TY - JOUR
T1 - Cretaceous Kuching accretionary orogenesis in Malaysia Sarawak
T2 - Geochronological and geochemical constraints from mafic and sedimentary rocks
AU - Wang, Yuejun
AU - Zhang, Aimei
AU - Qian, Xin
AU - Asis, Junaidi Bin
AU - Feng, Qinglai
AU - Gan, Chengshi
AU - Zhang, Yuzhi
AU - Cawood, Peter A.
AU - Wang, Weitao
AU - Zhang, Peizhen
N1 - Funding Information:
We thank the National Natural Science Foundation of China ( 41830211 and U1701641 ), Natural Science Foundation of Guangdong Province ( 2018B030312007 , 2019B1515120019 and 2019QZKK0703 ), and Australian Research Council (grant FL 160100168 ) for financial support. Dr. Asri Jaya, another anonymous reviewer and editor-in-chief (Prof. X-H Li) are thanked for their critical and constructive comments. Drs. S N. Wu, X-H. Lu, Y. Wang, X. Qiu, Z. Liu, H Y. He, X. Yang, Q-Y. Gou, X-Q, Yu, C. Xu and T-X. Yang are gratefully acknowledged for their field and experimental help.
Publisher Copyright:
© 2021
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/11/1
Y1 - 2021/11/1
N2 - The Kuching zone, the most important tectonic boundary in Borneo, separates the Sibu zone in Central Sarawak from the Schwaner Mountains granitoids in SW Borneo. It potentially provides a key window for probing the paleo-Pacific subduction process. This paper presents new geochronological, elemental and Sr[sbnd]Nd isotopic data for the Pakong-Serabang and Serian mafic rocks, along with detrital zircon U[sbnd]Pb age-data for the associated greywacke in the Sarawak Kuching zone. These mafic rocks are dated at ~77–98 Ma and show distinctive geochemical signatures. The Pakong- Serabang mafic rocks are subalkaline basalt with SiO2 = 46.22–51.75 wt%, TiO2 = 0.49–2.42 wt% and MgO = 6.30–10.54 wt%. They exhibit MORB-like PM-normalized patterns with depletion in LILEs and HFSEs. Their 87Sr/86Sr(t) and εNd(t) range from 0.70285 to 0.70728 and + 7.4 to +9.4, respectively, originating from a slab-derived fluid-modified MORB-like source. The late Cretaceous Serian Volcanics are marked by SiO2 of 51.52–57.90 wt%, MgO of 3.50–5.06 wt% with mg-number = 36–46 and show arc-like geochemical signatures with (Nb/La)n = 0.37–0.47. They have 87Sr/86Sr(t) = 0.71188–0.71417 and εNd(t) = −11.1 ~ −7.3, and were derived from a mantle wedge with the input of recycled sedimentary components. The detrital zircon grains from the associated sandstones give similar age-spectra to those in East Peninsular Malaysia and SE Vietnam. Our data revealed a Cretaceous Kuching trench-arc system. In combination with other geological observations, it is concluded that NW Borneo to the southwest of the Sarawak Kuching zone was a part of the Indochina/East Peninsular Malaysia fragment in SE Asia prior to the Jurassic and re-activated as an active continental margin in the Cretaceous. Widespread accretionary orogenesis along the Kuching zone likely initiated at or before the early Cretaceous and ended no earlier than the latest Cretaceous in response to the westward subduction of the paleo-Pacific slab.
AB - The Kuching zone, the most important tectonic boundary in Borneo, separates the Sibu zone in Central Sarawak from the Schwaner Mountains granitoids in SW Borneo. It potentially provides a key window for probing the paleo-Pacific subduction process. This paper presents new geochronological, elemental and Sr[sbnd]Nd isotopic data for the Pakong-Serabang and Serian mafic rocks, along with detrital zircon U[sbnd]Pb age-data for the associated greywacke in the Sarawak Kuching zone. These mafic rocks are dated at ~77–98 Ma and show distinctive geochemical signatures. The Pakong- Serabang mafic rocks are subalkaline basalt with SiO2 = 46.22–51.75 wt%, TiO2 = 0.49–2.42 wt% and MgO = 6.30–10.54 wt%. They exhibit MORB-like PM-normalized patterns with depletion in LILEs and HFSEs. Their 87Sr/86Sr(t) and εNd(t) range from 0.70285 to 0.70728 and + 7.4 to +9.4, respectively, originating from a slab-derived fluid-modified MORB-like source. The late Cretaceous Serian Volcanics are marked by SiO2 of 51.52–57.90 wt%, MgO of 3.50–5.06 wt% with mg-number = 36–46 and show arc-like geochemical signatures with (Nb/La)n = 0.37–0.47. They have 87Sr/86Sr(t) = 0.71188–0.71417 and εNd(t) = −11.1 ~ −7.3, and were derived from a mantle wedge with the input of recycled sedimentary components. The detrital zircon grains from the associated sandstones give similar age-spectra to those in East Peninsular Malaysia and SE Vietnam. Our data revealed a Cretaceous Kuching trench-arc system. In combination with other geological observations, it is concluded that NW Borneo to the southwest of the Sarawak Kuching zone was a part of the Indochina/East Peninsular Malaysia fragment in SE Asia prior to the Jurassic and re-activated as an active continental margin in the Cretaceous. Widespread accretionary orogenesis along the Kuching zone likely initiated at or before the early Cretaceous and ended no earlier than the latest Cretaceous in response to the westward subduction of the paleo-Pacific slab.
KW - Cretaceous accretionary orogenesis
KW - Cretaceous mafic rocks
KW - Kuching trench-arc system
KW - Meta-sandstone
KW - NW Borneo
KW - Paleo-Pacific subduction
UR - http://www.scopus.com/inward/record.url?scp=85113602876&partnerID=8YFLogxK
U2 - 10.1016/j.lithos.2021.106425
DO - 10.1016/j.lithos.2021.106425
M3 - Article
AN - SCOPUS:85113602876
SN - 0024-4937
VL - 400-401
JO - Lithos
JF - Lithos
M1 - 106425
ER -