A sedimentologic and 14C dating study of five eastern Australian upper continental slope submarine landslides

Sedimentologic and AMS 14C age data are reported for calcareous hemipelagic mud samples taken from gravity cores collected at sites within, or adjacent to five submarine landslides identified with multibeam bathymetry data on the Nerrang Plateau segment and surrounding canyons of eastern Australia's continental slope (Bribie Bowl, Coolangatta-2, Coolangatta-1, Cudgen and Byron). Sediments are comprised of mixtures of calcareous and terrigenous clay (10-20%), silt (50-65%) and sand (15-40%) and are generally uniform in appearance. Their carbonate contents vary between and 17% and 22% by weight while organic carbon contents are less than 10% by weight. Dating of conformably deposited material identified in ten of the twelve cores indicates a range of sediment accumulation rates between 0.017mka-1 and 0.2 mka-1 which are consistent with previous estimates reported for this area. One slide-adjacent core, and four within-landslide cores present depositional hiatus surfaces located at depths of 0.8 to 2.2 meters below the present-day seafloor and identified by a sharp, colour-change boundary; discernable but small increases in sediment stiffness; and a slight increase in sediment bulk density of 0.1 gcm-3. Distinct gaps in AMS 14C age of at least 20ka are recorded across these boundary surfaces. Examination of sub-bottom profiler records of transects through three of the within-slide core-sites and their nearby landslide scarps available for the Coolangatta-1 and Cudgen slides indicate that: 1) the youngest identifiable sediment layer reflectors upslope of these slides, terminate on and are truncated by slide rupture surfaces; and 2) there is no obvious evidence in the sub-bottom profiles for a post-slide sediment layer draped over or otherwise burying slide ruptures or exposed slide detachment surfaces. This suggests that both these submarine landslides are geologically recent and suggests that the hiatus surfaces identified in Coolangatta-1's and Cudgen's within-slide cores are either: a) erosional features that developed after the occurrence of the landslide in which case the hiatus surface age provides a minimum age for landslide occurrence or b) detachment surfaces from which slabs of near-surface sediment were removed during landsliding in which case the post-hiatus sediment dates indicates approximately when landsliding occurred. In either case, it is reasonable to suggest that these two spatially adjacent slides occurred penecontemporaneously approximately 20,000 years ago.

Special issue on the 6th Portuguese Conference on Automatic Control (Controlo 2004)

The Portuguese Association of Automatic Control (APCA) organizes, every two years, the Portuguese Conference on Automatic Control. Its 6th edition (Controlo 2004) was held from 7 to 9 June, 2004 at the University of Algarve, Faro, Portugal, by its Centre for Intelligent Systems (CSI). CONTROLO 2004 International Program Committee (IPC) has decided, from the very start, to ask for submission of full draft papers, to encourage special sessions with well-defined themes, and for student papers. All papers have been reviewed by three separate reviewers. From the 122 contributions submitted, the IPC selected 89 oral papers, 20 special session papers, and 5 student posters. CONTROLO 2004 Technical Programme consists of 33 oral sessions (5 being special sessions) and 1 poster session, covering a broad range of control topics, both from theory and applications. The programme also includes three plenary lectures, given by leading experts in the field, Professors Ricardo Sanz, João Miranda Lemos and Rolf Isermann.

Letter, Greensboro, NC, to George Washington Spencer, Chesterfield, SC, 1890 January 11

This letter is from G. W. Winstead and A. M. Scales to G. W. Spencer regarding Reverend Dr. J. W. Blosser.

Letter, Redwine Jackson Parish, LA, to George Washington Spencer, Chesterfield, SC, 1887 February 21

This letter is from J. J. Spencer to G. W. Spencer.

Letter, Society Hill, SC, to George Washington Spencer, Chesterfield, SC, 1892 February 22

This letter is from the King Iron Bridge Manufacturing Company to G. W. Spencer.