Neoproterozoic palaeogeography of the Cadomia and Avalon terranes: constraints from detrital zircon U–Pb ages
Neoproterozoic palaeogeography of the Cadomia and Avalon terranes: constraints from detrital zircon U–Pb ages
复制标题
卡多米亚和阿瓦隆地体的新元古代古地理：碎屑锆石 U-Pb 年龄的限制
DOI：
10.1144/0016-764904-003
复制
发表时间：
2005
影响因子：
2.7
通讯作者：
M. Hamilton
中科院分区：
文献类型：
--
作者：
S. Samson;R. D'lemos;B. Miller;M. Hamilton
来自法国北部Cadomia地体和海峡群岛3个新元古代砂岩单元的碎屑锆石可划分为晚新元古代（650 ~ 600 Ma）、早古元古代（2.4 ~ 2.0 Ga）和太古代（> ~ 2.5 Ga） 3个大群。中元古代锆石晶体的缺乏，加上2.20 ~ 2.00 Ga之间的高丰度颗粒，与西非克拉通出露岩石的年龄密切对应，因此表明卡多米亚在约580 Ma时与西非非常接近。新元古代阿瓦隆地体碎屑锆石年龄以中元古代为主，在2.40 ~ 2.05 Ga之间存在明显的年龄差距。这些显著差异表明，在新元古代晚期，这两个地体相对于冈瓦南主要克拉通处于不同的位置。
Detrital zircons from three Neoproterozoic sandstone units from the Cadomia terrane of northern France and the Channel Islands yield ages in three broad groups: late Neoproterozoic (650–600 Ma), early Palaeoproterozoic (2.4–2.0 Ga) and Archaean (>2.5 Ga). The lack of Mesoproterozoic zircon crystals, combined with the high abundance of grains between 2.20 and 2.00 Ga, corresponds closely to the ages of exposed rocks in the West Africa Craton, and thus it is suggested that Cadomia was in close proximity to West Africa by c. 580 Ma. In contrast, the main age groups of detrital zircon from the Neoproterozoic Avalon terrane are Mesoproterozoic and there is a distinct gap of ages between 2.40 and 2.05 Ga. These significant differences suggest that the two terranes were in different locations relative to major Gondwanan cratons in latest Neoproterozoic time.