Sea-level control of New Jersey margin architecture: Palynological evidence from Integrated Ocean Drilling Program Expedition 313
Sea-level control of New Jersey margin architecture: Palynological evidence from Integrated Ocean Drilling Program Expedition 313
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DOI：
10.1130/ges00853.1
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发表时间：
2013-12
期刊：
影响因子：
2.5
通讯作者：
F. McCarthy;M. Katz;U. Kotthoff;J. Browning;K. Miller;Ryan Zanatta;Ross H. Williams;Matea Drljepan;S. Hesselbo;C. Bjerrum;G. Mountain
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作者：
F. McCarthy;M. Katz;U. Kotthoff;J. Browning;K. Miller;Ryan Zanatta;Ross H. Williams;Matea Drljepan;S. Hesselbo;C. Bjerrum;G. Mountain
综合海洋钻探计划远征313号在新泽西州浅陆架的M0027A和M0029A孔恢复了中新世层序，其中含有典型的耐酸有机成分。每个层序内的孢粉相反映了中新世陆源与自生通量的变化，这些变化与海平面变化有关。陆源地貌与海相地貌、抗氧化地貌与易感地貌的高比率与地震层序边界有关，这与它们在低海平面时期产生的层序边界不整合的解释相一致。通过比较孢粉与岸线的距离估算与有孔虫数据得出的古深度估算，可以重建两个地点的相对海平面。用恐龙囊生物地层学确定的年龄与其他年代地层学指标一致，使层序边界与中新世氧同位素（Mi）事件相关联。来自花粉记录的古气候证据支持氧同位素数据中看到的全球气候变化。虽然时间控制相对粗糙，但在相对深水中沉积的厚层序中可以看到米兰科维奇尺度的周期性，这些层序存在大量的调节，例如在29号遗址（中新世中期气候最佳）的朗始期早期。因此，孢粉学分析支持了长期以来的假设，即冰川游动是控制大陆边缘构造的主要过程。
Integrated Ocean Drilling Program Expedition 313 recovered Miocene sequences at Holes M0027A and M0029A on the New Jersey shallow shelf that contain a characteristic acid-resistant organic component. The palynofacies within each sequence reflects variations in terrigenous versus authigenic flux through the Miocene that are associated with sea-level change. Very high ratios of terrigenous versus marine palynomorphs and of oxidation-resistant versus susceptible dinocysts are associated with seismic sequence boundaries, consistent with their interpretation as sequence-bounding unconformities generated at times of low sea level. Comparison of palynological distance from shoreline estimates with paleodepth estimates derived from foraminiferal data allows relative sea level to be reconstructed at both sites. Ages assigned using dinocyst biostratigraphy are consistent with other chronostratigraphic indicators allowing sequence boundaries to be correlated with Miocene oxygen isotope (Mi) events. Paleoclimatic evidence from the pollen record supports the global climate changes seen in the oxygen isotope data. Although chronological control is relatively crude, Milankovitch-scale periodicity is suggested for parasequences visible in thick sequences deposited in relatively deep water where substantial accommodation existed, such as during the early Langhian at Site 29 (Middle Miocene Climatic Optimum). Palynological analysis thus supports the long-held hypothesis that glacioeustasy is a dominant process controlling the architecture of continental margins.