7B: Provenance and tectonic significance of the Keweenaw an interflow sedimentary rocks

1982 ◽  
pp. 97-105 ◽  
Author(s):  
George P. Merk ◽  
Mark A. Jirsa
Keyword(s):  
Sedimentary Rocks ◽  
Tectonic Significance

Early Cambrian Seismic Events and Their Tectonic Significance in Western Zhejiang

2012 ◽  
Vol 524-527 ◽  
pp. 42-48
Author(s):  
Fu Sheng Guo ◽  
Zhao Bin Yan ◽  
Liu Qin Chen
Keyword(s):  
Seismic Event ◽  
Regional Distribution ◽  
Sedimentary Rocks ◽  
Seismic Events ◽  
Time Interval ◽  
Early Cambrian ◽  
Distribution Characteristics ◽  
Early Paleozoic ◽  
Tectonic Events ◽  
Tectonic Significance

The two early Cambrian seismic events could be found from sedimentary rocks at Peilingjiao section of Kaihua County, Baishi and Fangcun sections of Changshan County in western Zhejiang, except for Jiangshan area. The seismic event at Baishi outcrop can be correlated to the second seismic event at Peilingjiao section. Taking Fangcun as epicenter of the second seismic event, the magnitude of paleoseism in western Zhejiang is about 7~7.6. According to investigation on regional distribution of seismic events, the two seismic activities should be regulated by large Kaihua-Chun’an fault, but unrelated with Jiangshan-Shaoxing fault or Changshan-Xiaoshan fault. However, the formation time of Kaihua-Chun’an fault has not yet been determinate. Based on controlling on Silurian, the possible formation age was inferred to early Paleozoic. The distribution characteristics of seismites indicate that the Kaihua-Chun’an fault was already being active during early Cambrian and seismic activities may be response to Sinian tectonic events in western Zhejiang. By the way of analysis on paleoseismic rhythm, the time interval of the two seismic events in western Zhejiang is less than 5.0 Ma, which may be the result of early frequent activities of Kaihua-Chun’an fault.

Composition variations of the Sinian-Cambrian sedimentary rocks in Hunan and Guangxi provinces and their tectonic significance

2013 ◽  
Vol 56 (11) ◽  
pp. 1899-1917 ◽  
Author(s):  
PengMing Wang ◽  
JinHai Yu ◽  
Tao Sun ◽  
Yu Shi ◽  
PeiRong Chen ◽  
...  
Keyword(s):  
Sedimentary Rocks ◽  
Tectonic Significance

Tectonic significance of the Carboniferous Big Pond Basin, Cape Breton Island, Nova Scotia

1986 ◽  
Vol 23 (12) ◽  
pp. 2000-2011 ◽  
Author(s):  
Dwight C. Bradley ◽  
Lauren M. Bradley
Keyword(s):  
Sedimentary Rocks ◽  
Sedimentary Basins ◽  
Strike Slip ◽  
Fault System ◽  
Cape Breton Island ◽  
Cape Breton ◽  
Pull Apart Basin ◽  
Tectonic Significance ◽  
Basin Margin ◽  
Faulted Basin

Detailed mapping in southeastern Cape Breton Island has revealed a strike-slip origin for the small Carboniferous outlier at Big Pond. Topographically low Carboniferous sedimentary rocks occur between splays of a previously unrecognized, northeast-trending set of high-angle faults, the Big Pond fault system. The section is dominated by fanglomerates, which coarsen toward the faulted basin margins and which were deposited and (or) reworked by currents flowing toward the basin's center and along its axis. We interpret the fanglomerates as syntectonic. Interbedded limestones of Visean age (Windsor B Subzone) provide age control for the upper part of the 300 m section and, by inference, for at least some of the fault motion. Dextral motion on the Big Pond fault system is indicated by (1) slickenside stepping directions on minor faults, which juxtapose basement against basement and which parallel the main northeast-striking fault; (2) northeast-striking mesoscale faults within the basin, which produce dextral offsets; and (3) shear and extension fractures in fanglomerate clasts along the northeast-striking basin margin faults, which reveal dextral and down-to-basin motion. The location of the basin at a right step in the through-going dextral fault system implies that it is a pull-apart basin. We suggest that during Visean times, southern Cape Breton Island was cut by several such dextral wrench faults and associated sedimentary basins and that the tectonic climate was similar to that recognized by previous workers in Newfoundland and New Brunswick. No evidence was found in support of the paleomagnetically based hypothesis for sinistral strike slip during this time.

Late Cretaceous metamorphism of sedimentary rocks in the eastern Gangdese magmatic arc and its tectonic significance

2021 ◽  
Vol 37 (11) ◽  
pp. 3445-3463
Author(s):  
LI ZhongYao ◽  
◽  
DING HuiXia ◽  
YUAN Yue ◽  
ZHANG ZeMing
Keyword(s):  
Late Cretaceous ◽  
Sedimentary Rocks ◽  
Magmatic Arc ◽  
Tectonic Significance

Tectonic significance of the Late Proterozoic Economy River gneiss, Cobequid Highlands, Avalon Composite Terrane, Nova Scotia

1993 ◽  
Vol 30 (3) ◽  
pp. 474-479 ◽  
Author(s):  
Ronald Doig ◽  
J. Brendan Murphy ◽  
R. Damian Nance
Keyword(s):  
Nova Scotia ◽  
Sedimentary Rocks ◽  
Early Cambrian ◽  
Zircon Age ◽  
Late Proterozoic ◽  
Tectonic Significance ◽  
Minimum Age

A 734 ± 2 Ma U–Pb (zircon) age for the Economy River orthogneiss, Coboquid Highlands, Nova Scotia, is interpreted as being representative of a regionally extensive ca. 820–660 Ma event that is recorded in many parts of the Late Proterozoic – Early Cambrian Avalon Composite Terrane and the Gondwanan margin. The geochemistry of the gneiss is consistent with an arc environment. Although the gneiss may represent part of the sialic basement to the terrane, field relationships indicate that some of the basement is significantly older. The date may provide a minimum age for the platformal sedimentary rocks (Gamble Brook Formation) that the orthogneiss intruded and thus help constrain the Late Proterozoic paleogeographic position of Avalon relative to Gondwanaland.

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