(Table 1) Depth-age points used for initial chronology and adjusted ages of ODP Site 162-982@en

Ocean Drilling Program (ODP) Site 982 in the North Atlantic contains a complete latest Miocene to early Pliocene section that was tuned to the astronomical timescale by correlating the record of gamma ray attenuation (GRA) bulk density to summer insolation at 65°N and the benthic d18O signal to orbital obliquity for the interval from 4.6 to 7.5 Ma. The astronomical tuning of the Site 982 record permits a direct bed-to-bed correlation to the cyclostratigraphy of Messinian sections in the Mediterranean (Krijgsman et al., 1999a, doi:10.1038/23231, 2001, doi:10.1016/S0037-0738(00)00171-8). The benthic d18O signal at Site 982 records a latest Miocene glacial period that lasted from ~6.26 to 5.50 Ma and consisted of 18 glacial-to-interglacial oscillations that were controlled by the 41-kyr cycle of obliquity. Although the intensification of glaciation at 6.26 Ma may have contributed to the restriction of the Mediterranean, it preceded the depositional onset of the lower evaporite unit at 5.96 Ma by some 300 kyr. The transition from Stage TG12 to TG11 at 5.5 Ma marks the end of the latest Miocene glacial period and precedes the Miocene/Pliocene boundary by 170 kyr. Although benthic d18O values are relatively low and d18O of bulk carbonate reaches a minimum at the Miocene/Pliocene boundary at 5.33 Ma, there is no single \"event\" that would indicate deglaciation and sea level rise as the cause of the reflooding of the Mediterranean. We conclude that glacioeustatic changes alone were not responsible for either the start or end of evaporite deposition during the Messinian, suggesting that tectonic or local climate changes in the Mediterranean region were the dominant cause(s).北大西洋的大洋钻探计划（Ocean Drilling Program, ODP）982站位保存有完整的晚中新世至早上新世地层序列。研究人员通过将伽马射线衰减（GRA）体密度记录与北纬65°夏季日照量进行对比，并将4.6~7.5 Ma时段的底栖有孔虫δ¹⁸O信号匹配至轨道斜偏率周期，完成了该地层的天文轨道调谐。本次对982站位地层记录的天文调谐，可实现与地中海墨西拿期地层旋回地层学的层位对层位直接对比（Krijgsman等，1999a，doi:10.1038/23231；2001，doi:10.1016/S0037-0738(00)00171-8）。982站位的底栖有孔虫δ¹⁸O信号记录了一场持续约6.26 Ma至5.50 Ma的晚中新世冰期，该冰期包含18次受4.1万年轨道斜偏率周期调控的冰期-间冰期旋回。尽管6.26 Ma时的冰川作用增强可能推动了地中海的海域局限化，但该事件比下伏蒸发岩单元的沉积起始时间（5.96 Ma）早了约30万年。5.5 Ma时从TG12期向TG11期的转换标志着本次晚中新世冰期的结束，且该转换事件较中新世-上新世界线（5.33 Ma）早17万年。虽然在5.33 Ma的中新世-上新世界线处，底栖有孔虫δ¹⁸O值相对偏低，且整体碳酸盐的δ¹⁸O达到最小值，但并未发现可证明冰川消融与海平面上升是地中海重新被海水淹没诱因的单一“事件”。研究结论认为，仅靠冰川海平面变化无法解释墨西拿期蒸发岩沉积的起始与结束过程，这表明地中海地区的构造活动或局地气候变化才是控制该时期蒸发岩沉积的主导因素。