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我们在进行兰州地区大震对策研究的地震地质考察工作中,在西固区西梁园乡西梁园村南山半坡采到四颗马牙化石,经兰州大学谷祖纲老师鉴定为:Equus Sameniensis(三门马)的上牙第四枚前臼齿(P_(m4))和三枚臼齿(m_1、m_2、m_3)。这四枚马牙化石,产于上第三纪未期剥夷面上的洪积砾石、碎石层夹浅枯黄色之砂质亚粘土层中。其上覆为中更新统的浅黄色石质黄土,下覆为上新统之冲、洪积棕红色含砾砂岩夹泥岩,以中等倾角向东北倾斜,二者为典型的角度不整合接触关系。上述上第三纪未期的剥夷面,在兴隆山山前广泛发育,向东可延经榆中县直达定西县。
In the seismological and geological survey of the study on the major earthquakes in Lanzhou, we collected four horseshoe fossils from Banpo, Nanshan, Xiliangyuan Village, Xiliangyuan Township, Xigang District. They were identified by Gu Gu Zang Gang from Lanzhou University as Equus Sameniensis ( Three horses), the fourth premolar (P_ (m4)) and the three molars (m_1, m_2, m_3). These four horses teeth fossils, produced in the late Tertiary peeled surface of the alluvial gravel, gravel folder folder light yellowish sandy loam layer. Its overlying is the mid-Pleistocene pale yellow stony loess, which is covered by bluff red-grained reddish pebbly sandstone mudstone beneath the Lower Pleistocene and tilted to the northeast at moderate inclination. The two are typical angular unconformities . The aforementioned third-generation peel-off surface of the past, extensive development in Xinglongshan before the east can extend Yuzhong County Dingxi County.