Introduction to the Huangnitang Section: The main landscape of the Golden Nails Scenic Area is the Paleozoic standard stratum. Among them, the Huangnitang Section is a global standard stratum from the middle Ordovician (460 million years ago). All parts of the world must confirm this The stratigraphy of time intervals must be compared with the Huangnitang section. The global standard profile is commonly known as the golden nail profile, and the Huangnitang profile is my country's first golden nail.