(Table 1) Ooze/chalk cycles: frequency of occurrence at DSDP Leg 74 Sites

Shallow- to deep-water environments are represented by the sediments and rocks recovered from the Walvis Ridge- Angola Basin transect. These calcareous oozes, chalks, limestones, and volcaniclastic sedimentary rocks are used to define and correlate four lithostratigraphic units. The sediments were deposited in cycles which represent recurring tectonic or Oceanographic events and may be related to climatic fluctuations and orbital perturbations.
Turbidites are the most common and easily identified sedimentary cycle. They are Late Cretaceous to Paleocene in age and are repeated in intervals ranging from thousands to tens of thousands of years. They are also found interbedded between basalt layers. Turbidites are easily distinguished from the other cycles present by their sedimentary structures, mineral composition, alteration products, and physical properties (GRAPE) data. Large-scale turbidites, debris, or slump breccias are found at or just above the Cretaceous/Tertiary boundary and indicate an event of considerable energy possibly related to intense tectonic activity.
Diagenetic cycles, interpreted as small-scale dissolution cycles or sequences produced by biogenic activity, occur in early Paleocene chalks. The recurrence intervals average -20,000 y. but have a wide range of values. Variations in CaCO3 content, color, gradational boundaries, and trace fossil content characterize these sediments. These cycles reflect bottom-water conditions.
Ooze-chalk cycles occur in upper Oligocene to upper Paleocene sediments and represent conditions that once existed at the sediment/water interface where they obtained their diagenetic potential. These oscillations are repeated over tens of thousands of years and may have no modern analogs.
Color variations in sediments at the Cretaceous/Tertiary boundary indicate local fluctuations in oxygen content within the sediments or the water column. This situation lasted for several hundred thousand years and is not repeated elsewhere in the sequence.
Large dissolution cycles are recorded in the sediments at Site 527 that are of middle Miocene and early Oligocene to middle Eocene age. During this time the seafloor at this site appears to have been located at or subsided to a depth occupied by a fluctuating CCD and lysocline.

沃尔维斯海岭-安哥拉盆地剖面采集获得的沉积物与岩石，代表了从浅海至深海的各类沉积环境。这些钙质软泥、白垩、灰岩以及火山碎屑沉积岩，被用于界定并对比四个岩石地层单位。沉积物以旋回形式沉积，这些旋回对应周期性发生的构造或海洋学事件，且可能与气候波动及轨道扰动存在关联。
浊积岩是最为常见且易于识别的沉积旋回。其形成时代为晚白垩世至古新世，旋回间隔介于数千年至数万年之间，且常夹于玄武岩层之间。可通过沉积构造、矿物组成、蚀变产物以及物理性质（GRAPE）数据，将浊积岩与其他沉积旋回清晰区分。在白垩/古近纪界线处或其紧邻上方，可见大型浊积岩、碎屑岩或滑塌角砾岩，这指示了一场能量极强的事件，可能与强烈的构造活动相关。
成岩旋回被解释为由生物作用形成的小型溶解旋回或序列，发育于古新统早期的白垩岩层中。其旋回重现间隔平均约为2万年，但数值分布范围较广。碳酸钙（CaCO₃）含量、颜色、渐变接触界线以及遗迹化石组成的变化，是这类沉积物的典型特征，此类旋回可反映底层水体环境。
软泥-白垩旋回发育于渐新统上部至古新统上部的沉积物中，其代表了沉积物-水界面处曾经存在的沉积环境，这类界面正是沉积物获得成岩潜能的场所。此类旋回振荡以数万年为周期重复出现，且可能不存在现代类似物。
白垩/古近纪界线处沉积物的颜色变化，指示了沉积物内部或水体柱中局部的氧含量波动。这一状况持续了数十万年，且在该剖面的其他层位中并未重复出现。
在527站位的中中新统、早渐新世至中始新统沉积物中，记录有大型溶解旋回。在此期间，该站位的海底原本处于或沉降至一个随方解石补偿深度（Calcite Compensation Depth）与溶跃面（lysocline）波动变化的深度区间。