ИСТИНА |
Войти в систему Регистрация |
|
ФНКЦ РР |
||
There are the results of the study paleomagnetism of the chaya suite akitkan formation of the Early Proterozoic Minya river within the North Baikal volcanoplutonic belt. This belt was formed at the end of the Early Proterozoic as a result of orogenic collapse on the basis of Akitkan orogenic belt - the structure of the basement of the Siberian craton – the suture contact terranes of the North-West and South-East (Rosen et al, 2006). The rocks are low metamorphosed red siltstones, quartz latites and rhyodacites. Volcanics of the Chaya suite are according to (Buldygerov, Sobachenko, 2005) Minya paleovolcano formation and combined in lambor volcanic complex. Obtained isotopic age dating of the U/Pb zircon - 1823+7 Ma (Neymark et al, 1991) makes this complex of the youngest in the Akitkan formation. For all samples chaya suite carried out a complete thermal treatment. In the high temperature range NRM observed two components formed two narrow clusters. The component HT1 is a characteristic, fold test positive for it. Its average direction correlates well with the directions in the chaya suite of the Chaya river remote from the Minya river for about 160 km. Calculated pole (Plat=-23.7º Plong=100.1º dp/dm=4.6/8.9) almost the same as the pole chaya suite (Didenko et al, 2009). The component HT2 has a bipolar distribution, reversion test is a positive (/c=12.3/19.5), fold test indeterminate. Calculated pole from the component ht2 (Plat=-22.2º Plong=140.8º dp/dm=7.8/15.3) lies on the Early Proterozoic APWP of the Siberian craton (Vodovozov, 2010) to the east of the oldest poles akitkan formation. A similar view can be interpreted by the two phases of generation of the chaya suite Minya river. The first phase conform to the time of the chaya suite Chaya river (about 1860 Ma), the second phase is associated with the introduction of the youngest volcanic rocks of the Minya paleovolcano 1823 Ma ago. These data can be used to develop the Early Proterozoic APWP of the Siberian craton.