Introducing Carbonatites of ‌Bafq Metallogenic Area, Central Iran, Economic Geology of the REEs based on petrology and geochemistry, Unique geodynamic model of continental arc changed to rift in Early Cambrian

Carbonatites are among the rare kind of rocks on this planet. These igneous rocks are included by share of more than 50% carbonate minerals; dolomite, calcite & ankerite. Specific look in petrography and mineralography studies is needed to investigate these rocks, especially for silicates and minor phases from macroscopic as well as to microscopic scales. On the last databases of carbonatites of the world, Iran is represented empty of carbonatites. While there are many unexplored carbonatitic outcrops exists in the Bafq Metallogenic Area, (hereafter BMA). BMA as a significant metallogenic province of Iran, has the largest cluster of riftogenic Kiruna-type Iron Oxide-Apatite (IOA) deposits in the world, its iron resources are estimated over 2 bt in 50 aeromagnetic anomalies. The geological story of BMA at the middle of Posht-e Badam Block (hereafter PBB) is magnificently beautiful. The BMA recorded the oldest major geological events in Central Iranian Microcontinent (hereafter CIM). From the early years of field surveys and published geological maps to recent works which are cited in thousands of papers and dissertations, subvolcanic mineralized carbonatite intrusions within metamorphic complexes and trondhjemites of before Middle Cambrian age in the area, mistaken for marble interlayers, limestone enclaves or just non-important sedimentary carbonate rocks. In spite of the brief hints that carbonatites are related to the huge (IOA) mineralization in the area which is available in the old papers, unfortunately these rocks still remained invisible, even in the new studies. In here, on the basis of provided field and petrography evidences as well as to depicted petro-chemical diagrams, the nature of carbonatites of the area is discussed from different geological aspects. In fact, carbonatites are the most important riftogenic units in lithological columns of PBB, specifically in BMA. These naked virgin multiple peaks should get under the detailed study in the aim for valuable exploration potential of REEs. Moreover, these rocks provide a magnificent case of geodynamic investigation about the Earth history which has occurred during the changing season of Proterozoic to Phanerozoic. CIM is located at the heart of the greatest orogen in the world; The Alp-Himalaya orogenic belt in between Gondwana & Eurasia Paleo-Supercontinents. During late Precambrian to Early Cambrian, the study area had suffered by complicated gigantic orogenic phases. The late units of the phenomena described here unconformably overlaied by the Middle Cambrian trilobite-bearing Mila Formation. Thereupon, the unique, and major geological incidents of BMA have occurred right before Biological Big Bang which is also known as the Cambrian Life Explosion, beneath the only great ice grip of the planet throughout its entire history.