{
 "schema": "ausmt-survey-metadata",
 "version": "0.1",
 "survey_id": "carpentaria-north-1995",
 "title": "Carpentaria Array 1995 (Northern Sub-array)",
 "dates": {
  "coverage": {
   "year_start": 1995,
   "year_end": 1995
  }
 },
 "abstract": "From the Southwest Queensland Anomaly of 1976 - 77, Dennis Woods and Frederick (Ted) Lilley proposed that the current concentrated along the western edge of the Eromanga Basin might continue north to form a conducting path across the continent, and Francois Chamalaun and Charlie Barton, reading the AWAGS array of 1989 - 90, suggested that path extended north into the Gulf of Carpentaria. In 1995 the Australian National University and Flinders University, under the ANU Institute of Advanced Studies' collaboration scheme and led in the field by Ted Lilley and Francois Chamalaun, set out to map that northward extension with forty-three magnetometer sites across northern Queensland at an average spacing of 100 km. The work went in two stages with one fleet of Flinders digital fluxgate magnetometers, twenty-one of them in the first stage, recording three components once a minute and referenced throughout to the Australian Geological Survey Organisation's Charters Towers observatory. Liejun Wang analysed the results for his doctoral thesis.\nThe first stage ran from June to August 1995 across north-west Queensland and the Gulf country, the twenty sites carried here reaching from the Mount Isa Inlier at Urandangi and Camooweal east to Julia Creek and Canobie on the Great Artesian Basin and north to Doomadgee and Normanton near the Gulf. In the raw magnetograms, before any modelling, the vertical variations during a substorm on 16 July 1995 were strongly enhanced at the inlier sites, subdued at Normanton and at the site AusMT reads as Cannington, and reversed in phase at the basin sites, a pattern that indicates a north-south zone of enhanced conductivity between the Mount Isa region and the basin. Robust processing against the observatory gave induction arrows that pointed east on one side of a line of zero response and west on the other, and Wang's northernmost inversion profile, running through Hells Gate, Doomadgee and Alexandra River some 40 km south of the Gulf, found shallow good conductors of 1 to 5 ohm m above 4 km depth, a broad conductive zone connecting north to the seawater of the Gulf. The two stages together established the Carpentaria Anomaly as a linear structure of roughly north-south strike along the boundary between the Mount Isa Inlier and the basin, within the basin sediments and most likely saline aquifers, joined to the Southwest Queensland Anomaly in the south and unmapped further north, where it may run up the west margin of Cape York rather than joining the Gulf directly. In 2003 Ted Lilley, Wang, Chamalaun and Ian Ferguson described it as a major structure of the Australian Plate. A magnetotelluric profile across the anomaly in 1997 narrowed its width at the crossing to about 10 km.\nTwenty-one magnetometers recorded in the first stage of 1995, and transfer functions survive for all twenty of the sites carried here, though for Corella River only as rows in Liejun Wang's Australian Electromagnetic Database. The served values arrive without uncertainties, so they cannot be weighted by error.\nThe numbers served here are magnetic response functions, seventeen periods from 360 to 27,300 s at each station, computed by Francois Chamalaun, Ted Lilley and Liejun Wang from the 1995 array with the robust technique of Chave and others (1987) against the Charters Towers Magnetic Observatory as remote reference. They were published as Chamalaun, Lilley and Wang (1999), Physics of the Earth and Planetary Interiors 116, pages 105 to 115, and tabulated in Appendix 4 of Wang (1998), doctoral thesis, Australian National University, hdl:1885/145955, with the arrows mapped in Figures 6.6a, 6.6b and 6.7 and the site positions listed in Table 6.2. The served rows are the ones this array carries in Liejun Wang's Australian Electromagnetic Database, which prints no uncertainty columns for it, so the values arrive without the error estimates Wang reports in section 6.5 of the thesis as generally under one per cent, and the coordinates are the positions printed in the register. The original recordings are not held.",
 "subjects": [
  {
   "code": "370602",
   "scheme": "ANZSRC-FoR-2020",
   "label": "Electrical and electromagnetic methods in geophysics",
   "uri": "https://linked.data.gov.au/def/anzsrc-for/2020/370602"
  }
 ],
 "creators": [
  {
   "name": "F. H. Chamalaun",
   "name_type": "person"
  },
  {
   "name": "F. E. M. Lilley",
   "name_type": "person"
  },
  {
   "name": "Liejun Wang",
   "name_type": "person"
  }
 ],
 "organisations": [
  {
   "name": "Flinders University",
   "ror": "https://ror.org/01kpzv902",
   "roles": [
    "custodian"
   ],
   "primary_custodian": true
  },
  {
   "name": "Australian National University",
   "ror": "https://ror.org/019wvm592",
   "roles": [
    "custodian"
   ]
  }
 ],
 "rights": {
  "license": "CC-BY-4.0",
  "access": "open"
 },
 "relationships": [
  {
   "identifier": "hdl:1885/145955",
   "identifier_type": "Handle",
   "relation": "IsDocumentedBy"
  },
  {
   "identifier": "https://ausmt.auscope.org.au/collections/australia-legacy-gds",
   "identifier_type": "URL",
   "relation": "IsPartOf"
  }
 ],
 "provenance": {
  "generated": "2026-09-09T06:47:27Z",
  "generator": "ausmt/extract.build_portal 0.2.1"
 }
}