The southern Great Xing’an Range (SGXR) is the most important tin-polymetallic metallogenic belt in northern China and is also highly prospective for rare metal deposits (e.g., Li, Be, Nb, Ta), making it one of the country’s most significant rare metal metallogenic belts. Notably, some deposits in the SGXR feature the coexistence of rare metal and tin-polymetallic mineralization. Previous studies on rare metal deposits in this region have primarily focused on geochronology of mineralization and related igneous rocks. However, research on the mineralization mechanisms and the genetic links between magmatic evolution and rare metal enrichment remains limited, which hinders a comprehensive understanding of rare metal metallogeny in the SGXR. To address this gap, this study focuses on the Tailaihua Be-Nb-Ta deposit. By integrating field investigation with detailed petrography, mineralogy, zircon and columbite-group mineral (CGM) U-Pb geochronology, whole-rock geochemistry, and mineral chemistry, we aim to determine the mineralization age, magma evolution process, and the occurrence and genesis of Nb-Ta-bearing minerals in the Tailaihua deposit, thereby providing theoretical support for rare metal deposit research and exploration in the SGXR. The Tailaihua Be-Nb-Ta deposit is hosted within an albite granite intrusion. The CGMs are predominantly euhedral to subhedral, displaying oscillatory zoning or core-rim textures, and coexist with albite, muscovite, and quartz. The cores and mantles of the CGMs are primarily manganocolumbite, whereas the rims are composed of manganotantalite. Magmatic zircon from the albite granite yielded a lower intercept age of (148±5) Ma. Two CGM samples yielded a weighted mean 206Pb/238U age of (150±1) Ma and a lower intercept age of (151±2) Ma, respectively. These results indicate that both the ore-bearing granite and the mineralization formed during the Late Jurassic. The Tailaihua albite granite is peraluminous, high in silica and alkalis, and poor in Fe, Mg, and Ca. It is characterized by strong negative Eu anomalies, as well as enrichment in Cs, Rb, U, Ta, Nd, and Hf, and depletion of Ba, Sr, P, Eu, and Ti, identifying it as a highly fractionated granite. Fractional crystallization of K-feldspar, plagioclase, biotite, hornblende, monazite, rutile, ilmenite, and sphene was a key process during magma evolution. The CGMs generally have high Nb and low Ta contents, with a notable compositional discontinuity between the cores/mantles and the rims. Mica minerals in the deposit are muscovite with high Si, Al, and K contents and low Mg and Ta contents. The texture, composition, and cross-cutting relationships of the CGMs suggest that the manganocolumbite (cores/mantles) formed during the magmatic stage and was closely related to residual melt from granitic fractional crystallization. These early-formed CGMs were subsequently metasomatized by a melt/fluid during the magma-hydrothermal transition stage, leading to the formation of Ta-rich manganocolumbite and manganotantalite in rims. We conclude that the Tailaihua Be-Nb-Ta deposit is a typical magmatic rare metal deposit.
