Pollen record of sediment core MD99-2348

Palynology has been performed for the first time on Late Quaternary sediments of the Gulf of Lions. The aim is both to tighten the chronology of seismic profiles in the region, and to elucidate the vegetation of southern France during the Last Climatic Cycle.
Four cores, taken on the shelf, mostly record Marine Isotope Stages (MIS) 1 and 2 and part of MIS 3 and MIS 5. The latter sediments might have been preserved in a paleodepression on the emergent shelf between the Rhône and the Hérault rivers. It would explain their preservation against transgression and regression erosions of more recent stages.
This study also provides a synthesis of palynological continental data collected during the last 40 years in southern Europe. Preliminary comparisons made between the latter and new marine data demonstrate that refugia of Picea and Abies existed in southern France during MIS 3 and MIS 2. The dynamics of Artemisia, deciduous Quercus and Corylus, Abies and finally Fagus is also reconstructed for the last deglaciation. First results obtained in the Gulf of Lions confirm and complete that synthesis.

本研究首次针对里昂湾（Gulf of Lions）晚第四纪沉积物开展孢粉学（Palynology）研究。研究目标兼具双重意义：一是完善该区域地震剖面的年代学框架，二是阐明末次气候旋回期间法国南部的植被特征。
本次采集的4支陆架岩芯，主要记录了海洋同位素阶段（Marine Isotope Stages, MIS）1、2以及部分MIS 3和MIS 5沉积序列。MIS 5阶段的沉积物可能保存于罗纳河（Rhône）与埃罗河（Hérault）之间出露陆架上的古洼地中，该古洼地可解释其为何能免受晚近阶段海侵与海退的侵蚀破坏。
本研究同时对南欧地区近40年来收集的孢粉学陆地数据进行了综合梳理。将该类历史数据与本次新获得的海洋孢粉数据开展初步对比后发现，在MIS 3和MIS 2时期，法国南部存在云杉属（Picea）与冷杉属（Abies）的冰期避难所。本研究还重建了末次冰消期期间蒿属（Artemisia）、落叶栎属（Quercus）、榛属（Corylus）、冷杉属以及山毛榉属（Fagus）的植被动态变化。里昂湾的初步研究结果验证并完善了上述综合结论。