甘肃平凉官庄中-上奥陶统剖面具有以下几个显著的特征：（1）岩性以灰岩和页岩互层为特点，同时发育丰富的可以系统建带的笔石和牙形石生物群；（2）牙形石既有北美中大陆型又有北大西洋型的特征分子；（3）发育多套薄层凝灰岩（或为钾质斑脱岩）。单剖面同时具备这些特点在全球奥陶系剖面中都很罕见。基于此，可以在该剖面中-上奥陶统界线附近同步开展笔石和牙形石生物地层、锆石U-Pb年代地层以及碳同位素地层综合研究。由此，可以（1）获得具有高精度笔石和牙形石生物地层控制的界线附近的U-Pb年龄值，以有效地校验国际地质年代表上桑比阶底界现有的估算年龄值（458.4±0.9Ma）；（2）建立具有精确生物地层和U-Pb年龄控制的中-上奥陶统的碳同位素曲线。同时，为了更好地查明中-上奥陶统界线附近碳同位素演化特征，拟在该界线国际副层型剖面——新疆柯坪大湾沟剖面同步开展研究。

The Darriwilian-Sandbian Guanzhuang section in Pingliang, Gansu Province is outstandingly characterized by (1) alternative distribution of limestone and shale which contain biostratigraphically highly diagnostic conodonts and graptolites, (2) including conodont species used for biozonations in Baltoscandia and North American Midcontinent, and (3) developing more than ten layers of K-bentonites. Based on such almost unique geological conditions, studies on conodont and graptolite biostratigraphy, zircon geochronology, and carbon isotope chemostratigraphy could be carried out synchronously at the Middle-Upper Ordovician boundary (i.e. Darriwilian-Sandbian boundary) interval of the Guanzhuang section. The results could be used for (1) attaining the 206Pb/238U ages of the datum near or even at the base of the Sandbian Stage, which are invaluable for the calibration of the Sandbian age in the International Chronostratigraphic Chart, and (2) establishing the Darriwilian-Sandbian δ13C curves restricted by U-Pb ages. Both the 206Pb/238U ages and δ13C curves will be well controlled by precise conodont and graptolite biozones. Carbon isotope research will also be carried out at Dawangou section, the auxiliary stratotype for the base of the Upper Series of the Ordovician System, to understand the variations of δ13C values from the O2/O3 boundary interval better.