Described are concepts involved with the formation and actions of the Mid-Ocean Ridge. Sea-floor spreading, the magma supply model, discontinuities, off-axis structures, overlaps and deviation, and aquatic life are discussed. (CW)

Describes a simple application of the seismic refraction method, using a two layer system, and extending it to a three layer system. (GA)

Discusses the destabilizing influences that affect feedback systems in the earth and trigger disorganization. Presents information that integrates mantle degassing with feed-back systems, and the Sun-Earth-Space energy flow system which is the primary source of energy that drives the Earth's biosphere. (RT)

Describes a demonstration of P and S (longitudinal and transverse waves), using students' bodies as media, to explain seismic waves in a geology course. (GA)

Continental crust underlies the continents, their margins, and also small shallow regions in oceans. The nature of the crust (much older than oceanic crust) and its dynamics are discussed. Research related to and effects of tectonics, volcanism, erosion, and sedimentation on the crust are considered. (JN)

Discussed is the physicists' impact on the revolution in the earth sciences particularly involving the overthrow of the fixist notions in geology. Topics discussed include the mobile earth, the route to plate tectonics, radiometric dating, the earth's magnetic field, ocean floor spreading plate boundaries, infiltration of physics into geology and…

Considers cosmic rays and relationship to fields of geophysics and astrophysics. Reveals importance of solar eclipses in the study of cosmic radiation. (CP)

Intended as a supplement to undergraduate college geography courses, this resource paper describes the science of geomorphology, the study of landforms. The general aim of this paper is to review the developments which have made geomorphology what it is today, to indicate its present character and status, to demonstrate its increasingly close…

The nature of the earth's core is described. Indirect evidence (such as that determined from seismological data) indicates that it is an iron alloy, solid toward its center but otherwise liquid. Evidence also suggests that it is the turbulent flow of the liquid that generates the earth's magnetic field. (JN)

The nature and dynamics of the earth's mantle is discussed. Research indicates that the silicate mantle is heated by the decay of radioactive isotopes and that the heat energizes massive convention currents in the upper 700 kilometers of the ductile rock. These currents and their consequences are considered. (JN)

Discusses magnetic polarity stratigraphy as a tool for correlation of fossiliferous terrestrial deposits. Explains the strengths, weaknesses, limitations, preferred conditions, sampling, laboratory analysis, and applications of this technique. A table of paleomagnetic studies on vertebrate-bearing terrestrial sections arranged by age and locality…

Describes the three processes of folding in rocks: buckling, bending, and passive folding. Discusses how geometrical properties and strain distributions help to identify which processes produce natural folds, and also provides information about the mechanical properties of rocks, and the sense of shear in shear zones. (TW)

The earth's oceanic crust is created and destroyed in a flow outward from midocean ridges to subduction zones, where it plunges back into the mantle. The nature and dynamics of the crust, instrumentation used in investigations of this earth feature, and research efforts/findings are discussed. (JN)

Discussed are some of the reasons for earthquakes which occur in stable crust away from familiar zones at the ends of tectonic plates. Crust stability and the reactivation of old faults are described using examples from India and Australia. (CW)