PALAEOMAGNETISM OF THE ABITIBI DYKE SWARM

1966 ◽  
Vol 3 (5) ◽  
pp. 671-683 ◽  
Author(s):  
A. Larochelle

Previous data published on the palaeomagnetism of a group of Precambrian diabase dykes, referred to as the Abitibi swarm, were characterized by considerable angular dispersion attributed to a number of possible factors. The relative importance of these factors was investigated in the light of data obtained for an independent suite of samples from the same group of dykes. Most of the previous interpretation is probably no longer valid because the magnetization of the swarm was found to be distributed tightly about three mean directions rather than dispersed widely about one mean direction, as originally thought. It is concluded that the dykes forming the swarm were injected intermittently during several widely distinct periods and that, accordingly, long-range correlation of diabase dyke swarms on the sole basis of their palaeomagnetism may be more hazardous than was realized earlier.

1995 ◽  
Vol 51 (5) ◽  
pp. 5084-5091 ◽  
Author(s):  
S. V. Buldyrev ◽  
A. L. Goldberger ◽  
S. Havlin ◽  
R. N. Mantegna ◽  
M. E. Matsa ◽  
...  

PLoS ONE ◽  
2018 ◽  
Vol 13 (6) ◽  
pp. e0198238 ◽  
Author(s):  
Xiaohui Zheng ◽  
Yi Lian ◽  
Qiguang Wang

1995 ◽  
Vol 32 (3) ◽  
pp. 273-280 ◽  
Author(s):  
S. L. Kamo ◽  
T. E. Krogh ◽  
P. S. Kumarapeli

U–Pb baddeleyite and zircon ages for three diabase dykes from widely spaced localities within the Grenville dyke swarm indicate a single age of emplacement at [Formula: see text] Ma. The 700 km long Grenville dyke swarm, located in the southeastern part of the Canadian Shield, was emplaced syntectonically with the development of the Ottawa graben. This graben may represent a plume-generated lapetan failed arm that developed at the onset of the breakup of Laurentia. Other precisely dated lapetan rift-related units, such as the Callander Alkaline Complex and the Tibbit Hill Formation volcanic rocks, indicate a protracted 36 Ma period of rifting and magmatism prior to volcanism along this segment of the lapetan margin. The age of the Grenville dykes is the youngest in a progression of precisely dated mafic magmatic events from the 723 Ma Franklin dykes and sills to the 615 Ma Long Range dykes, along the northern and northeastern margins of Laurentia, respectively. Thus, the age for these dykes represents a key time marker for continental breakup that preceded the formation of the Iapetus ocean.


2004 ◽  
Vol 53 (2) ◽  
pp. 373
Author(s):  
Liu Feng ◽  
Shan Xiu-Ming ◽  
Ren Yong ◽  
Zhang Jun ◽  
Ma Zheng-Xin

Author(s):  
В.Н. Сычёв ◽  
М.А. Мищенко ◽  
С.А. Имашев ◽  
М.Е. Чешев

На Камчатке в пункте комплексных геофизических наблюдений ИКИР ДВО РАН Карымшина для регистрации сигналов сейсмоакустической эмиссии на поверхности земли установлен измерительный комплекс. В качестве датчика сигналов используется трехкомпонентный пьезокерамический сейсмоприемник, который регистрирует колебательное ускорение в частотном диапазоне 0.5-400 Гц. Рассмотрен сейсмоакустический отклик на несколько региональных землетрясений с энергетическим классом Ks 11:0 в период 2017-2018 гг. При помощи статистических методов установлено самоподобие их структуры на ограниченном интервале временных масштабов. Это, в свою очередь, указывает на наличие дальних корреляций в рассматриваемой системе и позволяет получить оценку масштабов корреляций. A measurement complex is installed on the ground surface at Karymshina complex geophysical observation site of IKIR FEB RAS (Kamchatka) to record seismoacoustic emission signals. A three-component piezoceramic seismic receiver, which records oscillatory acceleration in the frequency range from 0.2 to 400 Hz, is used as the signal sensor. A series of seismoacoustic responses on regional earthquakes of 2017-2018 with the energy class Ks 11:0 has been considered. Self-similarity of their structures has been established in a limited interval of time scales by statistical methods. That, in its turn, indicates the presence of long-range correlations in the system under consideration and allows one to estimate correlation scales.


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