Detailed chronology of the southeast Indian ridge in the mid-indian basin of the Indian ocean (Chrons C1-C18)

The analysis of the distribution of the relative instant spreading rates fr om the data of the schematic of chrons C1-C18 compiled for the Southeast In dian Ridge in the Mid-Indian Basin allows us to refine the history of the c ollision between the Indian-Australian and Eurasian lithospheric plates ove r the past 40 My. The regular spreading at the western portion of the Mid-I ndian Ridge started not earlier than 40.9 Ma. The northward movement of the Indian-Australian plate was not monotonic and is characterized by a period icity estimated at 19 +/- 2.5 My. The northward propagation of the plate wa s accompanied by the accumulation of intraplate deformations. The position of the local minimums of the relative instant spreading rate corresponds we ll to the moments of formation of the intraplate deformations from the geol ogical data in the intervals of chrons C3B-C4 (7.091-8.072 Ma), C2A-C3 (3.5 80-4.180 Ma), and in the recent Bruhnes epoch of normal magnetic polarity. The existence of intraplate deformations in the interval of chrons C6-C7 (2 0.131-25.183 Ma) is suggested.