IMPORTANT MESSAGE. We need your support now to keep mindat.org running. Click here to find out why.
Log InRegister
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for Educators
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsUsersBooks & MagazinesMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Coocoran Opal Fields, Lightning Ridge, Finch Co., New South Wales, Australia

This page is currently not sponsored. Click here to sponsor this page.
 
Latitude & Longitude (WGS84): 29° 27' 48'' South , 147° 45' 39'' East
Latitude & Longitude (decimal): -29.46333,147.76083
Köppen climate type:BSh : Hot semi-arid (steppe) climate


The Coocoran opal fields consist of about 50 named opal fields are located about 21 kilometres east of the town of Lightning Ridge. A "field" is an area where opal mineralisation has been found. Locally an opal field is known as a "rush" and is often named after the opal miner that initially found mineralisation in that area.

On the Coocoran opal fields a rush can range in area from about 1 hectare up to more than 20 hectares. Peak production occurred in the period from late 1980s to late 1990s.

Underground and open cut mining techniques are used to extract opal from depths ranging from near surface up to 25 metres underground. The host rock is the Cretaceous Griman Creek Formation which is predominantly composed of freshwater (rarely estuarine?) claystones and sandstones.

Most gem opal from the Coocoran opal fields is found as "nobby" opal. Nobby opal occurs as spheroidal or disc like pieces of opal that range from about 1 to 15cm in diameter sporadically distributed through claystone layers.

Opalised fossils also occur sporadically. Fossils include bivalve shells, gastropod shells, dinosaur bones & teeth, turtle shell & bones, crustacean gastroliths, plant stems & fruiting bodies, plesiosaur bones & teeth, monotreme bones, etc.


Mineral List

Mineral list contains entries from the region specified including sub-localities

1 valid mineral.

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org

Cenozoic
0 - 66 Ma



ID: 871117
sedimentary rocks 72357

Age: Cenozoic (0 - 66 Ma)

Description: Undifferentiated consolidated Cenozoic sedimentary rocks; sandstone, limestone, conglomerate, siltstone, duricrust; commonly ferruginised or silicified; may be poorly consolidated, highly weathered, and dissected by present day drainage.

Comments: sedimentary siliciclastic; regolith; synthesis of multiple published descriptions

Lithology: Sedimentary siliciclastic; regolith

Reference: Raymond, O.L., Liu, S., Gallagher, R., Zhang, W., Highet, L.M. Surface Geology of Australia 1:1 million scale dataset 2012 edition. Commonwealth of Australia (Geoscience Australia). [5]

Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License


Localities in this Region


This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Aracic, Stephen (1999), Rediscover Opals in Australia, published 1999 by the Kingswood Press.
Smith, E. & R. (1999): Black Opal Fossils of Lightning Ridge - Treasures from the Rainbow Billabong, Kangaroo Press, East Roseville.
Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.

External Links


Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2018, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: November 13, 2018 03:21:30 Page generated: January 12, 2018 19:47:43
Go to top of page