EGU2020-1147
https://doi.org/10.5194/egusphere-egu2020-1147
EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Physical modeling of the formation of the microcontinent Jan Mayen

Grigory Agranov1, Eugene Dubinin2, Andrey Grokholsky2, and Anna Makushkina3
Grigory Agranov et al.
  • 1Lomonosov Moscow State University, Faculty of Geology, Dynamic Geology, Russian Federation (agranovgr@gmail.com)
  • 2Lomonosov Moscow State University, Museum of the Earth, Russian Federation
  • 3Australian National University, Research School of Earth Sciences, Australia

The split between the North American and Eurasian plates began in the Late Pleistocene - Early Eocene (58-60 million years). As the stretching took place, overlapping rift cracks formed. With further evolution, the crack that came from the north fully formed, while the south at that time died out, forming the axis of paleospreading (early Ypresian Age, 49.7 Ma). A hot spot was already functioning near Greenland at that time. In the Priabonian Age (33.1 million years), the hot spot ended under the axis of paleospreading. As a result, the spreading axis jumped (Peron-Pinvidic et al., 2012) creating the Jan Mine main microcontinent and the Kolbeinsain spreading ridge. In addition, the northern branch of the spreading ridge died out and the Aegir paleospreading ridge formed. These raises a number of questions arise:

-What is the mechanism for the separation of the Jan Mine continental block?

-Why did the spreading axis jumped and the Aegir Ridge wither away?

-What is the effect of the Icelandic hot spot on microblock formation?

-Are there similar structures in the world formed through a similar mechanism?

To answer these questions, a physical simulation was performed. Some of these issues were considered in (Muller et al., 2001, Gaina et al., 2003, Mjelde et al., 2008, Mjelde, Faleide, 2009).

Modelling was based on the initial geometry of rift cracks, known oldest magnetic anomalies and existing reconstructions. It showed two possibilities for the formation of the Jan Mayen microcontinent.

The first model is associated with parallel or oblique strike of rift cracks, the oncoming movement of which leads to their overlap, isolation of the microcontinental block, which experienced deformation and rotation.

The second model is associated with the presence of a local heat source (hot spot), the influence of which led to a jump of one branch of the rift towards the hot spot, and to the generation of a significant amount of magmatic material, which could significantly change the initial continental structure of the microblock. The second method, which combines the influence of the overlap zone and the hot spot, showed the best correlation with natural structures.

How to cite: Agranov, G., Dubinin, E., Grokholsky, A., and Makushkina, A.: Physical modeling of the formation of the microcontinent Jan Mayen, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1147, https://doi.org/10.5194/egusphere-egu2020-1147, 2019

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