# Torlesse composite terrane > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Torlesse_composite_terrane > Markdown URL: https://mediated.wiki/source/Torlesse_composite_terrane.md > Source: https://en.wikipedia.org/wiki/Torlesse_composite_terrane > Source revision: 1281622140 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) Terrane found in New Zealand Torlesse composite terrane Stratigraphic range: Carboniferous-Cretaceous ~320–130 Ma PreꞒ Ꞓ O S D C P T J K Pg N View of Torless composite terrane at Aoraki / Mount Cook Type Terrane Unit of Austral superprovince Sub-units Kaweka, Rakaia & Pahau terranes, Esk Head Belt, Pahaoa & Clent Hills Groups Underlies Caples terrane, Momotu, Waka & Haerenga Supergroups Lithology Primary Greywacke, schist, basalt Location Region Canterbury, Marlborough & Otago regions Country New Zealand Type section Named for Torlesse Range Cross-section of New Zealand's stratigraphy The **Torlesse composite terrane** is a plate tectonic [terrane](/source/Terrane) forming part of the [South Island](/source/South_Island) of New Zealand. It contains the Rakaia, Aspiring and Pahau terranes and the Esk Head Belt.[1] [Greywacke](/source/Greywacke) (or **Torlesse Greywacke**) is the dominant rock type of the composite terrane; [argillite](/source/Argillite) is less common and there are minor basalt occurrences. The Torlesse composite terrane is found east of the [Alpine Fault](/source/Alpine_Fault) in the [Southern Alps](/source/Southern_Alps_(New_Zealand)) of New Zealand. Its southern extent is a cryptic boundary with the [Caples terrane](https://en.wikipedia.org/w/index.php?title=Caples_terrane&action=edit&redlink=1) within the [Haast Schists](/source/Haast_Schist) in Central Otago.[2] It is named for the Torlesse Range in [Canterbury](/source/Canterbury%2C_New_Zealand). ## Description The Rakaia terrane rocks, of Permian to late Triassic age (300–200 Ma), occur south of [Rangiora](/source/Rangiora). The Pahau terrane rocks, of [Late Jurassic](/source/Late_Jurassic) to [Early Cretaceous](/source/Early_Cretaceous) age (160–100 Ma), occur to the north, and are probably derived from the Rakaia terrane. At the boundary between these two terranes is the Esk Head Belt, an 11-kilometre (6.8 mi) wide [mélange](/source/M%C3%A9lange) of broken and deformed rocks. The Aspiring terrane (Aspiring lithologic association) is officially included within the Torlesse composite terrane; however, it has a higher proportion of igneous rocks and a different sedimentary source.[3] Its original relationship with the Rakaia terrane is obscured by the Haast Schist. ## Deposition The greywacke of the Torlesse composite terrane was deposited on the eastern side of New Zealand from the [Late Carboniferous](/source/Late_Carboniferous) through to the Middle [Cretaceous](/source/Cretaceous). It was deposited in giant [deep sea fans](/source/Deep_sea_fan) that extended beyond the ends of ancient submarine canyons. A fan starts with a [submarine canyon](/source/Submarine_canyon) on the [continental shelf](/source/Continental_shelf). Then [turbidity currents](/source/Turbidity_current) rush down the canyon like giant undersea avalanches. They carry all sorts of sediments from the shallower [seafloor](/source/Seafloor) of the continental shelf. At the end of the canyon the turbidity current spreads out and creates giant fans of sediment that blanket the deep seafloor. These sediments may have derived in part from the [granitic](/source/Granite) rocks of northeastern [Australia](/source/Australia), as suggested by studies of the mineral grains.[4] ## Metamorphism The Torlesse composite terrane has undergone [metamorphism](/source/Metamorphism) and been transformed into Haast Schist. In the Haast Schists, the [minerals](/source/Mineral) that make up greywacke became coarser grained and altered to other minerals including quartz, feldspar and biotite.[5] Rare pods of [pounamu](/source/Pounamu) ([jade](/source/Jade)) are found in the higher metamorphic grades near the Alpine Fault.[6] ## Fossil content - *[Torlessia](https://en.wikipedia.org/w/index.php?title=Torlessia&action=edit&redlink=1)*[7] - *[Monotis](https://en.wikipedia.org/w/index.php?title=Monotis&action=edit&redlink=1)*[7] - [Hector's Ichthyosaur](/source/Hector's_Ichthyosaur)[8] - [Nothosaur](/source/Nothosaur)[9] - [Conodont](/source/Conodont)[10] ## See also - [Geology of the Canterbury region](/source/Geology_of_the_Canterbury_region) - [Geology of the Tasman District](/source/Geology_of_the_Tasman_District) - [Stratigraphy of New Zealand](/source/Stratigraphy_of_New_Zealand) - [Takaka terrane](/source/Takaka_terrane) - [Dun Mountain–Maitai terrane](/source/Dun_Mountain%E2%80%93Maitai_terrane) ## References 1. **[^](#cite_ref-1)** ["New Zealand Stratigraphic Lexicon"](https://data.gns.cri.nz/). GNS Science. 1. **[^](#cite_ref-2)** ["New Zealand Geology: an illustrated guide"](https://www.geotrips.org.nz/downloads/Ballance_NZ_Geology-V2.pdf) (PDF). *www.geotrips.org.nz*. 1. **[^](#cite_ref-JugumNorris2013_3-0)** Jugum, D; Norris, RH; Palin, JM (2013). ["Late Jurassic detrital zircons from the Haast Schist and their implications for New Zealand terrane assembly and metamorphism"](https://doi.org/10.1080%2F00288306.2013.815639). *New Zealand Journal of Geology and Geophysics*. **56** (4): 223–228. [Bibcode](/source/Bibcode_(identifier)):[2013NZJGG..56..223J](https://ui.adsabs.harvard.edu/abs/2013NZJGG..56..223J). [doi](/source/Doi_(identifier)):[10.1080/00288306.2013.815639](https://doi.org/10.1080%2F00288306.2013.815639). [ISSN](/source/ISSN_(identifier)) [0028-8306](https://search.worldcat.org/issn/0028-8306). [S2CID](/source/S2CID_(identifier)) [128551272](https://api.semanticscholar.org/CorpusID:128551272). 1. **[^](#cite_ref-4)** ["Building a continent – Te Ara Encyclopedia of New Zealand"](https://www.teara.govt.nz/en/geology-overview/page-4). 1. **[^](#cite_ref-5)** ["The Geology of New Zealand: Greywacke"](https://www.gns.cri.nz/Home/Our-Science/Earth-Science/Regional-Geology/The-Geology-of-New-Zealand/Stratigraphy/Greywacke). *www.gns.cri.nz*. GNS Science. 1. **[^](#cite_ref-CooperIreland2015_6-0)** Cooper, Alan F.; Ireland, Trevor R. (2015). "The Pounamu terrane, a new Cretaceous exotic terrane within the Alpine Schist, New Zealand; tectonically emplaced, deformed and metamorphosed during collision of the LIP Hikurangi Plateau with Zealandia". *Gondwana Research*. **27** (3): 1255–1269. [Bibcode](/source/Bibcode_(identifier)):[2015GondR..27.1255C](https://ui.adsabs.harvard.edu/abs/2015GondR..27.1255C). [doi](/source/Doi_(identifier)):[10.1016/j.gr.2013.11.011](https://doi.org/10.1016%2Fj.gr.2013.11.011). [ISSN](/source/ISSN_(identifier)) [1342-937X](https://search.worldcat.org/issn/1342-937X). 1. ^ [***a***](#cite_ref-auto_7-0) [***b***](#cite_ref-auto_7-1) J. D. Campbell; Guyon Warren (1965-07-22). ["Fossil Localities of the Torlesse Group in the South Island"](https://paperspast.natlib.govt.nz/periodicals/TRSGEO19650722.2.2). *Transactions of the Royal Society of New Zealand: Geology*. **3** (8): 99. 1. **[^](#cite_ref-8)** ["Hectors Ichthyosaur(True Organism Size Parameters)"](https://icebergdb.com/hectors-ichthyosaurtrue-organism-size-parameters-2/). 29 March 2022. 1. **[^](#cite_ref-9)** ["Fossil Evidence"](https://sci.waikato.ac.nz/evolution/FossilEvidence.shtml). 1. **[^](#cite_ref-10)** ["Oldest fossils – Paleozoic – Te Ara Encyclopedia of New Zealand"](https://teara.govt.nz/en/fossils/page-2). ## Further reading - The Rise and Fall of the Southern Alps, G. Coates published 2002 --- Adapted from the Wikipedia article [Torlesse composite terrane](https://en.wikipedia.org/wiki/Torlesse_composite_terrane) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Torlesse_composite_terrane?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.