• Home
  • News
  • Short Films
  • Learning Resources
  • Reporting Issues
  • Media
    • Media 2006
    • Media 2007
    • Media 2008
    • Media 2009
    • Media 2010
    • Media 2011
    • Media 2012
    • Media 2013
    • Media 2014
    • Media 2015
    • Media 2016
    • Media 2017
    • Media 2018
    • Media 2019
    • Media 2020-21
  • Research
  • Contact

Natural Values

Lay of the Bay: Basic Geography

Regional map. Press image to enlarge. © 2009 RBWG

Roebuck Bay is an embayment (30 by 20 km) south-west of the Dampier Peninsula on the coast of north-western Australia. The west of the bay merges with the Indian Ocean. Eroded orange cliffs with narrow sandy beaches line the northern shores and mangrove systems occur east and south of the Bay.

Defining the bay’s boundaries is a challenge. Maps typically show the sea meeting the base of the beaches and mangroves of Roebuck Bay. However, at low tide the sea edge is separated from these points by kilometres of mud and sandy intertidal flats. On the lowest tides more than 150 sq km of intertidal flats are exposed and the extraordinary benthic life.

Saltmarsh on Roebuck Plains. © Kandy Curran

On the highest tides, the sea flows through the mangroves into the salt marshes and clay pans beyond. The tidal inundation of these habitats has profound effects on their ecology, so they can be regarded as part of the bay. Also included are the saline grasslands of Roebuck Plains, Cable Beach and the shores of Broome peninsula.

Geology

The oldest exposed rock type around Roebuck Bay is the Broome Sandstone, deposited in shallow water 120-150 million years ago. Dinosaurs roamed the region in those days, leaving behind remarkable tracks that are preserved in the sandstone.

Dinosaur trackway on the northern shores of Roebuck Bay. Up to 21 species of dinosaurs have been recorded on the Dampier Peninsula © Kandy Curran

Changes in sea levels since dinosaur days resulted in the deposition of sediments that now cover much of the region. They include the Bossut Formation, variable and poorly cemented sedimentary rocks that form well exposed and attractively weathered outcrops behind the narrow beaches of northern Roebuck Bay. Sand eroded from the Bossut Formation (and other sources) was reworked, shifted by the winds, weathered and somewhat cemented, eventually forming pindan. Deep orange pindan form low crumbling cliffs along the northern shores but, for the most part, pindan country is flat with a distinctive vegetation dominated by acacias.

References: (September 2003), Life along land’s edge Wildlife on the shores of Roebuck Bay, Broome. Rogers, DI. Piersma, T, Lavaleye M, Pearson GB, de Goeij P.

Find out more

  • BIG TIDES
  • INVERTEBRATE LIFE IN THE MUDFLATS
  • DINOSAUR TRACKS
  • DOLPHINS DUGONGS TURTLES
  • FISH
  • RAMSAR LISTING
  • SEAGRASS MEADOWS
  • SHOREBIRDS
  • Natural Values

    Keep Our Bay Clean

    Mud and Salt Film Fest

    Science on the Broome Coast

    Volunteering

    Roebuck Bay Working Group

  • About Us

    Roebuck Bay Working Group is comprised of Traditional Owners and government, local community, conservation groups and business. We work collaboratively to solve issues, raise awareness and encourage research and monitoring which supports responsible management and protection of Roebuck Bay.

  • Sponsors

    Rangelands NRM

    National Landcare

    Inspiring Australia

    WA Parks and Wildlife

  • Contact Us

    Roebuck Bay Working Group

    Follow us on Facebook

Roebuck Bay Working Group Inc.: Protection and advocacy of Roebuck Bay's outstanding natural and cultural values.

© 2017 Roebuck Bay Working Group Inc • Read our Privacy Policy • Site by Tasty Pixels Studio • Admin

  • Home
  • News
  • Short Films
  • Learning Resources
  • Reporting Issues
  • Media
    ▼
    • Media 2016
    • Media 2015
    • Media 2014
    • Media 2013
    • Media 2012
    • Media 2011
    • Media 2010
    • Media 2009
    • Media 2008
    • Media 2007
    • Media 2006
  • Roebuck Bay
    ▼
    • Dampier Peninsula
  • Contact