alive and well - Geological Society of Australia

Society UpdateStratigraphic ColumnTraditional names and other exceptions –sometimes confusingThe International Stratigraphic Guide (ISG) has severalclauses that allow the retention of lithostratigraphic unitnames that do not meet the current guidelines. Findingthese non-compliant names in the Australian Stratigraphic UnitsDatabase can sometimes create confusion about what iscurrently permitted, so I thought it would be worth discussingsome of these exceptions.One clause that was mainly applied when we first adopted theISG in 1978 was the provision to ‘preserve traditional and wellestablishednames’ (3.B.3.g.). This allowed the retention of namesthat did not include a geographic component, such as the Olderand Newer Volcanics of Victoria (now being replaced) and theSpirifer yassensis Limestone Member, New South Wales. This clausealso gave rise to some uncertainty about whether Tasmania’s‘Jurassic dolerite’ should be capitalised and considered a formalname or continue as an informal reference to all dolerite of thatage in Tasmania. Tasmanian Dolerite is the agreed name used inthe Surface Geology of Australia 1:1 000 000-scale datasets,although we are still lacking a formal definition.Other kinds of well-established names that were allowedto continue under this clause were those that did not use a lithologicalor other accepted term. The Widgiemooltha Dyke Suite isin this category because is uses a ‘form’ term — dyke — rather thana lithological term such as dolerite or gabbro. The Crystal BrookVolcanic Neck and the Bagstowe Ring Dyke Complex are otherexamples of unit names that use ‘form’ terms, and would not beaccepted as new names now.The more recent adoption of the International Union ofGeological Sciences (IUGS) ‘Classification of Igneous Rocks’, inconjunction with the ISG, is gradually seeing the replacement of‘Adamellite’ units, mostly with ‘Monzogranite’ units. However, insome areas the ‘traditional’ name has been retained until someonehas time to review the original name and unit definition.Another clause to do with the geographic component of unitnames is 3.B.3.a. This allows a stratigraphic unit to retain its namewhen a place name changes its spelling; for example KosciuskoGranite (place name now Kosciuszko) and the KombolgieSandstone (place name now Kambolgie). This also holds if the placename changes altogether; for example Violet Town, NSW changedto Tingira Heights in 1960s. In this case the decision to go aheadand change the Violet Town Conglomerate Member allowed theuse of Violet Town Volcanics in Victoria later on.Accepted indexing practice for the Australian StratigraphicUnits Database (ASUD) may also be a source of some confusion.All new names should be checked for suitability prior topublication. A simple way of doing this is to send an email tostratnames@ga.gov.au, which circulates proposed names toappropriate State and Territory representatives on the AustralianStratigraphy Commission. Nevertheless, some unsuitable namesslip through the cracks and get into print. The ASUD indexersrecord what is published, but do try to indicate if they know a nameis misspelt or does not meet the guidelines in other ways. Indexersdo this by recording the name as informal. Sadly some authors andreviewers fail to check the status or currency of units they readand write about.Regrettably there is also a backlog of published material awaitingindexing, so the database is not always as up-to-date as wewould like. However, the priority system aims to ensure that newmaps and significant State and Territory Survey publications areindexed as soon as possible after publication. The reservationprocess for new names also assists in getting approved names intothe database promptly. Although names are established bydefinition and publication, there can often be useful notes attachedto reserved name entries too.I hope this review of some of the exceptions to the namingconventions of the ISG helps in understanding some of the entriesin the ASUD, but questions are always welcome, as is advice onany updates that need to be made.CATHY BROWNNational Convener, Australian Stratigraphy Commissionc/- Geoscience AustraliaGPO Box 378, Canberra ACT 2601cathy.brown@ga.gov.au or cathyeb@netspeed.com.auOther Stratigraphy Commission contacts are available at:http://www.gsa.org.au/management/standing_committee.htmlor throughhttp://www.ga.gov.au/products-services/data-applications/reference-databases/stratigraphic-units.htmlTAG September 2012| 17