在1∶25万红宝石幅区调野外调研过程中,在甘肃北山北带红石山地区陆相沉积地层中,发现软体动物化石。经中国科学院南京地质古生物研究所鉴定,有双壳纲蚬、蚌类,腹足纲螺类,属热河动物群,其时代定为早白垩世。结合岩石地层及区域地层对比研究,将该套地层划归赤金堡组。该组的确定其意义在于澄清了长期以来,人们认为红石山地区缺失早白垩世沉积的认识。 In the 1: 250,000 ruby ​​area adjustment field research, molluscan fossils were found in the terrestrial sedimentary formations in the Hongshishan area of ​​Beishan, northern Gansu. Identified by the Institute of Geology and Palaeontology, Chinese Academy of Sciences, there are bivalve clam, mussels and gastropods, belonging to the Jehol fauna, whose age was defined as Early Cretaceous. Combined with the comparison of lithostratigraphy and regional stratigraphy, this set of strata is classified as Chijinbao Formation. The significance of this group is to clarify the long-held belief that the absence of Early Cretaceous sediments in Hongshishan area was considered.