Late Ordovician trilobites from northwest Iran and their biogeographical affinities

Author(s):  
Talia S. Karim

ABSTRACTA diverse, previously undescribed trilobite fauna from northwest Iran sheds new light on the Early Palaeozoic geography of the Alborz terrane. The structural history of the Alborz region is well known, though faunal data for the area are sparse, especially for the Ordovician. Trilobites, brachiopods, conodonts, bryozoans and echinoderms occur in a red grainstone/packstone near the village of Tatavrud, 35 km southwest of Bandar-e-Anzali. The fossils indicate a Late Ordovician age, although lithologically similar outcrops in northern Iran have previously been considered Silurian. Trilobite genera occurring include Trinodus, Geragnostus, Illaenus, Panderia, Phorocephala, Ovalocephalus, Dicranopeltis, Symphysops, Cyclopyge, and Sphaerexochus. Similar assemblages have been reported from the Late Ordovician of Ireland, Spain, Poland, Norway, northwest China, Kazakhstan and the Turkistan–Alai Ridge (Uzbekistan–Kyrgyzstan border). Reconstructions of Late Ordovician geography place the Alborz terrane near the eastern margin of Gondwana, but there is doubt as to its precise location. Some workers have considered it part of the margin while others have considered it a separate terrane. Several species present, including Mezzaluna tatavrudensis n. sp. and Phorocephala cf. ulugtana (Petrunina, 1975) are very similar to taxa described from the Turkistan–Alai Ridge. In addition, the isocolid genus Paratiresias has only been reported from Iran, the Turkistan–Alai Ridge and northwest China. The presence of these taxa indicates that the Alborz terrane was in close proximity to the eastern margin of Gondwana at this time.

1984 ◽  
Vol 75 (2) ◽  
pp. 245-258 ◽  
Author(s):  
G. J. H. Oliver ◽  
J. L. Smellie ◽  
L. J. Thomas ◽  
D. M. Casey ◽  
A. E. S. Kemp ◽  
...  

ABSTRACTA model for the early Palaeozoic metamorphic history of the Midland Valley and adjacent areas to the S in Scotland, England and Ireland is based on the results of new field mapping, thin section petrography, electron probe microanalysis, X-ray diffractometry, conodont and palynomorph colouration and graptolite reflectance measurement.The oldest metamorphic rocks of the Midland Valley of Scotland, excluding xenoliths in post-Silurian lavas, are possibly the blueschist occurrences in the melange unit of the Ballantrae complex. These may be tectonised remnants of (?)pre-Arenig ocean-floor subducted during closure of the Iapetus Ocean. In the early Ordovician, the melange terrane was dynamothermally metamorphosed during obduction of newly-formed ocean crust. The obduction process piled up a thick sequence of various ocean-floor types such that burial metamorphism in parts reached pumpellyite-actinolite facies; elsewhere prehnite-pumpellyite and zeolite facies was attained.Whilst the Midland Valley acted as an inter- or fore-arc basin during the Late Ordovician and Silurian and experienced burial metamorphism, an accretionary prism was formed to the S. Accretion, tectonic burial and metamorphism of ocean-floor and trench sediment was continuous in the Southern Uplands and the Longford-Down massif of Ireland through Late Ordovician to Late Silurian times. Rocks at the present-day surface vary from zeolite facies to prehnitepumpellyite facies. Silurian trench-slope basin sediments can be recognised in part by their lower grade of burial metamorphism. Greenschist facies rocks of the prism probably lie close to the surface.The Lake District island-arc terrane of Northern England has an early Ordovician history of burial metamorphism up to prehnite-pumpellyite facies. The Late Ordovician and Silurian metamorphic history is one of sedimentary burial complicated by tectonism and intrusion of granite plutons to a relatively high level. The Iapetus suture is marked by a weak contrast in metamorphic grade.


2003 ◽  
Vol 140 (6) ◽  
pp. 685-705 ◽  
Author(s):  
HAROLDO VIZAN ◽  
JOHN N. CARNEY ◽  
PETER TURNER ◽  
ROBERT A. IXER ◽  
MARK TOMASSO ◽  
...  

Palaeomagnetic studies have been carried out on Neoproterozoic, Cambrian and Ordovician rocks in the Nuneaton inlier, England (52.5° N, 1.5° W). Three magnetic components were recognized, which provide a consistent structural and magnetic history of the inlier. Neoproterozoic volcaniclastic and intrusive rocks acquired a characteristic remanent magnetization (ChRM) dated at 603Ma. Late Ordovician rocks are represented by lamprophyre and diorite intrusions and their ChRMs were probably imprinted during their emplacement, at about 442 Ma. The Lower Cambrian sedimentary sequence of the Hartshill Sandstone Formation, which unconformably overlies the Neoproterozoic rocks and hosts the Ordovician intrusions, does not preserve a primary magnetization but shows the imprints of the Late Ordovician (442 Ma) remagnetization, as well as a probable end-Carboniferous remagnetization. Palaeolatitudes calculated for the late Neoproterozoic rocks and Ordovician intrusions are in good agreement with other palaeolatitudes calculated for Avalonia during those times. Both the late Neoproterozoic and Late Ordovician rocks additionally show ChRMs with declination anomalies indicating a large tectonic rotation of the Nuneaton area, possibly during one of the Caledonian phases of deformation affecting southern Britain.


2019 ◽  
Vol 25 (2) ◽  
pp. 202-219
Author(s):  
Aminta Arrington

The Lisu are a largely Christian minority group in south-west China who, as an oral culture, express their faith more through a set of Christian practices done as a group and less through bible reading as individuals. Even so, the Lisu practice of Christianity specifically, and Lisu culture more generally, was profoundly impacted by the written scriptures. During the initial evangelisation of the Lisu by the China Inland Mission, missionaries created a written script for the Lisu language. Churches were constructed and organised, which led to the creation of bible schools and the work of bible translation. In the waves of government persecution after 1949, Lisu New Testaments were hidden away up in the mountains by Lisu Christians. After 1980, the Lisu reclaimed their faith by listening to the village elders tell the Old Story around the fires and reopening the churches that had been closed for twenty-two years. And they reclaimed their bible by retrieving the scriptures from the hills and copying them in the evening by the light of a torch. The Lisu bible has its own narrative history, consisting of script creating, translating, migrating, and copying by hand. At times it was largely influenced by the mission narrative, but at other times, the Lisu bible itself was the lead character in the story. Ultimately, the story of the Lisu bible reflects the Lisu Christian story of moving from missionary beginnings to local leadership and, ultimately, to local theological inquiry.


Author(s):  
Valentina M. Patutkina

The article is dedicated to unknown page in the library history of Ulyanovsk region. The author writes about the role of Trusteeship on people temperance in opening of libraries. The history of public library organized in the beginning of XX century in the Tagai village of Simbirsk district in Simbirsk province is renewed.


Author(s):  
E. V. Sitnikova

The article considers the historical and cultural heritage of villages of the former Ketskaya volost, which is currently a part of the Tomsk region. The formation of Ketsky prison and the architecture of large settlements of the former Ketskaya volost are studied. Little is known about the historical and cultural heritage of villages of the Tomsk region and the problems of preserving historical settlements of the country.The aim of this work is to study the formation and development of the village architecture of the former Ketskaya volost, currently included in the Tomsk region.The following scientific methods are used: a critical analysis of the literature, comparative architectural analysis and systems analysis of information, creative synthesis of the findings. The obtained results can be used in preparation of lectures, reports and communication on the history of the Siberian architecture.The scientific novelty is a study of the historical and cultural heritage of large settlements of the former Ketskaya volost, which has not been studied and published before. The methodological and theoretical basis of the study is theoretical works of historians and architects regarding the issue under study as well as the previous  author’s work in the field.It is found that the historical and cultural heritage of the villages of the former Ketskaya volost has a rich history. Old historical buildings, including religious ones are preserved in villages of Togur and Novoilinka. The urban planning of the villages reflects the design and construction principles of the 18th century. The rich natural environment gives this area a special touch. 


Radiocarbon ◽  
2021 ◽  
pp. 1-21
Author(s):  
Chris Urwin ◽  
Quan Hua ◽  
Henry Arifeae

ABSTRACT When European colonists arrived in the late 19th century, large villages dotted the coastline of the Gulf of Papua (southern Papua New Guinea). These central places sustained long-distance exchange and decade-spanning ceremonial cycles. Besides ethnohistoric records, little is known of the villages’ antiquity, spatiality, or development. Here we combine oral traditional and 14C chronological evidence to investigate the spatial history of two ancestral village sites in Orokolo Bay: Popo and Mirimua Mapoe. A Bayesian model composed of 35 14C assays from seven excavations, alongside the oral traditional accounts, demonstrates that people lived at Popo from 765–575 cal BP until 220–40 cal BP, at which time they moved southwards to Mirimua Mapoe. The village of Popo spanned ca. 34 ha and was composed of various estates, each occupied by a different tribe. Through time, the inhabitants of Popo transformed (e.g., expanded, contracted, and shifted) the village to manage social and ceremonial priorities, long-distance exchange opportunities and changing marine environments. Ours is a crucial case study of how oral traditional ways of understanding the past interrelate with the information generated by Bayesian 14C analyses. We conclude by reflecting on the limitations, strengths, and uncertainties inherent to these forms of chronological knowledge.


2021 ◽  
Vol 21 (1) ◽  
pp. 28-52
Author(s):  
Sam Harper ◽  
Ian Waina ◽  
Ambrose Chalarimeri ◽  
Sven Ouzman ◽  
Martin Porr ◽  
...  

This paper explores identity and the recursive impacts of cross-cultural colonial encounters on individuals, cultural materials, and cultural practices in 20th-century northern Australia. We focus on an assemblage of cached metal objects and associated cultural materials that embody both Aboriginal tradition and innovation. These cultural materials were wrapped in paperbark and placed within a ring of stones, a bundling practice also seen in human burials in this region. This ‘cache' is located in close proximity to rockshelters with rich, superimposed Aboriginal rock art compositions. However, the cache shelter has no visible art, despite available wall space. The site shows the utilisation of metal objects as new raw materials that use traditional techniques to manufacture a ground edge metal axe and to sharpen metal rods into spears. We contextualise these objects and their hypothesised owner(s) within narratives of invasion/contact and the ensuing pastoral history of this region. Assemblage theory affords us an appropriate theoretical lens through which to bring people, places, objects, and time into conversation.


2021 ◽  
pp. 1-17
Author(s):  
Behnam Shafiei Bafti ◽  
István Dunkl ◽  
Saeed Madanipour

Abstract The recently developed fluorite (U–Th)/He thermochronology (FHe) technique was applied to date fluorite mineralization and elucidate the exhumation history of the Mazandaran Fluorspar Mining District (MFMD) located in the east Central Alborz Mountains, Iran. A total of 32 fluorite single-crystal samples from four Middle Triassic carbonate-hosted fluorite deposits were dated. The presented FHe ages range between c. 85 Ma (age of fluorite mineralization) and c. 20 Ma (erosional cooling during the exhumation of the Alborz Mountains). The Late Cretaceous FHe ages (i.e. 84.5 ± 3.6, 78.8 ± 4.4 and 72.3 ± 3.5 Ma) are interpreted as the age of mineralization and confirm an epigenetic origin for ore mineralization in the MFMD, likely a result of prolonged hydrothermal circulation of basinal brines through potential source rocks. Most FHe ages scatter around the Eocene Epoch (55.4 ± 3.9 to 33.1 ± 1.7 Ma), recording an important cooling event after heating by regional magmatism in an extensional tectonic regime. Cooling of the heated fluorites, as a result of thermal relaxation in response to geothermal gradient re-equilibration after the end of magmatism, or exhumation cooling during extensional tectonics characterized by lower amount of erosion are most probably the causes of the recorded Eocene FHe cooling ages. Oligocene–Miocene FHe ages (i.e. 27.6 ± 1.4 to 19.5 ± 1.1 Ma) are related to the accelerated uplift of the whole Alborz Mountains, possibly as a result of the initial collision between the Afro-Arabian and Eurasian plates further to the south.


Sign in / Sign up

Export Citation Format

Share Document