Massif-type anorthosites are voluminous, plagioclase-dominated batholiths that occur worldwide, but only during the Proterozoic Eon. Granitoids are closely associated with the anorthosites, and they collectively may form an AMCG suite (i.e., anorthosite, mangerite, charnockite, granite). Many fundamental questions regarding the origin of the AMCG complexes remain unresolved, including their tectonic setting and mode of emplacement. Here, we present new data from reconnaissance structural mapping, U–Pb LA-ICP-MS zircon dating, and ⁴⁰Ar/³⁹Ar amphibole and mica dating from a 500 km² area straddling the western margin of one of the world’s largest (≥ 15,000 km²), but also least studied AMCG suites, the Kunene Complex (KC) in Angola. The oldest recognized (pre-Kunene) deformation event D₁ produced a steep WNW–ESE-striking S₁ fabric in supracrustal rocks, migmatite and Paleoproterozoic (1800–1780 Ma) granodiorite before ~ 1680 Ma. This was folded by the D₂ event, resulting in steep, N–S-striking S₂ leucosomes and gneissosity in the rocks surrounding the KC. Concordant magmatic layering and lamination, and high- to low-temperature gneissic foliation in the marginal Kunene anorthosite and coeval megacrystic granite are parallel with S₂ fabrics in the Paleoproterozoic country rocks. Mineral stretching lineations L₂ in all rock types across intrusive contacts are steep and associated with west-side-up (thrust) shearing. Overlapping U–Pb zircon/baddeleyite ages from the Kunene megacrystic granite and Kunene anorthosite, with ⁴⁰Ar/³⁹Ar mica ages from the mantling Paleoproterozoic country rocks, attest to progressive contraction, thrusting and exhumation of the Paleoproterozoic country rocks onto the Kunene anorthosite in the interval 1410–1380 Ma. We suggest that thermal softening of the country rocks caused by heat dissipation from the earliest phase (1500–1410 Ma) of ponding of hot anorthositic magma in the deep crust localized D₂ deformation at the margin of the KC. Our data point to a tectonic model whereby anorthosite sheets were emplaced at a high angle to the shortening direction and along host-rock S₂ anisotropy deep in the crust and cooled during progressive ductile thrusting and exhumation of the country rocks. These results question the current view that Proterozoic AMCG suites are emplaced in extensional environments as large diapiric bodies and favor formation in a continental arc setting.

断层型无钙铁长石是大量的斜长石支配的岩基岩，遍布世界各地，但仅在元古代时期发生。花岗岩类与钙长石密切相关，它们共同构成了AMCG套件（即钙长石，锰铁矿，菱锰矿，花岗岩）。关于AMCG复合体起源的许多基本问题仍未解决，包括其构造背景和进位方式。在这里，我们提供了来自侦察结构测绘，U–Pb LA-ICP-MS锆石测年以及跨越世界上最大的西部之一的西缘500 km ²区域的⁴⁰ Ar / ³⁹ Ar闪石和云母的新数据。15,000千米²），但也研究最少的AMCG套件，即安哥拉的Kunene Complex（KC）。公认的最古老的（库内烯前）变形事件D ₁在〜1680 Ma之前的上地壳岩石，蒙脱石和古元古代（1800-1780 Ma）花岗闪长岩中产生了陡峭的WNW–ESE撞击S ₁织物。D ₂事件将其折叠，在KC周围的岩石中产生陡峭的，N–S打击的S ₂脂质体和片麻岩。边缘岩相钾长石原位岩和同年龄的巨晶花岗岩中一致的岩浆分层和叠层，以及高温至低温片麻质岩层与古元古代乡村岩石中的S ₂织物平行。矿物拉伸线条L ₂在所有岩石类型中，侵入性接触都是陡峭的，并伴有西侧倒推（推力）剪切作用。来自Kunene巨晶花岗岩和Kunene钙长石的U–Pb锆石/铅锌矿年龄重叠，来自古老的元古界乡村岩石的年龄为⁴⁰ Ar / ³⁹ Ar云母年龄，证明了古元古代乡村岩石逐渐收缩，逆冲和掘出到Kunene钙长石中间隔1410–1380 Ma。我们建议，深部地壳局部D ₂的热无原浆形成的最早阶段（1500–1410 Ma）的热耗散引起的乡村岩石热软化在KC边缘变形。我们的数据指向一种构造模型，在该构造模型中，斜长岩片材以与缩短方向成较大角度并沿地壳岩石的S ₂各向异性深埋于地壳中，并在陆续岩石的延性延性推挤和掘出过程中冷却。这些结果质疑了目前的观点，即元古代AMCG套件在伸展环境中被放置为大的根尖体，并倾向于在大陆弧环境中形成。