The pressure–temperature (P–T) evolution of a deformed garnet-bearing granite of La Virgen hill, located 25 km south of the town of Azul, Argentina, was studied as an example of the slightly peraluminous and deformed granites widespread in the Paleoproterozoic Tandilia Belt of the Rio de la Plata Craton. An early isobaric magmatic–submagmatic cooling path followed by exhumation was derived by the appraisal of microstructures, chemical compositions of minerals and P–T pseudosection modeling in the system Si–Ti–Al–Fe–Mn–Mg–Ca–Na–K–O–H (1 wt.% of H₂O) using the software PERPLE_X. Slightly zoned magmatic garnet with a core composition of pyr₄(grs + adr)₁₁sps₁₀alm₇₅ equilibrated with plagioclase (X_An = 0.37) at 6.0 kbar and 655 °C in a crystal mush with < 7 vol.% of melt. The garnet rim composition of pyr₃(grs + adr)₁₂sps₁₄alm₇₁, texturally equilibrated with biotite (Mg/(Mg + Fe) = 0.21) at the granitic solidus of 5.9 kbar and 645 °C. The subsequent cooling path is constrained by isopleths of low-Ti muscovite with Si contents of 3.17 per formula unit commonly located around K-feldspar and recrystallized plagioclase (X_An = 0.35). Ductile deformation at low amphibolite- to greenschist-facies metamorphic conditions produced the subvertical main foliation. Forty-two chemical analyses in seven monazite grains of the granite yielded two groups of U–Th–Pb ages at 2126 ± 10 (2σ) Ma and 2089 ± 3 Ma, interpreted to be inherited from widespread magmatic events of the Tandilia Belt and resulted from the granite crystallization, respectively. The exhumation of the deformed granite from middle (~ 22 km) to upper and cold crustal levels was probably a long-lasting process after 1.9 Ga.

以古元古代广泛分布的微过铝质和变形花岗岩为例，研究了位于阿根廷阿祖尔镇以南 25 公里处的 La Virgen 山的变形含石榴石花岗岩的压力-温度 ( P – T ) 演化拉普拉塔克拉通的坦迪利亚带。通过对Si-Ti-Al-Fe-Mn-Mg-Ca-Na-K- 体系中的微观结构、矿物化学成分和P - T假截面模型的评估，推导出了早期等压岩浆-亚岩浆冷却路径，然后进行了折返。O–H（H ₂ O 的1 wt.% ）使用 PERPLE_X 软件。微带岩浆石榴石，核心成分为 pyr ₄ (grs + adr) ₁₁ sps₁₀ alm ₇₅用斜长石 ( X _An  = 0.37) 在 6.0 kbar 和 655 °C 下在具有 < 7 vol.% 熔体的结晶糊中平衡。pyr ₃ (grs + adr) ₁₂ sps ₁₄ alm ₇₁的石榴石边缘成分，在 5.9 kbar 和 645 °C 的花岗岩固相线与黑云母（Mg/(Mg + Fe) = 0.21）结构平衡。随后的冷却路径受到通常位于钾长石和重结晶斜长石 ( X _An = 0.35）。在低角闪岩到绿片岩相变质条件下的韧性变形产生了近垂直的主要叶理。对花岗岩的七个独居石颗粒进行的 42 次化学分析得出两组 U-Th-Pb 年龄分别为 2126 ± 10 (2 σ ) Ma 和 2089 ± 3 Ma，解释为继承自坦迪利亚带和分别由花岗岩结晶引起。变形花岗岩从中部（约 22 公里）到上地壳和冷地壳水平的折返过程可能是 1.9 Ga 之后的一个长期过程。