Proterozoic anorthosite massifs can host significant amounts of critical and strategic metals such as Ti, V, and P, associated with magmatic Fe-Ti oxides and apatite. Yet their petrogenesis is much less understood than Fe-Ti-V-P deposits hosted in layered intrusions within large igneous provinces. Several mineralized lenses of Fe-Ti-P outcrop near the border of the 1080 (±2) Ma Vanel and the 1016 (±2) Ma Mattawa Anorthosite Massifs, in the Central Grenville Province, Quebec, Canada. For example, the Lac à l’Orignal Fe-Ti-P deposit, hosted in the Vanel Anorthosite near the northern border of the Mattawa Anorthosite, comprises a lenticular structure of oxide apatite norite (OAN) with thin layers of apatite-bearing anorthosite and minor amounts of nelsonite (massive Fe-Ti oxides and apatite), indicating accumulation by density differences. Oxide settling generated the melanocratic OAN cumulates and nelsonite. Plagioclase flotation generated the leucocratic apatite-bearing anorthosite layers. The mineralization is dominated by hemo-ilmenite, accompanied by apatite and a minor amount of magnetite at the borders, whereas the core is dominated by ilmenite, magnetite, and apatite. In-situ U-Pb dating of magmatic zircon indicates that the Lac à l’Orignal deposit is a multistage intrusion with two different crystallization ages between the younger core (993 ± 13 Ma) and the older upper border (1069 ± 12 Ma) of the intrusion. These ages are similar to those of nearby anorthosite-massifs (Mattawa and Vanel Anorthosites, respectively). In-situ trace element analysis of plagioclase, apatite and oxides, by laser ablation ICP-MS, reveals subtle variations in certain trace elements (e.g., Cr, Ni, V) related to differentiation under relatively high-fO₂ conditions (FMQ = +0.9 to +1.7). Calculated melt compositions from apatite indicate a similar parental magma for both the border and core that matches the composition of high-Fe-Ti-P ferrodiorite dykes at Lac à l’Original. This high-Ti-P ferrodiorite magma was probably residual after anorthosite formation. Sub-solidus inter-oxide equilibration modified the original composition of the different cumulates in the intrusion. The absence of extensive massive oxide cumulates and the presence of higher amounts of cumulus magnetite and apatite, supported by mineral chemistry, denotes a more evolved character for the Lac à l’Orignal deposit compared with other Fe-Ti-(P) deposits in the Grenville Province (e.g., Lac Tio Fe-Ti and Grader intrusion Fe-Ti-P deposits in the Havre St. Pierre Anorthosite, eastern Quebec). Petrogenetically, the Lac à l’Orignal Fe-Ti-P deposit corresponds to an evolved part of a low-Ti/Fe system in the Grenville Province in the late stages of differentiation of ferrodiorite/jotunite magmas.

元古界斜长岩地块含有大量的关键和战略金属，如钛、钒和磷，与岩浆铁钛氧化物和磷灰石有关。然而，与大型火成岩省内层状侵入岩中的 Fe-Ti-VP 矿床相比，人们对其岩石成因的了解要少得多。位于加拿大魁北克省中部格伦维尔省的 1080 (±2) Ma Vanel 和 1016 (±2) Ma Mattawa 斜长岩地块边界附近有几个铁钛磷矿化透镜体露头。例如，Lac à l'Orignal Fe-Ti-P 矿床位于马塔瓦斜长岩北部边界附近的 Vanel 斜长岩中，由氧化磷灰石钙长岩 (OAN) 的透镜状结构和薄层含磷灰石斜长岩组成，少量的钠长石（大量的铁钛氧化物和磷灰石），表明密度差异引起的积累。氧化物沉降产生黑素 OAN 累积物和钠长石。斜长石浮选产生了含淡色磷灰石的斜长岩层。矿化以铁血钛铁矿为主，边界处伴生磷灰石和少量磁铁矿，而核心以钛铁矿、磁铁矿和磷灰石为主。岩浆锆石原位 U-Pb 测年表明，Lac à l'Orignal 矿床是一个多期侵入体，在较年轻的核心 (993 ± 13 Ma) 和较老的上边界 (1069 ± 12 Ma) 之间有两个不同的结晶年龄。入侵。这些年龄与附近斜长岩地块（分别为马塔瓦斜长岩和瓦内尔斜长岩）的年龄相似。通过激光烧蚀 ICP-MS 对斜长石、磷灰石和氧化物进行原位微量元素分析，揭示了某些微量元素（例如 Cr、Ni、V）的细微变化，这些变化与相对高 f O 2 条件下的分化相关（_FMQ = +0.9 至 +1.7）。计算得出的磷灰石熔体成分表明，边界和核心都有相似的母岩浆，与 Lac à l'Original 的高 Fe-Ti-P 铁闪长岩岩脉的成分相匹配。这种高 Ti-P 铁闪长岩岩浆可能是钙长石形成后残留的。亚固相线氧化间平衡改变了侵入体中不同累积物的原始组成。矿物化学证实，Lac à l'Orignal 矿床不存在大量块状氧化物堆积物，且存在大量积云磁铁矿和磷灰石，这表明与该地区其他 Fe-Ti-(P) 矿床相比，Lac à l'Orignal 矿床具有更进化的特征。格伦维尔省（例如，魁北克东部 Havre St. Pierre 斜长岩中的 Lac Tio Fe-Ti 和 Grader 侵入 Fe-Ti-P 矿床）。从岩石成因上看，Lac à l'Orignal Fe-Ti-P 矿床对应于格伦维尔省铁闪长岩/佐辉石岩浆分异后期阶段的低 Ti/Fe 系统的演化部分。