this group during the Maastrichtian extended to both terrestrial and marine environments in Asia and North America.
•We report a new material of a hesperornithiform from the lower Maastrichtian of southwest Japan.•This is the first Hesperornithiformes from the Maastrichtian marine deposits in Asia.•This indicates Maastrichtian hesperornithiforms inhabited both terrestrial and marine environments in Asia and North America.
Detrital zircon U-Pb ages were measured for nine non-fossiliferous sandstones from the uppermost Izumi Group, a “Late Cretaceous” forearc clastic sequence in the eastern Izumi Mountains of western ...Kii Peninsula, SW Japan. Seven out of nine sandstones yielded Paleocene grains. These results confirm that the uppermost Izumi Group was deposited in the Paleogene (Selandian-Thanetian or younger), extending the total depositional duration of the group to ca. 27 myr, almost double the previous estimate. The new age data raise the possibility that a stratigraphic interval across the Cretaceous-Paleogene extinction boundary may be preserved within the group. The occurrence of Paleogene strata further constrains the onset of the low-angle Median Tectonic Line to post-Paleocene.
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