New Zealand's Biggest Spherical Concretions

Koutu Boulders in Northland are thought to be the biggest spherical sedimentary concretions in New Zealand, much bigger than the more famous Moeraki Boulders in the South Island. But how did they form and why are they gathered on the beach of Hokianga Harbour? Bruce Hayward explains. SIGN UP for Out There Learning news, articles and updates: https://julianthomson.substack.com/ WORK WITH ME: Are you into science communication? Want to put yourself at a massive career advantage? Learn more: https://tinyurl.com/mts3mx74