Paleomagnetic study of lower Mesozoic diabase dikes and sills of Connecticut and Maryland

1976 ◽  
Vol 13 (4) ◽  
pp. 597-609 ◽  
Author(s):  
Timothy E. Smith
Keyword(s):  
Middle Jurassic ◽  
Pole Position ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Sea Floor ◽  
Good Convergence ◽  
Faunal Assemblages ◽  
Paleomagnetic Study ◽  
Intrusive Rocks ◽  
Stratigraphic Position

Paleomagnetic results from 61 sites on diabase dikes and sills in Connecticut and Maryland yield a mean pole of position of 100.9 °E. 68.6 °N, α95 = 1.6°. These results combined with those from 7S sites on four diabase sills in the Gettysburg Basin of Pennsylvania produce a mean pole position of 101, 6 °E. 65.4 °N, α95 = 1.3 °from 139 VGPs. These rocks arc probably of Early to early Middle Jurassic age by stratigraphic and inferred stratigraphic position. The paleomagnetic results indicate that the Gettysburg and Hartford Basins did not subside simultaneously.The dispersion of virtual geomagnetic poles about the mean pole of the Connecticut, Pennsylvania, and Maryland intrusive rocks is probably the result of 'homogenization' of magnetic directions during low-temperature oxidation of titanomagnetite to titanomaghemite over a period long enough to erase a considerable amount of dispersion due to secular variation.Rotation of Europe against North America in the prerifting configuration causes good convergence of European Jurassic mean poles and the pole of the Connecticut. Maryland, and Pennsylvania intrusive rocks. This is evidence that separation of the two continents had not begun by Early to early Middle Jurassic time, which is in agreement with earlier findings based on sea-floor magnetic anomalies and faunal assemblages.

The Paleomagnetism of Diabase Dikes from the Grenville Province

1971 ◽  
Vol 8 (7) ◽  
pp. 802-812 ◽  
Author(s):  
G. S. Murthy
Keyword(s):  
Primary Component ◽  
Low Temperature Oxidation ◽  
Grenville Province ◽  
Temperature Oxidation ◽  
Dike Swarm ◽  
Grenville Orogeny ◽  
Paleomagnetic Pole ◽  
Paleomagnetic Study ◽  
The Mean ◽  
Magnetic Stability

A paleomagnetic study was attempted of the diabase dike swarm intruding the Grenville structural province of the Canadian Shield. Both the alternating field and thermal demagnetization studies indicated that the dikes have varying degrees of stability of magnetization. Some dikes were shown to have stable primary component of magnetization. Microscopic observations indicated that, in most cases, the primary magnetic mineral titanomagnetite was altered to titanomaghemite, probably due to low temperature oxidation. A good correlation is obtained between magnetic stability and relative abundance of titanomagnetite to titanomaghemite in that dike. The mean paleomagnetic pole for the Grenville dike swarm, which is probably of late Precambrian age, was computed to lie at 3.0° N, 29.0° W with A25 = 11.0°. Comparison of this result with other Precambrian pole positions of similar age relative to North America suggests that the dikes were intruded after the Grenville orogeny.

Paleomagnetism of Carboniferous strata from the Stellarton Gap

2002 ◽  
Vol 39 (10) ◽  
pp. 1527-1540 ◽  
Author(s):  
W A Morris
Keyword(s):  
Large Scale ◽  
Early Period ◽  
Pole Position ◽  
Subsidence Basin ◽  
Pull Apart Basin ◽  
Paleomagnetic Study ◽  
Acquisition Sequence ◽  
Stratigraphic Position ◽  
Stratigraphic Sequences ◽  
Thermal Subsidence

Deposition of Carboniferous sediments within the Stellarton Graben of Nova Scotia was controlled by displacements on the bounding Hollow and Cobequid fault systems. Periods of both normal and transcurrent faulting have occurred on both faults. As a result, models for the development of the Stellarton Basin have included a pull-apart basin and a thermal subsidence basin. Paleomagnetic study of stratigraphic sequences from within the graben showed evidence for three separate periods of remanence acquisition (ST3 – ST2 – ST1). Ordering the acquisition sequence for these three magnetizations is mainly circumstantial, being based on the distribution of each remanence phase relative to stratigraphic position and deformation of the strata. The oldest magnetization ST3 is grossly divergent from previously reported Carboniferous results suggesting an early period of large-scale clockwise rotation. Magnetization ST2 has a similar pole position to many others from Maritime Carboniferous basins located within the Appalachian orogenic belt. The divergence of these poles from the cratonic poles is interpreted as indicating that these magnetizations were acquired at a time when the reference horizontal was different to the present horizontal. The third magnetization ST3 is identical to a large number of late-stage Carboniferous regional overprint magnetizations. In summary, the paleomagnetic evidence suggests that the Stellarton Basin was formed in an early (Westphalian B to C) pull-apart phase that was followed by a later thermal subsidence phase.

scholarly journals Influence of Co-Precipitation Agent on the Structure, Texture and Catalytic Activity of Au-CeO2 Catalysts in Low-Temperature Oxidation of Benzyl Alcohol

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 641
Author(s):  
Lukasz Wolski ◽  
Grzegorz Nowaczyk ◽  
Stefan Jurga ◽  
Maria Ziolek
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Low Temperature ◽  
Benzyl Alcohol ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Oxidation Of Benzyl Alcohol ◽  
Key Factor ◽  
Au Particle Size ◽  
Co Precipitation

The aim of the study was to establish the influence of a co-precipitation agent (i.e., NaOH–immediate precipitation; hexamethylenetetramine/urea–gradual precipitation and growth of nanostructures) on the properties and catalytic activity of as-synthesized Au-CeO2 nanocomposites. All catalysts were fully characterized with the use of XRD, nitrogen physisorption, ICP-OES, SEM, HR-TEM, UV-vis, XPS, and tested in low-temperature oxidation of benzyl alcohol as a model oxidation reaction. The results obtained in this study indicated that the type of co-precipitation agent has a significant impact on the growth of gold species. Immediate co-precipitation of Au-CeO2 nanostructures with the use of NaOH allowed obtainment of considerably smaller and more homogeneous in size gold nanoparticles than those formed by gradual co-precipitation and growth of Au-CeO2 nanostructures in the presence of hexamethylenetetramine or urea. In the catalytic tests, it was established that the key factor promoting high activity in low-temperature oxidation of benzyl alcohol was size of gold nanoparticles. The highest conversion of the alcohol was observed for the catalyst containing the smallest Au particle size (i.e., Au-CeO2 nanocomposite prepared with the use of NaOH as a co-precipitation agent).

Low temperature oxidation of copper alloys—AEM and AFM characterization

2007 ◽  
Vol 42 (12) ◽  
pp. 4684-4691 ◽  
Author(s):  
Mari Honkanen ◽  
Minnamari Vippola ◽  
Toivo Lepistö
Keyword(s):  
Low Temperature ◽  
Copper Alloys ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation

scholarly journals A study of the low-temperature oxidation of a long chain aldehyde: n-hexanal

2017 ◽  
Vol 36 (1) ◽  
pp. 365-372 ◽  
Author(s):  
Anne Rodriguez ◽  
Olivier Herbinet ◽  
Frédérique Battin-Leclerc
Keyword(s):  
Low Temperature ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Long Chain ◽  
Chain Aldehyde
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