?dolomite

dolomite發(fā)音

英：['d?l?ma?t]　　美：['d?l??ma?t]

英：　　美：

dolomite中文意思翻譯

n.白云石

dolomite詞形變化

名詞: dolomitization | 動(dòng)詞: dolomitize | 形容詞: dolomitic |

dolomite常見例句

1 、The Huanggoushan Pb Zn deposit,occurring in the dolomite marble of Mesoproterozoic Zhenzhumen formation,is obviously controlled by strata.───吉林荒溝山鉛鋅礦床賦存于中元古界老嶺群珍珠門組白云石大理巖中,層控特征明顯。

2 、In most parasequences, dolomite in the lower part seems coarser than that in the upper part, and within most beddings pressure solution also occurs more likey at the bottom than in the upper part.───壓溶作用形成的縫合線在層組底部的出現(xiàn)概率遠(yuǎn)大于層組上部。

3 、Slag resistance of dolomite refractories under different conditions───不同條件下白云石耐火材料抗侵蝕性的研究

4 、Dolomite reservoir is regarded as one of the most important carbonate reservoir, and the dolomitization is the prerequisite for the development of high-quality carbonate reservoirs in Sichuan Basin.───四川盆地海相碳酸鹽巖白云石化埋藏成因模式與混合水模式受到廣泛質(zhì)疑，可能為熱液成因。

5 、The most common minerals in seep carbonates are microcrystalline calcite, microcrystalline aragonite and dolomite, and pyrite as well.───冷泉碳酸鹽巖的常見礦物有微晶方解石、文石、白云石和黃鐵礦。

6 、Application of JASON in dolomite reservoir prediction in Miyang sag───JASON軟件在泌陽(yáng)凹陷白云巖儲(chǔ)層預(yù)測(cè)中的應(yīng)用

7 、For lime, magnesite and dolomite kiln plants───為石灰,菱鎂礦和白云石石灰工廠

8 、The reaction mechanism of carbonation for the production of light magnesium carbonate from dolomite is discussed.───探討了白云石碳酸化法生產(chǎn)輕質(zhì)碳酸鎂過(guò)程中碳酸化反應(yīng)機(jī)理。

9 、Incongruent dissolution of calcite and dolomite───方解石與白云石的非全等溶解

10 、A major topic is the origin of dolomite.───主要話題是白云巖的起源。

11 、It is estimated that about half of the carbonate oil and gas reservoirs in North America are in dolomite.───據(jù)估計(jì)，北美的碳酸鹽巖油氣藏有一半是在白云巖內(nèi)。

12 、The Juventus players have received a warm reception in the Dolomite resort of Pinzolo where their pre-season preparations are in full swing and the fans are in confident mood.───“尤文在多羅密特·皮佐羅度假，受到了很好的接待，那里他們?nèi)缁鹑巛钡臏?zhǔn)備新賽季，球迷也充滿信心?！?/p>

13 、Moreover, two types of cements of limnic calcite and limnic dolomite and hydrothermal dolomite of reburial period are included in the karst rocks.───巖溶巖中發(fā)育有淡水方解石和淡水白云石2種膠結(jié)物類型，以及再埋藏期沉淀的熱液異形白云石。

14 、They are made from different materials? Dolomite, tough silk, organdie etc.───它們是用不同的材料做的,白云石、綃、蟬翼紗等。

15 、Selecting natural dolomite as raw materials, the authors made a new kind of pearl nuclei through mechanic grinding and surface treatment.───摘要篩選天然白云巖為原料，采用機(jī)械磨削和表面處理等工藝，制成新型珠核。

16 、Tacan Well 1 , as the first ultra-deep exploratory well in Tarim so far, encountered severe wellbore collapsing and hardly continue drilling in dolomite formation.───塔參1井是迄今為止在塔里木盆地鉆成的陸上第一超深井。該井在鉆進(jìn)奧陶系、寒武系白云巖地層時(shí)，井眼發(fā)生嚴(yán)重坍塌，導(dǎo)致難以繼續(xù)鉆進(jìn)。

17 、Calcium-based sorbents such as limestone and dolomite are widely used as desulphurizers in a FBC. The measurement methods of sorbent characteristics and an evaluation system are described.───介紹了流化床燃燒脫硫過(guò)程中脫硫劑反應(yīng)活性的測(cè)試方法,并提出一種脫硫劑性能的評(píng)價(jià)標(biāo)準(zhǔn)與體系,為經(jīng)濟(jì)高效選取脫硫劑提供理論指導(dǎo)。

18 、The influence of adding dolomite fines on sintering technico-economic indices was investigated in laboratory,with modeling the conditions of plant site.───在實(shí)驗(yàn)室條件下,以模擬生產(chǎn)現(xiàn)場(chǎng)的方式,研究了添加白云石粉對(duì)燒結(jié)技術(shù)經(jīng)濟(jì)指標(biāo)的影響。

19 、There are two types of fractures in the muddy gravel and the tuffaceous dolomite in Qingxi oilfield, Jiuquan Basin.───摘要甘肅酒泉盆地青西油田泥礫巖相和泥云巖相儲(chǔ)層中發(fā)育兩種裂縫系統(tǒng)。

20 、In dolomite reservoir,the acidizing fluid leakoff is one of the key factors for the acid fracturing effects.───在白云巖儲(chǔ)集層中，酸液濾失是影響酸化壓裂效果的關(guān)鍵參數(shù)之一。

21 、The constructive diagenesis are primarily dolomization and dissolution.The pore types primarily are dolomite intercrystal pores and solution pores.───建設(shè)性成巖作用主要有白云石化和溶蝕作用，孔隙類型主要為白云石晶間孔及溶蝕孔。

22 、Most dolomite is obviously the result of replacement of precursor calcite but certainly not all.───多數(shù)白云石顯然是原來(lái)方解石交代的結(jié)果，但肯定不是全部。

23 、Yingmaili upper cambrian qiulitage lower subgroup is the largest area of denudation exposed section of Yingmai32 area.Rock is dolomite rock.───摘要英買力地區(qū)英買32區(qū)塊為研究區(qū)內(nèi)上寒武統(tǒng)丘里塔格下亞群地層剝蝕出露面積最大的區(qū)域，其巖性為粉細(xì)晶-中晶白云巖。

24 、The argillaceous dolomite and algal dolomite discaved in Permian, which were formed probably by hybrid process in high salinity lake which had the fresh water interfused in.───二疊系**征的泥云巖和藻云巖可能是在有淡水注入的較高鹽度湖泊中經(jīng)混合作用而形成的。

25 、THE USE OF DOLOMITE IN SLAGMAKING IN BOF───怎樣正確使用白云石造渣

26 、Limestone bearing dolomite and calcitic dolomite are the main reservoir rocks with reference to the component of dolomite.───從白云巖成分上來(lái)講，含灰云巖與灰質(zhì)云巖是白云巖儲(chǔ)層的主要巖性；

27 、Especially,when dopping CeO_2,the effect of hydration-resistance of dolomite was remarkable.───尤以添加氧化鈰對(duì)提高白云石熟料抗水化性能的效果最為顯著；

28 、They are made from different materials--dolomite, tough silk, organdie, etc.───它們是用不同的材料做的，白云石、硬絲、蟬翼紗等。

29 、To understand and find favorable carbonate reservoir, characteristics of Permian carbonate reservoir in Malang sag have been reviewed which shows that they fall into two kinds: limestone and dolomite.───為正確認(rèn)識(shí)碳酸鹽巖儲(chǔ)層 ,尋找有利儲(chǔ)集區(qū) ,對(duì)馬朗凹陷二疊系碳酸鹽巖的儲(chǔ)層特征進(jìn)行了研究和論述。

30 、Ore lead, quartz porphyry lead and dolomite lead of Changcheng System have similar and relatively stable composition, implying that they might have been derived from the lo...───小青溝礦床經(jīng)歷了礦源層形成和燕山期成礦二個(gè)過(guò)程,作者建立了礦床的成礦模式。

31 、Cow-shaped ceramic tableware series, made from dolomite, environmental-friendly. Item includes: milk cups, mugs, plates, cookie jars, forks, spoons, etc.───[相關(guān)分類:成套餐具,一次性餐具,紙杯，盤子，食品托盤

32 、The phosphate mineral in the ore is cellophane, in which I dispersed and the associate mineral is dolomite.───伴生礦物以白云石為主；碘呈分散狀態(tài)賦存于**酸鹽礦物中；

33 、Feixianguan Formation of lower Triassic is an important reservoir, which mainly consists of the dense oolitic dolomite and limestone altered by the late dolomitization of oolitic bars.───摘要四川盆地東北部的三疊系下統(tǒng)飛仙關(guān)組是重要的油氣儲(chǔ)層，其儲(chǔ)集巖體主要為經(jīng)晚期白云巖化改造的鮞灘壩沉積的致密鮞粒白云巖、鮞?；?guī)r。

34 、The reservoir rocks are the Archaean migmatitic granite,biotite plagiogneiss,leucogranulitite and cataclasite and the Middle Proterozoic dolomite and quartzose sandstone.───巖石儲(chǔ)集空間以密集發(fā)育的微觀裂縫系統(tǒng)為主,宏觀裂縫系統(tǒng)主要起滲流通道作用。

35 、There is abundant karst fissure water in the limestone and dolomite of Cambrian and Ordovician.───寒武系、奧陶系地層主要為灰?guī)r和白云巖,其間賦存有較豐富的巖溶裂隙水。

36 、The reservoir rocks include contain oolitic limestone, micritic dolomite and residual oolitic dolomite, of them the residual oolitic dolomite is the best reservoir.───指出該類氣藏儲(chǔ)集巖主要有殘余鮞粒白云巖、鮞粒灰?guī)r和泥-粉晶白云巖，其中殘余鮞粒白云巖是最好的儲(chǔ)層；

37 、Pass the iron ore, barite, limestone, dolomite, 5 kinds of clay minerals modeling UN top three in Gansu Province.───嘉峪關(guān)的鐵礦、重晶石、石灰石、白云巖、造型粘土5種礦種居甘肅省前三位。

38 、And the main reservoirs include Cambrian sandstones, Ordovician sandstones and Triassic sandstones.Thick marls, dolomite, anhydrite and rock salt are excellent regional seals.───主要儲(chǔ)層包括寒武系、奧陶系和三疊系砂巖，區(qū)域良好蓋層是巨厚的泥灰?guī)r、白云巖、硬石膏和巖鹽。

39 、unfired brick of dolomite agglomerated with tar───與焦油凝結(jié)的白云石制未焙燒磚

40 、We found calcite, dolomite and a few cinnabar samples there.───我們?cè)诙磧?nèi)找到一些方解石、白云石及少量辰砂晶體。

41 、The rocks around Austin are mostly limestone, but dolomite, clay, basalt, tuff, sandstones, and river gracel are also present.───奧斯汀的巖石大部份是石灰?guī)r,但也有大理石,粘板巖,玄武巖,凝灰?guī)r,沙石等。

42 、We have vast collection of Cups and Saucers made of Porcelain, Dolomite, Ceramic and Melamine to suit your requirements. Please contact us for more details.───[相關(guān)分類:促銷禮品,杯子和啤酒杯,廚房附件,茶具和咖啡具,其它餐具

43 、A study of new pearl nuclei of dolomite───新型白云巖珠核的研究

44 、The ground floor there are oil, natural gas, coal, geothermal, limestone, dolomite, hard iron bauxite and other mineral resources, rich reserves, the exploitation of high value.───地下蘊(yùn)藏著石油、天然氣、煤炭、地?zé)?、石灰?guī)r、白云石、硬鐵礬土等礦產(chǎn)資源，儲(chǔ)量豐富，具有較高的開采價(jià)值。

45 、By applying DTA/T/EGD/GC on-line coupled simultaneous technique and rel-evant equipments,the trace pyrite in the dolomite was identified in air.───應(yīng)用DTA/T/EGD/GC在線聯(lián)用技術(shù)，在空氣下鑒定了白云石中的微量黃鐵礦；

46 、Marble basically is comprised by calcite, limestone, serpentine and dolomite.───大理石主要由方解石、石灰石、蛇紋石和白云石組成。

47 、Show dark amaranth or amaranth, granule structure, lump is tectonic, quality of a material is close harder, main and mineral component is dolomite, limonite to wait.───呈暗紫紅色或紫紅色,細(xì)粒結(jié)構(gòu),塊狀構(gòu)造,質(zhì)地細(xì)密較堅(jiān)硬,主要礦物成份為白云石、褐鐵礦等。

48 、Mr Ng said that marble is Dali rock is sedimentary rock, limestone from the high-pressure, high-temperature change from the impact of external factors, mainly by calcite and dolomite particles.───吳先生說(shuō)，大理石實(shí)際上是大理巖，是由沉積巖中的石灰?guī)r經(jīng)高溫高壓等外界因素影響變質(zhì)而成的，主要由方解石及白云石顆粒組成。

49 、The secondary dolomite and paleokarst of the Lower Permian Series in Sichuan Basin is one of the important atectonic reserviors in the basin.───四川盆地下二疊統(tǒng)中次生白云巖及古巖溶是下二疊統(tǒng)主要的非構(gòu)造圈閉儲(chǔ)層之一。

50 、Fluxes (burnt lime or dolomite )are fed into the vessel to form slag which absorbs impurities of the steelmaking process .───加入配料（生石灰或白云石）形成礦渣，吸收鋼生產(chǎn)過(guò)程中的雜質(zhì)。

51 、In addition, limestone, dolomite, coal, manganese, marble, granite, mineral, feldspar, muscovite, vermiculite, copper, beryl, shale, bauxite and other reserves are of sufficient size.───另外，石灰石、白云巖、煤炭、錳礦、大理石、花崗巖、麥飯石、長(zhǎng)石、白云母、蛭石、銅、綠柱石、頁(yè)巖、鋁礬土等均有相當(dāng)規(guī)模的儲(chǔ)量。

52 、In furnace sorbent injection the limestone or dolomite is injected with or without coal in the high temperature zone of the combustor where calcination and sulfation takes place and as a result removal of SO2 is achieved.───在爐內(nèi)吸附劑注入法中，石灰石或白云石在燃燒爐的高溫區(qū)同煤一起注入（或分別注入），煅燒作用和硫酸鹽化作用都發(fā)生在這個(gè)高溫區(qū)，同時(shí)可消除二氧化硫。

53 、Technique for prediction of dolomite fractured reservoir has been quite urgent for petroleum exploration and development in Biyang sag.───摘要白云巖裂縫型儲(chǔ)集層預(yù)測(cè)技術(shù)是目前在勘探開發(fā)中迫切需要解決的問(wèn)題。

54 、Locally dolomite and anhydrite are important as cements, together with minor authigenic quartz.───在局部地方白云石和硬石膏也是重要的膠結(jié)物；還有少量自生石英。

55 、Many carbonate masses older than Middle Palaeozoic are of dolomite rather than calcite.───中古生代以前的許多碳酸鹽類礦物是白云石而不是方解石。

56 、Abstract: Lacustrine dolomite reservoir in the hinterland of Biyang Sag is mainly distributed at No.2 and No.3 sections of Hetaoyuan with its development controlled mainly by the lithology diagenesis and nose?like structure.───文摘:泌陽(yáng)凹陷腹部湖相白云巖油層主要分布在核二3和核三2段,其發(fā)育程度主要受巖性、成巖作用和鼻狀構(gòu)造控制。

57 、Proterozoic dolomite and quartzite in Damintun Depression are best buried hill reservoir rocks, and study of Proterozoic distribution is of significant importance in buried hill exploration.───摘要大民屯凹陷元古界白云巖、石英巖為古潛山最佳儲(chǔ)集巖性，因而元古界分布研究在古潛山勘探中占有重要地位。

58 、TSR and its products, CO_2 and H_2S, make the dolomite and anhydrite dissolved, which increases the porosity and then improve the physical property of reservoir.───3TSR相關(guān)流體(烴類和H2S等)與儲(chǔ)層巖石之間的相互作用使儲(chǔ)層被溶蝕和硬石膏發(fā)生蝕變,造成儲(chǔ)層孔隙度增大,從而對(duì)改善其物性具有重要意義。

59 、The dolomite with high reservoir quality which is mainly formed by penetration reflux dolomitization superimposed with the burial dolomitization or hydrothermal fluid dolomitization.───儲(chǔ)集性能好的白云巖主要為滲透回流白云巖化疊加埋藏白云巖化或者熱液白云巖化作用而形成。

60 、dolomite for industrial purposes───工業(yè)用白云石

61 、For example, glasses containing MgO where dolomite is cheaper than limestone, and low alumina glasses where feldspar or feldspathic sands are at a premium.───再舉個(gè)例子,在白云石比石灰石廉價(jià)的地區(qū)出產(chǎn)的玻璃里會(huì)含MgO;在長(zhǎng)石或長(zhǎng)石質(zhì)砂價(jià)格高漲的地區(qū)會(huì)出產(chǎn)低鋁玻璃。

62 、The final stage in the production of dead burned Dolomite requires that the "Green Briquettes" produced in the briquetting area be treated by application of very high temperatures for a period of time.───在鍛燒白云石產(chǎn)品的最后工序里，要求對(duì)在塊狀區(qū)域產(chǎn)生的“綠色煤球”進(jìn)行一段時(shí)間的高溫?zé)崽幚怼?/p>

63 、Locally dolomite and anhydrite are important as cements.───局部地方白云石和硬石膏也是重要的膠結(jié)物。

64 、Keywords Calcite vein Ore quality Dolomite deposit;───方解石脈;礦石質(zhì)量;白云巖礦;

65 、Analysis is made of calcination of dolomite under controlled temperature, reaction mechanism, micro-structure, and water resistance of magnesium chloride oxide cement.───對(duì)白云石控溫煅燒、氯氧鎂水泥反應(yīng)機(jī)理、微觀結(jié)構(gòu)、抗水性等方面進(jìn)行了分析研究，并進(jìn)行了該水泥噴射混凝土的現(xiàn)場(chǎng)試驗(yàn)。

66 、The dolomite of Upper Sinian Dengying Formation is favorable ore-source rock and useful ore-preserving country rock.───上震旦統(tǒng)燈影組碎裂狀白云巖是有利的礦源層及有利的賦礦圍巖。

67 、There are not only illite, but also asphalt, microcrystalline quartz, dolomite, calcite, anorthite, gypsum, and such as potential damage materials.───儲(chǔ)層不僅含伊利石，還發(fā)育瀝青、微晶石英、白云石、方解石、鈣長(zhǎng)石和石膏等潛在損害物質(zhì)。

68 、Triassic evaporite series in Sichuan basin contains high amounts of carbonate components made up of calcite, dolomite as well as of rich magnesite.───四川盆地三疊紀(jì)蒸發(fā)巖系普遍含碳酸鹽組分,除方解石、白云石外,常出現(xiàn)大量菱鎂礦。

69 、The mechanism of dodecyl phosphate ester and water glass in flotation separation of magnesite from dolomite is described.───介紹了十二烷基**酸酯和水玻璃浮選分離菱鎂礦與白云石的作用機(jī)理。

70 、Abstract: As cement, authigenic mineral or vein, dawsonite is found not only in marine dolomite and oil shale, but also in terrigenous fragmentary rock and coal measures.───摘要: 片鈉鋁石作為膠結(jié)物、自生礦物或脈體，不僅分布在海相白云巖、油頁(yè)巖中，而且還廣泛分布在陸源碎屑巖及煤系地層中。

71 、To improve the CO2 capture capability of limestone and dolomite during cyclic calcination-carbonation reaction process it is proposed to modify the limestone and dolomite by acetic acid solution.───摘要提出了采用醋酸溶液調(diào)質(zhì)石灰石和白云石的方法來(lái)提高它們?cè)谘h(huán)煅燒-碳酸化過(guò)反應(yīng)過(guò)程中吸收CO2的能力。

72 、They are made from different materialmdashmdash;dolomite，tough silk，organdie etc.───它們是用不同的材料做的，白云石、綃、蟬翼紗等。

73 、The reservoir spaces were corroded pores ,holes and fractures in Dengying Formation dolomite .───晚侏羅世一早白堊世的燕山運(yùn)動(dòng)使其上覆蓋層抬升、剝蝕，從而使其徹底破壞。

74 、The reservoir lithologies are shallow facies crystalline dolomites, dolomitic limestone, and paleokarst dolomite breccia.───儲(chǔ)層巖性為淺灘相的結(jié)晶白云巖、白云質(zhì)灰?guī)r與古巖溶角礫狀白云巖。

75 、A new better source rock of gray dark politic micrite dolomite was found in the Jurassic Qiakemake Formation of Awate river profile.───在阿瓦特河剖面的侏羅系恰克馬克組新發(fā)現(xiàn)了一套更好的湖相灰黑色泥質(zhì)泥晶云巖源巖。

76 、Abstract : As cement, authigenic mineral or vein, dawsonite is found not only in marine dolomite and oil shale, but also in terrigenous fragmentary rock and coal measures.───摘要 ： 片鈉鋁石作為膠結(jié)物、自生礦物或脈體，不僅分布在海相白云巖、油頁(yè)巖中，而且還廣泛分布在陸源碎屑巖及煤系地層中。

77 、The County-leveled reserves of calcite,limestone,dolomite,hopfnerite,zeolite,etc.alll rank the first in China.───方解石、石灰石、白云石、透閃石、沸石等縣級(jí)儲(chǔ)量均為全國(guó)之冠。

78 、Companies specializing in the production of potassium, sodium-powder, fluorite powder, dolomite, calcite powder, widely used in glass, glass bulbs, ceramics, iron and steel industry.───公司專業(yè)生產(chǎn)鉀，鈉長(zhǎng)石粉，螢石粉，白云石，方解石粉，廣泛用于玻璃，玻殼，陶瓷，鋼鐵行業(yè)。

79 、A metamorphic rock formed by alteration of limestone or dolomite, often irregularly colored by impurities, and used especially in architecture and sculpture.───大理石由石灰?guī)r或白云巖變化而來(lái)的一種變質(zhì)巖，常有不規(guī)則的雜質(zhì)色塊，專門用于建筑和雕塑

80 、One of Portland spar, barite, magnesite, dolomite and other resources to reserves is the highest in Hebei.───其中蘭晶石、重晶石、菱鎂礦、白云巖等資源儲(chǔ)量屬河北之冠。

大理石的英文除了marble還有一個(gè)是？

還有一個(gè)是：dolomite、griotte。　　釋義：大理石，紅紋大理巖；紅紋大理石。　　大理巖原指產(chǎn)于云南省大理的白色帶有黑色花紋的石灰?guī)r，剖面可以形成一幅天然的水墨山水畫，古代常選取具有成型的花紋的大理石用來(lái)制作畫屏或鑲嵌畫，后來(lái)大理石這個(gè)名稱逐漸發(fā)展成稱呼一切有各種顏色花紋的，用來(lái)做建筑裝飾材料的石灰?guī)r。白色大理石一般稱為漢白玉，但對(duì)翻譯西方制作雕像的白色大理石也稱為大理石。關(guān)于大理石的名稱，有一種說(shuō)法—以前我國(guó)大理的大理石質(zhì)量最好，故得名。

Ro ute Geological section of the Proterozoic in Jixian

Jixian County,an ancient county(previously Yuyang County)in North China,is located at the southern foot of the Yanshan Range and in the northern outer suburbs of Tianjin municipality.It is about 90 km east of Beijing and 100 km west of Tianjin.

Well-developed Proterozoic sequences crop out in the northern parto f the Jixian area(Fig.3-6).A NW-trending syncline with a core of Cambrian rocks occurs between Hongshuizhuang and Jing'eryu villages.A thrust fault parallel to the strike of the rocks between Yangzhuang and Chuancangyu villages caused a repetition of the strata.In addition,a large N-S trending fault from Huangyaguan to Yangzhuang with ENE-trending thrusts occurs along the front of the hill,north of Jixian(Fig.3-6).

The Proterozoic geology of the Jixian area and its vicinity was firsts tudied by Gao Zhenxi(C.C.Kao)et al.in 1934.These authors and many subsequent studies provided detailed descriptions of the lithology and subdivided the rocks into formations.They also properly identified the stromatolites occurring in the rocks.Based on these works,the Jixian section has been regarded as a typical section of the Middle and Upper Proterozoic in North China.

Fig.3-6 Geological map and cross-section of Jixian and adjacent areas

1—Quaternary;2—Cambrian;3—Jing'eryu Fm.;4—Luotuolingfm.;5—Xiamaling Fm.;6—Tieling Fm.;7—Hongshuizhuang Fm.;8—Wumishan Fm.;9—Yangzhuang Fm.;10—Gaoyuzhuang Fm.;11—Dahongyu Fm.;12—Tuan Shanzi Fm.;13—Chuanlinggou Fm.;14—Changzhougou Fm.;15—Archean;16—Pluton;17—Unconformity

At the beginning of the 1970's,the Proterozoic sequences around Jixian and Yanshan Range have been studied by many geologists,and numerous papers and monographs have been published on the lithology,paleontology,geochemistry,geochronology,paleomagnetism and paleogeography of these rocks.

The Proterozoic sequences in the Jixian area are underlain by Archean rocks and overlain by lower Cambrian strata.These sequences have a total thickness of 9193 m,which can be divided into 12 formations that define 3 systems,the Changcheng,Jixian and Qingbaikou systems.

Geochronological results date the Proterozoic sequences in Jixian area as ranging ca.1800 to 850 Ma.The Changcheng System is dated at ca.1800-1 600Ma,and the Jixian System at ca.1600～1000Ma and the Qingbaikou System at ca.1000-850Ma,and these systems belong to the late Paleoproterozoic,Mesoproterozoic and Early Neoproterozoic,respectively.The stratigraphic succession of these units is described as below:

1.The Late Paleoproterozoic Changcheng System

The Changcheng system con Sists of four formations with a total thickness of 2762 m.The lowermost Changzhougou Formation rests unconformably over the Archean metamorphic Zunhua Complex-Group,and is chiefly composed of conglomerate,pebble-bearing sandstone and arkosic sandstone of fluvial origin in the lower portion and sandstone of marine facies in the middle-upper part.The second formation,the Chuanlinggou Fm.,is mostly composed of neritic shales grading upward into the dolomitic Tuanshanzi Fm.The fourth formation,the Dahongyu Fm.,co nsists o f littoral and neritic sandstone,shale and K-rich trachyte with cherty dolo stone in the upper part.

(1)The Changzhougou Formation

Location:North top of Changzhougou(40°13′03″N,117°30′47″E,494m)

Content:Unconformity between Changzhougou Formation(Chch)and Archean(Fig.3-7).

Fig.3-7 Unconformity between Changzhougou Formation and Archean in Changzhougou

A—the unconformity of Chch/Ar;B—the river conglomerate and cross-bed in Chch

The Changzho ugo u Fo rmatio n,the lo wermost unit of the Changcheng System,co nsists o f grayish purple,massive to thick-bedded co nglo merate and co arse-grained sandsto ne,pinkish and white quartz sandsto ne,sedimentary quartzite and so me thin-bedded sandsto ne,fine-grained sandsto ne,clayey and feldspathic sand Sto ne with a thickness o f 859 m.The quartzite and quartzitic sandsto ne of shallo w marine o rigin are the chief co mpo nents o f the fluvial conglomerate,and coarse grained sandstone dominates in the lower part.

So far,no stromatolites have been identitied in this formation.However,a numbero fa critarches,including ssme unicellular eukaryotes,have been identified from the intercalated beds of muddy siltstone in the upper part of the formation.

（2)The Chuanlinggou Formation

Location:Chuanglinggou(40°11′52″N,117°28′50″E,295m).

Content:Boundary of Chuanglinggou Formation/Changzhougou Formation(Chc/Chch).

The Chuanlinggou Formation consists chiefly of silty and illitic lenses.It has a thickness of 889m in Jixian area,but much less in the eastern and western parts of the Yanshan Range.

This formation can be subdivided into three sections based on the quantity of sandstone and the color of rocks.The lower section of supratidal to intertidal origin is characterized by a large amount of yellowish-green sandstone,and the middle section is composed of black shale of subtidal to lagoonal facies with many intercalations of intertidal sandstone.Mud cracks are spectacularly developed and sand veinlets are common in the sandstone of the lower section.

Acritarchs are abundant in this formation and they include the following groups:Sphaeromorphida(e.g.Leiominuscula,Margominuscula,Dictgosphaera,Kildinellaand Leiosphaerida），Scaphomorphida(e.g.Dictgosphaera,Kildinellaand Schizovalvia），Versimorphida,including blade-like,lobe-like,valve-like and band-like forms(e.g.Pholimorphaaa,Lobomorphaand Valvimorpha）：and Nematomorphida(e.g.Qingshaniaand Changchengonema).In addition,some macroscopic,ribbon-shaped fossil algae have been reported.

There are no stromatolites in this formation in Jixian area,but two horizons containing stromatolites have been found in the western Yanshan Range.

(3)The Tuanshanzi Formation

Location:40°10′32″N,117°27′59″E,291m.

Content:Tuansanzi Formation/Chuanglinggou Formation(Cht/Chc).

The Tuanshanzi Formation is composed mainly of muddy and silty,micritic dolomite with a total thickness of 518 m(Chen et al.,1980).The lower member of this formation contains abundant muddy,silty and carbonaceous material,with pyrite impregnations and black carbonaceous films on the bedding planes.In the upper member,the content of clastic material increases considerably resulting in micritic sandstone,sandy dolostone,thin-bedded sandstone and small stromatolite bioherms.

The lower member of the Tuanshanzi Formation is characterized by even bedding indicating deposition in a quiet,weakly reducing,subtidal environment(lagoonal facies）,whereas the upper part formed in an unstable environment probably between the intertidal and supratidal zones.Previously,the Tuanshanzi Formation was regarded as being poor in fossils,containing only a few of stromatolites,microfossils and doubtful megafossils dominated by Tyrasotaenia(Hofmann and Chen,1981).However,a large collection of megafossils represented by Iongfenshanids(Antiqufolia,gixianfolium and others)have been identified in the lower part of this formation in recent years,and interpreted as Paleoproterozoic megasc Opic eukaryotes Or metaphytes.

(4)The Dahongyu Formation

Location:40°10′28″N,117°28′00″E,258m.

Content:Dahongyu Formation/Tuansanzi Formation(Chd/Cht).

The Dahongyu Formation can be subdivided into two units.The lower unit consists mainly of white quartz sandstone and sandy dolostone,intercalated With purple and green tuffaceous siltstone or tuffaceous silty shale,locally accompanied by beds of volcanic breccia,tuffaceous sandstone and high-K lava.The upper section consists of micritic dolomite and cherty micritic dolomite with abundant stromatolites.A fe W poorly preserved acritarches have also been found mainly in the lower section of this formation.Some microscopic algal fossils occur in the cherty beds of the upper unit.

2.The Mesoproterozoic Ji Xian System

Disconformably overlying the Changcheng System,the Jixian system consists of five conformable formations with a total thickness of about 6088 m.The Gaoyuzhuang Formation at the base,is composed of littoral-neritic dolostone and dolomitic limestone.The overlying Yangzhuang Formation i S chiefly made up of alternating red-white marine dolostone with minor limestone.In the middle,the Wumishan Formation is composed of thick beds of siliceous dolostone intercalated with abundant cherty bands,and it grades upward into the Hongshuizhuang Formation composed dominantly of black shale.The uppermost Tieling Formation consists of shale and limestone with abundant stromatolites.

(5)The Gaoyuzhuang Formation

The Gaoyuzhuang Formation disconformably overlies the Dahongyou Formation of the Changcheng Group.Because it has sedimentary and paleontological characteristics typical of the“Jixianian System”.

This formation consists chiefly of carbonates and is subdivided into four members:

Member 1 is characterized chiefly by dark-gray cherty micritic dolomite,containing lenses of muddy and sandy dolomite.It also contains intercalations of thin-bedded,clayey,micritic dolomite and shale or silty shale.In addition,a bed of sandstone,about three meters thick,with ripple marks occurs at the base,where it overlies an erosional surface.

Member 2 could be further subdivided into two parts.The lower part consists of thin-bedded manganiferous,sandy micritic dolomite intercalated with dolomitic siltstone.Thick-bedded to massive dolomite with wavy bedding surfaces and large-scale ripple marks makes up the upper part of this Subformation.

Member 3 i S characterized by dark-gray muddy dolomite,calcareous micritic dolomite and dolomitic and micritic limestone with platy bedding,intercalated with some clastic layers and nodular limestone.

Member 4 begin S with dark,thick-bedded,calcareou S dolomitic micrite and dolomite,interca-lated with black,bituminous and muddy dolomite.This passes upward into gray,micritic dolomite with siliceous layers.All of these rocks in the upper part are thin-bedded and contain wavy bedding and cherty concretions.

The Gaoyuzhuang Formation contains various fossils.Stromatolites occur mainly in member 1 and are represented by Confusoconophytonmultiangulum,Gaoyuzhuangiacrassibrevis,G.Bulbosa,G.gaoyuzhuangensis,Tabuloconigera paraepiphyta,Conophyton garganicum and C.cylindricum.Microfossils interpreted as microscopic algae occur mainly in the cherty rocks of member 1.Although the microfossils are poorly preserved in the Jixian area,they are abundant in the same horizon in adjacent areas.Acritarchs are generally sparse and poorly preserved in the formation,and occur only member 1 and 3.The carbonaceous megafossils are represented by G.rvpaniaspiralis(namely Sangshuaniaspiralis,S.sangsuanensis and S.buccinata)and they occur only in the lower part of member 3.

(6)The Yangzhuang Formation

The Yangzhuang Formation consists of brick-red argillic,silty micritic dolomite with alternating white layers.Near both the base and top of the unit,there are thick layers of siliceous micritic or sparry dolomite.Many of the red layers have small,white spots.

This formation is subdivided into three members based on lithology.Both the lower and middle members contain ripple marks,mud cracks,cross-beds,and gypsum and salt casts indicating that they formed in supra-and intertidal lagoonal environments in a hot,dry climate.However,these features are absent in the upper member,which consists of bituminous dolostone.The Se rocks probably formed in a hot,wet,lagoonal environment.

Fossils are sparse and poorly preserved in the Yangzhuang Formation.Only some small stromatolites(Microstylus,Scyphus,Yangzhuangia)and a few achritarchs have been found in the lower and upper members.

(7)The Wumishan Formation

The Wumishan Formation,with a thickness of3336m,makes up one third oft he total Proterozoic section in the Jixian system.The rocks of this formation are rich in organic matter and show many cycles,suggesting deposition in a tidal environment.This formation includes four members:

1)The Lozhuang Member

The lower part of this unit contains alternating layers of white,muddy to silty,micritic dolomite,banded cherty micritic and sparry dolomite with intercalations of bituminous dolostone.The upper part is composed mainly of gray and dark-gray,medium-to thick-bedded,sparry dolomite with bands of chert and black,bituminous dolostone.These microbial deposits are characterized by small,wavy,laminated and columnar stromatolites.

2)The Mopanyu Member

This member consists chiefly of white silty to shaly micritic dolomite and thick-bedded stromatolitic,sparry dolomite.Chert layers,chert concretions and flat-pebble cherty conglomerates occur in the lower part of the unit.The upper part contains some thick-bedded,bituminous sparry dolomite with wavy laminae of algae,with several large,conic stromatolitic and silicified oolitic beds atthe top.

3)The Ershilipu Member

This member is subdivided into a lowera nd an upper parts.The lowerp art consists of white,rhythmically layered shaly to silty micritic dolomite,gray calcareous to muddy dolomite and gray，calcareous micritic dolomite with layers of black chert.Red,shaly,silty or sandy micritic dolomite occur in the base of the lower unit.The upper part generally consist S of dark-gray and thick-bedded calcareous,micritic dolomite.

4)The Shanpoling Member

This member can be subdivided into al owera nd an upperp arts.The lowerp arti s composed of gray to grayish-white,calcareous,micritic dolomite and cherty micritic dolomite intercalated with bituminous dolostone.The upper part consists mainly of light gray,thin-bedded calcareous,micritic dolomite without chert.In addition,a bed of white dolomitic sandstone occurs at the bottom of the formation in the Jixian area,and a bed of glauconite-bearing stromatolite dolostone,several tens of meters thick,occurs at the top.

The Wumishan Formation contains abundant stromatolites and microscopic fossil algae.In addition to large varieties,there are many small stromatolites in this formation,namely Psoudogvmnosollen moponyueuse,S'chuphus parvas and Mlcrostylus deusus.These mini-stromatolites occur mainly in the Lozhuang(1 st)member and the lower part of the Ershilipu(3rd)member.The larger varieties,represented by Conophyteslituum,C.shanpolingese，Jacutophytonfurcatum and Colonnelladiscreta,occur mainly in the Mopanyu(2nd)member and the upper part of the Ershilipu(3rd)member.Some medium-sized stromatolites,such as Pseudochihsienela,Wumishanellaand Paraconophyton,occur at the top of the Shanpoling(4th)member.A multitude of fossil algae have been found in the black cherty layers of this formation.The most important are Palaeolynbya,Sphonophycus,Eoentophysalis,Oscillatoriopsis,Sacdyngbya,Hyxococcodes.Harythrixand Archeaoellipsotdes.In addition,Some eukaryotic algae,Such a S Pandorinepsis,Uronemopsi,Hyalothecopsis and Templuma,Pseudochihsienela,Wumishanellaand Paraconophytonare also present.

(8)The Hongshuizhuang Formation

This formation is only 131 m thick and is subdivided into a lowera nd an upper members.The lower member is composed of grayish or dark yellow,thin-bedded,muddy dolostone with some intercalations of black and green shale.The upper member is dominated by black and green shale containing very fine silty laminations.Al1 of these sediments were probably formed in a lagoon or bay.Many distinctive acritarchs with quadrangular,triangular,global and scaffold forms,such as Quadratimorpha,Triangumarpha,Leiofusa,Scaphida,Trachysphaeridium and Pseudezonosphera have been reported by Xing and Liu(1973).In addition,a few of filamental forms and carbonaceous megafossils such as Chuaria are also present.

(9)The Tie Iing Formation

The Tieling Formation,the uppermosts tratigraphic unito ft he Mesoproterozoic Jixian System,consists of two members:the lower shale member and the upper limestone member,which combined total about 330m in thickness.Based on the existence of a layer of“ferruginous sandstone”，a disconformity was formerly thought to exist between the two members.However,recent study shows that the“ferruginous sandstone”and associated rocks may simply be the products of hydrothermal alteration.This layer,about 2m thick,consists ofjasper and Mn-bearing,dolomitic limestone.

Microscopic acritarchs and stromatolites have been found in the lower shale member and the upper limestone beds,respectively.The stromatolite S are very well developed and constitute a“stromatolitic palace”（Fig.3-8)in the Jixian area.They are represented by Kussiella,Scopulimorpla,Anabaria,Baicalia,Tielingellaand Chihsienella.The Tieling Formation i S disconformably overlain by the Xiamaling Formation,which belongs to the Neoproterozoic Qingbaikou System.

Fig.3-8 Stromatolites are very well developed in Tieling Formation

A—shape in longitudinal thin section;B—shape in transverse thin section

3.The Qingbaikou System

This system includes three formations,which constitute two integrated sedimentary cycles.The Xiamaling Formation,which consists of conglomerate,sandstone and shale,disconformably overlies the Tieling Formation,and is overlain by conglomerate,arkosic sandstone,glauconitic sandstone and shale of the Luotuoling Formation.The uppermost unit,the Jingeryu Formation,con Sists of limestone.The Qingbaikou System has a total thickness of 370 m and is disconformably overlain by the Cambrian Fujunshan Formation.

In the Jixian area,as in the mostp arts of North China,there was no sedimentation untilt he middle of the Early Cambrian.

(10)The Xiamaling Formation

A 168-m-thick layer of yellowish-green to grayish-green,clayey siltstone with lenticular sandstone beds disconformably overlying the Tieling Formation,is named as the Xiamaling Forma-tion after its original locality in the western Hills of Beijing(compare this with Stop 6in Route 2).These rocks have current marks,such as furrow casts and groove casts on the sandstone bedding planes along with mud cracks,suggesting deposition in a supratidal or intertidal environment.

Abundant acritarchs,such as Microconcentrica,Gloeocapsomorpha,Symplasso-sphaerdium and Tasmanites,have been recovered from the silty shales.These acritarchs have shapes and ornamen-tation that distinguish them from those in the underlying strata.

（11)The Luotuoling/Changlongshan Formation

This formation was formerly considered to be the lowerp arto ft he Jing'eryu Formation,and was designated the Changlongshan Subformation(Chen et al.,1980).Wang et al.(1980)named it the Changlongshan Formation,whereas Xing et al.(1989)suggested the name Luotuoling Formation after its type locality in the Jixian area.It disconformably overlies the Xiamaling Formation in the Jixian area or other older horizons in adjacent areas,and conformably underlies the Jing'eryu Formation.

The Luotuoling Formation,which is 118 m thick,begins with basal conglomerate followed successively upward by green and yellowish-green shale and glauconite-bearing,arkosic sandstone.The upper part of the formation is characterized by purple,gray and black shale.Two types of glauconite are present in the sandstones,a granular variety distributed along cross-bedding planes and interstitial cement.

(12)The Jing'eryu Formation

The Jing'eryu Formation was formerly designated as the upperp arto ft he“Jing'eryu Formation”（Chen et al.,1980),but many workers regard it as an independent formation.This unit is only 100 m thick in the Jixian area and consists mainly of variably colored limestone.The color changes successively upward from red,to grayish-green,light green,and grayish-brown to green at the top.Based on its sedimentary structures,these rocks were deposited in a subtidal environment.

The Jing'eryu Formation is disconformably overlain by the middle-lower Cambrian Fujunshan Formation,which contains a trilobite fauna of Redlichiachinensls(Walcott)and Megapalaeolenus fengyangensis(Chu)in dolomitized limestone.