Haast Schist
Encyclopedia
The Haast Schist is a New Zealand
schist
that is found on the eastern side of the Alpine Fault
. Metamorphic grade progresses from greenschist
through biotite
schist to garnet
schist. Myrmekitic textures occur within oligoclase
within the garnet zone.
The schists were named after Julius von Haast
for his contributions to geology
. The schists were originally brought to the surface of the Earth's crust during the Kaikoura Orogeny
.
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
schist
Schist
The schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is...
that is found on the eastern side of the Alpine Fault
Alpine Fault
The Alpine Fault is a geological fault, more specifically known as a right-lateral strike-slip fault, that runs almost the entire length of New Zealand's South Island. It forms a transform boundary between the Pacific Plate and the Indo-Australian Plate. Earthquakes along the fault, and the...
. Metamorphic grade progresses from greenschist
Greenschist
Greenschist is a general field petrologic term applied to metamorphic or altered mafic volcanic rock. The term greenstone is sometimes used to refer to greenschist but can refer to other rock types too. The green is due to abundant green chlorite, actinolite and epidote minerals that dominate the...
through biotite
Biotite
Biotite is a common phyllosilicate mineral within the mica group, with the approximate chemical formula . More generally, it refers to the dark mica series, primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more aluminous endmembers...
schist to garnet
Garnet
The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives. The name "garnet" may come from either the Middle English word gernet meaning 'dark red', or the Latin granatus , possibly a reference to the Punica granatum , a plant with red seeds...
schist. Myrmekitic textures occur within oligoclase
Oligoclase
Oligoclase is a rock-forming mineral belonging to the plagioclase feldspars. In chemical composition and in its crystallographic and physical characters it is intermediate between albite and anorthite . The albite:anorthite molar ratio ranges from 90:10 to 70:30.Oligoclase is a high sodium...
within the garnet zone.
The schists were named after Julius von Haast
Julius von Haast
Sir Johann Franz "Julius" von Haast was a German geologist. He founded Canterbury Museum at Christchurch.-Biography:...
for his contributions to geology
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
. The schists were originally brought to the surface of the Earth's crust during the Kaikoura Orogeny
Kaikoura Orogeny
The Kaikoura Orogeny is a New Zealand orogeny that has given birth to the Southern Alps. It began 25 million years ago along the Alpine Fault.In this orogeny the Southern alps are being formed because the Pacific Plate is being pushed up over the Australian Plate...
.