Tie points for Gondwana reconstructions from a structural interpretation of the Mozambique Basin, East Africa and the Riiser-Larsen Sea, Antarctica
Movements within early East Gondwana dispersal are poorly constrained, and there is debate about conjugate geologic structures and the timing and directions of the rifting and earliest seafloor spreading phases. We present a combined structural interpretation of multichannel reflection seismic profi...
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ftdoajarticles:oai:doaj.org/article:6caec14ffce34f35a921ff3545cdc2b8 2023-05-15T13:45:56+02:00 Tie points for Gondwana reconstructions from a structural interpretation of the Mozambique Basin, East Africa and the Riiser-Larsen Sea, Antarctica J. Klimke D. Franke E. S. Mahanjane G. Leitchenkov 2018-01-01T00:00:00Z https://doi.org/10.5194/se-9-25-2018 https://doaj.org/article/6caec14ffce34f35a921ff3545cdc2b8 EN eng Copernicus Publications https://www.solid-earth.net/9/25/2018/se-9-25-2018.pdf https://doaj.org/toc/1869-9510 https://doaj.org/toc/1869-9529 doi:10.5194/se-9-25-2018 1869-9510 1869-9529 https://doaj.org/article/6caec14ffce34f35a921ff3545cdc2b8 Solid Earth, Vol 9, Pp 25-37 (2018) Geology QE1-996.5 Stratigraphy QE640-699 article 2018 ftdoajarticles https://doi.org/10.5194/se-9-25-2018 2022-12-31T12:48:08Z Movements within early East Gondwana dispersal are poorly constrained, and there is debate about conjugate geologic structures and the timing and directions of the rifting and earliest seafloor spreading phases. We present a combined structural interpretation of multichannel reflection seismic profiles from offshore of northern Mozambique (East Africa) and the conjugate Riiser-Larsen Sea (Antarctica). We find similar structural styles at the margins of both basins. At certain positions at the foot of the continental slope close to the continent–ocean transition, the basement is intensely deformed and fractured, a structural style very untypical for rifted continental margins. Sediments overlying the fractured basement are deformed and reveal toplap and onlap geometries, indicating a post-breakup deformation phase. We propose this unique deformation zone as a tie point for Gondwana reconstructions. Accordingly, we interpret the western flank of Gunnerus Ridge, Antarctica as a transform margin similar to the Davie Ridge offshore of Madagascar, implying that they are conjugate features. As the continental slope deformation is post-rift, we propose a two-phase opening scenario. A first phase of rifting and early seafloor spreading, likely in NW–SE direction, was subsequently replaced by a N–S-directed transform deformation phase overprinting the continent–ocean transition. From previously identified magnetic chrons and the sediment stratigraphy, this change in the spreading directions from NW–SE to N–S is suggested to have occurred by the late Middle Jurassic. We suggest that the second phase of deformation corresponds to the strike-slip movement of Madagascar and Antarctica and discuss implications for Gondwana breakup. Article in Journal/Newspaper Antarc* Antarctica Riiser-Larsen Sea Directory of Open Access Journals: DOAJ Articles Riiser-Larsen ENVELOPE(50.667,50.667,-66.783,-66.783) Riiser-Larsen Sea ENVELOPE(24.000,24.000,-68.000,-68.000) Gunnerus Ridge ENVELOPE(33.750,33.750,-66.500,-66.500) Solid Earth 9 1 25 37 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 Stratigraphy QE640-699 |
spellingShingle |
Geology QE1-996.5 Stratigraphy QE640-699 J. Klimke D. Franke E. S. Mahanjane G. Leitchenkov Tie points for Gondwana reconstructions from a structural interpretation of the Mozambique Basin, East Africa and the Riiser-Larsen Sea, Antarctica |
topic_facet |
Geology QE1-996.5 Stratigraphy QE640-699 |
description |
Movements within early East Gondwana dispersal are poorly constrained, and there is debate about conjugate geologic structures and the timing and directions of the rifting and earliest seafloor spreading phases. We present a combined structural interpretation of multichannel reflection seismic profiles from offshore of northern Mozambique (East Africa) and the conjugate Riiser-Larsen Sea (Antarctica). We find similar structural styles at the margins of both basins. At certain positions at the foot of the continental slope close to the continent–ocean transition, the basement is intensely deformed and fractured, a structural style very untypical for rifted continental margins. Sediments overlying the fractured basement are deformed and reveal toplap and onlap geometries, indicating a post-breakup deformation phase. We propose this unique deformation zone as a tie point for Gondwana reconstructions. Accordingly, we interpret the western flank of Gunnerus Ridge, Antarctica as a transform margin similar to the Davie Ridge offshore of Madagascar, implying that they are conjugate features. As the continental slope deformation is post-rift, we propose a two-phase opening scenario. A first phase of rifting and early seafloor spreading, likely in NW–SE direction, was subsequently replaced by a N–S-directed transform deformation phase overprinting the continent–ocean transition. From previously identified magnetic chrons and the sediment stratigraphy, this change in the spreading directions from NW–SE to N–S is suggested to have occurred by the late Middle Jurassic. We suggest that the second phase of deformation corresponds to the strike-slip movement of Madagascar and Antarctica and discuss implications for Gondwana breakup. |
format |
Article in Journal/Newspaper |
author |
J. Klimke D. Franke E. S. Mahanjane G. Leitchenkov |
author_facet |
J. Klimke D. Franke E. S. Mahanjane G. Leitchenkov |
author_sort |
J. Klimke |
title |
Tie points for Gondwana reconstructions from a structural interpretation of the Mozambique Basin, East Africa and the Riiser-Larsen Sea, Antarctica |
title_short |
Tie points for Gondwana reconstructions from a structural interpretation of the Mozambique Basin, East Africa and the Riiser-Larsen Sea, Antarctica |
title_full |
Tie points for Gondwana reconstructions from a structural interpretation of the Mozambique Basin, East Africa and the Riiser-Larsen Sea, Antarctica |
title_fullStr |
Tie points for Gondwana reconstructions from a structural interpretation of the Mozambique Basin, East Africa and the Riiser-Larsen Sea, Antarctica |
title_full_unstemmed |
Tie points for Gondwana reconstructions from a structural interpretation of the Mozambique Basin, East Africa and the Riiser-Larsen Sea, Antarctica |
title_sort |
tie points for gondwana reconstructions from a structural interpretation of the mozambique basin, east africa and the riiser-larsen sea, antarctica |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/se-9-25-2018 https://doaj.org/article/6caec14ffce34f35a921ff3545cdc2b8 |
long_lat |
ENVELOPE(50.667,50.667,-66.783,-66.783) ENVELOPE(24.000,24.000,-68.000,-68.000) ENVELOPE(33.750,33.750,-66.500,-66.500) |
geographic |
Riiser-Larsen Riiser-Larsen Sea Gunnerus Ridge |
geographic_facet |
Riiser-Larsen Riiser-Larsen Sea Gunnerus Ridge |
genre |
Antarc* Antarctica Riiser-Larsen Sea |
genre_facet |
Antarc* Antarctica Riiser-Larsen Sea |
op_source |
Solid Earth, Vol 9, Pp 25-37 (2018) |
op_relation |
https://www.solid-earth.net/9/25/2018/se-9-25-2018.pdf https://doaj.org/toc/1869-9510 https://doaj.org/toc/1869-9529 doi:10.5194/se-9-25-2018 1869-9510 1869-9529 https://doaj.org/article/6caec14ffce34f35a921ff3545cdc2b8 |
op_doi |
https://doi.org/10.5194/se-9-25-2018 |
container_title |
Solid Earth |
container_volume |
9 |
container_issue |
1 |
container_start_page |
25 |
op_container_end_page |
37 |
_version_ |
1766232783624077312 |