2026-06-28T10:13:36Zhttps://docta.ucm.es/rest/oai/request
oai:docta.ucm.es:20.500.14352/137802023-08-28T14:48:27Zcom_20.500.14352_14col_20.500.14352_15
Docta Complutense author Escavy Fernández, José Ignacio author Herrero Fernández, María Josefa 2023-06-17T13:34:24Z 2023-06-17T13:34:24Z 2019-10 0037-0746, ESSN: 1365-3091 ttps://doi.org/10.1111/sed.12588 https://hdl.handle.net/20.500.14352/13780 https://onlinelibrary.wiley.com/doi/full/10.1111/sed.12588 Enterolithic structures are stratigraphically localized folds in gypsum beds found in certain saline evaporitic sedimentary units in a wide variety of basins. Different models of formation have been proposed, all related to inorganic processes. These models include: diagenetic transformation of gypsum beds producing either displacive growth of crystals or volume changes; mechanical folding caused by compressional stress; and folding produced by slumping. The analysis of three Cenozoic evaporite sequences in Spain reveals that none of the previous models explains their origin and existence. In these outcrops, gypsum enterolithic structures occur in horizontal beds with parallel troughs and crests of the folds. They appear in shoreline facies of lacustrine environments and did not undergo major diagenetic transformations after the primary lithification of the original sediment. Based on these observations, together with the study of a modern analogue in Minorca, Spain, a new model is proposed for the genesis of enterolithic structures. This new model is based on the existence of a microbial mat exposed to brine concentration–dilution cycles and strong wind events. The high wind flow events enhanced folding of the microbial mat that became subaerially exposed and lithified due to subsequent evaporation. Therefore, the presence of enterolithic structures could be used as an indicator of shallow water environmental conditions subject to variations in brine concentration in areas with strong wind flow events. Previous studies of some evaporitic successions should be revisited, taking into account the proposed model, which would imply new depositional environment interpretations. At the same time, the proposed model could explain the existence of Kinneyia‐type structures, also known as wrinkle structures, formed beneath microbial mats in peritidal zones. Moreover, considering enterolithic structures as microbially induced sedimentary structures could be useful as evidence of microbial life in the ancient geological record and on other planets such as Mars. eng Enterolithic folds in evaporites as microbially induced sedimentary structures: New model of formation and interpretation in the geological record journal article URL https://docta.ucm.es/bitstreams/94e97fee-3273-477e-8611-90f3f6953315/download File MD5 d17ea4d0245a5f8a1fd56555d7f78462 12915773 application/pdf Enterolithic folds in evaporites as microbially induced sedimentary structures.pdf