Magmatic and Deformational History of the Cadomian Orogenic Belt, North Armorican Massif

Avalon、Carolina和Cadomia等几个环大西洋新元古代地体总体上具有相似的特征，表明这些地体有直接联系的可能性。然而，在充分评估有关可能的地体关系的假设之前，需要确定地体特征的许多关键方面。对任何有意义的对比至关重要的地体特征方面包括：确定基底与地体的年龄和性质，确定岩浆作用和随后地体内岩浆事件的开始时间，记录每一次岩浆事件的地球化学性质，记录一级变形事件的开始、持续时间和类型，以及确定盆地发展和沉积的历史。这些方面的地体特征将在法国北阿莫里卡地块的卡多米亚造山带的两个主要部分进行，该地区仅受瓦里斯坎变形的影响最小。这些结果有望增进对这些新元古代地体的发育和扩散的了解，这些地体曾经非常接近，但现在广泛分布在大西洋边缘。

9903032SamsonSeveral circum-Atlantic Neoproterozoic terranes, such as Avalon, Carolina, and Cadomia, have generally similar characteristics, suggesting the possibility that these terranes are directly related. However, many critical aspects of terrane characterization need to be determined before hypotheses about possible terrane relationships can be fully evaluated. Aspects of terrane characterization that are crucial to any meaningful comparisons include establishing the age and nature of the basement to the terrane, determining the timing of initiation of magmatism and subsequent magmatic events within the terranes, documenting the geochemical character of each magmatic episode, documenting the initiation, duration, and style of first-order deformational events, and determining the history of basin development and sedimentation. These aspects of terrane characterization will be carried out for two major segments of the Cadomian orogenic belt in the North Armorican Massif of France, a region only minimally affected by Variscan deformation. Results are expected to improve understanding of the development and dispersion of these neoproterozoic terranes that were once in close proximity, but now are widely distributed around the margins of the Atlantic.