Identification of spores, acritarchs, and chitinozoans in weakly metamorphosed (≥ 300 °C) turbidites demonstrates the usefulness of palynological dating for hitherto unfossiliferous strata that underlie much of the Gander terrane in Maine. Identification of spores, acritarchs, and chitinozoans in weakly metamorphosed (≥ 300 °C) turbidites demonstrates the usefulness of palynological dating for hitherto unfossiliferous strata that underlie much of the Gander terrane in Maine. Combined with sparse macrofossil ages and geochronologic data from detrital zircons, volcanic horizons, and plutons, the fossils constrain the ages of strata in the Central Maine/Aroostook-Matapedia (CMAM) basin and Fredericton trough and help to resolve paleogeographic and tectonic problems. Ages for the provisional Brewer (Upper Ordovician to Llandovery) and Bangor (Wenlock) formations in the Bangor area fill the last remaining gap in CMAM basin stratigraphy and permit correlation across the entire basin, from western Maine to the New Brunswick border. Resulting lithofacies patterns document basinward facies changes from both eastern and western external sources, and also indicate internal sources within the basin. A progressive decrease in carbonate sediment in the CMAM basin toward the south suggests interaction between axial and basinward currents in which micrite transported by axial currents from the Matapedia platform in northern New Brunswick was progressively overwhelmed to the south by clastic sedimentation from flanking highland sources. Middle to late Silurian age ranges for the Flume Ridge Formation, the most extensive unit in the Fredericton trough, and the newly named County Road Formation permit correlation with rocks in similar structural positions in New Brunswick. Recent geologic mapping, the new age control, and improved understanding of facies relationships show that the CMAM basin was perhaps as wide as 800 to 1000 km prior to deformation; developed on continental crust after mid-Ordovician plate accretion; contained a body of deep water with anoxic bottom conditions and mostly pelagic organisms; and contains a series of overlapping submarine fans derived from multiple sources.

中文翻译：

---

低品位变质岩的孢粉学测年：在美国缅因州东部和中东部缅因州中部/Aroostook-Matapedia 盆地和弗雷德里克顿海槽（北阿巴拉契亚山脉）早古生代岩石中的应用

在弱变质 (≥ 300 °C) 浊积岩中鉴定孢子、acritarchs 和几丁质动物证明了孢粉学测年对缅因州大部分 Gander 地层的迄今未见化石地层的有用性。在弱变质 (≥ 300 °C) 浊积岩中鉴定孢子、acritarchs 和几丁质动物证明了孢粉学测年对缅因州大部分 Gander 地层的迄今未见化石地层的有用性。结合来自碎屑锆石、火山层和岩体的稀疏宏观化石年龄和地质年代学数据，这些化石限制了缅因州中部/Aroostook-Matapedia (CMAM) 盆地和 Fredericton 海槽的地层年龄，有助于解决古地理和构造问题。班戈地区临时 Brewer（上奥陶纪至 Llandovery）和班戈（Wenlock）地层的年代填补了 CMAM 盆地地层中最后剩余的空白，并允许从缅因州西部到新不伦瑞克边界的整个盆地进行对比。由此产生的岩相模式记录了东部和西部外部来源的盆地相变，也表明了盆地内的内部来源。CMAM 盆地中碳酸盐沉积物向南的逐渐减少表明轴向和盆地流之间的相互作用，其中由来自新不伦瑞克省北部 Matapedia 平台的轴向流输送的泥晶逐渐被来自侧翼高地源的碎屑沉积物淹没到南部。Flume Ridge组的中至晚志留纪年龄范围，Fredericton 海槽中最广泛的单元，新命名的 County Road Formation 允许与新不伦瑞克省类似结构位置的岩石相关联。最近的地质填图、新时代控制以及对相关系的深入理解表明，CMAM 盆地在变形前可能有 800 至 1000 公里宽；中奥陶世板块增生后在大陆地壳上发育；包含一个深水体，底部缺氧，主要是远洋生物；并包含一系列来自多个来源的重叠海底扇。对相关系的深入了解表明，CMAM 盆地在变形前可能有 800 至 1000 公里宽；中奥陶世板块增生后在大陆地壳上发育；包含一个深水体，底部缺氧，主要是远洋生物；并包含一系列来自多个来源的重叠海底扇。对相关系的深入理解表明，CMAM 盆地在变形前可能有 800 至 1000 公里宽；中奥陶世板块增生后在大陆地壳上发育；包含一个深水体，底部缺氧，主要是远洋生物；并包含一系列来自多个来源的重叠海底扇。