Question: Which opened first, the Ptarmigan and Tom Mine or the Colomac Mine?

Context paragraphs:
Anina Mine: Anina Coal Mine is an underground mine that is now closed.  It was one of the largest mines in Romania.  It is located in South-Western Romania, in Anina, Caraş-Severin County in the historical Banat region.  The mine still has large reserves of anthracite, lignite, brown coal and oil shale amounting to over 1.3 billion tonnes.  It was owned by Miniera Banat a state owned company that specialised in the management of coal mines in the Banat region.  The mine opened in 1790 making it the longest running mine in Romania until its closure in 2006.  Its galleries are hundreds of kilometers in length and reach a depth of 1200 m making it the deepest mine in Romania and one of the deepest in Europe.  The mine supplied oil shale to the nearby Crivina Power Station, a 990 MW thermal power station, the first oil shale power station in Romania, that had to be supplied with around 4 million tonnes of oil shale per year.

Brockman 4 mine: The Brockman 4 mine is an iron ore mine located in the Pilbara region of Western Australia, 60 kilometres north-west of Tom Price.  The mine, located near the existing Brockman mine, was opened in 2010.

Samira Hill Gold Mine: The Samira Hill Gold Mine (fr.  "Mine d'Or du Mont Samira") is a Gold mine in Téra Department of the Tillabéri Region in Niger.  Opened in late 2004, it is the first industrial scale gold mine in the nation, and while operated by a Canadian/Moroccan consortia, the government of Niger owns both a 20% stake in its operation, and functions under government concession.  The mine, and the possibility that other gold concessions will follow, is projected to be an important component of future export revenue for the West African state.

Stobcross Railway: The Stobcross Railway was a railway line built by the North British Railway to connect from Maryhill to the new dock being built at Stobcross; the dock became the Queen's Dock, opened in 1877.  The line was opened first, in 1874, and gave the North British company access to the north bank of the River Clyde; there was a goods depot at Partick.

Colomac Airport: Colomac Airport (TC LID: CFY8) , was located near Colomac Mine in the Northwest Territories, Canada where caribou may be found on the runway.  Prior permission was required to land except in the case of an emergency.

Ptarmigan and Tom Mine: The Ptarmigan and Tom Mine were gold producers located in the Northwest Territories, Canada at Yellowknife.  The property was staked by prospectors in 1936 and acquired by Cominco in 1938.  The mine first produced between 1941 and 1942 but closed due to wartime restrictions.  The old property was demolished in 1969–1970.  A new company, Treminco Resources Limited, reopened the workings in 1985 and production from the Tom ( ) portal began in 1986 with material being trucked to Giant Mine.  The old Ptarmigan ( ) mine shaft was dewatered and production began in 1987.  A new mill was built at the property and was operational in July 1989.  Low gold prices forced the company to close the mines in 1997.  Total gold production has been approximately 120,000 troy ounces (3700 kg).

Colomac Mine: The Colomac Mine was a privately owned and operated open pit gold mine located 220 km northwest of Yellowknife in the Northwest Territories in Canada .  The Colomac mine operated between 1990–1992, and 1994–1997.  It was operated by Neptune Resources Limited that had little success in making a profit during its operation.  In 1994, the mine had reopened under Royal Oak Mines Inc.  Both Neptune Resources and Royal Oak Mines where both owned and operated by Peggy Witte.  Due to low gold prices and high cost of mining, Royal Oak Mines was forced into bankruptcy.  The Federal Government of Canada became owners of the mine, along with the related environmental issues.  A major cleanup effort is under way to prevent the mine from polluting the environment, but this might be too late at this stage.  This mine is now owned and controlled by the Indigenous and Northern Affairs department of the Federal government, while Public Works and Government services is the current contracting authority.

Chengdu Metro: Chengdu Metro (branded as metro) is the local mass rapid train transportation system in Chengdu, the capital of Sichuan Province, China.  The system has four lines.  Line 1 was constructed between December 2005 and 2010, and opened at Sep 27th, making it the first heavy-rail metro line in south and west China.  (Chongqing Rail Transit Line 2 opened first in 2005 but is Heavy-Monorail); and Line 2 began operations in September 2012.  Line 4 opened to public at the end of December 2015, while Line 3 opened in July 2016.  Metro lines are operated by Chengdu Metro Limited Liability Company.  Commuter rail lines such as the Chengdu–Dujiangyan Intercity Railway are operated by Chengdu City Commuter Railway Limited Liability Company.  It is China's first joint venture between a local government and China's national rail operator.  The city and the Ministry of Railways worked together in building metro lines and high speed commuter rail lines.  A light rail system northwest of Chengdu began construction at October 2015, and will open to public in 2017.  There are currently over 350km of subway lines under construction.

Trams in Bursa: The Bursa tram network (sometimes stylized as Burtram) forms part of the public transport system in the city Bursa, Marmara Region, Turkey.  The tram network is operated by Burulaş, which also operates Bursa's metro system called Bursaray.  Bursa's tramway is made up of two lines: a metre gauge heritage tramline called T3 that opened first in 2011, and a standard gauge modern tramline called T1 that opened in 2013.

Lost Lemon Mine: The Lost Lemon Mine is a legendary lost mine said to be located in the Canadian Province of Alberta.  The story has been retold in countless books with the authoritative version being "The Lost Lemon Mine" by Tom Primrose.The story first appeared in the 1946 edition of the "Alberta Folklore Quarterly" and later in magazines such as "Canada West".  The Lost Lemon Mine has also been featured in television documentary series "Northern Mysteries", and worked into the plot of "The Final Sacrifice".  Countless people have searched for the mine.  A number of searchers have never returned.

Supporting paragraphs: Ptarmigan and Tom Mine Colomac Mine
Answer: The Ptarmigan and Tom Mine