Geology, Tectonics and Stratigraphy of the Construction Site of the New Bushehr NPP Units in the Islamic Republic of Iran as Part of Recent Geotechnical Studies

Abstract

Southern Iran in the area of Zagros and the borders of the Arabian and Eurasian plates is a seismically active territory in which large industrial facilities are located, including Bushehr NPP. In this regard the relevance of studying modern geodynamics and geology of the region is understandable. The geological structure of the territory after engineering surveys of 1974-2001 no longer seemed questionable. However, after completion of engineering surveys for new NPP units in 2015, new views on some positions on seismotectonics, and later on the geology of the area, appeared. The article provides information about the geology, tectonics and stratigraphy of the region and the research area, including not covered earlier in domestic reporting materials and scientific articles, and also considered the possible reasons for the appearance of other interpretations regarding seismotectonics and geology of the area where the NPP site is located. A brief analysis of the research results, both previously completed and completed relatively recently, is presented. An additional argument is considered in favor of the presence of fault zones within the Bushehr anticline proposed by Iranian researchers. In particular, the Khark-Mish fault supposed by them may be part of the buried ancient anticlinal fold before the position of its axis changes in the modern period as a result of neotectonic processes common to the region as a whole. The geology and tectonics of the Bushehr anticline are compared with similar structures on Fr. Hark and the nearest islands. Updated information on the stratigraphy of individual geological formations of the region and the research area is also provided. In spite of the reasoned justification of various positions on the geology and tectonics of the region, it seems necessary to conduct a number of additional special direct and indirect studies aimed at ensuring the safety of the Bushehr NPPs under construction and operating.