Enhancing event stratigraphic correlations in the ultra‐deep Japan Trench using XRF‐CS cluster‐based chemostratigraphy
Journal
The Depositional Record
ISSN
2055-4877
2055-4877
Date Issued
2025-09-17
Author(s)
Abstract
Establishing along-strike correlations of event deposits in deep-sea environments allows for the reconstruction of spatial and temporal patterns of geological processes, such as seismically triggered turbidites. However, in settings like the ultra-deep Japan Trench, highly variable seafloor topography and limited chronological tie points pose significant challenges for tracing individual deposits between semi-isolated trench basins. Using cores from International Ocean Discovery Program (IODP) Expedition 386 at the central Japan Trench, this study examines how non-destructive X-ray fluorescence core scanning (XRF-CS) combined with multivariate statistics can be used to distinguish and correlate individual event deposits across contrasting depositional settings, based on their geochemical fingerprints. The results of the five-cluster model demonstrate that the XRF-CS properties of event deposits are clearly distinguishable from background sediments, as well as from one another. The chemostratigraphic cluster sequence can be correlated between cores from basin depocentres—where event deposits are thicker but the record is shorter, and cores from topographic highs—where the record extends further back in time but event deposits are thin and difficult to distinguish using previously applied event correlation methods. The high-resolution chemostratigraphy enables a more detailed, geochemically-enhanced stratigraphic interpretation, identifying several previously unrecognised event deposits with unique internal structures that suggest varying depositional processes. Notably, excluding the 2011 event deposit, the three most recent event deposits are allocated to different clusters, implying compositional heterogeneity probably linked to sediment provenance. The results of this study therefore demonstrate a rapid and reproducible technique for using chemostratigraphy to establish high-resolution event correlations in submarine sediment cores, leading to several working hypotheses for Japan Trench palaeoseismology to be tested with future work.
Subjects
chemostratigraphy
event deposits
Japan trench
Palaeoseismology
XRF Core Scanning (XRF-CS)
SDGs
Publisher
Wiley
Type
journal article