FIRST PALEOMAGNETIC DATA ON THE OKHOTSK-MONGOLIAN BELT Available to Purchase

The paper considers the results of paleomagnetic investigations of Upper Paleozoic-Mesozoic geological complexes from the Okhotsk-Mongolian belt (West and East Transbaikalia). New paleomagnetic poles that are compared with those of Siberia and North China are present. Coordinates of paleomagnetic poles obtained within the suture are as follows: Chiron trough (Middle Carboniferous) – latitude Φ = 59°, longitude Λ = 304°, half-axes of confidence ellipse for 95% level dp = 5.5°, dm = 9.3°, number of vectors involved in the statistics N = 31; Early Permian – Φ = –2°, Λ = 141°, dp = 8.5°, dm = 12.8°, N = 13; Borzinsky region (Late Permian) – Φ = –28°, Λ = 146°, dp = 6.0°, dm = 11.9°, N = 19. Unda-Dain trough (Late Jurassic) – Φ = 77°, Λ = 17°, dp = 7.8°, dm = 9.7°, and N = 26. The coordinates of paleomagnetic poles for the Siberian continent: Khilok region (Late Permian) – Φ = 66°, Λ = 164°, dp = 8.4, dm = 9.4°, N = 24; Mogan trough (Late Jurassic) – Φ = 71°, Λ = 153°, dp = 9.9°, dm = 10.8°, N = 26. On the basis of these data it was concluded that a large ocean existed in the Late Paleozoic-Mesozoic – between Siberia and the Amuria microcontinent situated to the south of the Okhotsk-Mongolian belt. The closing of this ocean in East Transbaikalia occurred in the end of the Late Jurassic.