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archean n.,adj.= Archaean.

arched

The comparison of cenozoic basalts and their mantle xenoliths from both sides of the taihangshan gravity lineament reveals that : ( 1 ) cenozoic basalts from western and eastern north china display opposite temporal trends , suggesting lithospheric thinning in western north china during the cenozoic and lithospheric thickening in eastern north china ; ( 2 ) the lithospheric mantle in the west is mostly late - archean to proterozoic in age , whereas that in the east has a modern age with minor proterozoic age ; ( 3 ) the crust mantle transition in the west is considerably thicker than in the east , probably due to different extents of magmatic underplating 摘要通過對比華北太行山重力梯度帶兩側新生代玄武巖及其中幔源包體的成分,發現: ( l )華北東、西部新生代玄武巖具有相反的演化趨勢,說明新生代以來西部巖石圈逐漸減薄,而東部巖石圈逐漸加厚; ( 2 )西部巖石圈地幔組成相對復雜,年齡多為晚太古代元古代;而東部巖石圈地幔組成相對單一,年齡多為現代值,少數為元古代; ( 3 )西部殼幔過渡帶較厚而東部較薄,反映兩地不同的巖漿底侵作用程度。

In the light of tectonic evolution stage and metallogenesis , these metallogenic system ( assemblage ) could be classified as follows : ( 1 ) the pre - divergent metallogenic system in the southwest margin of north china paleocontinent in the archean - meso proterozoic : dongdashan iron , jinchuan nickel - copper . ( 2 ) the divergent metallogenic system in the northern margin of the qaidam paleoplate in the middle - late proterozoic : huashugou - liugouxia iron . ( 3 ) the metallogenic system in the active margin in the early paleozoic : the metallogenic assemblage in the island arc - rift in the early stage ( baiyinchang - qingshuigou copper - polymetallic ) ; the metallogenic assemblage in island arc in the middle - late stage ( honggou - jiaolongzhang copper - polymetallic ) ; the back - arc extensional basin ( zhuzhuiyaba - jiugequan - shijuli copper ) ; the metallogenic assemblage in connection with subduction and magmatic - hydatogenesis ( taergou - xiaoliugou wolfram ; huashugou - liugouxia copper ; dadonggou - diaodaban lead - zinc ) ; the metallogenic assemblage is related to the oceanic crustal shards ( dadaoerji chromite ; yushigou chromite ) . ( 4 ) the metallogenic system has something to do with collision - type orogeny : the metallogenic assemblage in foreland basin ( tianlu copper ) ; the metallogenic assemblage with the intracontinental orogeny and ductile shear ( hanshan - yingzhuishan gold ) 根據構造發展階段和成礦作用特點,確定本區成礦系統及組合如下: ( 1 )華北板塊西南邊緣太古宙中元古代裂解期前成礦系統:東大山鐵成礦組合,金川鎳銅成礦組合; ( 2 )柴達木板塊北緣中、新元古代裂解成礦系統:樺樹溝柳溝峽鐵成礦組合; ( 3 )加里東期活動大陸邊緣成礦系統:早期島弧裂谷成礦組合(白銀廠清水溝銅及多金屬成礦組合) ,中、晚期島弧成礦組合(紅溝蛟龍掌銅及多金屬成礦組合) ,弧后擴張盆地成礦組合(豬咀啞巴九個泉石居里銅及多金屬成礦組合) ,與俯沖作用有關的巖漿熱液成礦組合(塔爾溝小柳溝鎢成礦組合,樺樹溝柳溝峽銅成礦組合,大東溝吊大坂鉛鋅成礦組合) ,洋殼殘片成礦組合(大道爾吉鉻成礦組合,玉石溝鉻成礦組合) ; ( 4 )碰撞造山成礦系統:前陸盆地成礦組合(天鹿銅成礦組合) ,陸內造山韌性剪切成礦組合(寒山鷹咀山金成礦組合) 。

Abstract : to the principle and project that tu guangazhi proposed in 1990 , the gold ore deposits in qinling ( shaanxi ) may be classified into fouowing types : archean high - grade gneiss type , fine grained fragmental rock - carbonate rock - silicilith type , metamorphic fragmental rock type , volcanic rock type , explosive breccia type , intrusive rock exo - and endo - contact zone type . inthis paper , the geological characteristics , metallogenic geological setting , the source of ore - forming materials , digenic mechanism and metallogenetic epoch of gold ore deposits are also discussed 文摘:參照涂光熾先生( 1990 )提出的礦床類型劃分原則與金礦分類方案,將陜西秦嶺地區原生金礦劃分為太古界綠巖建造型、細碎屑巖-碳酸鹽巖-硅質巖建造型、變質碎屑巖型、火山巖建造型、隱爆角礫巖型和侵入巖內外接觸型金礦,并對各類型金礦的地質特征、成礦地質背景、成礦物質來源、礦床形成機制及形成時代等問題進行了論述和討論。

2 . 6 2 . 7ga , these granitoids are most likely to be derived from the partial melting of hybrids both 2 . 6ga metavolcanic materials in archean wutaishan magmatic arc and older continent crustal materials under lower than 1 . 2gpa . petrological and geochemical characteristics of wangjiahui granitoid intrusion suggest that is probably fored under post - collisional tectonic background 2 . 1ga在- 3 . 82 - 2 . 80范圍,表明王家會古元古代花崗巖最有可能形成于大約2 . 6ga五臺山大洋島弧火山巖物質和更老的陸殼物質在

Based on the study of the 1 : 50000 geological mapping and field survey in some places , the rock groups of proterozic alashan group that was mapped by 1 ? 200000 geological survey in 1978 may be correlated the neo - archean seertengshan group in middle inner mongolia , and the third bed of zhuzhongmaodao formation is actually a series of structural conglomerate 摘要通過巴彥諾日公地區1 / 5萬地質填圖和重點解剖研究,認為原1 / 20萬區調中所劃下元古界阿拉善群大部分巖石組合可與內蒙古中部地區色爾騰山巖群進行對比,且祖宗毛道組三段實際上是一套構造礫巖。

The research for metallogenic evolution mechanism in the region indicates that gold ore formation has undergone three stages : gold elementary source bed formation stage from the neo - archean to the paleo - proterozoic and meso - proterozoic , regional metamorphism - migmatization gold reenrichment stage at the late meso - proterozoic , structure - fluid - gold mineralization stage at the yanshan period 對礦帶成礦演化機理的研究表明,金礦形成經歷了3個階段:新太古至古、中元古代金初始礦源層形成階段;中元古代末期區域變質混合巖化金再富集階段和燕山期構造流體金成礦作用階段。

In this paper , the authors used such geophysical exploration methods as the high - precision geomagnetic method , the resistivity profiling method and the induced polarization method to synthetically study the exhausted areas of the archean sedimentary metamorphic iron mines in eastern hebei , built an effective geophysical exploration combination model for the exhausted areas , and summarized the serviceability and validity of various geophysical exploration methods in the exploration of exhausted areas under different geological settings 摘要應用高精度磁法、電阻率剖面法、激發化法等常規地球物理勘查方法對冀東地區太古宙沉積變質鐵礦采空區進行綜合研究,建立冀東鐵礦采空區有效的地球物理勘查組合模型,總結不同地質環境條件下各種地球物理勘查方法在冀東鐵礦采空區勘探中的適用性和有效性。

According to the constructive principles of these diagrams , the following aspects must be thought carefully : the rock types to be studied must be the same or nearly the same as those that can be discriminated by the diagram ; to avoid mixed or incorrect signals that could be produced , two or more such diagrams shall have to be jointly used ; for special rock types , such as a - type granites or potassic igneous rocks , special discriminative diagrams have to be determined and selected respectively ; the samples to be studied can not be altered ; in general , the diagrams must be used carefully with archean samples ; the petrotectonic assemblage or an expert system are recommended to be used together with the discrimination diagrams 強調指出:所采集的樣品必須新鮮(無蝕變或極弱蝕變) 、非堆晶的巖石;選擇的判別圖解必須與判別的巖石類型相一致,即對花崗巖類要用花崗巖的判別圖解,不能用玄武巖的判別圖解;對特殊類型巖石要選擇專門用于該類型巖石的判別圖解,如堿性花崗巖,鉀質火成巖;要應用多種圖解綜合判斷;不能用單個樣品,而應作多個樣品分析;要注意所選擇判別圖解的特別說明等。

Four tectonic evolution phases have been made out in this area . they are original crust formed in the archean - early proterozoic era , continental crust shearing in the middle - new proterozoic era , plate tectonic developed in sinian - triassic period and intracontinental orogeny in the middle cenozoic period 將區內構造演化歸納為太古?早元古代原始地殼形成、中新元古代大陸地殼裂解、震旦?三疊紀板塊構造體制、中新生代陸內造山等四個演化階段。

It agrees with the fact that the gabbro is intruded by late ordovician granitic pluton . the pre - sinian basement strata exposed in the north kunlun massif are later archean - neoproterozoic milan group , changcheng system kaqiang group , jixian system liushui formation and qingbaikou system sulu formation 被蛇綠巖所分隔的昆北地塊上出露的前震旦紀基底地層為:晚太古代-新元古代米蘭巖群,長城系卡羌巖群,薊縣系流水巖組和青白口系絲路巖組。

Through the ree charactheristics being studied , it suggests that the xenoliths from hannuoba , ximeng , and puning area have no the trend of lree enrichment , which ratios of lree / hree approximate 1 . therefore , , it is not different from archean lithospheric mantle 稀土元素地球化學研究表明,漢諾壩、錫盟、普寧等地區包體則無lree富集的趨勢, lree hree接近于1 ,因此它們與太古代巖石圈地幔不同,稀土元素特征表明它們遭受了強烈虧損。

The paper analysis the geological feature of wuyang iron doposit , it study the archean geohistory of wuyang iron deposit , the paper research the developed process of zhao - an iron deposit and tie shan iron deposit , matemorphic effect , oxidation remake process of the iron deposit 摘要分析了舞陽鐵礦地質概況,追溯了舞陽鐵礦田太古代古地史和趙案莊式鐵礦、鐵山廟式鐵礦的形成過程以及變質作用,氧化作用對礦床的改造作用過程。

The peak is composed of banded biotite tonalite of fine mediate grain developing in mengshan rock suit of fuping period of archean era about 2 . 7billion years ago . it ' s very steep 由27億年左右形成的太古代阜平期蒙山巖套條帶狀中細粒黑云母英云閃長巖構成,柱狀節理發育,差異性風化剝蝕作用強烈,組成云蒙“山”峰,俗稱“掛心崛子” ,形容云蒙峰之陡峻。

Alternatively , the continental collision models postulated that the ncc consists of two archean blocks ( the eastern and the western ) , separated by ca . 1800 ma proterozoic erogenic belt 而大陸碰撞拼合模型認為華北陸塊東部帶和西部帶于1870 - 1800ma沿中部帶碰撞拼合, 1800 - 1750ma左右發生強烈的碰撞后伸展作用。

Isua ' s four - kilometer - wide belt of archean rocks stretches 35 kilometers along the western edge of the bluish - gray monolith of the greenland ice cap 這片礦藏可不好找,它是四公里寬的太古代巖層,沿著藍灰色格陵蘭冰帽硬塊的西緣延伸35公里。

On the age of metamorphic rocks of the yudongzi group and the archean crystalline basement of the qinling orogen 魚洞子群變質巖年齡及秦嶺造山帶太古宙基底

Such low levels of sulfate indicate that the archean atmosphere was virtually devoid of oxygen 如此低的硫酸鹽濃度,表示太古代大氣中的氧氣極為稀薄。

The nickel mineralization is contained in a layered basic mass if surrounded and underlain by an archean gneiss complex . 此處鎳礦化產于一層狀基性巖塊內,其四周和下面都為太古代片麻巖雜巖圍繞。