Occurence of marine palynomorphs of sediment core CRP-1 (Table 1)

The first core of the Cape Roberts Project, CRP-1, penetrated a Quaternary and lower Miocene section rather than the anticipated Palaeogene sediments. Initial palynologic study was conducted at the Crary Science and Engineering Laboratory, McMurdo Station, concurrent with drilling. Rapid and environmentally safe sample processing was made possible by the use of a focused microwave digestion unit that scrubbed acid fumes. In situ and/or reworked dinocysts (dinoflagellate cysts), acritarchs (leiospheres and acanthomorphs), and prasinophyte phycomata are present in the 35 samples studied. Overall, the CRP-1 assemblages are similar to Arctic marine palynomorph assemblages that are used there as ice margin indicators. Some of the acanthomorph acritarchs recovered from the CRP-1 core closely resemble cysts of extant Antarctic autotrophic sea-ice dinoflagellates. It is possible that some of these acanthomorphs are actually dinocysts, and could be used as indicators of sea-ice conditions similar to today.
Most of the in situ marine palynomorphs are undescribed taxa and thus are presently of little biostratigraphic value. Dating of the core was based on diatom, palaeomagnetic and strontium isotope studies. The upper 43.55 mbsf of the core are Quaternary in age and the rest of the core, down to the bottom at 147.69 mbsf, is of early Miocene age. Although not biostratigraphically significant, the dinocysts are the first in situ Quaternary and Miocene dinocysts reported from East Antarctica, and constitute the most diverse assemblage recovered from any firmly dated Neogene section from Antarctica. In addition, they confirm that cyst-producing dinoflagellates were present in Antarctic waters during the Neogene and Quaternary.
The core can be divided into three intervals based on their palynomorph assemblages (Quaternary, 0-43.55 mbsf; lower Miocene, 43.55-99.10 mbsf; and lower Miocene, 99.10- 147.69 mbsf). The distinctive palynomorph assemblages are interpreted to reflect changing climatic conditions that prevailed at the time of deposition. Overall, conditions appear to have deteriorated up-section.

开普罗伯茨项目（Cape Roberts Project）的首个钻孔CRP-1所揭露的地层为第四纪与中新世早期沉积，而非预期的古近纪沉积物。钻探同步开展的初始孢粉学研究于麦克默多站（McMurdo Station）克拉里科学与工程实验室（Crary Science and Engineering Laboratory）完成。实验采用可净化酸雾的聚焦微波消解装置，实现了样品的快速且环境友好的处理流程。在所分析的35件样品中，产出了原地和/或再沉积甲藻孢囊（dinocysts, dinoflagellate cysts）、疑源类（acritarchs，含光滑疑源类leiospheres与刺丝囊疑源类acanthomorphs）以及绿藻藻孢囊（prasinophyte phycomata）。整体而言，CRP-1的孢粉型组合与用作冰缘环境指示标志的北极海洋孢粉型组合高度相似。从CRP-1岩芯中回收的部分刺丝囊疑源类与现生南极自养型海冰甲藻的孢囊形态极为相近，推测其中部分类群实际为甲藻孢囊，可作为与现今相似的海冰环境的指示标志。

多数原地产出的海洋孢粉型类群尚未被正式描记，因此目前其生物地层学应用价值有限。该岩芯的年代学定年基于硅藻、古地磁与锶同位素分析完成。岩芯上部43.55海底以下米（meters below seafloor, mbsf）段为第四纪沉积，直至147.69海底以下米处的下部层位则属于中新世早期。尽管甲藻孢囊本身不具备显著的生物地层学意义，但它们是东南极洲首个被报道的原地产出第四纪与中新世甲藻孢囊，同时也是南极地区所有经精确定年的新近纪沉积序列中物种多样性最高的孢粉型组合。此外，该发现证实了在新近纪与第四纪期间，南极海域中存在可产生孢囊的甲藻种群。

依据孢粉型组合特征，该岩芯可划分为三个层段：第四纪（0~43.55 mbsf）、中新世早期（43.55~99.10 mbsf）以及中新世早期（99.10~147.69 mbsf）。独特的孢粉型组合被认为反映了沉积时期气候条件的动态演变，整体来看，向上的地层序列对应的环境条件呈逐步恶化趋势。