A Great late Ediacaran ice age

Ruimin Wang; Bing Shen; Xianguo Lang; Bin Wen; Ross N Mitchell; Haoran Ma; Zongjun Yin; Yongbo Peng; Yonggang Liu; Chuanming Zhou

doi:10.1093/nsr/nwad117

A Great late Ediacaran ice age

Natl Sci Rev. 2023 Apr 25;10(8):nwad117. doi: 10.1093/nsr/nwad117. eCollection 2023 Aug.

Authors

Ruimin Wang¹, Bing Shen¹, Xianguo Lang², Bin Wen³, Ross N Mitchell^{4

5}, Haoran Ma⁶, Zongjun Yin⁷, Yongbo Peng⁶, Yonggang Liu⁸, Chuanming Zhou⁷

Affiliations

¹ Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education and School of Earth and Space Sciences, Peking University, Beijing100871, China.
² State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, and Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu610059, China.
³ State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan430074, China.
⁴ State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
⁵ College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing100049, China.
⁶ School of Earth Sciences and Engineering, Nanjing University, Nanjing210023, China.
⁷ State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing210008, China.
⁸ School of Physics, Peking University, Beijing100871, China.

Abstract

The emergence of the Ediacara biota soon after the Gaskiers glaciation ca. 580 million years ago (Ma) implies a possible glacial fuse for the evolution of animals. However, the timing of Ediacaran glaciation remains controversial because of poor age constraints on the ∼30 Ediacaran glacial deposits known worldwide. In addition, paleomagnetic constraints and a lack of convincing Snowball-like cap carbonates indicate that Ediacaran glaciations likely did not occur at low latitudes. Thus, reconciling the global occurrences without global glaciation remains a paradox. Here, we report that the large amplitude, globally synchronous ca. 571-562 Ma Shuram carbon isotope excursion occurs below the Ediacaran Hankalchough glacial deposit in Tarim, confirming a post-Shuram glaciation. Leveraging paleomagnetic evidence for a ∼90° reorientation of all continents due to true polar wander, and a non-Snowball condition that rules out low-latitude glaciations, we use paleogeographic reconstructions to further constrain glacial ages. Our results depict a 'Great Ediacaran Glaciation' occurring diachronously but continuously from ca. 580-560 Ma as different continents migrated through polar-temperate latitudes. The succession of radiation, turnover and extinction of the Ediacara biota strongly reflects glacial-deglacial dynamics.

Keywords: Shuram excursion; Tarim Block; carbonate carbon isotopes; hankalchough glaciation; inertial interchange true polar wander (IITPW).