The active Aleutian arc is currently classified as an accreting margin as most of the arc has a well-developed frontal accretionary prism that formed in the Plio-Pleistocene. We focus on the central ...Aleutian island arc where the arc massif was built to near its current size by the Late Eocene and has since seen limited growth and endured episodic erosion prior to the development of the accretionary prism. As a result, the volcanic front has migrated northwards tens of kilometers since inception. Along with previous mapping, dating and geochemical data, sixteen new 40Ar/39Ar dates and new geochemical data for volcanic rocks on several central Aleutian Islands supplement recent geochronologic data from six other islands in this region and facilitate an attempt to understand how and where Aleutian arc volcanism has migrated with time. Long-term average arc migration rates range from 0.6 to 5 km/Ma in three distinct locations. The arc migration rate increases to the west and is greatest over the last five million years as the arc migrated from a 7–5 Ma volcanic front to its current location. Arc migration and erosion during this most recent period may have been expedited by either the subduction of the Kula Ridge, which ceased spreading in the early Eocene, or clockwise rotation of the Pacific plate in the late Miocene. Some central Aleutian lavas and plutonic rocks have elevated La/Yb, Sm/Yb, and Sr/Yb, most of which were emplaced during times of arc migration or in the waning stages of a peak in magmatic activity. The strongly fractionated trace element patterns are similar to the basaltic andesites to dacites from the western Aleutian seafloor, which are interpreted to be the result of residual garnet during partial melting of eclogite in the subducting oceanic crust. However, the existing subduction parameters coupled with the timing of the central Aleutian adakite-like lavas favors a model in which significant subduction erosion of the mafic forearc, including erosion and subsequent melting of the trapped Kula plate (i.e., MORB-like oceanic crust) as well as early Aleutian arc basalts in the mid-crust, may be partly responsible for the eclogitic component observed in central Aleutian magmas.
•We have attempted to quantify Aleutian arc migration for the last 35+ million years.•The arc has migrated the most over the last five million years.•Significant erosion of the forearc has likely occurred during periods of arc migration.•The former Kula plate trapped within the arc may influence central Aleutian magmas.
Kula is a district rich in cultural values. There are many historical and traditional residences in this region. These historical structures have undergone great and different changes over time. It ...is aimed to determine the transformations related to facade, structural element, and interior use in traditional houses. In addition, by looking at the obtained data, namely the architectural changes, it was determined as a secondary purpose to make suggestions about conservation. The study consists of a combination of two basic methods: literature research and field research. After determining the subject of the study, written sources related to the subject were searched and the research was supported by field studies. The method of the study is the comparison of the data obtained from the sources and the evidence in the field study. Findings were obtained by analyzing the detected differences. In the study, which was carried out with the comparative analysis method, the historical process was examined, and information, architectural drawings and photographs were obtained about the conditions of the buildings 50 years ago. For this reason, scope of the study consists of both the data obtained and the houses that provide both conditions depending on the availability of these data today. In this context, the study is limited to 14 traditional Turkish residences in the Kula site, from which both historical data and locations can be accessed. In the studies carried out in the field of architectural restoration and conservation, the current situations are examined in the studies on conservation. However, in this study, not only the current situation of the buildings, but also the conditions of the previous years and even the comparison of the data was obtained. Although this study was carried out within the scope of Kula district, it gives an idea about the change and usage of interiors of the residences.
Northwest Pacific-Izanagi subduction histories along Eurasia are poorly constrained due to extensive subduction, which partially consumed the western Pacific plate and the entire Izanagi plate, its ...hypothesized conjugate margin. Here we reconstruct NW Pacific-Izanagi plate tectonics since Cretaceous times by mapping and structurally restoring (i.e. unfolding) the subducted western Pacific slabs from regional and global tomography, and re-creating the vanished Izanagi plate as its conjugate rift flank. Unfolding of the western Pacific slabs based on their cross-sectional areas, corrected for ‘tomographic smearing’, reveals that 2230 to 5000 km of western Pacific plate was subducted between Kamchatka and the southern Marianas. We add our restored western Pacific and Izanagi plates to a global plate model to reveal that Izanagi subduction under Eurasia after the mid-Cretaceous was limited between the present Bohai Bay-Yellow Sea, China, and northern Russia. The southern limit of Izanagi subduction was a NW-SE sinistral transform that intersected Eurasia near present Qingdao, China, and segmented eastern Eurasia continental magmatism during the late Cretaceous; we call this transform the ‘Qingdao line’. We reconstruct a low-angle Izanagi-Pacific ridge-trench intersection with Eurasia at ∼50 ± 10 Ma between Bohai Bay-Yellow Sea and northern Russia. The ∼50 Ma Pacific plate motion change initiated subduction along the Qingdao line transform, forming the Izu-Bonin-Marianas arcs and reorganizing the Bohai Bay-Yellow Sea faults. We show tomographic and geodynamic modeling evidence that a 4000 km-long, laterally-continuous, NE-SW trending, seismically-slow ‘slab gap’ at 1000 ± 250 km depth between present northern Sakhalin and central China is the tomographic signature of the subducted Izanagi-Pacific ridge.
The Eocene (~50–45 Ma) major absolute plate motion change of the Pacific plate forming the Hawaii‐Emperor bend is thought to result from inception of Pacific plate subduction along one of its modern ...western trenches. Subduction is suggested to have started either spontaneously, or result from subduction of the Izanagi‐Pacific mid‐ocean ridge, or from subduction polarity reversal after collision of the Olyutorsky arc that was built on the Pacific plate with NE Asia. Here we provide a detailed plate‐kinematic reconstruction of back‐arc basins and accreted terranes in the northwest Pacific region, from Japan to the Bering Sea, since the Late Cretaceous. We present a new tectonic reconstruction of the intraoceanic Olyutorsky and Kronotsky arcs, which formed above two adjacent, oppositely dipping subduction zones at ~85 Ma within the north Pacific region, during another Pacific‐wide plate reorganization. We use our reconstruction to explain the formation of the submarine Shirshov and Bowers Ridges and show that if marine magnetic anomalies reported from the Aleutian Basin represent magnetic polarity reversals, its crust most likely formed in an ~85‐ to 60‐Ma back‐arc basin behind the Olyutorsky arc. The Olyutorsky arc was then separated from the Pacific plate by a spreading ridge, so that the ~55‐ to 50‐Ma subduction polarity reversal that followed upon Olyutorsky‐NE Asia collision initiated subduction of a plate that was not the Pacific. Hence, this polarity reversal may not be a straightforward driver of the Eocene Pacific plate motion change, whose causes remain enigmatic.
Key Points
At 85‐80 Ma, a plate reorganization occurred in the northern Pacific that included the formation of two subduction zones and the Kula plate
Our reconstruction predicts that the Aleutian Basin crust formed between 85 and 60 Ma in a back‐arc basin behind the Olyutorsky arc
Subduction polarity reversal from Kamchatka to Sakhalin at ~50 Ma is not a straightforward driver of the Eocene Pacific plate motion change
Malinowsky for today? Damon, Frederick H
Anthropologica del Departamento de ciencias sociales,
2022, Letnik:
40, Številka:
49
Journal Article
Recenzirano
Odprti dostop
From the point of view of a contemporary Kula Ring ethnographer, this paper surveys Malinowski’s heritage, sums up the current state of Kula Ring research, and asks of the status of the ethnographic ...research heritage Malinowski did much to define. All recent Kula Ring anthropologists partly define themselves with respect to Malinowski’s tradition. And the results of their work over the last 50 years again made the region central to the discipline for part of the recent past. But today Malinowski’s Trobriand corpus is being redefined. New lines of inquiry are contributing to our understanding of the area. And Malinowski’s methods have fertilized other portions of our social system and branches for self-reflection. As it should be, what Malinowski helped define is very much with us.
Desde el punto de vista de un etnógrafo contemporáneo del anillo del kula, este documento examina la herencia de Malinowski, resume el estado actual de la investigación sobre el kula y se pregunta por la investigación etnográfica, la cual Malinowski contribuyó en gran medida a definir. Todos los antropólogos recientes del kula se definen en parte con respecto a la tradición de Malinowski. Y los resultados de su trabajo durante los últimos cincuenta años volvieron a convertir a la región en el centro de la disciplina durante parte del pasado reciente. Pero hoy el corpus Trobriand de Malinowski se está redefiniendo. Nuevas líneas de investigación están contribuyendo a nuestra comprensión del área. Y los métodos de Malinowski han enriquecido el estudio de otras partes de nuestro sistema social y abierto líneas para la autorreflexión. Como debe ser, lo que Malinowski ayudó a definir esta muy presente en nosotros.
Abstract
The Massim, a cultural region that includes the southeastern tip of mainland Papua New Guinea (PNG) and nearby PNG offshore islands, is renowned for a trading network called Kula, in which ...different valuable items circulate in different directions among some of the islands. Although the Massim has been a focus of anthropological investigation since the pioneering work of Malinowski in 1922, the genetic background of its inhabitants remains relatively unexplored. To characterize the Massim genomically, we generated genome-wide SNP data from 192 individuals from 15 groups spanning the entire region. Analyzing these together with comparative data, we found that all Massim individuals have variable Papuan-related (indigenous) and Austronesian-related (arriving ∼3,000 years ago) ancestries. Individuals from Rossel Island in southern Massim, speaking an isolate Papuan language, have the highest amount of a distinct Papuan ancestry. We also investigated the recent contact via sharing of identical by descent (IBD) genomic segments and found that Austronesian-related IBD tracts are widely distributed geographically, but Papuan-related tracts are shared exclusively between the PNG mainland and Massim, and between the Bismarck and Solomon Archipelagoes. Moreover, the Kula-practicing groups of the Massim show higher IBD sharing among themselves than do groups that do not participate in Kula. This higher sharing predates the formation of Kula, suggesting that extensive contact between these groups since the Austronesian settlement may have facilitated the formation of Kula. Our study provides the first comprehensive genome-wide assessment of Massim inhabitants and new insights into the fascinating Kula system.
This article interprets the kula system through the lens of the Laozi, a Chinese classic of the 6th century BCE. Laozi's ideas regarding “esteeming goods,” “non‐accumulation,” and “small realms with ...few people” allow us to understand why kula shells and names are precious but impossible to accumulate and how kula serves to keep societies small and peaceful with its subtle practice of organizations, technologies, and calendars. Through exemplary “elders” who esteem goods hard to accumulate, the kula operates as a void system close to the spontaneous order idealized by Laozi, who promoted the ideal of the non‐accumulative Sage. Epistemologically, the article continues the anthropological tradition of perspectivist comparison by proposing a Sinic interpretation, a version of multi‐universalism that does not intend to invalidate the existing universalism but seeks to transcend the view of a singular western universalism and multiple non‐Western exceptionalisms.
Résumé
Cet article interprète le système kula au prisme de Laozi, un classique chinois du 6ème siècle avant notre ère. Les idées de Laozi concernant “estime des biens”, “non‐accumulation” et “petits royaumes avec peu d'habitants” nous permettent de comprendre pourquoi les coquilles et les noms du kula sont précieux mais impossibles à accumuler et comment le kula sert à maintenir des sociétés petites et pacifiques grâce à sa pratique subtile des organisations, des technologies et des calendriers. A travers des “anciens” exemplaires qui estiment les biens difficiles à accumuler, le kula fonctionne comme un système vide proche de l'ordre spontané idéalisé par Laozi, qui promouvait l'idéal du Sage non accumulateur. Sur le plan épistémologique, cet article poursuit la tradition anthropologique de la comparaison perspectiviste en proposant une interprétation sinique, une version du multi‐universalisme qui n'a pas l'intention d'invalider l'universalisme existant mais cherche à transcender la vision d'un universalisme occidental singulier et celle de multiples exceptionnalismes non‐occidentaux. Laozi, kula, paradigme du don, perspectivisme sinique
Resumen
Este artículo interpreta el sistema kula a través de los lentes de Laozi, un clásico chino del siglo VI AEC. Las ideas de Laozi acerca de “estimar los bienes”, “no acumulación” y “esferas pequeñas con pocas personas” nos permite entender por qué las conchas kula y los nombres son preciosos pero imposibles de acumular, y cómo Kula sirve para mantener las sociedades pequeñas y pacíficas con su práctica sutil de organizaciones, tecnologías y calendarios. A través de los “mayores” ejemplares quienes estiman los bienes difíciles de acumular, el Kula opera como un sistema nulo cercano al orden espontáneo idealizado por Laozi, quien promovió el ideal del Sage no acumulativo. Epistemológicamente, el artículo continúa la tradición antropológica de la comparación perspectivista al proponer una interpretación Sinic, una versión de multiuniversalismos que no intenta invalidar el existente universalismo, pero busca trascender la visión del universalismo occidental singular y múltiples excepcionalismos no occidentales. Laozi, kula, paradigma de regalos, perspectivismo Sinic
A vast ocean basin has spanned the region between the Americas, Asia and Australasia for well over 100Myr, represented today by the Pacific Ocean. Its evolution includes a number of plate ...fragmentation and plate capture events, such as the formation of the Vancouver, Nazca, and Cocos plates from the break-up of the Farallon plate, and the incorporation of the Bellingshausen, Kula, and Aluk (Phoenix) plates, which have been studied individually, but never been synthesised into one coherent model of ocean basin evolution. Previous regional tectonic models of the Pacific typically restrict their scope to either the North or South Pacific, and global kinematic models fail to incorporate some of the complexities in the Pacific plate evolution (e.g. the independent motion of the Bellingshausen and Aluk plates), thereby limiting their usefulness for understanding tectonic events and processes occurring in the Pacific Ocean perimeter. We derive relative plate motions (with 95% uncertainties) for the Pacific–Farallon/Vancouver, Kula–Pacific, Bellingshausen–Pacific, and early Pacific–West Antarctic spreading systems, based on recent data including marine gravity anomalies, well-constrained fracture zone traces and a large compilation of magnetic anomaly identifications. We find our well-constrained relative plate motions result in a good match to the fracture zone traces and magnetic anomaly identifications in both the North and South Pacific. In conjunction with recently published and well-constrained relative plate motions for other Pacific spreading systems (e.g. Aluk–West Antarctic, Pacific-Cocos, recent Pacific–West Antarctic spreading), we explore variations in the age of the oceanic crust, seafloor spreading rates and crustal accretion and find considerable refinements have been made in the central and southern Pacific. Asymmetries in crustal accretion within the overall Pacific basin (where both flanks of the spreading system are preserved) have typically deviated less than 5% from symmetry, and large variations in crustal accretion along the southern East Pacific Rise (i.e. Pacific–Nazca/Farallon spreading) appear to be unique to this spreading corridor. Through a relative plate motion circuit, we explore the implied convergence history along the North and South Americas, where we find that the inclusion of small tectonic plate fragments such as the Aluk plate are critical for reconciling the history of convergence with onshore geological evidence.
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