Research Article| July 01, 2003 Soft-sediment deformation at the base of the Neoproterozoic Puga cap carbonate (southwestern Amazon craton, Brazil): Confirmation of rapid icehouse to greenhouse transition in snowball Earth Afonso César Rodrigues Nogueira; Afonso César Rodrigues Nogueira 1Departamento de Geociências, Universidade Federal do Amazonas, Av. Gal. Rodrigo O. J. Ramos 3000, Manaus, AM 69.077-000, Brazil, and Programa de Pós-Graduação em Geologia Sedimentar, Instituto de Geociências, Universidade de São Paulo, Rua do Lago, 562, São Paulo, SP 05508-080, Brazil Search for other works by this author on: GSW Google Scholar Claudio Riccomini; Claudio Riccomini 2Departamento de Geologia Sedimentar e Ambiental, Instituto de Geociências, Universidade de São Paulo, São Paulo, SP 05508-080, Brazil Search for other works by this author on: GSW Google Scholar Alcides Nóbrega Sial; Alcides Nóbrega Sial 3Núcleo de Estudos de Granitos–Laboratório de Isótopos Estáveis, Departamento de Geologia, Universidade Federal de Pernambuco, Recife, PE 50732-970, Brazil Search for other works by this author on: GSW Google Scholar Candido Augusto Veloso Moura; Candido Augusto Veloso Moura 4Laboratório de Geologia Isotópica-Pará-Isso, Centro de Geociências, Universidade Federal do Pará, Belém, PA 66.075-900, Brazil Search for other works by this author on: GSW Google Scholar Thomas Rich Fairchild Thomas Rich Fairchild 5Departamento de Geologia Sedimentar e Ambiental, Instituto de Geociências, Universidade de São Paulo, São Paulo, SP 05508-080, Brazil Search for other works by this author on: GSW Google Scholar Author and Article Information Afonso César Rodrigues Nogueira 1Departamento de Geociências, Universidade Federal do Amazonas, Av. Gal. Rodrigo O. J. Ramos 3000, Manaus, AM 69.077-000, Brazil, and Programa de Pós-Graduação em Geologia Sedimentar, Instituto de Geociências, Universidade de São Paulo, Rua do Lago, 562, São Paulo, SP 05508-080, Brazil Claudio Riccomini 2Departamento de Geologia Sedimentar e Ambiental, Instituto de Geociências, Universidade de São Paulo, São Paulo, SP 05508-080, Brazil Alcides Nóbrega Sial 3Núcleo de Estudos de Granitos–Laboratório de Isótopos Estáveis, Departamento de Geologia, Universidade Federal de Pernambuco, Recife, PE 50732-970, Brazil Candido Augusto Veloso Moura 4Laboratório de Geologia Isotópica-Pará-Isso, Centro de Geociências, Universidade Federal do Pará, Belém, PA 66.075-900, Brazil Thomas Rich Fairchild 5Departamento de Geologia Sedimentar e Ambiental, Instituto de Geociências, Universidade de São Paulo, São Paulo, SP 05508-080, Brazil Publisher: Geological Society of America Received: 30 Jan 2003 Revision Received: 04 Apr 2003 Accepted: 05 Apr 2003 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2003) 31 (7): 613–616. https://doi.org/10.1130/0091-7613(2003)031<0613:SDATBO>2.0.CO;2 Article history Received: 30 Jan 2003 Revision Received: 04 Apr 2003 Accepted: 05 Apr 2003 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Afonso César Rodrigues Nogueira, Claudio Riccomini, Alcides Nóbrega Sial, Candido Augusto Veloso Moura, Thomas Rich Fairchild; Soft-sediment deformation at the base of the Neoproterozoic Puga cap carbonate (southwestern Amazon craton, Brazil): Confirmation of rapid icehouse to greenhouse transition in snowball Earth. Geology 2003;; 31 (7): 613–616. doi: https://doi.org/10.1130/0091-7613(2003)031<0613:SDATBO>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Stratigraphic and isotopic data identify the lower 45 m of the Araras Group, on the southwest margin of the Amazon craton, as a Neoproterozoic platform cap carbonate deposited below wave base upon Varanger glacial diamictites of the Puga Formation. The basal beds consist of moderately deep water pinkish dolomudstone with stratiform to wavy fenestral microbialites locally cut by tube-like structures and fenestral nonmicrobial planar laminites with tepee-like features. Above the basal carbonates are deep-water bituminous lime mudstones with alternating thin calcite crusts and lime mudstone laminae commonly disrupted by calcite crystal fans (pseudomorphs after aragonite). The basal contact of the Puga cap exhibits soft-sediment deformational structures (principally load casts) that are here attributed to rebound-induced seismicity acting upon both recently deposited carbonate sediments and underlying unconsolidated diamictite. These features constitute the first clearly recognized sedimentological evidence for the rapid change from icehouse to greenhouse conditions as postulated in the snowball Earth model of Neoproterozoic glaciation. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.