Structural characterization of the fracture systems in the porcelanites: Comparing data from the Monterey Formation in California USA and the Sap Bon Formation in Central Thailand

• Published in: Journal of structural geology 2016-09, Vol.90, p.177-184
• Main Authors: Kanjanapayont, Pitsanupong, Aydin, Atilla, Wongseekaew, Kanitsorn, Maneelok, Wichanee
• Format: Article
• Language: English
• Subjects: Fold and thrust belt; Fractures; Monterey Formation; Porcelanite; Sap Bon Formation
• ISSN: 0191-8141; 1873-1201
• DOI: 10.1016/j.jsg.2016.08.006

The fractures in the porcelanites from the Monterey Formation in California USA and the Sap Bon Formation in Central Thailand were documented for a comparative study of their modes, distribution, and their relationship to other structures such as folds and bedding planes. Both formations consist in thinly bedded stiff units that are prone to folding, flexural slip, and cross-bedding brittle fracturing under compression. There are two assemblages in the porcelanites. The first assemblage includes commonly vertical high-angle opening mode fractures, left-lateral strike-slip faults, normal faults, and thrust faults. The second one is sub-horizontal fractures which are associated with folds, bedding slip, and thrusts faults in both Monterey and Sap Bon formations. The structural architectures of these rocks and the associated groups of structures are remarkably similar in terms of both opening and shearing modes and their relationships with the bedding due to their depositional architecture and the compressional tectonic regimes, in spite of the fact that the two locations are more than ten thousand kilometers apart and have very different ages of deformation. •Two fracture systems in the porcelanites from the Monterey Formation USA and the Sap Bon Formation Thailand were documented.•The first is vertical high-angle opening mode fractures, left-lateral strike-slip faults, normal faults and thrust faults.•The second is sub-horizontal fractures associated with folds, bedding slip and thrusts faults.•Both systems are remarkably similar in terms of opening and shearing modes and their relationships with the bedding.