Abstract: We discuss the history of exploration of Red Clay vertebrate fossils of the Loess Plateau, and record observations on “Hipparion Red Clay” localities of Shanxiand Gansu provinces. Red clay is widespread across the Loess Plateau, but misleading as a descriptive term because many deposits are neither red nor dominated by clay-size sediment. Many red clay sequences contain paleosols, but also water-laid deposits. Our survey includes well-known localities of Yushe Basin, Renjiagou and Leijiahe near Lingtai, and sites of Qingyang and Qin’an. We discuss fossils found at Renjiagou, a new discovery of micromammals (Pliopentalagus) from Yucun, and Pliocene burrows observed at Hujiacun, both latter localities northeast of Lingtai. Observations are consistent with a high rate of supply of clay sized particles, likely air-fall origin, throughout the Loess Plateau during the Late Miocene. In some areas where fluvial or lake processes dominate, red clay particles are replaced in part or completely by water-laid coarse-grained deposits. We saw no evidence for a dry Late Miocene-Early Pliocene, but rather hypothesize well-watered habitat of high productivity. Locally diverse vertebrate fossils attest to high terrestrial biomass for Hipparion faunas.

摘要： 讨论了黄土高原地区红粘土中脊椎动物化石的考察历史，记录了山西和甘肃“三趾马红土”地点的观察结果。红粘土广泛分布于黄土高原地区，但常被误认为是一个描述性术语，因为其中的许多沉积物既非红色，又不以粘土级颗粒为主。不少红粘土序列中含有古土壤，也含有水成沉积物。此次考察包括榆社盆地的经典地点、灵台任家沟和雷家河，以及庆阳和秦安的一些地点。讨论了在任家沟发现的化石、在玉村新发现的小哺乳动物上新五褶兔(Pliopentalagus)和在胡家村观察到的上新世潜穴，后两个地点都位于灵台东北面的庆阳地区。观察结果与晚中新世遍布黄土高原、很可能来自降尘的粘土级颗粒的快速堆积吻合。但在一些区域则以河流或湖泊过程为主，红粘土颗粒部分或全部被水成的粗碎屑沉积物代替，没有找到晚中新世-早上新世干旱化的证据，反而支持高生产力的湿润环境假说。局部富集的脊椎动物化石证明三趾马动物群具有很高的陆生生物量。