Neoproterozoic glacial deposits commonly serve as important stratigraphic markers at interregional scales and provide significant insights into our understanding of the extreme climate during this period. More importantly, these glacial deposits are probably related to the breakup of the Rodinia supercontinent and, consequently, are tectonically significant. The Neoproterozoic sedimentary sequence along the southwestern margin of the North China Craton (NCC) typically contains a unique glacial deposit, named the Luoquan Formation, but this deposit is poorly documented for its age. Here, we report new occurrences of the late Ediacaran index fossil Shaanxilithes from the Dongpo Formation along the southwestern margin of the NCC, which not only extends the palaeogeographic distribution of Shaanxilithes but also provides convincing evidence for the late Ediacaran age of the Dongpo Formation. Hence, the conformably underlying glacial deposits of the Luoquan Formation is constrained to pre-Shaanxilithes in age. In both the NCC and Qaidam Block, the Shaanxilithes-bearing marine siliciclastic rocks consistently disconformably underlie the Cambrian (Stage 3) phosphoric deposits and conformably overlie the characteristic Neoproterozoic glacial deposits that are unconformably underlain by the Mesoproterozoic successions. From this perspective, we re-evaluate the potential tectonic affinity of these Precambrian tectonic units as mentioned above.

新元古代冰川沉积物通常作为区域间尺度的重要地层标志，为我们对这一时期极端气候的理解提供了重要的见解。更重要的是，这些冰川沉积物可能与罗迪尼亚超大陆的分裂有关，因此具有重要的构造意义。沿华北克拉通 (NCC) 西南缘的新元古代沉积层序通常包含一个独特的冰川沉积物，称为罗泉组，但该沉积物的年代记录很少。在这里，我们报告了沿华北克拉通西南缘东坡组晚期埃迪卡拉纪化石陕西石的新发现，这不仅扩展了古地理分布。陕西石器也为东坡组埃迪卡拉纪晚期提供了令人信服的证据。因此，罗泉组的下伏冰川沉积物在年代上仅限于陕前石器时代。在华北克拉通和柴达木地块，含陕西石块的海相硅质碎屑岩始终不整合地位于寒武纪（第 3 期）磷矿床之下，并与不整合地位于中元古代系列之下的新元古代冰川沉积物整合地叠加。从这个角度来看，我们重新评估了上述这些前寒武纪构造单元的潜在构造亲和力。