Types of rock found on Norfolk Island

  1. Basalt is a dark rock with fine grains formed when lava cools quickly.  Basalt cools in thick “sheets” or in “pillows”. The sheet lava often cools into columns but the pillow lava cools into rounded balls.

  2. Tuff is formed from the dust and ash thrown out during volcanic eruptions.

  3. Breccia is also present.  It is made up of small pieces  of ash and bits of rock thrown out during an eruption and become cemented together.

  4. Calcarenite is a sedimentary rock formed when water passes through a mixture of coral, shell fragments and sand and the dissolved lime cements it all together.

  5. Rocks “weather” which means they are broken down to make soil.  “Erosion” is when the weathered rock is blown or washed away or removed by animals walking on it.

Norfolk Island

  1. The volcanic eruptions that formed the Norfolk Island rocks were about 3 million years ago.  Norfolk and Phillip Island were once joined into one big island but were separated when sea levels rose.

  2. On Norfolk Island there is a lot of basalt with smaller amounts of tuff.

  3. Mt Pitt and Mt Bates are the remains of an extinct volcano.  They are both about 330 metres high above sea level. 

  4. Most of the island is surrounded by cliffs from 60m to 90m high.  Where the rock has weathered, the cliffs are not as steep as where the rock is not as heavily weathered.

  5. At Kingston, you can easily see the fringing coral reef.  The coral reefs formed calcarenite about 120,000 years ago.  There are obvious layers in calcarenite.  The calcarenite was used to build many of the buildings in Kingston.  It was also burnt to make lime which was used to make cement

Phillip Island and Nepean Island

  1. There have been 3 volcanic vents on Phillip Island.  Phillip Island is made up of about equal amounts of tuff and basalt.  The tuff is softer than the basalt so it weathers and is eroded more rapidly than the basalt.

  2. The soils have been exposed and very badly eroded by feral sheep, pigs, rabbits and goats.

  3. Nepean Island is mainly made of calcarenite.



Kain o rok el fain et orn Norfuk Ailen

  1. Basalt – Baesolt es wun daak rok gata fain griens form et daa taim wen dem laava kuul faas.  Baesolt yuusa kuul iin thik “shiis” ala “paelos”. Daa shiit’ laava plenti taim el kuul iina kohlams bat daa paalo laava kuul iina raun borls.

  2. Tuff - Taf s’ form et fram daa dast ena aesh throen aut wen daa vohlkieno erapt.

  3. Breccia – Besiya es orlsoe ya.  Daa s’ miek et f’ iwi piis  o aesh ena  iis’ rok hiiw et t’gaeda dyuuren wan erapshan en dem pily t’gaeda.

  4. Calcarenite – Kaelkaerenait es wan sedimentri rok s’ form et d’ taim worta paas thruu daa mikscha o kohral, piisa shael ena sehn en dem laim disohlv en sement et orl t’gaeda.

  5. Roks “wetha” wich miin dem s’ brek daun f’ mieka soiyl.  “Eroeshan” es wen daa wethad rok s’ bloe ala wohsh wieh ala tek et wieh bai’ aenimals worken orn et.

Norfuk Ailen

  1. Dem volkaenik erapshans thaet bin miek Norfuk Ailens roks es baut 3 milyan yias agoe.  Norfuk en Felep Ailen wans bin es joind iin wan big ailen bat dem separiet wen dem sii lewel rais.

  2. Orn Norfuk Ailen gat plenti baesolt longf’ smorlar bits o taf.

  3. Mt Pit en Mt Biets es wathen laef’ wan ekstinkt vohlkieno.  Dem es boeth baut 330 miitas hai abav sii lewel. 

  4. Mus orl o daa ailen s’ sarraun et bai klifs fram 60m to 90m hai.  Wheya daa rok s’ wetharet, dem clif nor soe stiip aes said em rok nor s’ soo hewili wethad.

  1. Daun’taun, yuu el iisi si daa frinjen kohral riif.  Dem kohral riif s’ form from’  kaelkaeranait (calcarenite) baut 120,000 yias agoe.  Gata obviyas liehyas iin kaelkaeranait (calcarenite).  Dem kaelkaeranait (calcarenite) bin yus et f’ bild plenti o’ dem bildens iin Kingstan.  Dem orlsoe bin yuss’ ban et f’ miek laim wich dem yuus f’ mieka sement.

Felep Ailen en Nepiiyan Ailen

  1. Bin gat 3 vohlkaenik vent orn Felep Ailen. Felep Ailen s’ mieketap f’ baut iikwal amaunt o taf ena baesolt.  Daa taf es sorfa den dem baesolt soe el wetha en eroed faaer den dem em baesolt.

  2. Dem soil bin ekspoes et en s’ behdli eroedet bai  em feral shiip, pig, raebet ena got.

  3. Mus orl o Nepiiyan Ailen s’ miek et f’ kaelkaerenait (calcarenite).