The Adelaide Rift Complex: a classic record of the Rise of a Habitable Planet Ikara — Flinders Ranges
Jim Gehling — Honorary Research Fellow South Australian Museum In collaboration with: Steve Hore, Graeme Worboys, Peter Haslett, Trevor Mount, Nick Langsford, Pierre Kruse, Lidya Tarhan, Liesel Garrett and Mary Droser Adelaide Rift Complex &FRWH
Sir Douglas Mawson Serial Sites for Flinders Range World Heritage Nomination —Why? The Adelaide Rift Complex exhibits: 1. The Arkaroola “window” to our crystalline basement and mineral sources. 2. The best mapped, least deformed, most accessible Tonian, Cryogenian, Ediacaran, and early Cambrian stratigraphic successions on Earth. 3. The crucial geological record of the rise of a habitable Earth that documents the evolution of marine animal life. 4. A region were, in spite of 130 years of field work, most of its geological treasures are yet to be discovered and realized.
Arkaroola Wilderness Sanctuary
• A window to the crystalline basement and mechanisms that powered the Adelaide Rift Complex Cryogenian Ice Ages
• Record of two global ice ages at low palaeolatitudes • Sturt Tillite: from Wirrena & Sturt Gorge to Arkaroola & Bimbowrie • Elatina Ice Age: record of tidal rythmites formed beneath Ice Sheets Stromatolites and Organic Rich Rocks
Wolfgang Preiss and Malcolm Walter (Martin Glaessner) Elatina Tidal Rhythmites George Williams and Phil Schmidt: 1. Palaeo -magnetic record of low latitude, seasonal ice 2. Record of ~650 Ma old tidal rhythmites Golden Spike —Ediacaran GSSP
• First for southern hemisphere and for Australia • Base of the Nuccaleena Formation (cap carbonate) • Age: circa. 635 ma (base Doushantuo Fm. in South China South China — Geological Bar-Code Acraman Ejecta layer – Bunyeroo Fm
• Meteor impact crater in the Gawler Ranges —> Lake Acraman • Rock fragments blasted 300 km into the Adelaidean Ocean • A layer of ejected Gawler Ranges rock fragments in Bunyeroo shale —> ~ 580 million years Wonoka Formation
Pichi Richi Pass
Palaeopascichnus Brachina Gorge Brachina Gorge:Ediacara biota Oldest Ediacara fossils in South Australia are Trace Fossils Ediacarans that Inherited the Earth
Arkarua — echinoderm Parvancorina — arthropod
1 cm Marywadea — arthropod Kimberella — mollusc
Praecambridium — arthropod
Spriggina ‘protochordate’ — arthropod
‘prototrilobite’ Ediacara-Nilpena National Park Excavated samples of Ediacaran seafloor communities Nilpena Geology
Ediacaran – Cambrian Transition Castle Rock: Parachilna over Uratanna Formation
Sabellidites
Un-interepreted Body Fossils Archaeocyaths — bioherms — Ajax Plateau Early Cambrian Small Shelly Fossils Mernmerna Formation: Bunkers Range
Chancellorid Spicular Impressions Brachipod Cambrian: Tabulate-grade Corals
Morowie Formation — East end — Chambers Gorge Mid-Cambrian: Thrombolites Stromatolites grazed and burrowed by small Cambrian animals
Wirrealpa Formation And so to Phanerozoic Ecosystems Thank you to the people who made it a career privilege to work on Ediacaran rocks and fossils in:
• Flinders Ranges, South Australia • Rocky Mountains of Canada • The plateaus of central & southern Namibia • The Avalon terrain of Leicester and Sth. Wales • The Avalon Peninsula of Newfoundland My Career Associates & Mentors in Geoscience
Peter Haslett, Barry Fehlberg, Trevor Ireland, Maud McBriar, Martin Glaessner, Inara Gehling, Mary Wade, Brian Daily, Wolfgang Preiss, Malcolm Walter, Robin Oliver, Jim Jago, Soren Jensen, Rod Wells, Bren Thompson, Brian Forbes, Hans Mincham, Reg Sprigg, Ron Coats, Victor Gostin, Charles Gabielle, Frank Gaunt, Neville Pledge, John Cann, Haggis Shackleton, Ian Dyson, Chris von der Borch, Ian Dyson, Bruce Runnegar, Adolf Seilacher, Guy Narbonne, Bill Schopf, Charles Marshal, Soren Jensen, Bob Dalrymple, Simon Conway-Morris, Bob Dalgarno, Marg Fuller, Mary- Anne-Binnie, Mary Droser, Pat Vickers-Rich, Wenlong Zhang, Shuhai Xiao, Maoyan Zhu, Eric Sperling, John Paterson, Glenn Brock, John Paterson, Diego Garcia Bellido, Nick Langsford, Steve Hore, Lidya Tarhan, Felicity Coutts.