畸形岩盤

畸形岩盤（英語：chonolith）是一種侵入火成岩。是由地下岩漿冷卻結晶形成的火成岩體。由於岩漿侵入到岩層但未到達地球表面，所以被稱為侵入火成岩^[1]。然而，有時部分岩體，經過構造作用被擡升，會暴露在地球表面，因此可以觀察到這些岩石中的礦物。侵入火成岩是根據冷卻後的結晶岩漿所表現的不同形狀而命名的。例如，岩脈，岩床，岩蓋等是具有特定形狀的侵入火成岩。但具有不規則形狀的侵入火成岩都被稱為畸形岩盤^[2]。畸形岩盤一個獨特特徵是具有底板或基底，與其他類型的侵入火成岩不同^[2]。

形成

地球表面的岩石不斷受到不同類型的力的影響，包括拉應力、壓應力和剪應力。當岩石處於這種壓力下時，它們會變形，呈現出不同類型的形狀。例如，當構造板塊被推到一起時，由於地殼的縮短和增厚，岩石會承受壓縮應力，從而形成山脈。當構造板塊受拉應力時，會被拉開導致岩層出現斷層，從而形成裂谷^[3]。岩石在變形時，往往會在岩石圈留下空洞^[4]，岩漿就會從岩石圈下方升填充這些空洞^[4]。由於周圍的岩石通常是絕緣體，因此這種岩漿會慢慢冷卻。一旦它完全冷卻並結晶後，就形成一個火成岩。由於岩漿的緩慢冷卻，通常需要經過數萬年。火成岩體可以通過岩石之間的空間被動注入，也可以迫使岩層分開並主動注入。然後根據岩體的形狀和特徵對其進行分類^[4]。

畸形岩盤實例

美國內華達州埃爾科縣的 Spring Gulch 畸形岩盤由二雲母花崗岩組成。鉀含量高，斜長石含量低。估計年齡約為156.4±023萬年^[5]。

西澳大利亞西馬斯格雷夫地區輝長岩的尼波-巴別畸形岩盤主要由輝長石組成。為西澳大利亞西馬斯格雷夫區塊最大的硫化鎳礦。該畸形岩盤，延伸約 5 公里^[6]。

俄羅斯諾里爾斯克的畸形岩盤覆蓋西伯利亞大陸的玄武岩形成於二疊紀-三疊紀邊界，當時是由一個超幔柱溢出的玄武岩侵入洋殼板塊而成。這火成岩侵入持續了大約 2 到 4 百萬年。畸形岩盤形成在玄武岩下方，大量的 Cu-Ni-PGE 硫化物。畸形岩盤長20公里^[7]。

台灣金瓜石更新世英安岩的畸形岩盤台灣金瓜石的畸形岩盤是在更新世。侵入了含飽和水的中新世沉積物。這個岩盤由英安岩組成。礦石是在變質的泥質化的英安岩中。該地區的銅金礦，來自畸形岩盤中的砷銅金礦^[8]。

美國內華達州卡林附近科爾特斯山脈的白堊紀畸形岩盤^[9]

美國科羅拉多州沙瓦諾附近的安山岩畸形岩盤^[10].

參考文獻

^ "8.6: Igneous Rock Formation: Plutonic vs Volcanic". Geosciences LibreTexts. 2019-09-08. Retrieved 2021-02-25.
^ ^2.0 ^2.1 Lahee, Frederic H. (1961). Field Geology. McGraw-Hill Book Co. p. 143. ISBN 0070358087.
^ Geological Society - Deformation of Rocks". www.geolsoc.org.uk. Retrieved 2021-02-25
^ ^4.0 ^4.1 ^4.2 Daly, Reginald A. (September 1905). "The Classification of Igneous Intrusive Bodies". The Journal of Geology. 13 (6): 485–508. doi:10.1086/621251. hdl:2027/hvd.32044072250244. ISSN 0022-1376.
^ Ketner, Keith Brindley; Day, Warren C.; Elrick, Maya; Vaag, Myra K.; Zimmerman, Robert A.; Snee, Lawrence W.; Saltus, Richard W.; Repetski, John E.; Wardlaw, Bruce R.; Taylor, Michael E.; Harris, Anita G. (1998). "An outline of tectonic, igneous, and metamorphic events in the Goshute-Toano Range between Silver Zone Pass and White Horse Pass, Elko County, Nevada; a history of superposed contractional and extensional deformation". Professional Paper. doi:10.3133/pp1593. hdl:2027/uc1.31210020799068. ISSN 2330-7102.
^ Seat, Zoran; Beresford, Stephen W.; Grguric, Benjamin A.; Waugh, Rob S.; Hronsky, Jon M. A.; Gee, M. A. Mary; Groves, David I.; Mathison, Charter I. (2007-07-19). "Architecture and emplacement of the Nebo–Babel gabbronorite-hosted magmatic Ni–Cu–PGE sulphide deposit, West Musgrave, Western Australia". Mineralium Deposita. 42 (6): 551–581. doi:10.1007/s00126-007-0123-9. ISSN 0026-4598.
^ Yakubchuk, Alexander; Nikishin, Anatoly (2004-03-01). "Noril?sk?Talnakh Cu?Ni?PGE deposits: a revised tectonic model". Mineralium Deposita. 39 (2): 125–142. doi:10.1007/s00126-003-0373-0. ISSN 0026-4598.
^ Folinsbee, R. E.; Kirkland, K.; Nekolaichuk, A.; Smejkal, V. (1972), "Chinkuashih—a Gold-Pyrite-Enargite-Barite Hydrothermal Deposit in Taiwan", Geological Society of America Memoirs, Geological Society of America, pp. 323–336, ISBN 0-8137-1135-5, retrieved 2021-02-26
^ Jr, Herman L. Bauer; Cooper, James J.; Breitrick, Richard A. (1960). "Porphyry Copper Deposits in the Robinson Mining District White Pine County, Nevada": 220–228.
^ Kantor, Tedral (1961-01-01). "Geology of the east-central portion of the Nelson quadrangle, Clark County, Nevada". Masters Theses.

[”8.6:”-1] "8.6: Igneous Rock Formation: Plutonic vs Volcanic". Geosciences LibreTexts. 2019-09-08. Retrieved 2021-02-25.

[”-2] 2.0 ^2.1 Lahee, Frederic H. (1961). Field Geology. McGraw-Hill Book Co. p. 143. ISBN 0070358087.

[”Geolo”-3] Geological Society - Deformation of Rocks". www.geolsoc.org.uk. Retrieved 2021-02-25

[”Daly,”-4] 4.0 ^4.1 ^4.2 Daly, Reginald A. (September 1905). "The Classification of Igneous Intrusive Bodies". The Journal of Geology. 13 (6): 485–508. doi:10.1086/621251. hdl:2027/hvd.32044072250244. ISSN 0022-1376.

[”Ketn”-5] Ketner, Keith Brindley; Day, Warren C.; Elrick, Maya; Vaag, Myra K.; Zimmerman, Robert A.; Snee, Lawrence W.; Saltus, Richard W.; Repetski, John E.; Wardlaw, Bruce R.; Taylor, Michael E.; Harris, Anita G. (1998). "An outline of tectonic, igneous, and metamorphic events in the Goshute-Toano Range between Silver Zone Pass and White Horse Pass, Elko County, Nevada; a history of superposed contractional and extensional deformation". Professional Paper. doi:10.3133/pp1593. hdl:2027/uc1.31210020799068. ISSN 2330-7102.

[”Seat”-6] Seat, Zoran; Beresford, Stephen W.; Grguric, Benjamin A.; Waugh, Rob S.; Hronsky, Jon M. A.; Gee, M. A. Mary; Groves, David I.; Mathison, Charter I. (2007-07-19). "Architecture and emplacement of the Nebo–Babel gabbronorite-hosted magmatic Ni–Cu–PGE sulphide deposit, West Musgrave, Western Australia". Mineralium Deposita. 42 (6): 551–581. doi:10.1007/s00126-007-0123-9. ISSN 0026-4598.

[”Yaku”-7] Yakubchuk, Alexander; Nikishin, Anatoly (2004-03-01). "Noril?sk?Talnakh Cu?Ni?PGE deposits: a revised tectonic model". Mineralium Deposita. 39 (2): 125–142. doi:10.1007/s00126-003-0373-0. ISSN 0026-4598.

[”Folin”-8] Folinsbee, R. E.; Kirkland, K.; Nekolaichuk, A.; Smejkal, V. (1972), "Chinkuashih—a Gold-Pyrite-Enargite-Barite Hydrothermal Deposit in Taiwan", Geological Society of America Memoirs, Geological Society of America, pp. 323–336, ISBN 0-8137-1135-5, retrieved 2021-02-26

[”Jr”-9] Jr, Herman L. Bauer; Cooper, James J.; Breitrick, Richard A. (1960). "Porphyry Copper Deposits in the Robinson Mining District White Pine County, Nevada": 220–228.

[”Kantor”-10] Kantor, Tedral (1961-01-01). "Geology of the east-central portion of the Nelson quadrangle, Clark County, Nevada". Masters Theses.

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