Detailed stratigraphic analyses of Late Emsian and Early Eifelian (Lower to Middle Devonian) carbonate‐dominated strata in the northern Appalachian Basin indicate anomalous, locally varying relative sea level changes and inversions of topography. The distribution of a major basal‐bounding unconformity, basinal pinnacle reefs, local absence of parasequences, and eastward migration of shallow marine carbonate lithofacies and related biofacies in the Onondaga Limestone and underlying strata mark the retrograde migration of an elongate, northeast‐southwest‐trending area of positive relief, bordered on its cratonward side by a similarly migrating basin of intermediate depth. These features are thought to represent the forebulge and back‐bulge basin of the Appalachian foreland basin system as it developed during a time of relative quiescence within the Acadian Orogeny. However, the relatively small size of the bulgelike feature (ca. 80–100‐km‐wide, 20–50‐m positive relief), its great distance from the probable deformation front (>400 km), and the lack of a well‐developed foredeep immediately adjacent to the bulgelike feature may indicate that it represents a smaller‐scale flexural high (“flexural welt”) superposed over the cratonward edge of the larger‐scale classical forebulge of the basin. Development of shallow‐water reefs on the crest of the bulge during sea level lowstand, followed by migration of the bulge and widespread transgression, permitted growth of economically significant pinnacle reefs in the deep basin center. Further subsurface reef exploration should concentrate along the projected position of the bulge during the basal Onondaga lowstand.

中文翻译：

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泥盆纪阿巴拉契亚前陆盆地隆起迁移和尖峰礁发育

对阿巴拉契亚盆地北部以碳酸盐岩为主的晚埃姆斯世和早艾菲尔世（下至中泥盆世）的详细地层分析表明，相对海平面发生异常、局部变化和地形反转。Onondaga 石灰岩和下伏地层中主要的基底边界不整合面、盆地尖峰礁、局部无副层序以及浅海相碳酸盐岩相和相关生物相的向东迁移标志着一条细长的、东北-西南走向的逆行迁移正地貌的区域，在其克拉通一侧与一个中等深度的类似迁移盆地接壤。这些特征被认为代表了阿巴拉契亚前陆盆地系统的前隆起和后隆起盆地，因为它是在阿卡迪亚造山运动中相对静止的时期发展起来的。然而，凸起状特征的尺寸相对较小（约 80-100 公里宽，20-50 米正起伏），距离可能的变形前缘很远（>400 公里），并且缺乏井紧邻隆起状特征的发育前渊可能表明它代表了一个较小尺度的弯曲高位（“弯曲边缘”），叠加在盆地大型经典前隆起的克拉通边缘上。海平面低位期间隆起顶部浅水生物礁发育，随后隆起迁移和广泛海侵，允许在深盆地中心生长具有重要经济意义的尖峰礁。进一步的地下暗礁勘探应集中在 Onondaga 基底低位期间凸起的投影位置。