8 Deep-Sea Sediments - Patterns, Processes,
and Stratigraphic Methods
8.1 Background
As mentioned in the introduction deep-sea deposits were first explored in a comprehensive fashion during the British Challenger Expedition (1873-1876). Many thousands of samples were subsequently studied by John Murray (1841-1914), naturalist
on the Challenger. He and his co-worker A. F. Renard published a weighty report on
the results, which laid the foundation for all later work in this field of research. The
first great step beyond Murray's work were the results of the German Meteor Expedition, almost half a century later (1927-1929). A new branch of oceanography started
with the recovery of long cores by the Swedish Albatross Expedition (1947-1949),
that is, Pleistocene oceanography. It revolutionized our understanding of the great Ice
Ages. Another great step came in 1968 with GLOMAR Challenger and the Deep Sea
Drilling Project, which provided the samples for Tertiary and Cretaceous ocean history.
We shall treat ocean history separately (Chap. 9). Here we summarize the presentday patterns, as they appear in surface samples and in box cores (Fig. 8.1), and
discuss some of the important processes of sedimentation, as well as aspects of
dating.
8.2 Inventory and Overview
S.2.1 Sediment Types and Patterns. Let us first make an inventory of the types of
sediment that are present (Table 8.1). The main types are already familiar from the
last chapter. Pelagic clays are extremely fine-grained lithogenous and volcanogenic
deposits. Oozes consist of biogenous materials: shells of planktonic foraminifers,
radiolarians, coccolithophores, and diatoms. Hemipelagic deposits are the same as
clays and oozes except with large admixtures of shelf-derived sediment and of continental material. The list in Table 8.1 is not exhaustive, but includes the bulk of types
found on the sea floor. Categories may vary between authors.
The terms "ooze" and "clay" were introduced by Murray to describe pelagic
deposits ("Globigerina ooze" and "red clay"). Modem pelagic clays of the deep sea
are usually reddish brown (rather than red).
The broad outlines of deep-sea sediment patterns are rather simple (Fig. 8.2). The
major facies boundary in deep-sea deposits is the calcite compensation depth, that is,
and Stratigraphic Methods
8.1 Background
As mentioned in the introduction deep-sea deposits were first explored in a comprehensive fashion during the British Challenger Expedition (1873-1876). Many thousands of samples were subsequently studied by John Murray (1841-1914), naturalist
on the Challenger. He and his co-worker A. F. Renard published a weighty report on
the results, which laid the foundation for all later work in this field of research. The
first great step beyond Murray's work were the results of the German Meteor Expedition, almost half a century later (1927-1929). A new branch of oceanography started
with the recovery of long cores by the Swedish Albatross Expedition (1947-1949),
that is, Pleistocene oceanography. It revolutionized our understanding of the great Ice
Ages. Another great step came in 1968 with GLOMAR Challenger and the Deep Sea
Drilling Project, which provided the samples for Tertiary and Cretaceous ocean history.
We shall treat ocean history separately (Chap. 9). Here we summarize the presentday patterns, as they appear in surface samples and in box cores (Fig. 8.1), and
discuss some of the important processes of sedimentation, as well as aspects of
dating.
8.2 Inventory and Overview
S.2.1 Sediment Types and Patterns. Let us first make an inventory of the types of
sediment that are present (Table 8.1). The main types are already familiar from the
last chapter. Pelagic clays are extremely fine-grained lithogenous and volcanogenic
deposits. Oozes consist of biogenous materials: shells of planktonic foraminifers,
radiolarians, coccolithophores, and diatoms. Hemipelagic deposits are the same as
clays and oozes except with large admixtures of shelf-derived sediment and of continental material. The list in Table 8.1 is not exhaustive, but includes the bulk of types
found on the sea floor. Categories may vary between authors.
The terms "ooze" and "clay" were introduced by Murray to describe pelagic
deposits ("Globigerina ooze" and "red clay"). Modem pelagic clays of the deep sea
are usually reddish brown (rather than red).
The broad outlines of deep-sea sediment patterns are rather simple (Fig. 8.2). The
major facies boundary in deep-sea deposits is the calcite compensation depth, that is,