scholarly journals Progressive glaciotectonic deformation in Weichselian and Palaeogene deposits at Feggeklit, northern Denmark

1996 ◽  
Vol 42 ◽  
pp. 153-174
Author(s):  
Schack Pedersen
Keyword(s):  
Structural Analysis ◽  
Large Scale ◽  
Volcanic Ash ◽  
Fluvial Sediments ◽  
Final Phase ◽  
Thrust Faulting ◽  
Detailed Structural Analysis ◽  
Balanced Cross Section ◽  
Late Weichselian ◽  
Deformation Complex

Structural analysis of the glaciotectonic deformations at Feggeklit, Mors, Denmark, provide a unique record of succesive deformation phases in a progressive glaciotectonic deformation. The Feggeklit profile displays glaciotectonically folded, thrust-faulted and sheared Palaeogene diatomite with thin volcanic ash layers, the Fur Formation, overlain by a glacigene succession. The combination of stratigraphical and structural analysis shows that the Feggeklit was affected by three glaciodynamic events. The first event is of Saalian age and is represented by the deposition of a till and the formation of a para-authochthonous glacitectonite in the top of the Fur Formation deposits. The second event is only represented by the deposition of a till, probably of Saalian age. The third event is of Late Weichselian age. It includes: 1) deposition of proglacial glaciolacustrine and -fluvial sediments, 2) the formation of a glaciotectonic unit (the Feggeklit deformation complex) and 3) deposition of a till resting on a tectonic uncon-formity formed subglacially. A detailed structural analysis of the glaciotectonic unit provides a subdivision into five succesive deformation phases. The first four phases are related to the proglacial deformation and comprise 1) anastamosing jointing, 2) conjugate faulting, 3) buckle folding and listric thrust faulting, and 4) large scale ramp thrusting. The final phase (5) is related to subglacial shear deformation and loading which produced an allochthonous diatomiteglacitectonite at the sole of the overlying lodgement till. The formation of the structural complex at Feggeklit was caused by two glaciotectonic mechanisms: 1) a proglacial gravity spreading deformation, and 2) a subglacial cataclastic shearing. The balanced cross-section of the fold structures related to the first deformation mechanism indicates that the detachment of the dislocation is situated below the base of the diatomite formation in the plastic clay at a depth of 80-100 m below the surface. Based on the glaciodynamic analysis and considerations on the dating of regional glacigenic setting the velocity of the advancing ice is estimated at 10 m per year. This advance created the gravity spreading deformation reflected in the glaciotectonic structures preserved in the Feggeklit.

scholarly journals Chemical Modification of Combusted Coal Gangue for U(VI) Adsorption: Towards a Waste Control by Waste Strategy

2021 ◽  
Vol 13 (15) ◽  
pp. 8421
Author(s):  
Yuan Gao ◽  
Jiandong Huang ◽  
Meng Li ◽  
Zhongran Dai ◽  
Rongli Jiang ◽  
...  
Keyword(s):  
Structural Analysis ◽  
High Efficiency ◽  
Low Cost ◽  
Chemical Activation ◽  
Cost Effective ◽  
Coal Gangue ◽  
Order Kinetic ◽  
Practical Applications ◽  
Detailed Structural Analysis ◽  
Alkaline Conditions

Uranium mining waste causes serious radiation-related health and environmental problems. This has encouraged efforts toward U(VI) removal with low cost and high efficiency. Typical uranium adsorbents, such as polymers, geopolymers, zeolites, and MOFs, and their associated high costs limit their practical applications. In this regard, this work found that the natural combusted coal gangue (CCG) could be a potential precursor of cheap sorbents to eliminate U(VI). The removal efficiency was modulated by chemical activation under acid and alkaline conditions, obtaining HCG (CCG activated with HCl) and KCG (CCG activated with KOH), respectively. The detailed structural analysis uncovered that those natural mineral substances, including quartz and kaolinite, were the main components in CCG and HCG. One of the key findings was that kalsilite formed in KCG under a mild synthetic condition can conspicuous enhance the affinity towards U(VI). The best equilibrium adsorption capacity with KCG was observed to be 140 mg/g under pH 6 within 120 min, following a pseudo-second-order kinetic model. To understand the improved adsorption performance, an adsorption mechanism was proposed by evaluating the pH of uranyl solutions, adsorbent dosage, as well as contact time. Combining with the structural analysis, this revealed that the uranyl adsorption process was mainly governed by chemisorption. This study gave rise to a utilization approach for CCG to obtain cost-effective adsorbents and paved a novel way towards eliminating uranium by a waste control by waste strategy.

Chiral, Racemic, and Meso-Lithium Tartrate Framework Polymorphs: A Detailed Structural Analysis

2013 ◽  
Vol 13 (8) ◽  
pp. 3705-3715 ◽  
Author(s):  
Hamish H.-M. Yeung ◽  
Monica Kosa ◽  
Michele Parrinello ◽  
Anthony K. Cheetham
Keyword(s):  
Structural Analysis ◽  
Detailed Structural Analysis

scholarly journals Independent and complementary methods for large-scale structural analysis of mammalian chromatin

2007 ◽  
Vol 17 (6) ◽  
pp. 928-939 ◽  
Author(s):  
J. H. Dennis ◽  
H.-Y. Fan ◽  
S. M. Reynolds ◽  
G. Yuan ◽  
J. C. Meldrim ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Large Scale ◽  
Complementary Methods

scholarly journals The role of airborne volcanic ash for the surface ocean biogeochemical iron-cycle: a review

2009 ◽  
Vol 6 (4) ◽  
pp. 6441-6489 ◽  
Author(s):  
S. Duggen ◽  
N. Olgun ◽  
P. Croot ◽  
L. Hoffmann ◽  
H. Dietze ◽  
...  
Keyword(s):  
Large Scale ◽  
Volcanic Ash ◽  
Volcanic Eruptions ◽  
Research Field ◽  
Ash Deposition ◽  
Future Directions ◽  
Iron Cycle ◽  
Surface Ocean ◽  
Wide Range

Abstract. Iron is a key micronutrient for phytoplankton growth in the surface ocean. Yet the significance of volcanism for the marine biogeochemical iron-cycle is poorly constrained. Recent studies, however, suggest that offshore deposition of airborne ash from volcanic eruptions is a way to inject significant amounts of bio-available iron into the surface ocean. Volcanic ash may be transported up to several tens of kilometres high into the atmosphere during large-scale eruptions and fine ash may encircle the globe for years, thereby reaching even the remotest and most iron-starved oceanic areas. Scientific ocean drilling demonstrates that volcanic ash layers and dispersed ash particles are frequently found in marine sediments and that therefore volcanic ash deposition and iron-injection into the oceans took place throughout much of the Earth's history. The data from geochemical and biological experiments, natural evidence and satellite techniques now available suggest that volcanic ash is a so far underestimated source for iron in the surface ocean, possibly of similar importance as aeolian dust. Here we summarise the development of and the knowledge in this fairly young research field. The paper covers a wide range of chemical and biological issues and we make recommendations for future directions in these areas. The review paper may thus be helpful to improve our understanding of the role of volcanic ash for the marine biogeochemical iron-cycle, marine primary productivity and the ocean-atmosphere exchange of CO2 and other gases relevant for climate throughout the Earth's history.

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