Geology of the Pacific Ocean . The Pacific Ocean developed from the Panthalassa, a vast global ocean, following the breakup of the supercontinent Pangaea in the Mesozoic Era, gradually forming Gondwana and Laurasia, which in turn divided. There is no firm date for when the changeover occurred, as the replacement of the sea bed is a continuous process, though reconstruction maps often change the name from Panthalassic to Pacific around the time the Atlantic Ocean began to open. The Panthalassic Ocean first opened around 750 million years ago at the breakup of Rodinia, but the oldest Pacific Ocean floor is only around 180 Ma old.
Gondwana Choirs Australian composers. Gondwana Choirs Gondwana Choirs is an Australian national children's choir organisation. It was founded in 1989 as Sydney Children’s Choir by Lyn Williams OAM, who is its artistic director, and is located in Millers Point, New South Wales. Gondwana Choirs has three divisions, Sydney Children's Choir, Gondwana National Choirs and Gondwana Indigenous Children's Choir, and includes several different choirs: Gondwana Choirs auditions nationally and meets in January for a two-week camp of intensive rehearsal. Choirs then typically undertake one or more tours during the year. Gondwana Choirs also runs a Composer School and a Conducting Internship, and commissions