Southeast Asia Research Group

Reconstructing Southeast Asia’s Dynamic Earth

News

We are delighted to have re-launched the SEARG website after a 3-year hiatus

Amy Gough attended the Second Post Cruise Meeting for IODP405 ‘JTRACK’ in Sendai, Japan.

Max Webb attended a workshop held at the Lorentz Center in Leiden on ‘Merging Biology and Geology to Study Island Biodiversity’

Isbram Ginanjar Hikmy attended the Essential Scientific Computing for Environmental Scientists course run by the Edinburgh Parallel Computing Center

Basin Research

Please consider submitting to our Basin Research Special Issue: Source-to-Sink Systems in Asia and Oceania: Insights from Multi-Proxy Approaches across Geological Timescales. Deadline 31st December 2026

Banda Arc

The Banda Arc is composed of volcanic inner arc, outer arc islands and a trough parallel to the Australian continental margin which curves in horse-shoe shape around the Banda Sea. Being the source of the latest plate tectonics discoveries and having high hydrocarbon potential, it is the focus of active scientific debate.

Regional Tectonic Setting

The Banda Arc is one of the most spectacular tectonic structures in Southeast Asia. It forms a ~1,000 km long, tightly curved arc in eastern Indonesia that bends through nearly 180 degrees around the Banda Sea. The arc consists of a volcanic inner arc, an outer arc of islands, and a deep trough that parallels the northern margin of the Australian continent.

This region records the complex interaction between the Australian Plate and the Southeast Asian margin. Oceanic crust of the Banda Sea is surrounded by fragments of continental crust that were originally part of the northern Australian margin and were rifted away during the Mesozoic. Subsequent subduction, collision, and arc development have created a highly complex geological system that includes active volcanism, rapidly deforming sedimentary basins, and major hydrocarbon provinces.

Despite its importance, many aspects of the Banda Arc’s tectonic evolution remain poorly understood. In particular, the origins and distribution of continental fragments within the arc, and their relationship to the Mesozoic palaeogeography of northwest Australia, remain key questions.

Our Previous Research in the Banda Arc Includes:

Sedimentary Provenance

Research in the Banda Arc has focused on understanding sediment sources and transport pathways through the study of sandstones exposed on the outer arc islands.

Sandstones from islands surrounding the Banda Arc contain important records of the tectonic and sedimentary history of the region. By analysing the mineralogical and geochemical composition of these sediments, it is possible to determine the nature of the source rocks and reconstruct patterns of sediment dispersal. Heavy mineral analysis and detrital zircon studies provide particularly valuable information about the origin of sediments and the age of their source terrains.

These provenance studies contribute to broader efforts to understand how different crustal blocks were assembled in the Banda Arc and how sediment was transported across the region during the Mesozoic and Cenozoic.

Zircon Geochronology and Tectonic Reconstruction

Detrital zircon dating provides a powerful tool for reconstructing tectonic histories and palaeogeographic relationships. U–Pb dating of zircons using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) allows large numbers of grains from individual sandstone samples to be analysed efficiently.

Age distributions obtained from detrital zircon populations can be compared with known age signatures from potential source regions. Distinctive age peaks can therefore be used to identify sediment sources and test tectonic models for the development of the Banda Arc.

Because zircon data from the Banda Arc are relatively sparse, these analyses provide some of the first direct constraints on the age and distribution of basement terranes within the arc and on the position of continental fragments rifted from Australia during the Jurassic.

Mesozoic Palaeogeography

Provenance data from Banda Arc sandstones provide important clues about the Mesozoic palaeogeography of the region. By linking zircon age populations and mineral assemblages to known geological provinces, it is possible to reconstruct the positions of continental fragments and identify sediment pathways across the northern margin of Australia.

These results help test competing tectonic models for the origin of the Banda Arc and improve understanding of how continental fragments were rifted, transported, and incorporated into the evolving Indonesian plate boundary system.

Regional Significance

Research in the Banda Arc contributes to a broader understanding of the tectonic evolution of eastern Indonesia and the northern margin of Australia. Provenance studies of sandstones from the outer arc islands provide new insights into sediment sources, crustal structure and the distribution of continental fragments within the arc.

By combining heavy mineral analysis, detrital zircon geochronology and regional tectonic reconstruction, these studies help clarify the geological history of the Banda Arc and its relationship to the Mesozoic palaeogeography of northwest Australia. This work also has important implications for hydrocarbon exploration within the region’s sedimentary basins.