Torrance State Hospital

Sediment magnetic and geochemical studies of a suite of deep‐sea sediment cores from the Blake/Bahama Outer Ridge (BBOR), North Atlantic Ocean, have identified two current redox boundaries in surficial (Holocene), carbonate‐rich sediments over much of the BBOR. The upper Mn+4/Mn+2 redox boundary is associated with a spike in the concentration of solid‐phase Mn (as MnO2); the lower Fe+3/Fe+2 redox boundary is associated with a spike in the concentration of solid‐phase Fe (as goethite, αFeOOH). Over much of the BBOR, high sediment magnetic intensities occur in surficial, carbonate‐rich sediments associated with these redox boundaries and lower intensities occur in deeper (late Pleistocene) carbonate‐poor sediments. This relationship is opposite to that expected if sediment magnetism simply reflects the clastic (noncarbonate) sediment fraction. The surficial, high sediment magnetic intensities are due primarily to the following two factors: (1) magnetic mineral authigenesis associated with early diagenesis and (2) the presence of abundant <0.1 μm magnetite crystals interpreted to be bacterial magnetosomes. Magnetosomes are almost absent in the late Pleistocene low‐carbonate sediments owing, most likely, to local Pleistocene environmental conditions (high clastic flux, low organic flux) which did not favor their growth. The sediment natural remanent magnetization is strongly correlated with the sediment clastic fraction and is relatively unaffected by early diagenesis and the presence of abundant bacterial magnetite. If this is typical, bacterial magnetite may be more abundant in nature but less important to sediment paleomagnetic records, than previously thought.

For the past century educators have been forced to hold back from making needed changes and advances in the instructional programs of their schools in order to give tradition-bound public an opportunity to catch up with modern educational thought. There is much truth in the statement that a school can go no further than it can take its parents. Unfortunately, increased public relations activity in the form of parent-study groups, P.T.A. programs, school publications, and even newspaper and magazine articles has failed to materially narrow the gap between the research-founded knowledges of the professional educator and the tradition-biased prejudices of the lay public. Typical of this understanding-lag are today's pressures that all children must be involved in cut-throat intellectual competition if the gifted are to be challenged, or that the chief failure of the academically-slow student is lack of effort and appreciation. This conflict between enlightened theory and unenlightened opinion has always been, and will continue to be, an obstacle to educational progress. Moreover, it will remain major deterrent unless educators exercise some bold imagination in pursuing solution.