The Alliance for Earth Sciences, Engineering and Development in Africa, College of Earth and Mineral Sciences, Penn State University, University Park, PA 16802, USA.
J Hum Evol. 2012 Aug;63(2):274-83. doi: 10.1016/j.jhevol.2011.09.001. Epub 2012 Mar 8.
The Ngorongoro Volcanic Highland (NVH), situated adjacent and to the east of Olduvai Gorge in northern Tanzania, is the source of the immense quantities of lava, ignimbrite, air fall ash, and volcaniclastic debris that occur interbedded in the Plio-Pleistocene sedimentary deposits in the Laetoli and Olduvai areas. These volcanics have proven crucial to unraveling stratigraphic correlations, the age of these successions, the archaeological and paleontological remains, as well as the source materials from which the bulk of the stone tools were manufactured. The NVH towers some 2,000 m above the Olduvai and Laetoli landscapes, affecting local climate, run-off, and providing varying elevation - climate controlled ecosystem, habitats, and riparian corridors extending into the Olduvai and Laetoli lowlands. The NVH also plays a crucial role in addressing the genesis and history of East African Rift (EAR) magmatism in northern Tanzania. In this contribution, we provide age and petrochemical compositions of the major NVH centers: Lemagurut, basalt to benmorite, 2.4-2.2 Ma; Satiman, tephrite to phonolite, 4.6-3.5 Ma; Oldeani, basalt to trachyandesite, 1.6-1.5 Ma; Ngorongoro, basalt to rhyolite, 2.3-2.0 Ma; Olmoti, basalt to trachyte, 2.0-1.8 Ma; Embagai, nephelinite to phonolite, 1.2-0.6 Ma; and Engelosin, phonolite, 3-2.7 Ma. We then discuss how these correlate in time and composition with volcanics preserved at Olduvai Gorge. Finally, we place this into context with our current understanding as to the eruptive history of the NVH and relationship to East African Rift volcanism.
恩戈罗恩戈罗火山高原（NVH）位于坦桑尼亚北部的奥杜瓦伊峡谷东侧，是大量熔岩、火山灰、火山碎屑和降落火山灰的源地，这些物质与莱托利和奥杜瓦伊地区上新世至更新世的沉积矿床交错出现。这些火山岩对于解开地层对比、这些地层的年代、考古学和古生物学遗迹以及大部分石器制造所用的原料等问题至关重要。NVH 高出奥杜瓦伊和莱托利景观约 2000 米，影响当地气候、径流量，并提供不同海拔的气候控制生态系统、栖息地和滨水走廊，延伸到奥杜瓦伊和莱托利低地。NVH 还在解决坦桑尼亚北部东非大裂谷（EAR）岩浆作用的成因和历史方面发挥着关键作用。在本研究中，我们提供了 NVH 主要中心的年龄和岩石化学组成：Lemagurut，玄武岩到贝莫里岩，2.4-2.2 百万年；Satiman，火山碎屑岩到响岩，4.6-3.5 百万年；Oldeani，玄武岩到粗安岩，1.6-1.5 百万年；Ngorongoro，玄武岩到流纹岩，2.3-2.0 百万年；Olmoti，玄武岩到粗安岩，2.0-1.8 百万年；Embagai，霞石岩到响岩，1.2-0.6 百万年；和 Engelosin，响岩，3-2.7 百万年。然后，我们讨论了这些火山岩在时间和组成上如何与奥杜瓦伊峡谷保存的火山岩相关。最后，我们将这一情况与我们目前对 NVH 的喷发历史以及与东非大裂谷火山作用的关系的理解联系起来。
