The Role of Salt Tectonics, Glacioeustatic Variations, and High pH Evaporitic Groundwater in the Development of Synsedimentary Paleokarst within Carboniferous Polymictic Fanglomerate at Hopewell Cape, Atlantic Canada

2016 ◽  
Vol 124 (4) ◽  
pp. 447-462
Author(s):  
Pierre Jutras
Author(s):  
Christopher A. Miller ◽  
Bridget Carragher ◽  
William A. McDade ◽  
Robert Josephs

Highly ordered bundles of deoxyhemoglobin S (HbS) fibers, termed fascicles, are intermediates in the high pH crystallization pathway of HbS. These fibers consist of 7 Wishner-Love double strands in a helical configuration. Since each double strand has a polarity, the odd number of double strands in the fiber imparts a net polarity to the structure. HbS crystals have a unit cell containing two double strands, one of each polarity, resulting in a net polarity of zero. Therefore a rearrangement of the double strands must occur to form a non-polar crystal from the polar fibers. To determine the role of fascicles as an intermediate in the crystallization pathway it is important to understand the relative orientation of fibers within fascicles. Furthermore, an understanding of fascicle structure may have implications for the design of potential sickling inhibitors, since it is bundles of fibers which cause the red cell distortion responsible for the vaso-occlusive complications characteristic of sickle cell anemia.


Carbon ◽  
2005 ◽  
Vol 43 (3) ◽  
pp. 511-518 ◽  
Author(s):  
David W. Mazyck ◽  
Fred S. Cannon ◽  
Morgana T. Bach ◽  
Ljubisa R. Radovic
Keyword(s):  

2021 ◽  
pp. jgs2020-085 ◽  
Author(s):  
Laura Burrel ◽  
Antonio Teixell

Triassic Keuper evaporites have long been recognized as the main detachment level for thrusting in the Pyrenean fold–thrust belts. The deformed Late Cretaceous–Eocene foreland basin of the Southern Pyrenees has structures and stratal geometries that can be interpreted as related to salt tectonics (e.g. unconformities, rapid thickness variations, long-lived growth fans and overturned flaps), although they have been overprinted by shortening and thrusting. Based on field observations and published maps, we build new structural cross-sections reinterpreting two classic transects of the Southern Pyrenees (Noguera Ribagorçana and Noguera Pallaresa river transects). The sequential restoration of the sections explores the variations in structural style, addressing the role of halokinesis in the tectonic and sedimentary development. In the Serres Marginals area, we propose that salt pillows and diapirs started developing locally during the Mesozoic pre-orogenic episode, evolving into a system of salt ridges and intervening synclines filled with early synorogenic sediments. Rapid amplification of folds recorded by widespread latest Cretaceous–Paleocene growth strata is taken as marking the onset of contractional folding in the area. During Pyrenean compression, folding mechanisms transitioned from dominantly halokinetic to a combination of buckling and differential sedimentary loading. Squeezing of salt diapirs and thrust welding occurred as salt ridges were unroofed. We provide new field observations that lead to a reinterpretation of the regional structural development and contribute to the debate about the role of salt tectonics in the Pyrenees.Supplementary material: Table S1, giving the thickness of the main stratigraphic units, is available at https://doi.org/10.6084/m9.figshare.c.5287737


2020 ◽  
Author(s):  
Nicolas Saspiturry ◽  
Benoit Issautier ◽  
Philippe Razin ◽  
Thierry Baudin ◽  
Riccardo Asti ◽  
...  

2012 ◽  
Vol 91 (4) ◽  
pp. 517-534 ◽  
Author(s):  
S. Nelskamp ◽  
J.M. Verweij ◽  
N. Witmans

AbstractIn this paper we study the effects of timing of salt movement and mechanical compaction on the generation of overpressures in Mesozoic rocks. To that end we apply 2D basin modelling on two N-S trending cross sections in the Dutch Central Graben and Terschelling Basin, respectively. Several overpressuring scenarios were calculated by modifying the mechanical compaction of the sealing layer, the rate of sedimentation, and the timing of salt movement. Pressure and porosity measurements from several wells along the cross sections were used as calibration data. The results show that rapid sedimentation and early compaction of Pliocene to Quaternary mudstones explain most of the overpressures in the Cretaceous and Jurassic rocks. The modifications of the mechanical compaction of the Upper Cretaceous Chalk Group performed in this study could not explain the overpressure anomalies in the southern part of the Dutch Central Graben. Processes such as chemical compaction are probably more important in this respect. Overpressures in the Triassic are mainly controlled by the timing of salt movement and the closure of lateral seals. This study has lead to a better understanding of the processes that generate overpressures and those that are involved in their lateral distribution. The integration of modelling scenarios and information on the timing of seal formation enables to define new play concepts and is important for the assessment of possible drilling hazards as well.


1989 ◽  
Vol 25 (1) ◽  
pp. 35-39
Author(s):  
A. V. Vasilik ◽  
S. I. Girnyi ◽  
R. K. Melekhov

Author(s):  
Faye Margaret Kert

This journal examines privateering and naval prizes in Atlantic Canada in the maritime War of 1812 - considered the final major international manifestation of the practice. It seeks to contextualise the role of privateering in the nineteenth century; determine the causes of, and reactions to, the War of 1812; determine the legal evolution of prize law in North America; discuss the privateers of Nova Scotia and New Brunswick, and the methods they utilised to manipulate the rules of prize making during the war; and consider the economic impact of the war of maritime communities. Ultimately, the purpose of the journal is to examine privateering as an occupation in order to redeem its historically negative reputation. The volume is presented as six chapters, plus a conclusion appraising privateering, and seven appendices containing court details, prize listings, and relevant letters of agency.


2011 ◽  
Vol 68 (9) ◽  
pp. 1852-1856 ◽  
Author(s):  
Andrey Malyshev ◽  
Pedro A. Quijón

Abstract Malyshev, A., and Quijón, P. A. 2011. Disruption of essential habitat by a coastal invader: new evidence of the effects of green crabs on eelgrass beds. – ICES Journal of Marine Science, 68: 1852–1856. Eelgrass (Zostera marina) beds have been declining in Atlantic Canada and elsewhere, partly as a result of sediment disruption and direct feeding/cutting of basal meristems by the green crab (Carcinus maenas). Green crabs are detrimental to eelgrass beds, and field and laboratory experiments have confirmed that the deleterious role of this invasive species is mediated by at least two mechanisms, depending on the size/age of the crabs: uprooting by adults and grazing by juveniles. Eelgrass uprooting and grazing by green crabs are likely to contribute to further declines or a lack of recovery of eelgrass beds.


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