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ORIGINAL RESEARCH article

Front. Earth Sci.

Sec. Structural Geology and Tectonics

Volume 13 - 2025 | doi: 10.3389/feart.2025.1630039

Hybrid emplacement mechanisms and structural interactions: Insights into Dike-Fault-Fracture systems in SE Korea

Provisionally accepted
Jinhyun  LeeJinhyun Lee1Goeun  KimGoeun Kim2Young-Seog  KimYoung-Seog Kim1*
  • 1Pukyong National University, Busan, Republic of Korea
  • 2Other

The final, formatted version of the article will be published soon.

The structural evolution of dike-fault-fracture systems is governed by the combined effects of dike emplacement and structural inheritance, together with deformation that occurs after emplacement. Each magma injection can either forcefully fracture intact rock to create new pathways or passively intrude along pre-existing faults, reflecting a hybrid dike emplacement. Integrated field mapping and topological analysis reveal hybrid emplacement mechanisms in Eocene mafic dikes intruding Late Cretaceous granitic bedrock in southeastern Korea. Dikes in the study area display three distinct orientations. Geometric restoration indicates dike emplacement under NW–SE minimum principal stress. NE-striking dikes formed through forceful fracturing, creating continuous Mode I structure. ENE-and NNE-striking dikes developed via passive intrusion along pre-existing fracture sets, producing characteristic zigzag geometries, blunt terminations, and apparent offsets. Complex dike patterns reflect hybrid emplacement combining both mechanisms under local stress-field rotations. NE-striking dikes act as both barriers to fracture propagation and strain concentrators, partitioning deformation within the host rock. Post-emplacement deformation modified the dike-fault-fracture system architecture. Stress field rotation reactivated ENE-oriented fractures as sinistral faults, generating damage zones with fracture intensity (P21) up to 6.14 m⁻¹ and a connectivity (𝐶𝐶𝐵𝐵) of 1.29. Post-intrusion hydrothermal alteration produced calcite veins concentrated along dike margins and ENE fault-tip and linking damage zones. Superimposed slickenlines record multiple reactivation phases, indicating continued structural evolution after magmatic emplacement. These results demonstrate that hybrid emplacement mechanisms establish structurally heterogeneous frameworks governing subsequent tectonic overprinting, highlighting the coupled evolution of magmatic and structural processes in continental crust.

Keywords: Dike-Fault-Fracture systems, hybrid dike emplacement, Topological analysis, Pre-existing fracture, Cenozoic magma-tectonic crustal deformation

Received: 16 May 2025; Accepted: 14 Aug 2025.

Copyright: © 2025 Lee, Kim and Kim. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Young-Seog Kim, Pukyong National University, Busan, Republic of Korea

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