Reddish to black colored heavy mineral sands occur alongside the several hundred-kilometer long placer district in the Erongo and S-Kunene regions in Namibia and are the focus of this study. The sedimentary packages of these nearshore marine ‘garnet’ and ‘magnetite’ placers consist of millimeter to decimeter thick discontinuous, alternating layers of heavy minerals (ρ > 2.90 g/cm³) set into dominantly feldspatho-quartzose layers. The fine-to medium-grained sands are largely unimodal, well sorted, and have similar bulk mineralogical compositions. A clear trend in grain size distribution is evident with translucent (Al₂SiO₅ phases, apatite, epidote, garnet, monazite, pyroxene, rutile, schorl, sphene, staurolite, zircon, zoisite) and opaque heavy minerals (Fe–Ti oxides) mostly related to the fine-sand fraction and rock-forming minerals (quartz, feldspars, micas, carbonates) to the medium sand-fraction. Fines are negligible. Grain circularity varies largely between 0.9 and 0.8. Heavy mineral sands between the Omaruru and the Huab Rivers are garnet-dominated, whereas the southernmost heavy mineral sands close to Swakopmund are (titano)magnetite-ilmenite dominated. Overall, the heavy mineral content of sampled layers is ~22–94 vol%. Three placer areas (1) the area around Swakopmund, (2) the region north of the Omaruru River, straddling north beyond Cape Cross and (3) the Northern region, south of Horing bay to Toscanini, can be delineated based on mineralogical and grain parameters. The bulk of the heavy minerals is likely derived from metamorphic rocks within the catchment of the Orange River of South Africa, with minor contributions from the Kuiseb and Swakop Rivers in Namibia. A Damara provenance of some detrital material is indicated. The contribution of ephemeral hinterland rivers is negligible. Naturally occurring tidal actions of the Atlantic Ocean continually reshape, redeposit and replenish the high-grade heavy mineral sands and impinge on the regional sorting trends. Future mining and mineral processing activities may concentrate on the heavy mineral sands close to Swakopmund as they have the highest zircon and monazite potential and bear the most promising Ti resource. However, these coastal environments are eco-sensitive and most of the locations are within national parks belonging to the natural heritage of Namibia.

纳米比亚的Erongo和S-Kunene地区的几百公里长的砂矿区旁边出现红到黑色的重矿物砂，这是本研究的重点。这些近岸海洋“石榴石”和“磁铁矿”砂矿的沉积包裹由毫米至分米厚的不连续，交替的重矿物层（ρ> 2.90 g /cm³）层组成，这些层层主要为长石-石英-石英层。细粒至中粒砂基本上是单峰的，分类良好的，并且具有相似的大块矿物学组成。在粒度分布的明显的趋势是用半透明明显的（铝₂的SiO _5个阶段，磷灰石，绿帘，石榴石，独居石，辉石，金红石，金红石，榍石，十字石，锆石，锂铁矿）和不透明的重矿物（Fe-Ti氧化物），主要与细砂级分和成岩矿物（石英，长石）有关，云母，碳酸盐）到中等砂级分。罚款可以忽略不计。晶粒的圆形度在0.9到0.8之间变化很大。奥马鲁鲁河与瓦布河之间的重矿物砂主要是石榴石，而斯瓦科普蒙德附近最南端的重矿物砂主要是（钛铁矿）磁铁矿-钛铁矿。总体而言，采样层的重矿物含量约为22–94 vol％。可以根据矿物学和谷物划定三个砂矿区（1）斯瓦科普蒙德（Swakopmund）周围的区域，（2）奥马鲁河（Omaruru River）以北跨过海角十字架（Cape Cross）以外的区域，以及（3）霍林湾以南至托斯卡尼尼（Toscanini）的北部区域参数。大量的重矿物可能来自奥兰治河流域内的变质岩。南非，纳米比亚的Kuiseb河和Swakop河贡献了少量资金。指出了一些碎屑物质的达马拉来源。短暂内陆河流的贡献可忽略不计。大西洋自然发生的潮汐作用不断重塑，重新沉积和补充高等级重矿物砂，并影响区域分选趋势。未来的采矿和矿物加工活动可能集中在斯瓦科普蒙德附近的重矿物砂上，因为它们具有最高的锆石和独居石潜力，并拥有最有前途的钛资源。但是，这些沿海环境对生态敏感，大多数位置都在属于纳米比亚自然遗产的国家公园内。