Epilog
We have attempted, in this brief survey of sea floor studies, to show where we have
been and where we are now. But where are we going? An answer can only be
tentative, of course. Just like other fields in the earth sciences, marine geology has
experienced an exponential expansion of knowledge in the last two decades. This
knowledge explosion is largely driven by technological developments: satellites, submarines, deep-sea drilling, all sorts of remote sensing devices, highly sophisticated
laboratory equipment, and electronic information handling. Also, large-scale integration of geology with physics, chemistry, and biology has continued at a rapid pace,
with new specialities arising from this cross-fertilization in quick succession, and
recombining across disciplines to attack common targets: messages from the mantle,
ridge-crest processes, fluid circulation in the margins, large-scale extinction, global
environmental change.
The safe prediction is to postulate a continuation of these trends resulting in
ever-greater specialization in technological skills, and in increased cooperation across
disciplines when focusing these skills on studying sea-floor processes and on reconstructing sea-floor history, as well as the history of ocean and climate.
What were the "hot" topics of research and discussion in the last decade? How do
they stack up against the topics of the two preceding decades?
Sea-floor studies of the 1960s were characterized by the overwhelming success of
geophysics: discovery of the grand motions of the continents and the sea floor by
continuous echo sounding (for bathymetry), by the mapping of earthquake foci and
heat flow, by seismic profiling, and especially by the mapping of paleomagnetism.
The 1970s saw a great expansion of geologic knowledge based on testing and
applying the new paradigm of plate tectonics, the crowning achievement of marine
geophysics. This expansion owed much to deep-sea drilling, which provided the
"ground truth" for sea-floor spreading, and made available an enormous amount of
rocks and sediments, the likes of which had not been seen before, or only in bits and
pieces. In rapid succession we gained an understanding of the main structural features
of the sea floor, of processes involved in creating and destroying sea floor, and of the
growth of continents through mountain-building in subduction zones. Geochemistry
took the lead in starting to unravel messages from the mantle, in the shape of isotopic
composition and rare earth content of volcanic products in different settings, from
basement rock to island arcs to mantle plumes. These messages, combined with
large-scale mapping of heat flow, magnetism, and gravity, and seismologic modeling,
are providing glimpses of the structure of the mantle, and the character of the convec-
We have attempted, in this brief survey of sea floor studies, to show where we have
been and where we are now. But where are we going? An answer can only be
tentative, of course. Just like other fields in the earth sciences, marine geology has
experienced an exponential expansion of knowledge in the last two decades. This
knowledge explosion is largely driven by technological developments: satellites, submarines, deep-sea drilling, all sorts of remote sensing devices, highly sophisticated
laboratory equipment, and electronic information handling. Also, large-scale integration of geology with physics, chemistry, and biology has continued at a rapid pace,
with new specialities arising from this cross-fertilization in quick succession, and
recombining across disciplines to attack common targets: messages from the mantle,
ridge-crest processes, fluid circulation in the margins, large-scale extinction, global
environmental change.
The safe prediction is to postulate a continuation of these trends resulting in
ever-greater specialization in technological skills, and in increased cooperation across
disciplines when focusing these skills on studying sea-floor processes and on reconstructing sea-floor history, as well as the history of ocean and climate.
What were the "hot" topics of research and discussion in the last decade? How do
they stack up against the topics of the two preceding decades?
Sea-floor studies of the 1960s were characterized by the overwhelming success of
geophysics: discovery of the grand motions of the continents and the sea floor by
continuous echo sounding (for bathymetry), by the mapping of earthquake foci and
heat flow, by seismic profiling, and especially by the mapping of paleomagnetism.
The 1970s saw a great expansion of geologic knowledge based on testing and
applying the new paradigm of plate tectonics, the crowning achievement of marine
geophysics. This expansion owed much to deep-sea drilling, which provided the
"ground truth" for sea-floor spreading, and made available an enormous amount of
rocks and sediments, the likes of which had not been seen before, or only in bits and
pieces. In rapid succession we gained an understanding of the main structural features
of the sea floor, of processes involved in creating and destroying sea floor, and of the
growth of continents through mountain-building in subduction zones. Geochemistry
took the lead in starting to unravel messages from the mantle, in the shape of isotopic
composition and rare earth content of volcanic products in different settings, from
basement rock to island arcs to mantle plumes. These messages, combined with
large-scale mapping of heat flow, magnetism, and gravity, and seismologic modeling,
are providing glimpses of the structure of the mantle, and the character of the convec-