Deformation history and U–Pb zircon geochronology of the high grade metamorphic rocks within the Klaeng fault zone, eastern Thailand

Quantitative finite strain analysis of high-grade metamorphic rocks within the Mae Ping shear zone, western Thailand

“…However, the region where the two strike-slip systems potentially merge is structurally poorly documented. In many geological interpretations the Mae Ping strike-slip zone is extended to the Klaeng fault zone in eastern Thailand (Lacassin et al, 1993(Lacassin et al, , 1997Leloup et al, 1995;Gilley et al, 2003;Geard, 2008;Nantasin et al, 2012), which records ductile sinistral shearing during the Eocene (Kanjanapayont et al, 2013). The Ranong and Khlong Marui shear zones in the southern Thailand extend from the continental margin and Mergui basin to the Gulf of Thailand from W to E (Tapponnier et al, 1986;Lacassin et al, 1997;Charusiri et al, 2002).…”

Cenozoic tectonic evolution of southeastern Thailand derived from low-temperature thermochronology

“…Localized metamorphism in the Klaeng Fault strike-slip zone is constrained by monazite U-Pb ages of 42.54 ± 0.88 Ma and 35.5 ± 3.1 to 37.8 ± 4.8 Ma for titanite U-Pb (Geard 2008) and suggests a much later (Eocene) metamorphic overprint than previously suggested (Kawakami et al 2014). Based on NW-SE shearing indicators and additional zircon U-Pb dating on deformed basement rocks exposed in this area, ductile sinistral shearing of the Klaeng Fault zone has been shown to have occurred after 67 ± 1 Ma (Kanjanapayont et al 2013). Also, based on the unpublished monazite and titanite U-Pb ages of Geard (2008), an Eocene age for the NW-SE-directed sinistral shearing was assumed.…”

“…Structural geological data from our study area suggest Eocene sinistral ductile deformation in the high-grade metamorphic rocks in the Klaeng Fault zone area (Geard 2008;Kanjanapayont et al 2013). The Klaeng Fault gneisses are crosscut by leucogranites, with a Late Cretaceous crystallization age (78.1 ± 0.7 Ma) (Cobbing 2011;Kanjanapayont et al 2013). Sinistral ductile shearing post-dates leucogranites formed at 67 ± 1 and 72.1 ± 0.6 Ma (Kanjanapayont et al 2013).…”

“…Geochronological information in southeastern Thailand is rather limited to the aforementioned high-grade metamorphic rocks in the Klaeng Fault zone (Geard 2008;Kanjanapayont et al 2013;Kawakami et al 2014). Structural geological data from our study area suggest Eocene sinistral ductile deformation in the high-grade metamorphic rocks in the Klaeng Fault zone area (Geard 2008;Kanjanapayont et al 2013).…”

“…The Klaeng Fault gneisses are crosscut by leucogranites, with a Late Cretaceous crystallization age (78.1 ± 0.7 Ma) (Cobbing 2011;Kanjanapayont et al 2013). Sinistral ductile shearing post-dates leucogranites formed at 67 ± 1 and 72.1 ± 0.6 Ma (Kanjanapayont et al 2013). The complex tectonic history of these mylonitic gneisses is further constrained by a U-Pb monazite age of 42.54 ± 0.88 Ma, and U-Pb titanite ages of 35.5 ± 3.1 and 37.8 ± 4.8 Ma (Geard 2008;Crow 2011).…”