Upstairs-downstairs: supercontinents and large igneous provinces, are they related?

There is a correlation of global large igneous province (LIP) events with zircon age peaks at 2700, 2500, 2100, 1900, 1750, 1100, and 600 and also probably at 3450, 3000, 2000, and 300 Ma. Power spectral analyses of LIP event distributions suggest important periodicities at 250, 150, 100, 50, and 25 million years with weaker periodicities at 70–80, 45, and 18–20 Ma. The 25 million year periodicity is important only in the last 300 million years. Some LIP events are associated with granite-forming (zircon-producing) events and others are not, and LIP events at 1900 and 600 Ma correlate with peaks in craton collision frequency. LIP age peaks are associated with supercontinent rifting or breakup, but not dispersal, at 2450–2400, 2200, 1380, 1280, 800–750, and ≤200 Ma, and with supercontinent assembly at 1750 and 600 Ma. LIP peaks at 2700 and 2500 Ma and the valley between these peaks span the time of Neoarchaean supercraton assemblies. These observations are consistent with plume generation in the deep mantle operating independently of the supercontinent cycle and being controlled by lower-mantle and core-mantle boundary thermochemical dynamics. Two processes whereby plumes can impact continental assembly and breakup are (1) plumes may rise beneath supercontinents and initiate supercontinent breakup, and (2) plume ascent may increase the frequency of craton collisions and the rate of crustal growth by accelerating subduction.

全球大火成岩省（large igneous province, LIP）事件与多个锆石年龄峰值存在显著相关性，这些峰值分别位于2700、2500、2100、1900、1750、1100及600百万年（Ma）处，另外还可能存在3450、3000、2000与300 Ma的年龄峰值。对LIP事件分布开展的功率谱分析表明，其存在250、150、100、50及25 Ma的重要周期，同时还存在70~80、45以及18~20 Ma的较弱周期。其中25 Ma的周期仅在过去3亿年中具有研究意义。部分LIP事件与花岗岩形成（锆石生成）事件相关联，另一部分则无此关联；而1900 Ma与600 Ma的LIP事件，与克拉通碰撞频率的峰值存在显著相关性。LIP年龄峰值与多个时段的超大陆裂谷作用或裂解（而非大陆离散）相关联，这些时段包括2450~2400、2200、1380、1280、800~750以及≤200 Ma；同时LIP年龄峰值还与1750 Ma和600 Ma的超大陆聚合事件存在相关性。2700 Ma与2500 Ma的LIP峰值，以及二者之间的低谷时段，对应新太古代超级克拉通聚合的时期。上述观测结果与“地幔深部的地幔柱生成作用独立于超大陆旋回，并受下地幔与核幔边界的热化学动力学过程调控”的结论相一致。地幔柱可通过两种途径影响大陆的聚合与裂解：（1）地幔柱可能在超大陆下方上涌，进而引发超大陆裂解；（2）地幔柱上涌可通过加速俯冲作用，提升克拉通碰撞频率与地壳生长速率。