Paleomagnetic Record, Texture, and Mineralogy of Late Quaternary Sediments, Baffin Island Fiords, N.W.T., Canada^*

* Sedimentology of Arctic Fiords Experiment (S.A.F.E.) Contribution No. 9.

Abstract

Seven piston cores between 4 and 11 m in length were taken from McBeth, Itirbilung, Tingin, and Cambridge fiords and from Frobisher Bay, Baffin Island. The sediments consist of massive, laminated, and bioturbated muds, alternating silt and sand beds, or discrete sand beds. Ice-rafted sediments occur throughout most cores. Mica, quartz, and feldspar are the dominant clay-sized minerals. Radiocarbon control on core chronology is limited but suggests that all cores date from the last 10,000 yr. Sediment accumulation, uncorrected for density, varies between 5 and 0.25 m ka⁻¹. Our sampling interval for paleomagnetic purposes varied between 3 and 5 cm providing a time-specificity of between 6 and 200 yr per sample. Studies of both natural remnant magnetization (NRM) and postdepositional detrital remnant magnetization (PDRM) indicate that, in general, these sediments are suitable for paleoinclination and paleodeclination studies. However, certain sections of some cores have paleomagnetic records that are extremely noisy. The ¹⁴C-dated core, HU82-T13, has a series of significant oscillations in the paleoinclination record that provides a reasonable match to the “master” North American secular variation curve. The presence of a strong secular variation record in at least some of the cores indicates that paleomagnetic studies may be important to “fine tune” Holocene core chronologies. As a test of this curve matching between the paleoinclination record of HU82-T13 and undated core HU82-MC7 is used to propose a sediment accumulation history for the latter core.