| 词条 | Hook granite massif |
| 释义 |
The Hook granite massif is a large formation in central Zambia formed around 550 million years ago during the Pan-African orogeny. It lies in the inner part of the Lufilian arc. Today, the south-western extension of the massif lies under the Kafue National Park.[1] FormationField studies and U-Pb (uranium-lead) dating show that the massif is a large composite batholith that has intruded into the upper Katangan (Kundelungu) strata of sediments in the Lufilian arc during or after tectonic activity. Sample U-Pb dates for syntectonic granite in the massif are 559±18 and 566±5 Ma, and for post-tectonic granite 533±3 Ma. These show that the Kundelungu sediments date to before 570 Ma; the deformation of the inner Lufilian arc and voluminous syntectonic granite plutonism took place around 560–570 Ma; and the major tectonic activity had ended by around 530–540 Ma. The Hook massif is bounded to the south by the Mwembeshi dislocation, a Pan-African transcurrent shear zone. Syntectonic rhyolite intruded in this shear zone dates to 551±19 Ma, so the transcurrent shearing happened about the same time as the batholith intrusion and was probably due to the same causes. Syntectonic and post-tectonic granite plutonism also took place around the same time in the Damara belt in Namibia, indicating a link with the Lufilian arc and Zambezi belt during the Pan-African orogeny. References1. ^{{cite web |url=http://www.biodiversityfoundation.org/documents/BFA%20No.22_Zambia,%20Fanshawe%20District%20Surveys.pdf |title=VEGETATION DESCRIPTIONS OF THE UPPER ZAMBEZI DISTRICTS OF ZAMBIA |author=D.B. Fanshawe |date=December 2010 |publisher=Biodiversity Foundation for Africa |accessdate=2012-06-08}} }}{{palaeo-geo-stub}} 1 : Geology of Africa |
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