OICC Press Iranian Journal of Earth Sciences 2228-785X 18 3 2026 09 30 Provenance, palaeoclimate, and tectonic setting of the Shishtu-1 Formation (Late Devonian) in East-Central Iran: Based on geochemical evidence 10.57647/j.ijes.2025.17007 EN Samane Kianpour Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran Mohammad Khanehbad Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran https://orcid.org/0000-0002-6724-2237 Mohamad Hosein Mahmoudy Gharaie Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran Reza Moussavi-Harami Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran Journal Article 2026 09 30 The Shishtu-1 Formation in the Central Iran region developed during the Late Devonian with a succession of carbonate and siliciclastic rocks. The current study focuses on siliciclastic intervals to detect provenance, tectonic settings, palaeoclimatic conditions, and palaeogeographic reconstruction. Sandstones and shales were investigated separately in this study. According to petrographic and geochemical studies, the sandstones are quartzarenite and sublitharnite. The geochemical analysis revealed that SiO2, Al2O3, and Fe2O3 are the most abundant oxides in the samples of the study area. Also, trace elements such as Ba, Cr, Sr, V & Zr have a high concentration. The changes in these elements in the geochemical log can indicate the palaeoclimatic and palaeoenvironmental conditions. According to the SEM analysis, the presence of zircon, ilmenite, and clay minerals, especially illite, have been confirmed in the clastic rocks of the Shishtu-1 Formation, which indicates the existence of a warm climate. Based on geochemical studies, the sediments of the Shishtu-1 Formation originated from deeply weathered felsic to intermediate igneous rocks under oxic conditions, and shallow marine and deltaic environments. Source rocks of the Shishtu-1 Formation show a passive continental margin setting, suggesting tectonic quiescence during the Late Devonian.