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1、Chapter 4 Magmatism and Igneous Rocks中國(guó)石油大學(xué)雙語(yǔ)教學(xué)試點(diǎn)課程（2004）山東省高等學(xué)校首批雙語(yǔ)教學(xué)示范課程（ 2008）授課對(duì)象：地質(zhì)學(xué)專(zhuān)業(yè)本科學(xué)生課程性質(zhì)：專(zhuān)業(yè)基礎(chǔ)課開(kāi)課學(xué)期：第一學(xué)期主講教師：呂洪波（教授）An Outline of Earth Sciences主講教師簡(jiǎn)介：主講教師簡(jiǎn)介：呂洪波呂洪波 男，1957年10月生于內(nèi)蒙古赤峰。興趣與特長(zhǎng)：野外與科研，教學(xué)與教材（+文學(xué)+音樂(lè)+攝影+健身）。理念：教學(xué)與科研都需要奉獻(xiàn)精神。少談大師，多做事實(shí)，身教重于言傳。 學(xué)習(xí)及工作簡(jiǎn)歷： 1978年考入南京大學(xué)地質(zhì)系鈾礦地質(zhì)與地球化學(xué)專(zhuān)業(yè)，1985年在

2、南京大學(xué)地球科學(xué)系構(gòu)造地質(zhì)專(zhuān)業(yè)獲碩士學(xué)位并留校任教。1997年獲得碩士生導(dǎo)師資格，1998年底在職博士畢業(yè)。 1985.71999.9年在南京大學(xué)地球科學(xué)系任教，先后任助教（19851987）、講師（19871993）、副教授（19931999）。 1994.31995.11：蘇丹喀土穆大學(xué)地質(zhì)系教授（中國(guó)國(guó)家教委派遣援非任教）。 1999.92002.9：移居加拿大工作并學(xué)習(xí)。 2002年09月起長(zhǎng)期受聘于中國(guó)石油大學(xué)（華東），任地球科學(xué)系教授。2002年以來(lái)主講課程： 地球科學(xué)概論：20042009級(jí)地質(zhì)學(xué)專(zhuān)業(yè)（雙語(yǔ)） 專(zhuān)業(yè)英語(yǔ)：20042007級(jí)地質(zhì)學(xué)專(zhuān)業(yè) 地質(zhì)學(xué)基礎(chǔ)：20072009級(jí)

3、巴基斯坦留學(xué)生班（英語(yǔ)） 板塊構(gòu)造與沉積作用：20042009級(jí)地質(zhì)學(xué)研究生（雙語(yǔ)） 野外基礎(chǔ)地質(zhì)實(shí)習(xí)、魯東地質(zhì)綜合實(shí)習(xí)、綜合地質(zhì)實(shí)習(xí)等，2002年起每年夏天在新泰、秦皇島、巢湖等地 此外，還先后主講過(guò)構(gòu)造地質(zhì)學(xué)、海洋地質(zhì)學(xué)（雙語(yǔ)）等課程。 先后在下?lián)P子地區(qū)、滇黔桂地區(qū)、阿爾金地區(qū)、青藏高原、內(nèi)蒙古西部、赤峰、遼西、冀東北、山東等地進(jìn)行過(guò)沉積盆地構(gòu)造演化研究以及第四紀(jì)冰川地貌研究。在非洲的撒哈拉沙漠和加拿大西海岸進(jìn)行過(guò)多次野外實(shí)地考察。參與完成自然科學(xué)基金項(xiàng)目5項(xiàng)，橫向石油地質(zhì)課題6項(xiàng)，其他課題5項(xiàng)，已發(fā)表論文50多篇，獨(dú)自編寫(xiě)出版地質(zhì)學(xué)雙語(yǔ)教材1部。近期研究領(lǐng)域近期研究領(lǐng)域：1構(gòu)造地質(zhì)學(xué)：目

4、前主要從事軟沉積物構(gòu)造變形研究，將構(gòu)造地質(zhì)學(xué)與沉積學(xué)緊密結(jié)合起來(lái)，先后發(fā)現(xiàn)并命名了同沉積擠壓構(gòu)造同沉積擠壓構(gòu)造和同沉積布丁構(gòu)造同沉積布丁構(gòu)造，探討了不同板塊背景下的震積巖，并將這些構(gòu)造分別與擠壓和伸展背景下的盆地演化階段聯(lián)系起來(lái)。2沉積學(xué)與沉積盆地構(gòu)造演化研究：利用前積層前積層、垂直縫合線(xiàn)垂直縫合線(xiàn)、震積液化脈震積液化脈等構(gòu)造、地震剖面、碎屑巖物質(zhì)組成等綜合探討沉積環(huán)境與盆地構(gòu)造演化。先后在遼西、河北、山東等環(huán)渤海灣地區(qū)進(jìn)行多次野外地質(zhì)考察，在山東新泰地區(qū)野外識(shí)別出下古生界含油碳酸鹽巖下古生界含油碳酸鹽巖。主持并參與多項(xiàng)基礎(chǔ)石油地質(zhì)研究課題。3中國(guó)東部第四紀(jì)冰川地貌研究：四年來(lái)對(duì)內(nèi)蒙古、河北、

5、山東等地的花崗巖高山區(qū)進(jìn)行了詳細(xì)的野外考察，發(fā)現(xiàn)了大量獨(dú)特的第四紀(jì)冰川剝蝕地貌四紀(jì)冰川剝蝕地貌。明確指出：中國(guó)東部曾經(jīng)存在過(guò)第四紀(jì)大陸冰川，其南界至少曾經(jīng)達(dá)到北緯36o以南。這一認(rèn)識(shí)打破了近年來(lái)地學(xué)界“中國(guó)東部不存在第四紀(jì)冰川”的壟斷論點(diǎn)。通過(guò)對(duì)青島地區(qū)海岸山脈的詳細(xì)考察，提出了膠州灣的冰川剝蝕成因說(shuō)膠州灣的冰川剝蝕成因說(shuō)。4. 近年來(lái)參與中國(guó)地質(zhì)科學(xué)院地質(zhì)公園推廣研究中心多項(xiàng)地質(zhì)公園考察與研究項(xiàng)目，為中國(guó)地質(zhì)公園建設(shè)和地學(xué)科普工作提供科學(xué)依據(jù)。兩次野外考察太行山黎城段，在元古宙地層中識(shí)別出多種特殊的痕跡化石和重要的沉積構(gòu)造，為地球早期生命演化與華北地區(qū)沉積環(huán)境研究提供了重要的素材；在黑龍江伊

6、春地區(qū)考察了紅星地質(zhì)公園，為玄武巖石海的成因機(jī)制提供了科學(xué)的解釋?zhuān)煌ㄟ^(guò)對(duì)五大連池世界地質(zhì)公園考察，為其“火山彈”與“噴氣錐”景點(diǎn)的命名提供了科學(xué)的更正建議。2003年以來(lái)發(fā)表的第一作者學(xué)術(shù)論文年以來(lái)發(fā)表的第一作者學(xué)術(shù)論文 呂洪波呂洪波，任曉輝，許民，歐陽(yáng)江城，2010，再論山脊壺穴的冰川融水成因兼與施雅風(fēng)院士商榷。地質(zhì)論評(píng)，56（4）：693702。 呂洪波呂洪波，2009，魯西古生代碳酸鹽巖中的垂直縫合線(xiàn)及其在華 北板塊構(gòu)造演化中的意義。地質(zhì)論評(píng)，55（4）：473483。 呂洪波，呂洪波，章雨旭，2008，壺穴、鍋穴、冰臼、巖臼等術(shù)語(yǔ)的辨析與使用建議。地質(zhì)通報(bào)，27（6）：917922。

7、呂洪波，呂洪波，朱曉青，楊超，黃蝶芳，張成鳳，張林，2008，山東新泰野外露頭發(fā)現(xiàn)下古生界含油碳酸鹽巖。地質(zhì)論評(píng)，54（2）：252，277。 呂洪波，呂洪波，任曉輝，許民，歐陽(yáng)江城，2008，壺穴差異風(fēng)化或風(fēng)蝕作用成因質(zhì)疑。地質(zhì)論評(píng)，54（2）：192198。 Lu Hongbo, Yan Shiyong, and Zhang Yue, 2007, Quaternary glacio-erosional landforms in Laoshan Mountain and their constraints on the origin of Jiaozhou Bay, Qingdao, eas

8、t of China. Chinese Journal of Oceanology and Limnology, 25 (2): 139148. 呂洪波，呂洪波，2007，五大連池世界地質(zhì)公園中“火山彈”與“噴氣錐”景點(diǎn)定名商榷。地質(zhì)論評(píng)，53（3）：383388。 LU Hongbo, ZHANG Yuxu, ZHANG Qiling, XIAO Jiafei, 2006, Earthquake-related tectonic deformation of soft sediments and their constraints on the basins tectonic evoluti

9、on. ACTA GEOLOGICA SINICA (English Edition), 80 (5): 724732. (Sci.收錄) 呂洪波呂洪波，任曉輝，楊超，2006，赤峰等地第四紀(jì)大陸冰川的地貌證據(jù)。地質(zhì)論評(píng)，52（3）：379385。 呂洪波呂洪波，章雨旭，張綺玲，肖國(guó)望，2006，內(nèi)蒙古白云鄂博東南黑腦包腮林忽洞群發(fā)現(xiàn)地震滑塌巖塊。地質(zhì)論評(píng)52（2）：163169。（第一作者論文續(xù)） 呂洪波呂洪波，楊超，2005，山東新泰青云山發(fā)現(xiàn)第四紀(jì)大陸冰川遺跡。地質(zhì)論評(píng)，51（5）：608。 呂洪波呂洪波，章雨旭，肖加飛，2004，貴州貞豐中三疊統(tǒng)關(guān)嶺組中Chirotherium原始爬行

10、類(lèi)足跡研究。地質(zhì)學(xué)報(bào)，78（4）：468474。 呂洪波呂洪波，章雨旭，夏邦棟，方中，周偉明，彭陽(yáng)，吳智平，李偉，2003. 南盤(pán)江盆地中三疊統(tǒng)復(fù)理石中的同沉積擠壓構(gòu)造-一類(lèi)新的沉積構(gòu)造的歸類(lèi)、命名和構(gòu)造意義探討。地質(zhì)論評(píng)。49(5): 449-456.近年來(lái)發(fā)表的教學(xué)研究論文：近年來(lái)發(fā)表的教學(xué)研究論文： 呂洪波，呂洪波，2006，在高校低年級(jí)實(shí)施雙語(yǔ)教學(xué)的體會(huì)。中國(guó)石油大學(xué)學(xué)報(bào)（社會(huì)科學(xué)版），Z1: 127130。 呂洪波呂洪波，2007，編寫(xiě)地球科學(xué)概論雙語(yǔ)教材的體會(huì)。教育理論與實(shí)踐，27（2007年全國(guó)雙語(yǔ)教學(xué)研討會(huì)論文集專(zhuān)刊）：190192。 呂洪波，呂洪波，2009，指導(dǎo)大學(xué)生創(chuàng)新性

11、實(shí)驗(yàn)計(jì)劃的感受。中國(guó)石油大學(xué)學(xué)報(bào)（社會(huì)科學(xué)版），Z1：139141。出版教材：出版教材： 呂洪波呂洪波，2006，An Outline of Earth Sciences（高等學(xué)校雙語(yǔ)教材）。中國(guó)石油大學(xué)出版社，東營(yíng)，367頁(yè)。（已第二次印刷）聯(lián)系方式：聯(lián)系方式： 青島市黃島區(qū)長(zhǎng)江西路66號(hào)（郵編：266555）。 中國(guó)石油大學(xué) 地球科學(xué)系 Email: ; Rock（巖石）is any naturally formed, consolidated or unconsolidated material (excluding soil) composed of one or more rock

12、-forming minerals（造巖礦物）. In other words, all rocks are composed of minerals.According to the origin, rocks can be classified into three typesigneous rocks（火成巖）, sedimentary rocks（沉積巖）and metamorphic rocks（變質(zhì)巖）, and their percentages in the crust are as following: Igneous rocks-66% of volume of the c

13、rust Sedimentary rocks-8% of volume of the crust Metamorphic rocks-20% of volume of the crustChapter 4 Magmatism and Igneous RocksMagma is naturally occurring mobile material with high temperature, generated within the Earth and capable of intrusion（侵入作用）and extrusion（侵出作用，噴出作用）.Characteristics: Hig

14、h temperature: from 650oC (Si, Al) to 1400oC (Mg, Fe).Complex components:(A). Mainly liquid silicates（液態(tài)硅酸鹽）(Si, Al, O, Mg, Fe, Ca, K, Na.).(B). Volatile matter（揮發(fā)物）: (H2O, CO2, CO, N2, SO.).(C). Solid rock fragments (固態(tài)巖屑sometimes).Viscous (thick and sticky) and Mobile（粘滯而且流動(dòng)）:The viscosity（粘度）depe

15、nds on the components and the temperature of magma. The higher the silica content, the more viscous and the less mobile the magma is. The higher the temperature, the lower viscosity and the higher mobility the magma has.Magma 巖漿 SiO2 % 二氧化硅Mafic or sialic materials鐵鎂質(zhì) 或 硅鋁質(zhì) 物質(zhì)Ultrabasic magma 超基性巖漿B

16、asic magma 基性的巖漿Intermediate magma中性巖漿Acidic magma 酸性巖漿 65Rich in mafic (basic基性的): Fe, Mg, Ca, etc.Rich in sialic (felsic長(zhǎng)英質(zhì)): Si, Al, Na, K etc.Table 4.1 Magma Classifications （巖漿的分類(lèi)）Magmatism巖漿作用巖漿作用Magmatism（巖漿作用）is the development, movement, and solidification to igneous rock, of magma. The two

17、 major processes are intrusion（侵入作用）and extrusion（侵出作用）or eruption（噴出作用）.Intrusion forms intrusive rocksplutonic rocks（深成巖）that have a depth of more than 3 kilometers from the surface of the Earth and hypabyssal（淺成巖）rocks that have a depth of 1.5 to 3 km.Extrusion or eruption forms extrusive rocks（侵

18、出巖）or volcanic rocks（火山巖）that form on the surface of the Earth.Eruption and extrusive rocks (volcanic rocks) 噴出作用與侵出巖（火山巖）噴出作用與侵出巖（火山巖）Eruption （噴發(fā)作用）(Volcanism火山作用) is the ejection（噴射）of volcanic materials onto the surface of the Earth.A volcano（火山）is a vent（通道）in the surface of the Earth through w

19、hich magma and associated gases and ash erupt（噴發(fā)）; It is also, the form or structure, usually conical（圓錐狀的）, which is produced by the ejected materials. A volcano has a cone（火山錐）, a crater（火山口）or craters (calderas破火山口), a vent (or vents火山通道), a neck（火山頸）and a magma chamber（巖漿房）. http:/library.thinkq

20、uest.org/17457/volcanoes/erupt.php Structure of a V.au/./earth/volcanism.htm http:/www.kidscosmos.org/kid-stuff/mars-trip-graphics/volcano-diagram.gif 熔巖氣體，火山灰，熔渣火山口巖脈火山通道巖床Chamber 巖漿房巖漿房The products of eruption噴發(fā)作用的產(chǎn)物噴發(fā)作用的產(chǎn)物The main products of eruption are lava, gases and solid materials.Lava（熔巖）i

21、s the magma that has reached the surface of the Earth, or the rock that is solidified from it. When magma erupts onto surface and lost volatile materials it becomes lava.Gases（氣體） are volatile materials such as, H2O, CO2, H2S, SO2, CO, H2, HCl, NH3 etc.Solid materials（固體物質(zhì)）：are volcanic debris (pyro

22、clasts火山碎屑巖 and tephra火山灰，火山碎屑).Fig.4.1 Basaltic lava flow found in Wudalianchi, Heilongjiang Province, China (Photo by Hongbo Lu on Sept. 12, 2004) Fig.4.3 The black blocks of obsidian 黒曜巖(volcanic glass火山玻璃) (Adopted from http:/volcanoes.usgs.gov ) Fig.4.4 Pumice specimen from Wudalianchi, Heilong

23、jiang Province, China(Photo by Hongbo Lu on Sept. 17, 2004)浮巖，泡沫巖 Fig.4.5 Reticulite erupted from Kilauea Volcano, Hawaii (Adopted from http:/volcanoes.usgs.gov/Products/Pglossary/reticulite.html )Reticulite 網(wǎng)狀巖網(wǎng)狀巖 Fig.4.6 A fusiform (spindle) bomb （紡錘形火山彈）(Adopted from http:/www.gc.maricopa.edu/ear

24、thsci/imagearchive/bombs.htm )A volcanic bomb from Dalinoer, Inner Mongolia Photo by Hongbo Lu, 2007 幾維鳥(niǎo)（幾維鳥(niǎo)（ kiwi）形火山彈）形火山彈 Fig.4.7 Volcanic ash collected in Randle, Washington, USA (left) and SEM (scanning electron microscope) image (right)(Adopted from http:/volcanoes.usgs.gov/Products/Pglossary/

25、ash.html )Volcanic ash 火山灰火山灰電子顯微鏡下的火山灰電子顯微鏡下的火山灰Typical composite volcano. http:/pubs.usgs.gov/gip/volc/types.html Fig.4.11 The internal structure of a typical shield volcano(Adopted from http:/pubs.usgs.gov/gip/volc/types.html )Fissure eruption裂隙式噴發(fā)裂隙式噴發(fā)Central eruption中心式噴發(fā)中心式噴發(fā) Fig.4.12 Aa lava

26、(left) and pahoehoe lava (right)Wudalianchi, Heilongjiang Province, China (Photos by Hongbo Lu on Sept. 12, 2004)Aa lava 阿丫熔巖阿丫熔巖pahoehoe lava 繩狀熔巖繩狀熔巖 Fig.4.13 Pillow lava forming off Hawaii (left) and accretionary lava ball in Wudalianchi (right)(Left: http:/www.pmel.noaa.gov/vents/nemo/explorer/c

27、oncepts/pillows.html ) (Right: photo by Hongbo Lu, September, 2004)Pillow lava 枕狀熔巖枕狀熔巖Accretionary lava ball增生熔巖增生熔巖球球Columnar jointing（柱狀節(jié)理）is a kind of structure often formed in basaltic flows as a result of contraction during cooling of lava. Columnar jointing is a kind of parallel, prismatic co

28、lumns, either hexagonal or pentagonal in cross section (sometimes more than 6 or less than 5 columnar faces). Fig.4.14 Columnar jointing in the Cenozoic basalt, Changle, Shandong, China (Photo by Hongbo Lu in 2005)Columnar jointing 柱狀節(jié)理柱狀節(jié)理山東昌樂(lè)火山口下玄武巖中發(fā)育的柱狀節(jié)理山東昌樂(lè)火山口下玄武巖中發(fā)育的柱狀節(jié)理(Photo by Hongbo Lu in

29、 2005)Columnar jointing in the Cenozoic basalt, Changle, Shandong, China (Photo by Hongbo Lu in 2005) Columnar jointing found in the Upper Cretaceous sandstone, Darfur Province, Sudan (Photo by Hongbo Lu, 1995) Lava tubes in Wudalianchi, Heilongjiang Province, China (left) and in Hawaii (right) (Lef

30、t photo by Hongbo Lu, and the right one adopted from http:/volcanoes.usgs.gov )Lava tubes 熔巖隧道熔巖隧道Hornito（熔巖丘，熔巖錐）is a small rootless spatter cone（寄生熔巖錐）that forms on the surface of a basaltic lava flow (usually pahoehoe) is called a hornito. A hornito develops when lava is forced up through an open

31、ing in the cooled surface of a flow and then accumulates around the opening. Typically, hornitos are steep sided and form conspicuous（顯著的）pinnacles（小尖塔）or stacks（煙囪）(Fig. 4.17). They are rootless because they are fed by lava from the underlying flow instead of coming from a deeper magma conduit（管道）.

32、 A hornito cone atop the surface of the lava flow, Wudalianchi, Heilongjiang, China (Leftside view; righttop view. Photos by Hongbo Lu on Sept. 12, 2004)Hornito 熔巖丘熔巖丘Fumarole 噴氣孔噴氣孔 (http:/volcanoes.usgs.gov/Products/Pglossary/fumarole.html )Fumaroles（噴氣孔）are vents from which volcanic gas escapes i

33、nto the atmosphere (Fig. 4.18). Fumaroles may occur along tiny cracks or long fissures, in chaotic clusters or fields, and on the surfaces of lava flows and thick deposits of pyroclastic flows. They may persist for decades or centuries if they are above a persistent heat source or disappear within w

34、eeks to months if they occur atop a fresh volcanic deposit that quickly cools. Fig. 4.18 Close view of a fumarole on Kilauea Volcano: Elemental sulfur vapor escaping from the fumarole has cooled to form yellow-colored crystals around its margins (Photo by R.L. Christiansenon）Distribution of active v

35、olcanoes in the world世界活火山的分布世界活火山的分布More than 500 active volcanoes are distributed along the following four belts:Peri-Pacific-Ocean belt (fire ring): at subduction zone between continents and the ocean.Oceanic ridges: at divergent zone in oceans.MediterraneanIndonesian belt: collision belt between

36、 continents.Red SeaEast African Rift: divergent zone in the continent.Fig.4.19 A world map showing plate boundaries (blue lines), the distribution of recent earthquakes (yellow dots) and active volcanoes (red triangles). (Adopted from http:/www.geology.sdsu.edu/how_volcanoes_work/Volcano_tectonic.ht

37、ml )Intrusion（侵入作用）is the process of emplacement of magma in preexisting rock, forming igneous rock mass within surrounding rock. The igneous rock formed this way is called intrusive rock（侵入巖）and the surrounding rock hosting the intrusive body（侵入體）is called country rock（圍巖）. http:/artsandscience.con

38、cordia.ca/GEOG/course_notes/civi231/igneous_rock.htm Intrusion and intrusive rocks 侵入作用與侵入巖侵入作用與侵入巖Assimilation同化作用 and hybridization混染作用 A magma rising through the crust may assimilate（同化，吸收）country rock material as it passes from its source area to its site of crystallization. The assimilated mate

39、rial will change (contaminate) the chemical signature of the magma, resulting in a new liquid, which when solidified will be distinctly different from the original, uncontaminated magma.A sketch diagram showing xenolith and roof pendant in relation to intrusive body and country rock (1country rock;

40、2intrusive body; 3xenolith; 4roof pendant)Table 4.3 Bowens Reaction Series （鮑溫反應(yīng)序列）Discontinuous reaction series不連續(xù)系列Continuous reaction series連續(xù)系列Temperature /Color溫度/顏色 SiO2 in weight二氧化硅重量比IntrusiveRock 侵入巖ExtrusiveRock侵出巖、噴出巖Olivine橄欖石 Pyroxene 輝石 Amphibole 角閃石 Biotite 黑云母(Ca-rich) Plagioclase斜長(zhǎng)

41、石(Na-rich)High/DarkLow/LightUltrabasic45%Basic52%Intermediate65%AcidicPeridotite橄欖巖Gabbro輝長(zhǎng)巖Diorite閃長(zhǎng)巖Granite花崗巖Kimberlite金伯利巖Basalt玄武巖Andesite安山巖Dacite英安巖Rhyolite流紋巖 Potassium feldspar鉀長(zhǎng)石Muscovite白云母Quartz石英Bowens Reaction Series Texture and structure of igneous rocks 火成巖的結(jié)構(gòu)構(gòu)造火成巖的結(jié)構(gòu)構(gòu)造Texture（結(jié)構(gòu)）and

42、 structure（構(gòu)造）can be understood in the laboratory when we examine rock samples. Texture often refers to the minerals crystallization and grain size of an igneous rock, while structure indicates the form of mineral assemblage of an igneous rock.Aphanitic（隱晶質(zhì)的）minerals are too small to be seen with th

43、e unaided eye. These rocks must be studied with the microscope or by geochemical（地球化學(xué)的）methods. Volcanic rocks (extrusive) are at least partially aphanitic due to rapid cooling. Glassy lava cools so rapidly that the crystals dont have time to grow (unordered atomic arrangement) Example: obsidian.Pha

44、neritic（顯晶質(zhì)的）mineral grains can be seen with the unaided eye. Plutonic (intrusive) rocks are totally phaneritic due to slow rates of cooling. Pegmatite（偉晶花崗巖）is a kind of very coarse-grained rocks which crystallize from water-rich magmas. The water in these magmas lowers the viscosity and allows exc

45、essive ion migration and crystallization.Porphyritic texture（斑狀結(jié)構(gòu)）shows two distinct crystal sizes (can be either porphyritic or aphanitic). Larger crystals (phenocrysts斑晶) are surrounded by finer-grained crystals or glass (groundmass基質(zhì)). This texture records two distinct cooling histories.Andesite

46、line（安山巖線(xiàn)）: Along the Andes there are andesites (extrusive rocks); at the side of land there are intermediate and acidic rocks, while at the sea side there are basaltic rocks. So geologists call this line Andesite line.Geothermal gradient（地溫梯度）is the rate of increase of temperature in the Earth with

47、 depth. In the crust it is about 3oC/100m, but the rate decreases with the depth below the surface of the Earth.Table 4.4 Major igneous rocks （主要的火成巖）ClassificationSiO2% Major minerals(assemblages)ColorindexIntrusive rock侵入巖Extrusive rock噴出巖Ultrabasic rocks超基性巖 75Peridotite橄欖巖rare, such as Kimberlite金伯利巖Basic rocks基性巖4552Pyroxene輝石, Ca-rich plagioclase3575Gabbro輝長(zhǎng)巖Basalt玄武巖Intermediate rocks中性巖5265Amphibole角閃石,Andesine中長(zhǎng)石2035Diorite閃長(zhǎng)巖Andesite安山巖Acidic rocks酸性巖 65Quartz石英,Na-rich plagioclase斜長(zhǎng)石Potassium feldspar鉀長(zhǎng)石 20Granite花崗巖Rhyolite流紋巖建筑裝飾材料建筑裝飾材料-環(huán)斑花崗巖環(huán)斑花崗巖 Rapakivi Granite石英石英鉀長(zhǎng)石斑晶鉀長(zhǎng)石斑晶