Scales of Variability in Ridge Segmentation and Structure Along the MAR in Central North Atlantic

本研究旨在建立北大西洋中部一段相当长度的中大西洋脊的形态特征、分割几何和结构，并验证沿缓慢扩张的中大西洋脊的地壳增生过程的假设。需要解决的问题有：(1)亚速尔群岛热点对大西洋中脊的形态、分割几何和结构有何影响？(2)北大西洋中部主要断裂带是否将中大西洋洋脊分割成不同风格和不同波长的部分？(3)中大西洋洋脊地幔布格异常模式的差异与段间形态构造变异性有何关系？(4)沿中大西洋脊的常规转换断层和非转换不连续面相对丰度是多少？(5)是什么控制了大西洋中脊非变换偏移的形成、稳定和演化？主要调查人员将参加法国船只R/V l'Atalante的两次巡航。

This research is designed to establish the morphological character, segmentation geometry, and structure of a significant length of the Mid-Atlantic Ridge in the central North Atlantic, and to test hypotheses on crustal accretion processes along a slowly spreading mid-ocean ridge. Questions to be addressed are: (1) What is the effect of the Azores hotspot on the morphology, segmentation geometry, and structure of the Mid-Atlantic Ridge? (2) Do major fracture zones in the central North Atlantic separate portions of the Mid-Atlantic Ridge with significantly different styles and wavelengths of segmentation? (3) How are differences in the pattern of mantle Bouguer anomalies at the Mid-Atlantic Ridge related to inter-segment morphotectonic variability? (4) What is the relative abundance of conventional transform faults and non-transform discontinuities along the Mid-Atlantic Ridge? (5) What controls the formation, stability, and evolution of non-transform offsets on the Mid-Atlantic Ridge? The principal investigators will participate in two cruises of the French ship R/V l'Atalante.