Paleozoic to Cenozoic sedimentary bedrock geology and lithostratigraphy of Singapore

Abstract

A new lithostratigraphical framework for Singapore is proposed, based on the analysis of c. 20,000 m of core recovered from 121 c. 205 m deep boreholes and augmented with 218 field localities from across Singapore. The new framework describes a succession dating from the Carboniferous to the Quaternary. New U-Pb detrital zircon dates and fossil analysis were used to constrain the ages of key sedimentary units. The oldest known sedimentary rocks in Singapore are found to be the deformed Carboniferous (Mississippian) Sajahat Formation. These are succeeded by the newly erected, Middle and Upper Triassic, marine to continental Jurong Group and Sentosa Group successions that accumulated in the southern part of the Semantan Basin. The Jurong Group comprises four formations: the Tuas Formation, the Pulau Ayer Chawan Formation, the Pandan Formation and the Boon Lay Formation. The Sentosa Group contains two formations: the Tanjong Rimau Formation and the Fort Siloso Formation. In Singapore, the depositional record during this time is related to late Permian to Triassic arc magmatism in the southern part of the forearc basin to the Sukhothai Arc. The Jurong and Sentosa groups were deformed and weakly metamorphosed during the final stages of the Late Triassic to Early Jurassic orogenic event, deformation that led to the formation of the syn-orogenic conglomerates of the Buona Vista Formation. Following this, two distinct Lower Cretaceous sedimentary successions overstepped the Jurong and Sentosa group strata, including the Kusu Formation and the Bukit Batok Formation, both deposited in the southern part of the Tembeling Basin. A series of Neogene to Quaternary formations overly the Mesozoic and Palaeozoic stratigraphy, including the Fort Canning Formation, Bedok Formation and the Kallang Group.

Large-scale crustal structure beneath Singapore using receiver functions from a dense urban nodal array

“…Therefore it follows that the Bukit Timah fault is an approximately vertically dipping fault running throughout the crust. The presence of a significant fault also agrees with geological information showing that the ages of the two units are very similar (Dodd et al, 2019;Oliver & Manka, 2014). This suggests that significant tectonic movement must have occurred in order for sedimentary rocks to be adjacent to a granite pluton that formed at the same time.…”

“…However the geological structure beyond several hundreds of meters is almost entirely unknown. The near surface is composed of three principle geological units -Bukit Timah granite, Jurong Group metasediment and quaternary sediments (Dodd et al, 2019) (Figure 1a). The Bukit Timah granite underlies central Singapore and is the most extensive geological unit.…”

A tuffaceous volcaniclastic turbidite bed of Early Miocene age in the Temburong Formation of Labuan, North‐West Borneo and its implications for the Proto‐South China Sea subduction in the Burdigalian

“…The Cretaceous zircons in the Temburong Formation sandstones were most likely ultimately derived from the Schwaner Mountains of South‐West Borneo where numerous Cretaceous plutonic, volcanic and metamorphic rocks are exposed (Breitfeld et al, 2020b; Davies et al, 2014; Hennig et al, 2017; Williams et al, 1988). Permian‐Triassic zircons are reported from the Malay‐Thai Tin belt (Dodd et al, 2019; Gillespie et al, 2019; Oliver et al, 2014; Searle et al, 2012; Sevastjanova et al, 2011) and Triassic zircons from the West Borneo province (Breitfeld et al, 2017; Hennig et al, 2017; Setiawan et al, 2013). Recently, Burton‐Johnson et al (2020) reported Triassic zircons from Triassic granitoids in eastern Sabah, which could also have provided a minor contribution.…”

Large‐Scale Crustal Structure Beneath Singapore Using Receiver Functions From a Dense Urban Nodal Array

“…However the geological structure below several hundred meters depth remains almost entirely unknown. The near surface is composed of three principle geological units-variegated arc-derived plutonic rocks and dykes of the Bukit Timah Center granite (Gillespie et al, 2019), very low metamorphic grade sediments of the Jurong Group, and Quaternary shallow marine and terrestrial sediments (Dodd et al, 2019; Figure 1a). The Bukit Timah Center granite underlies central Singapore and is the most extensive geological unit, representing repeated igneous intrusions into existing Carboniferous metamorphic basement between ∼285 and 230 Ma (Oliver et al, 2014).…”

“…The nature of the original relationship between the Jurong Group and the Bukit Timah Centre granite is not clear, as the contact does not crop out. While age constraints suggest the Jurong Group could have originally (Dodd et al, 2019). Outer coastline marks the current coastline of Singapore which is built on reclaimed land.…”