(Table 1) Revised and corrected composite depth sections of ODP Site 160-964

High-resolution color reflectance records of KC01 and KC01B (Calabrian Ridge, Ionian Sea) are presented and compared with a modified spliced high-resolution color reflectance record of Ocean Drilling Program (ODP) Site 964. This comparison revealed that KC01B is characterized by intensive deformation between ~27 and 28.5 m piston depth and that some sapropels are tectonically reduced in thickness. Moreover, the piston coring has caused considerable stretching in the top of KC01 and KC01B. Using a new splice of ODP Site 964 as guide, previous astronomical tuned timescales of KC01B and ODP Site 964 were evaluated. This evaluation resulted in a new sapropel-based astronomical timescale for the last 1.1 Myr. The new timescale implies a much more uniform change in sedimentation rate for the Ionian Sea cores. Two prominent excursions to lighter values in the d18O record of the planktonic foraminiferal species Globigerinoides ruber occur during marine isotopic stages 12 and 16 applying the new timescale. These shifts correspond with maxima in obliquity and are punctuated by minima in the precession cycle. They are absent in global ice volume records and are interpreted as reflecting a (summer) low-salinity surface water lens that floats on top of extremely saline intermediate and deep waters at times of the very low sea levels during these glacial periods. All biostratigraphic and magnetostratigraphic events found in KC01B and ODP Site 964 were re-dated according to the new timescale, and the ages of 33 tephra layers were reviewed. The new ages for the Calabrian Ridge 2 and 3 magnetic events in the Brunhes are concordant with minima in the global Sint800 composite record, derived from worldwide deep-sea records of relative paleointensity and have been attributed to the Big Lost and La Palma excursions, respectively.

本文呈现了爱奥尼亚海卡拉布里亚海岭KC01与KC01B的高分辨率颜色反射率记录，并将其与经修正拼接的大洋钻探计划（Ocean Drilling Program, ODP）964站位的高分辨率颜色反射率记录进行对比。对比结果显示，KC01B在活塞取芯深度约27至28.5米区间内存在强烈构造变形，且部分腐泥层（sapropel）的厚度因构造作用发生减薄。此外，活塞取芯（piston coring）作用对KC01与KC01B的顶部地层造成了显著拉伸。以新拼接的ODP 964站位记录为参照，本文对KC01B与ODP 964站位原有的天文调谐时间标尺（astronomical tuned timescales）进行了评估，最终为过去110万年建立了一套基于腐泥层的全新天文时间标尺。新时间标尺表明，爱奥尼亚海岩芯的沉积速率变化更为均匀。应用新时间标尺后，浮游有孔虫（planktonic foraminifera）红拟抱球虫（Globigerinoides ruber）的氧同位素δ¹⁸O记录中，出现两次显著的低值偏移事件，分别对应海洋同位素阶段（marine isotopic stages）12与16。这两次偏移与黄赤交角（obliquity）的峰值相对应，且被岁差（precession）周期的极小值所分隔。此类偏移在全球冰量记录中并未出现，其被解释为：在这些冰川时期海平面极低之时，表层存在一层夏季低盐水透镜体，漂浮于高盐度中层水与深层水之上。本文依据新时间标尺，对KC01B与ODP 964站位中发现的所有生物地层（biostratigraphic）与磁地层（magnetostratigraphic）事件进行了重新定年，并对33层火山灰层（tephra layers）的年龄进行了厘定。布容正向极性时（Brunhes）内卡拉布里亚海岭2号与3号磁极性事件的新年龄，与基于全球深海相对古强度记录构建的Sint800综合记录（Sint800 composite record）的极小值相一致，且分别被归因于大失落地磁漂移（Big Lost excursion）与拉帕尔玛地磁漂移（La Palma excursion）。