Oxygenation of the oceans and the origin of animals

New multicellular marine macroalgae from the early Tonian of northwestern Canada

Katie M Maloney, Galen P Halverson, James D Schiffbauer, Shuhai Xiao, Timothy M Gibson, Maxwell A Lechte, Vivien M Cumming, Alexie EG Millikin, Jack G Murphy, Malcolm W Wallace, David Selby, Marc Laflamme

2021-03-22

Molecular phylogenetic data suggest that photosynthetic eukaryotes first evolved in freshwater environments in the early Proterozo..

Subglacial meltwater supported aerobic marine habitats during Snowball Earth

Maxwell A Lechte, Malcolm W Wallace, Ashleigh van Smeerdijk Hood, Weiqiang Li, Ganqing Jiang, Galen P Halverson, Dan Asael, Stephanie L McColl, Noah J Planavsky

2019-12-17

The Earth's most severe ice ages interrupted a crucial interval in eukaryotic evolution with widespread ice coverage during the Cr..

Neoproterozoic marine dolomite hardgrounds and their relationship to cap dolomites

Malcolm W Wallace, Ashleigh VS Hood, Joe Fayle, Emily S Hordern, Tessa F O'Hare

2019-07-15

Neoproterozoic cap dolomites are unusual and distinctive marker units that occur after large Cryogenian glaciations. Several thin ..

Glacio-marine iron formation deposition in a c. 700 Ma glaciated margin: insights from the Chuos Formation, Namibia

Maxwell A Lechte, Malcolm W Wallace, Karl-Heinz Hoffmann

2019-01-01

The Chuos Formation of Namibia is the sedimentary product of the Neoproterozoic Sturtian (c. 720-660 Ma) glaciation and contains m..

The effects of diagenesis on geochemical paleoredox proxies in sedimentary carbonates

Ashleigh von S Hood, Noah J Planavsky, Malcolm W Wallace, Xiangli Wang

2018-07-01

Metal and metal isotope records in carbonates have the potential to provide novel insights into ancient ocean–atmosphere redox con..

Cryogenian iron formations in the glaciogenic Kingston Peak Formation, California

Maxwell Alexander Lechte, Malcolm William Wallace, Ashleigh van Smeerdijk Hood, Noah Planavsky

2018-06-01

The Kingston Peak Formation records glacial sedimentation during the Cryogenian in Death Valley, California, and contains iron for..

The Tonian Beck Spring Dolomite: Marine dolomitization in a shallow, anoxic sea

Alice Mary Shuster, Malcolm William Wallace, Ashleigh van Smeerdijk Hood, Ganqing Jiang

2018-06-01

The reason for the abundance of dolomite lithologies in Earth's early geological record compared to modern environments remains co..

Zebra textures in carbonate rocks: Fractures produced by the force of crystallization during mineral replacement

Malcolm W Wallace, Ashleigh van S Hood

2018-06-01

Zebra textures are enigmatic banded fabrics that occur in many carbonate-hosted ore deposits, dolomite hydrocarbon reservoirs and ..

Oxygenation history of the Neoproterozoic to early Phanerozoic and the rise of land plants

Malcolm W Wallace, Ashleigh VS Hood, Alice Shuster, Alan Greig, Noah J Planavsky, Christopher P Reed

2017-05-15

There has been extensive debate about the history of Earth's oxygenation and the role that land plant evolution played in shaping ..

Enigmatic carbonates of the Ombombo Subgroup, Otavi Fold Belt, Namibia: A prelude to extreme Cryogenian anoxia?

AVS Hood, MW Wallace, CP Reed, K-H Hoffmann, EE Freyer

2015-07-01

The Ombombo Subgroup of the Otavi Fold Belt, Kaokoveld, Namibia preserves a succession of clastic and carbonate sediments with unu..

Extreme ocean anoxia during the Late Cryogenian recorded in reefal carbonates of Southern Australia

Ashleigh van Smeerdijk Hood, Malcolm William Wallace

2015-05-01

The Neoproterozoic was a time of great change in the Earth's surface and marine environments, including extensive climate variabil..

The Cryogenian Balcanoona reef complexes of the Northern Flinders Ranges: Implications for Neoproterozoic ocean chemistry

Malcolm W Wallace, Ashleigh VS Hood, Estee MS Woon, Jonathan A Giddings, Thomas A Fromhold

2015-01-01

The Cryogenian Balcanoona reef complexes of South Australia consist of several dolomite platforms with well-defined backreef, reef..

Enigmatic chambered structures in Cryogenian reefs: The oldest sponge-grade organisms?

Malcolm W Wallace, Ashleigh VS Hood, Estee MS Woon, Karl-Heinz Hoffmann, Christopher P Reed

2014-12-01

Previously undescribed chambered structures are common and widespread in the Cryogenian (post-Sturtian glacial) carbonates of the ..

Marine cements reveal the structure of an anoxic, ferruginous Neoproterozoic ocean

Ashleigh VS Hood, Malcolm W Wallace

2014-11-01

Neoproterozoic oceans provided the setting for the rise of animals, yet little is known of their chemical composition. Marine carb..