TY - JOUR

T1 - Formation and Evolution of Microcontinents of the Kerguelen Plateau, Southern Indian Ocean

AU - Leitchenkov, G. L.

AU - Dubinin, E. P.

AU - Grokholsky, A. L.

AU - Agranov, G. D.

PY - 2018/10/10

Y1 - 2018/10/10

N2 - The paper considers geological and geophysical data on the crustal structure of the volcanic Kerguelen Plateau and nearby Indian Ocean, as well as evolution of the Kerguelen Plateau during the Gondwana breakup. It is assumed that three isolated continental blocks (microcontinents) evolved within the Kerguelen Plateau. In order to provide insight into the mechanisms for the microcontinent formation, physical modeling under three different conditions has been carried out. The first experiment simulates a homogeneous lithosphere with two rift fractures propagating toward each one other; in the second experiment, the propagating rift fractures collide with a structural barrier having a stronger lithosphere; the third experiment simulated the effect of a local heat source (a hot spot). Based on these experiments and taking into account the available structural and geophysical data, it is suggested that isolation of continental block in the southern Kerguelen Plateau could have begun due to counterpropagation of rifting branches: oceanic from east to west and continental from west to east. The isolation of the southern block with attachment to the Antarctic Plate took place 120 Ma ago after extinction of the spreading ridge in the Princess Elizabeth Trough. Because of the structural inhomogeneity in the prebreakup lithosphere, which is represented by a zone of intracontinental Lambert-Mahanadi rifts, opening of the ocean could have developed in a more complex regime. Under the effect of a hot spot, a jump of the spreading axis occurred at the moment of its emplacement into the lithosphere.

AB - The paper considers geological and geophysical data on the crustal structure of the volcanic Kerguelen Plateau and nearby Indian Ocean, as well as evolution of the Kerguelen Plateau during the Gondwana breakup. It is assumed that three isolated continental blocks (microcontinents) evolved within the Kerguelen Plateau. In order to provide insight into the mechanisms for the microcontinent formation, physical modeling under three different conditions has been carried out. The first experiment simulates a homogeneous lithosphere with two rift fractures propagating toward each one other; in the second experiment, the propagating rift fractures collide with a structural barrier having a stronger lithosphere; the third experiment simulated the effect of a local heat source (a hot spot). Based on these experiments and taking into account the available structural and geophysical data, it is suggested that isolation of continental block in the southern Kerguelen Plateau could have begun due to counterpropagation of rifting branches: oceanic from east to west and continental from west to east. The isolation of the southern block with attachment to the Antarctic Plate took place 120 Ma ago after extinction of the spreading ridge in the Princess Elizabeth Trough. Because of the structural inhomogeneity in the prebreakup lithosphere, which is represented by a zone of intracontinental Lambert-Mahanadi rifts, opening of the ocean could have developed in a more complex regime. Under the effect of a hot spot, a jump of the spreading axis occurred at the moment of its emplacement into the lithosphere.

KW - Antarctica

KW - Indian Ocean

KW - Kerguelen Plateau

KW - oceanic spreading

KW - passive margin

KW - physical modeling

KW - structure and evolution of the lithosphere

UR - http://www.scopus.com/inward/record.url?scp=85054663806&partnerID=8YFLogxK

U2 - 10.1134/S0016852118050035

DO - 10.1134/S0016852118050035

M3 - статья

AN - SCOPUS:85054663806

VL - 52

SP - 499

EP - 515

JO - Geotectonics

JF - Geotectonics

SN - 0016-8521

IS - 5

ER -