The Staré Město Belt (SMB) in the Central Sudetes forms a Variscan tectonic boundary zone that is located between the Saxothuringian and Brunovistulian terranes of the Bohemian Massif. The three thrust-bounded upper, middle and lower lithotectonic units of the SMB are composed of metasedimentary and Late Cambrian metavolcanic rocks. A new LA-ICPMS zircon geochronology supported by zircon typology studies of the mica schists of the upper unit and the migmatitic paragneisses of the middle unit provides new insights into the provenance and evolution of the SMB. Our new data were obtained from metasedimentary rocks and compared to the previously published zircon ages of the SMB metavolcanic rocks. The results indicate that the metasedimentary and bimodal metavolcanic rocks in the separate lithotectonic units of the SMB originally formed Late Cambrian volcano-sedimentary successions. The source areas of the sedimentary basins studied were dominated by Neoproterozoic and Paleoproterozoic crystalline rocks that were presumably located near the West African Craton of Gondwana. A comparison of the detrital age spectra obtained with those previously published from the region indicates a strong association of the entire SMB with the Saxothuringian terrane of the Bohemian Massif. During partial melting of the metasedimentary rocks of the middle unit of the SMB, Cambrian and older zircon grains were affected by solid-state transformations that caused partial resetting of the U-Pb dates, changes in internal zircon textures and reductions in Th/U ratios.

中苏台德的 Staré Město 带 (SMB) 形成了一个位于波希米亚地块的萨克森林阶和布鲁诺维斯图里亚阶之间的华力斯坎构造边界带。SMB 以逆冲断层为界的上、中、下三个岩石构造单元由变质沉积岩和晚寒武世变质火山岩组成。新的 LA-ICPMS 锆石年代学得到上单元云母片岩和中单元混合岩副片岩的锆石类型学研究的支持，为 SMB 的起源和演化提供了新的见解。我们的新数据来自变沉积岩，并与之前发表的 SMB 变质火山岩的锆石年龄进行了比较。结果表明，SMB独立岩石构造单元中的变沉积和双峰变质火山岩最初形成了晚寒武世火山-沉积序列。所研究的沉积盆地的源区以新元古代和古元古代结晶岩为主，推测位于冈瓦纳西非克拉通附近。将获得的碎屑年龄光谱与先前从该地区公布的年龄光谱进行比较表明，整个 SMB 与波希米亚地块的萨克森林阶地体密切相关。在 SMB 中单元的变沉积岩部分熔融过程中，寒武系和较老的锆石颗粒受到固态转变的影响，导致 U-Pb 日期的部分重置，