Mass-accumulation rates for the non-authigenic, inorganic, crystalline, eolian component of sediments recovered at DSDP Sites 62-464 to 62-466

The mass-accumulation rate (MAR) of the non-authigenic, inorganic, crystalline component of deep-sea sediments from the Pacific aseismic rises apparently reflects influx of eolian sediment. The eolian sediment usually is dominated by volcanic material, except during glacial times. Sediments from Hess Rise provide a discontinuous record of eolian MARs. During Albian to Cenomanian time, the influx of volcanic material was fairly high (0.35-0.6 g/cm**2/10**3 yr), recording the latest stages of the Albian volcanism that formed Hess Rise. From the Campanian through the Paleocene, influx of eolian sediment was low, averaging 0.03 g/cm**2/10**3 yr. None of the four Hess Rise drill sites show evidence of the Late Cretaceous volcanic episode recorded at many sites now in the equatorial to subtropical Pacific. Pliocene to Pleistocene samples record a peak in volcanic influx about 4 to 5 m.y. ago, which has been well documented elsewhere. The several-fold increase in eolian accumulation rates elsewhere which are correlated with the onset of severe northernhemisphere glaciation 2.5 m.y. ago is not obvious in the Hess Rise data.

太平洋无震海隆（Pacific aseismic rises）深海沉积物（deep-sea sediments）中非自生无机结晶组分的质量堆积速率（mass-accumulation rate, MAR），显然反映了风成沉积物（eolian sediment）的输入通量。风成沉积物通常以火山物质为主，冰期（glacial times）除外。赫斯海隆（Hess Rise）的沉积物记录了不连续的风成MAR序列。在阿尔布期至森诺曼期，火山物质输入通量较高（0.35~0.6 g/cm²/10³ yr），记录了形成赫斯海隆的阿尔布期火山活动的最晚阶段。自坎潘期至古新世，风成沉积物输入通量较低，平均值为0.03 g/cm²/10³ yr。赫斯海隆的4个钻探站位均未发现晚白垩世火山事件的证据，而该事件在现今赤道至亚热带太平洋的多数站位中均有记录。上新世至更新世的样品记录了约4~5百万年前的火山输入峰值，这一现象在其他区域已有充分研究。此前研究表明，2.5百万年前北半球剧烈冰川作用启动时，全球多数区域的风成堆积速率出现数倍增长，但赫斯海隆的钻探数据并未显现这一变化。