We present major and trace element compositions of mineral concentrates comprising garnet xenocrysts, ilmenite, phlogopite, spinel, zircon, and uncommon minerals (titanite, calzirtite, anatase, baddeleyite and pyrochlore) of a newly discovered Late Cretaceous kimberlite (U-Pb zircon age 90.0 ± 1.3 Ma; 2σ) named Osvaldo França 1, located in the Alto Paranaíba Igneous Province (APIP), southeastern Brazil. Pyrope grains are lherzolitic (Lherz-1, Lherz-2 and Lherz-3), harzburgitic (Harz-3) and wehrlitic (Wehr-2). The pyrope xenocrysts cover a wide mantle column in the subcratonic lithosphere (66–143 km; 20–43 kbar) at relatively low temperatures (811–875 °C). The shallowest part of this mantle is represented by Lherz-1 pyropes (20–32 kbar), which have low-Cr (Cr₂O₃ = 1.74–6.89 wt.%) and fractionated middle to heavy rare earth elements (MREE-HREE) pattern. The deepest samples are represented by Lherz-2, Lherz-3, Harz-3, and Wehr-2 pyropes (36–43 kbar). They contain high-Cr contents (Cr₂O₃ = 7.36–11.19 wt.%) and are characterized by sinusoidal (Lherz-2 and Wehr-2) and spoon-like (Lherz-3 and Harz-3) REE patterns. According to their REE and trace elements, pyrope xenocrysts have enriched nature (e.g., Ce and Yb vs. Cr₂O₃), indicating that the cratonic lithosphere has been affected by a silicate melt with subalkaline/tholeiite composition due to their low Zr, Ti and Y concentrations. Besides minerals with typical kimberlitic signatures, such as ilmenite and zircon, the exotic compositions of phlogopite and ulvöspinel suggest an enriched component in the magma source. The formation of rare mineral phases with strong enrichment of light-REE (LREE) and high field strength elements (HFSE) is attributed to the late-stage kimberlitic melt. We propose a tectonic model where a thermal anomaly, represented by the low-velocity seismic anomaly observed in P-wave seismic tomography images, supplied heat to activate the alkaline magmatism from a metasomatized cratonic mantle source during the late-stages of Gondwana fragmentation and consequent South Atlantic Ocean opening. The metasomatism recorded by mineral phases is a product of long-lived recycling of subducted oceanic plates since the Neoproterozoic (Brasiliano Orogeny) or even older collisional events, contributing to the exotic character of the Osvaldo França 1 kimberlite, as well as to the cratonic lithospheric mantle.

我们展示了矿物浓缩物的主要和微量元素组成，包括石榴石异晶、钛铁矿、金云母、尖晶石、锆石和新发现的晚白垩世金伯利岩（U-Pb 锆石年龄 90. ± 1.3 Ma; 2 σ ) 命名为 Osvaldo França 1，位于巴西东南部的上巴拉那伊巴火成岩省 (APIP)。Pyrope 晶粒是锂辉石 (Lherz-1、Lherz-2 和 Lherz-3)、哈茨伯铁矿 (Harz-3) 和伟石 (Wehrlitic) (Wehr-2)。在相对较低的温度 (811-875 °C) 下，辉石外晶覆盖了亚克拉通岩石圈 (66-143 km; 20-43 kbar) 中的宽地幔柱。该地幔的最浅部分由 Lherz-1 pyres (20–32 kbar) 代表，其具有低 Cr (Cr ₂ O ₃ = 1.74–6.89 wt.%) 和分馏的中重稀土元素 (MREE-HREE) 模式。最深的样品由 Lherz-2、Lherz-3、Harz-3 和 Wehr-2 烟弹（36-43 kbar）代表。它们含有高 Cr 含量（Cr ₂ O ₃  = 7.36–11.19 wt.%），并具有正弦（Lherz-2 和 Wehr-2）和勺状（Lherz-3 和 Harz-3）REE 图案的特征。根据其稀土元素和微量元素，火梨石外晶具有丰富的性质（例如，Ce 和 Yb vs. Cr ₂ O ₃)，表明克拉通岩石圈受到亚碱性/拉斑沸石组成的硅酸盐熔体的影响，因为它们的 Zr、Ti 和 Y 浓度较低。除了具有典型金伯利岩特征的矿物（如钛铁矿和锆石）外，金云母和尖晶石的奇异成分表明岩浆源中含有丰富的成分。具有强烈富集轻稀土（LREE）和高场强元素（HFSE）的稀有矿物相的形成归因于晚期金伯利岩熔体。我们提出了一个构造模型，其中以在 P 波地震层析成像图像中观察到的低速地震异常为代表的热异常提供热量以激活冈瓦纳大陆破碎后期和随后发生的交代克拉通地幔源的碱性岩浆作用。南大西洋开放。