Abstarct: The area studied in this research includes a part of the north-northeast of Bafq and the Central Iran structural zone, covering approximately 1600 km2. Its main rock units can be categorized into two groups: 1- predominantly mextamorphosed and deformed baxsement complex (Late Neoproterozoic period), 2- volcanic-sedimentary rock complex (known as the Rizu and Desu series), along with intrusive masses and their related mineralizations (Late Ediacaran to Lower Cambrian age). Understanding the petrogenesis of intrusive masses associated with the second category is the focus of this research. These small-scale to large-scale intrusive igneous masses (from a few hundred km2 to about 100 km2) have the following bimodal compositional ranges: 1- gabbrodiorites, diorites, and syenites (basic-intermediate range) and 2- leucogranites (felsic range). In the basic-intermediate range, evidence of magmatic fractionation is observed from the field to the microscopic scale, from gabbro to syenite. Diorite, quartzdiorite, and rarely granodiorite are also found along with the basic-intermediate range. Basic-intermediate igneous rocks are alkaline to calc-alkaline in nature. Felsic igneous rocks with a dominant leucogranitic composition are also calc-alkaline in nature. The results of mineral chemical analysis indicate that the clinopyroxenes of the gabbroic-gabbrodiorite rocks are of the diopside and augite types. The amphiboles belong to the calcic group and have compositions that include magnesiohornblende, tschermakite, kaersutite, and ferrokaersutite. Biotites are rich in iron and magnesium. Plagioclases with unsual composition are mainly sodic and have a composition ranging from oligoclase to albite, which is likely due to the sodic mextasomatism imposed on these rocks. Apatite, monazite, pyrochlore, magnetite, titanomagnetite, titanite (sphene), and zircon are also accessory minerals. Geothermobarometric studies baxsed on the chemistry of pyroxene, amphibole, and biotite minerals indicate the cessation temperatures of geochemical exchanges and the final equilibrium of minerals as follows: 1270 to 1140°C (for pyroxenes), 890 to 790°C (for amphiboles), and 780 to 745°C (for biotites), and pressures cover a range between 12.33 and 0.5 kbar. baxsed on the patterns of rare earth element variations and spider diagrams, basic-intermediate igneous rocks can be divided into the four groups: 1- Gabbro, gabbrodiorite, and monzogabbroc to monzodiorite (in the form of intrusive masses) (with a clear enrichment of light rare earth elements, large ion lithophile elements, and elements with high field strength) and with a concave pattern in spider diagrams) 2- Diorites, quartz diorites, and rarely granodiorites (with a clear depletion of Ba, Nb, and Ta and a pattern almost different from gabbros and gabbrodiorites). 3- Basic rocks that are dike in nature are mafic and show greater depletion of Nb, Ta, La, Ce, Nd, Sm, Zr, Hf, and P than the previous rocks. Most likely, the rapid ascent of magma to higher levels and the consequent reduction of crustal contamination can be effective in showing this trend. 4- Syenitic rocks rich in light earth elements and poor in heavy REE. The petrological characteristics of the studied rocks are very similar to those of appinite rocks. The parent magmas of the monzogabbro-monzodiorite intrusions or in general basic-intermediate term are mainly alkaline in nature and originate from the partial melting of subcontinental mextasomatized mantle or subcontinental lithospheric mantle (SCLM) in a continental rift tectonic environment. The resulting magmas evolved with partial crystallization and possibly crustal contamination and were then emplaced in the continental crust around the Late Ediacaran - Early (or Lower) Cambrian boundary (550-520 Million years ago). Whole-rock geochemical data, including major and trace elements, together with Rb-Sr and Sm-Nd isotopic results, suggest an alkaline nature and an enriched mantle origin (similar to OIB) or subcontinental lithospheric mantle (SCLM). baxsed on field observations, petrography, mineral chemistry, whole-rock chemistry, isotopic geochemistry, and U-Pb dating on zircon grains, magmatism in the studied area occurred in an intracontinental rift environment during the late Neoproterozoic-Lower Cambrian time frxame.