3-D tomographic seismic inversion of a paleochannel system in central New South Wales, Australia

Tara Deen, Karsten Gohl

    Research output: Contribution to journalArticle

    16 Citations (Scopus)

    Abstract

    Buried paleochannels are of significant interest for understanding hydrological mechanisms and their potential as alluvial gold deposits. Seismic tomographic methods are a suitable solution for resolving the vertical and horizontal structure of such features. We assess a method for seismic 3‐D tomographic inversion from refraction arrivals with reflection control over a suspected paleochannel adjacent to the Wyalong gold fields in the Lachlan fold belt of central New South Wales, Australia. A standard multichannel engineering seismic recording and cable–receiver system was used on a 3‐D field geometry of multiple linear arrays. More than 3000 P‐wave first‐arrival traveltime values were inverted using a regularized inversion scheme for which simplified 2‐D models served as initial velocity–depth models for the complete 3‐D inversion. Seismic reflection arrivals provided additional depth estimates to the bedrock and compensated for a lack of refraction phases at that depth. Correlating the 3‐D seismic velocity–depth data with existing drillhole and nonseismic geophysical data resulted in a detailed structural and compositional interpretation of the paleochannel and the incised regolith. The model suggests the presence of a system of deposits from meandering channels overlying a metasedimentary bedrock formation. The general paleodrainage deposit is relatively conductive in electromagnetic surveys, indicating a potential saline storage or transport mechanism.
    Original languageEnglish
    Pages (from-to)1364-1371
    Number of pages8
    JournalGEOPHYSICS
    Volume67
    Issue number5
    DOIs
    Publication statusPublished - 2002

    Fingerprint Dive into the research topics of '3-D tomographic seismic inversion of a paleochannel system in central New South Wales, Australia'. Together they form a unique fingerprint.

  • Cite this