An early Miocene spatangoid assemblage on a submarine volcanic ash dune from Patagonia (Argentina). (June 2021)

• Record Type: Journal Article
• Authors: Palópolo, E.E.; Kroh, A.; Harzhauser, M.; Griffin, M.; Casadio, S.; Carmona, N.
• Is Part Of: Journal of South American earth sciences. Volume 108(2021)
• Publication Date: 2021-06
• Subjects: Brisaster -- Echinoid assemblage -- Spatangoida -- Santa cruz province -- Miocene; Geology -- Latin America -- Periodicals; Earth sciences -- Latin America -- Periodicals; Geology -- Antarctica -- Periodicals; Earth sciences -- Antarctica -- Periodicals; Geology -- Caribbean Area -- Periodicals; Earth sciences -- Caribbean Area -- Periodicals; Géologie -- Amérique latine -- Périodiques; Sciences de la terre -- Amérique latine -- Périodiques; Géologie -- Antarctique -- Périodiques; Sciences de la terre -- Antarctique -- Périodiques; Géologie -- Caraïbes (Région) -- Périodiques; Sciences de la terre -- Caraïbes (Région) -- Périodiques; Earth sciences; Geology; Antarctica; Caribbean Area; Latin America; Periodicals; 550.5
• DOI: 10.1016/j.jsames.2021.103214
• Languages: English
• ISSNs: 0895-9811

Abstract

Abstract: A single 27 m 2 spatangoid-dominated bed yielding 65 specimens from the Punta Entrada Member of the Monte León Formation was studied. Most of the fossils were preserved oral side down, with clusters of spines attached to the tests, showing no evidence of preburial transport. The deposit is interpreted as the result of sedimentation in a subtidal environment coeval with strong and continuous explosive volcanic activity, indicated by the significant amount of volcanic ash within the sediment. Echinoids assigned to Brisaster aff. B. iheringi De Loriol, 1902 colonized a distal part of the subtidal environment dominated by large-scale migrant bedforms. During dormant periods, it was characterized by low energy and low sedimentation rate, allowing colonization by several groups of infaunal organisms. Upon reactivation of sediment migration, a high sedimentary influx trapped the echinoids and prevented them from escaping. Highlights: A single 27m2 echinoid-dominated bed yielding 65 specimens from the Patagonian Miocene. The deposit is interpreted as the result of sedimentation in a subtidal environment coeval with explosive volcanic activity. Echinoids colonized a distal part of the subtidal environment dominated by large-scale migrant bedform.