none 10.1144/SP373.19 Geological Society of London Geological Society of London 1881 61926076 65091 2024072310094500277 10.1144 2024-07-23T19:38:55Z 2013-04-26T00:01:47Z 1 Geological Society, London, Special Publications SP 0305-8719 2041-4927 07 02 2013 01 2013 373 1 Emilio Herrero-Bervera Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, HI 96822, USA Luigi Jovane Department of Geology, Western Washington University, Bellingham, WA 98225, USA Instituto Ocenográfico, Universidade de São Paulo, São Paulo 05508-120, Brazil Abstract We have studied the rock magnetic and palaeomagnetic properties of a 41 m long core (Hole M0058A) recovering calcareous sediments located seaward of Noggin Reef, offshore Queensland, Australia to decipher the magnetostratigrapy of the site. We deployed 1 cm 3 samples at every 10 cm down-core and subsampled the core by means of U-channels in order to obtain a continuous record. Stepwise alternating field demagnetization from natural remanent magnetization to 80 mT showed that the characteristic remanent magnetization was isolated at low demagnetization fields between 0 and 15 mT. We conducted magnetic granulometry analyses and Curie point determinations. The low-field v. temperature analyses indicate the presence of Ti-poor magnetite with Curie points from 560 to 563 °C. Hysteresis loop experiments were performed. The results show M rs / M s and H cr / H c ratios corresponding to single domain to multi-domain and super-paramagnetic to single domain ranges. Both discrete and continuous inclination results indicate a remarkable correlation of three excursional inclinations occurring during intervals of low intensity of magnetization closely corresponding to the Laschamp ( c. 41 ka), Skálamælifell ( c. 94 ka) and Blake ( c. 115–120 ka) ‘aborted reversals,’ and indicate that the base of the core is much older than the Blake excursion. 04 25 2013 01 2013 279 291 10.1144/SP373.19 https://doi.org/10.15223/policy-002 10.1144/SP373.19 https://www.lyellcollection.org/doi/10.1144/SP373.19 https://www.lyellcollection.org/doi/pdf/10.1144/SP373.19 https://pubs.geoscienceworld.org/books/book/1857/chapter/107606767/on-the-palaeomagnetic-and-rock-magnetic https://pubs.geoscienceworld.org/UrlRedirectHandler.ashx?routename=books&chapterdoi=10.1144/SP373.19&request=chapter 10.2973/odp.proc.sr.133.261.1993 10.2973/odp.proc.sr.133.285.1993 10.1038/scientificamerican1281-58 10.1016/j.epsl.2006.01.021 10.1029/2001JB000487 10.2204/iodp.proc.325.106.2011 10.1038/20420 10.1029/2002GL014963. 10.1111/j.1365-246X.1992.tb04634.x 10.1098/rsta.1997.0089 10.1016/0031-9201(87)90034-3 10.1111/j.1365-246X.1994.tb03987.x 10.1111/j.1365-246X.1997.tb04506.x 10.5636/jgg.36.45 10.1016/j.epsl.2011.08.007 10.1111/1758-2229.12000 10.1029/GM128p0051 10.1111/j.1365-246X.1980.tb02601.x 10.1017/CBO9780511535635 10.1016/j.epsl.2010.03.002 10.1029/95JB02811 10.1007/978-1-4020-4423-6_266 10.1016/S0012-821X(03)00701-5 10.1038/366234a0 10.1038/nature03674 10.1016/j.epsl.2008.07.056 10.1016/0012-821X(91)90122-X