Timing and extent of late neogene glacials/interglacials using magnetostratigraphy

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Ongoing studies reveal complexities of Earth's climate system.  Realities of global warming (and cooling) affect all people.  Quality of life is strongly allied to economic productivity, environmental health, and population dynamics, and each are affected by or adapt to climate changes. Glaciation and deglaciation of Canada rank amongst the most extreme and fundamental climatic events. Investigations of northern and western regions of Canada reveal extensive suites of sediments containing paleoclimatic proxies extending back 3.0 million years.  Sediments from these regions occur in climate zones that are particularly sensitive to global warming and cooling.   Sedimentary records span a wide spectrum of time scales, ranging from decades to millions of years and are expressed with varying powers of resolution.  A longstanding issue in use of proxy data is correlation of terrestrial and marine records.  Each contains valuable information that can assist in the interpretation of the other.  Magnetostratigraphy affords the best opportunity to correlate sedimentary and fossil records from these two environments, largely because reversals of the Earth's magnetic field are essentially synchronous over the surface of the earth and are independent of the type of sedimentary facies in which the record is held. Ongoing research will focus on: (1) new magnetostratigraphies that will better constrain timing and extent of ice sheets.  Particularly important are paleomagnetic measurements of glacial tills and outwash (direct evidence of glaciation), and paleosols which develop during ice-free periods.  (2)  The magnetic "finger-printing" of preglacial, glacial, and non-glacial sediments in gold and diamond producing areas can  provide valuable information about provenance, age, mode of deposition, and relationship to ice margins, explaining why only some deposits contain placers. (3) In the past 4 years paleosecular records have been developed from rythmites deposited by glacial outburst floods.  Here magnetostratigraphy provides a means to assess length of time over which deposits were laid down, and a better understanding of dynamics of deglaciation.