The role of contemporaneous faulting on Late Silurian sedimentation in the eastern M'Clintock Basin, Prince of Wales Island, Arctic Canada

1986 ◽  
Vol 23 (9) ◽  
pp. 1401-1411 ◽  
Author(s):  
Paul S. Mortensen ◽  
Brian Jones
Keyword(s):  
Carbonate Platform ◽  
Fold Belt ◽  
Arctic Canada ◽  
Early Devonian ◽  
Eastern Margin ◽  
Basement Faults ◽  
Somerset Island ◽  
East West

During the Late Silurian, the eastern margin of the M'Clintock Basin was the site of slow sedimentation on a relatively stable carbonate platform. It is apparent, however, that contemporaneous (syndepositional) faults segmented this basin into several quasi-independent subbasins during deposition of the Cape Storm, Douro, and Somerset Island formations. Differential subsidence of these subbasins played a major role in controlling sedimentation patterns and stratigraphie thickness. These subbasins may have been sustained into the Early Devonian, as is evident from the facies of the overlying Peel Sound Formation. The east–west orientated, reactivated basement faults bounding the subbasins served as zones of weakness during the development of the Cornwall is Fold Belt and are evident in the present-day outcrop.

The allochthonous origin of the reefal facies of the Stuart Bay Formation (Early Devonian), Bathurst Island, arctic Canada

1984 ◽  
Vol 21 (6) ◽  
pp. 657-668 ◽  
Author(s):  
Kevin P. Polan ◽  
Colin W. Stearn
Keyword(s):  
Deep Water ◽  
Lower Devonian ◽  
Linear Groups ◽  
Fold Belt ◽  
Arctic Canada ◽  
Catastrophic Events ◽  
Early Devonian ◽  
Bedding Planes ◽  
Reefal Facies ◽  
Reef Tract

Blocks of limestone and dolomite up to tens of metres across occur near the base of the Lower Devonian (Siegenian–Emsian) Stuart Bay Formation at six sites on eastern Bathurst Island. These blocks occur in groups of up to 30. At the two localities with the greatest number of blocks they are disposed in two or three roughly linear groups reflecting their occurrence on bedding planes. The blocks are mostly wackestones and floatstones and they contain abundant fossils of the reefal biofacies of which stromatoporoids and corals are most prominent.The blocks have weathered from a matrix of finely laminated deep-water siltstone. Most of the blocks are unbedded but where bedding attitudes can be measured they are discordant with that of the siltstone and those of neighbouring blocks. Although they have been described as bioherms that grew in place, the evidence indicates that they are allochthonous blocks derived when several catastrophic events such as earthquakes disturbed a Devonian reef tract developed on the western flank of the Cornwallis Fold Belt.

A Processual Investigation of a Thule Whale Bone House, Somerset Island, Arctic Canada

2004 ◽  
Vol 41 (2) ◽  
pp. 204-221 ◽  
Author(s):  
J. M. Savelle ◽  
J. Habu
Keyword(s):  
Arctic Canada ◽  
Somerset Island

Role of rigid block in tectonic transformation zone at east Tibet 

2021 ◽  
Author(s):  
Tuo Shen ◽  
Xiwei Xu ◽  
Shiyong Zhou ◽  
Shaogang Wei ◽  
Xiaoqiong Lei
Keyword(s):  
Tibet Plateau ◽  
Rigid Block ◽  
Strain Partitioning ◽  
Transformation Models ◽  
Transformation Zone ◽  
Northern Margin ◽  
Eastern Margin ◽  
Bayan Har ◽  
The Tibet Plateau

<p>In recent decades, plateau margins have attracted attention because the understanding of their dynamics and history provides insights into the modes of crustal deformation responsible for the plateau structure and morphology and more widely into the deformation of continental lithosphere. The slip transformation and strain partitioning mechanism at the eastern termination of the Kunlun fault system remain unclear. Geophysics investigations revealed the Ruoergai Basin as a rigid block; however, insufficient information is available on the role of this block in tectonic transformation zone at east Tibet. We employed the finite element method in our simulations to delimitate the presence of the Ruoergai block and determine how it affects the surrounding area. We found that the Ruoergai block moves independently to the east or northeast, and its motion differs from that of the Bayan Har block in the eastward escape process of this last-named block. The formation and behavior of Awancang fault and Longriba fault seems to impact by the Ruoergai block. The influence of the Ruoergai block in the east margin should not be ignored. The Awancang fault and Ruoergai block absorbed the north vector velocity of the Bayan Har block, after which the Bayan Har block started moving southeast. The strain partitioning at the eastern margin of the Tibet Plateau is progressively complete[A1]  from the Awancang fault, Ruoergai block, and Longriba fault area to the Longmenshan block. The presence of the Ruoergai block could decrease the strike-slip rate of the Maqin–Maqu section of the Kunlun fault. Given its influence in the region, the Ruoergai block should be incorporated in future studies on regional deformation and in deformation and tectonic transformation models. Then we compared the deformation and tectonic transformation models in the northern margin of the Tibet Plateau. Proposed a rigid block compression pattern unite the tectonic transformation and deformation issue, further explain most of the fault behaviors in the northern margin and eastern margin of Tibet.</p><p> </p>

Bridging East and West

2016 ◽  
Author(s):  
Eglė Rindzevičiūtė
Keyword(s):  
Global Governance ◽  
Soft Power ◽  
Great Powers ◽  
International Institute ◽  
Think Tank ◽  
Systems Research ◽  
Lyndon Johnson ◽  
East And West ◽  
East West

This chapter details the establishment of International Institute for Applied Systems Analysis (IIASA) to demonstrate the crucial role of East-West cooperation in shaping global governance. IIASA as a diplomatic initiative was the result of actions by top governmental officials: US president Lyndon Johnson proposed creating an East-West think tank and Soviet Prime Minister Aleksei Kosygin accepted his proposal, both sides considering this step as part of cultural diplomacy or an exercise of “soft power” in the presumably less ideological areas of science and technology. The chapter then suggests that the establishment of IIASA can be interpreted as precisely such a forward-oriented arrangement to enable a certain form of cooperation between the opposing great powers: mutual predictability was enhanced by bringing together leading policy scientists from East and West, whereas shared goals were articulated through applied systems research.

scholarly journals The innovation of the final moult and the origin of insect metamorphosis

2019 ◽  
Vol 374 (1783) ◽  
pp. 20180415 ◽  
Author(s):  
Xavier Belles
Keyword(s):  
Common Ancestor ◽  
Adult Stage ◽  
Postembryonic Development ◽  
Prothoracic Gland ◽  
Last Common Ancestor ◽  
Early Devonian ◽  
Final Moult ◽  
Insect Metamorphosis ◽  
Complete Metamorphosis

The three modes of insect postembryonic development are ametaboly, hemimetaboly and holometaboly, the latter being considered the only significant metamorphosis mode. However, the emergence of hemimetaboly, with the genuine innovation of the final moult, represents the origin of insect metamorphosis and a necessary step in the evolution of holometaboly. Hemimetaboly derives from ametaboly and might have appeared as a consequence of wing emergence in Pterygota, in the early Devonian. In extant insects, the final moult is mainly achieved through the degeneration of the prothoracic gland (PG), after the formation of the winged and reproductively competent adult stage. Metamorphosis, including the formation of the mature wings and the degeneration of the PG, is regulated by the MEKRE93 pathway, through which juvenile hormone precludes the adult morphogenesis by repressing the expression of transcription factor E93, which triggers this change. The MEKRE93 pathway appears conserved in extant metamorphosing insects, which suggest that this pathway was operative in the Pterygota last common ancestor. We propose that the final moult, and the consequent hemimetabolan metamorphosis, is a monophyletic innovation and that the role of E93 as a promoter of wing formation and the degeneration of the PG was mechanistically crucial for their emergence. This article is part of the theme issue ‘The evolution of complete metamorphosis’.

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