塔里木盆地東部地區(qū)寒武紀海盆局限期深水準同生白云巖化作用研究

余寬宏 金振奎 周 勇 李 鵬 李 娜 官全勝

(中國石油大學(北京)地球科學學院 北京 102249)

塔里木盆地東部地區(qū)寒武紀海盆局限期深水準同生白云巖化作用研究

余寬宏 金振奎 周 勇 李 鵬 李 娜 官全勝

(中國石油大學(北京)地球科學學院 北京 102249)

塔東地區(qū)寒武紀盆地相以及斜坡相發(fā)育泥晶白云巖及泥質(zhì)泥晶白云巖,具有深水環(huán)境標志。通過樣品巖石學特征研究、碳、氧同位素分析、有序度分析、鍶同位素比值分析以及陰極發(fā)光特征分析,提出了塔東地區(qū)海盆局限期海水咸化深水準同生白云化機理。海盆局限階段水體鹽度變高,使得斜坡以及海底松軟碳酸鹽沉積物發(fā)生白云石化形成深水環(huán)境的泥粉晶白云巖。深水準同生白云巖由泥粉晶級白云石構(gòu)成、有序度值低、碳、氧同位素值高、鍶同位素比值高,與潮坪準同生白云石晶體粒級相同且地球化學特征相同,但深水準同生白云巖發(fā)育于盆地相以及斜坡相,以此與潮坪準同生泥粉晶白云巖相區(qū)別。

泥晶白云巖 深水 盆地相 斜坡相 準同生成巖階段 白云巖化作用

0 引言

白云巖成因主要是從白云巖巖石結(jié)構(gòu)[1,2]、結(jié)晶有序度、陰極發(fā)光特征、地球化學分析等方面來進行研究[3～7]。塔里木盆地白云巖類型多樣,經(jīng)受的成巖改造作用復(fù)雜。特別是塔東地區(qū)寒武系-奧陶系白云巖成因類型較多且復(fù)雜。巖石類型有泥粉晶白云巖以及砂糖狀白云巖。通常認為泥粉晶白云巖為潮坪環(huán)境準同生白云巖[8～10],但是塔東地區(qū)巖性及沉積相綜合分析表明,泥粉晶白云巖普遍發(fā)育于深水環(huán)境,即盆地相以及斜坡相。這些泥粉晶白云巖如果用潮坪蒸發(fā)泵機理來解釋其成因顯然不合適,因此本文在綜合研究沉積相以及泥粉晶白云巖的巖石學特征、白云石結(jié)晶有序度、陰極發(fā)光特征、碳、氧、鍶同位素特征等基礎(chǔ)上,提出了海盆局限階段海水咸化深水準同生白云巖化機理。

1 研究區(qū)概況

研究區(qū)位于塔里木盆地東部,面積約10萬平方千米,構(gòu)造單元主要有塔東低凸起、滿加爾凹陷、英吉蘇凹陷,南北受車爾臣大斷裂及孔雀河斷裂的控制[11]。塔東地區(qū)也是塔里木盆地深水相發(fā)育的主要區(qū)域。在構(gòu)造單元中,塔東低凸起帶是塔東地區(qū)下古生界碳酸鹽巖油氣勘探最有利的地區(qū)。自海西期以來,塔東低凸起帶發(fā)育成北東走向的大型正向構(gòu)造單元[12,13]。目前研究區(qū)能揭示寒武紀-奧陶紀碳酸鹽巖特征的鉆井共有6口井,都分布于塔東低凸起帶上(圖1),不同程度地揭示了塔東地區(qū)白云巖發(fā)育的情況。

圖1 塔東低凸起帶構(gòu)造單元及沉積單元Fig.1 Tectonic and sedimentary units in the eastern Tarim Basin

塔東沉積相類型較齊全,古城地區(qū)以及羅布泊地區(qū)為碳酸鹽巖緩坡逐漸發(fā)育而來的鑲邊臺地,發(fā)育臺地邊緣、開闊臺地、潮坪、斜坡等相類型,塔東1井、塔東2井為繼承性發(fā)育的盆地相,米蘭1井、英東2井一帶也為盆地相逐漸發(fā)育為斜坡相。白云巖在不同相帶發(fā)育狀況差異較大。

2 研究區(qū)白云巖特征

本論文所重點研究的深水泥粉晶白云巖主要分布在斜坡相和盆地相。斜坡相的泥粉晶白云巖成薄層狀分布于塊狀砂糖狀白云巖中,而最典型的深水環(huán)境泥晶白云巖分布于盆地相[14]。

深水盆地泥晶白云巖厚度小,而且通常呈硅質(zhì)白云巖或者白云質(zhì)硅巖以及白云質(zhì)泥巖出現(xiàn)。圖2為塔東地區(qū)中下寒武統(tǒng)東西向沉積相橫向?qū)Ρ?可見在深水盆地相的厚層泥巖、硅質(zhì)巖中普遍發(fā)育薄層狀的泥晶白云巖。

盆地相巖石學特征如圖3,硅質(zhì)巖及硅質(zhì)頁巖是主要的巖石類型。圖3(A、C、D)為盆地相巖石類型的微觀特征,均以暗色為主,而且發(fā)育深水化石,如放射蟲。圖3(B)為深水準同生泥晶白云巖的微觀特征,晶粒細小,富含泥質(zhì)及硅質(zhì)。圖3(E、F)為深水泥晶白云巖與硅質(zhì)巖宏觀特征,白云巖呈夾層狀分布于硅質(zhì)巖中。

3 巖石學特征

3.1 結(jié)構(gòu)特征

深水泥粉晶白云巖晶粒細小,為泥粉晶級(圖3 (B)、圖4(A))。圖4(A)樣品來自米蘭1井,沉積環(huán)境分析為下斜坡相,巖性主要為泥質(zhì)泥粉晶白云巖,具有紋層狀。宏觀上厚度小,與其伴生的主要為砂糖狀白云巖,晶體粒徑差距較大。該樣品從巖石學上找不出任何潮坪環(huán)境的標志,例如鳥眼構(gòu)造、石膏鑄?？紫?、藻紋層等。

圖2 塔東地區(qū)中下寒武統(tǒng)沉積相對比及深水泥晶白云巖分布特征Fig.2 Horizontal comparison diagram of basin facies of Lower-Middle Cambrian in the eastern Tarim Basin

白云巖晶粒粗細是判斷白云巖成因的重要標志之一[7～10],因為晶粒粗細與水中鈣、鎂離子濃度和白云石結(jié)晶速度有關(guān)。鈣、鎂離子濃度越高,形成的白云石晶核就越多,而且結(jié)晶速度越高,晶粒也就越小。因此,晶粒粗細是鹽度的反映。根據(jù)現(xiàn)代白云巖特征研究,泥粉晶白云巖是蒸發(fā)濃縮的海水使松軟未固結(jié)的灰質(zhì)沉積物發(fā)生白云石化而形成的。蒸發(fā)濃縮的海水中鈣、鎂離子濃度高,同時松軟的沉積物孔隙度和滲透率高,保證了孔隙流體流動通暢,及時供應(yīng)白云石化消耗的鈣、鎂離子。高鹽度和沉積物松軟是形成泥粉晶白云巖的兩個必要條件,反過來,泥粉晶白云巖可以反映白云化流體是濃縮的海水,而且是在準同生期發(fā)生的白云石化。英東2井、米蘭1井、塔東1井、塔東2井深水準同生白云巖在斜坡相區(qū)主要為紋層狀泥粉晶白云巖,與其它成因的細晶、粗晶白云巖相伴生。在盆地相發(fā)育的深水準同生白云巖主要呈夾層狀分布于混積盆地中。泥粉晶白云巖與深水沉積相伴生,這一點與潮坪環(huán)境的準同生泥-粉晶白云巖相區(qū)別[15]。

圖3 塔東地區(qū)中下寒武統(tǒng)盆地相巖石學特征A。黑色碳質(zhì)硅巖,含深海放射蟲,典型盆地相巖石類型,塔東2井,∈1,西大山組,4 917.31 m,X 10;B。泥質(zhì)泥晶白云巖,深水白云巖類型,呈巖溶角礫狀,塔東2井,∈1,西大山組,4 970.63 m,X4;C。硅質(zhì)泥巖,典型硅質(zhì)盆地巖石類型,塔東1井,∈1,西大山組,4 660.88 m,X10;D。含云硅巖,硅化+白云石脈,英東2井,∈2,莫合爾山組,4 803.77 m,X 4;E。巖性界面,砂質(zhì)泥巖與硅質(zhì)泥晶白云巖的界面,英東2井,∈2, 4804.39m;F。下部灰黑色砂質(zhì)泥晶與硅化泥晶白云巖,上部灰綠色含粉砂質(zhì)泥巖,英東2井,∈2,4 801.00～4 807.10 mFig.3 Petrologic characteristics of basinal facies of lower Cambrian in the eastern Tarim BasinA.Carboniferous silicalite,Radiolaria,typical rock of basinal facies,Well Tadong2,∈1,Xidashan group,4 917.31 m,X10;B.Argillaceous dolomicrite, formed in deepwater environments,karstbreccia,Well Tadong2,∈1,Xidashan group,4 970.63 m,X4;C.Siliceous shale,formed in deepwater environments,Well Tadong 1,∈1,Moheershan Group,4 803.77 m,X4;D.Dolomitic siliceous rocks,silification&dolomitic gangue,Well Yingdong 2,∈2, Moheershan Group,4 803.77 m,X4;E.Lithologic interface,sandymudstone&siliceous dolomicrite,Well Yingdong 2,∈2,4804.39m;F.Siliceous dolomicrite&sandymudstone,Well Yingdong 2,∈2,4 801.00～4 807.10 m

圖4 深水白云巖微觀特征及陰極發(fā)光特征A。紋層狀粉晶白云巖,米蘭1井,4 588.53 m,∈,X140(單偏光);B。深水準同生白云巖陰極發(fā)光特征,米蘭1井5 252.49 m,∈,X60Fig.4 Microscopic properties and cathodoluminescence features of deepwater dolomicriteA.Microscopic properties of deepwater dolomicrite,Well Milan 1,5252.49m,∈,X60; B.Cathodoluminescence features of deepwater dolomicrite,Well Milan 1,5252.49m,∈,X60

3.2 陰極發(fā)光特征

塔東地區(qū)的泥粉晶白云巖普遍呈灰黑色、深灰色等還原色,而且其黃鐵礦含量較高,呈結(jié)核、條帶狀出現(xiàn),也反映強還原環(huán)境。根據(jù)巖相古地理研究,塔東地區(qū)在寒武紀和奧陶紀為深水盆地。此外,與潮坪準同生白云巖不同,本區(qū)深水準同生白云石的陰極發(fā)光普遍呈暗紅色(圖4(B)),反映Mn2+和Fe2+含量較高[14]。Fe和Mn作為類質(zhì)同象離子置換白云石晶格中鈣、鎂離子的主要是低價離子,因此,只有在還原環(huán)境中生成的白云石,才可能具有較高的Fe2+、Mn2+含量[14]。所以,這也表明這類白云巖是在較深的還原性海底形成的。

3.3 有序度

白云石有序度是其結(jié)晶程度好壞的標志,與白云石結(jié)晶速度密切相關(guān),而結(jié)晶速度與海水鹽度有關(guān)[16]。在同生和準同生成巖環(huán)境中,沉積物松軟,孔隙度和滲透率都很高,孔隙水能自由流動,當水溶液鹽度高、CO、Mg2+、Ca2+等離子濃度高時,白云石的結(jié)晶速度較快,形成的白云石具有低的有序度。

本次研究區(qū)泥粉晶白云巖樣品主要取自于米蘭1井、英東2井、塔東1井、塔東2井混積盆地相泥粉晶白云巖,另外細晶白云巖及中粗晶白云巖樣品也取自相鄰的巖芯段。根據(jù)本區(qū)68個白云巖樣品統(tǒng)計分析,塔東地區(qū)泥粉晶白云巖有序度明顯偏低,峰高分布范圍0.26～0.9,平均值0.5573,峰面積分布范圍0.4～1.33,平均值0.749 8(表1)。

表1 塔東地區(qū)白云巖有序度分布范圍及平均值Table1 Distribution range and average of degree of order of dolom ite in the eastern Tarim Basin

圖5為不同粒徑白云巖有序度值分布圖,準同生泥粉晶白云巖有序度值小,離散度大。有序度普遍低反映這類準同生白云巖是咸化海水在準同生階段白云化石形成的。

4 地球化學特征

4.1 碳、氧同位素

圖5 塔東地區(qū)白云巖不同粒度白云巖有序度分布Fig.5 Distribution scatter of degree of order of dolomite in the eastern Tarim Basin

深水準同生泥粉晶白云巖碳、氧同位素呈高值。碳、氧同位素組成也表明,泥粉晶白云巖是濃縮海水白云化形成的。塔東地區(qū)的泥粉晶白云巖的δ13C及δ18O值普遍比細晶、中粗晶白云巖的高。表2為塔東地區(qū)不同粒徑白云巖碳、氧同位素值的分布范圍及其平均值。泥-粉晶白云巖的δ13C值分布范圍為0 ～2.5‰(PDB),平均值為1.2‰,基本上都為正值。 δ18O值分布范圍-8‰～-2.5‰(PDB),平均值為-5.8‰(PDB),相對于細-中晶及粗晶白云巖的碳氧同位素值要偏正。

表2 塔東地區(qū)碳、氧同位素分布范圍及平均值Table2 Distribution range and average ofδ13 C andδ18O of dolom ite in the eastern Tarim Basin

圖6為米蘭1井和塔東地區(qū)白云巖按照不同晶徑統(tǒng)計的δ13C及δ18O值分布,泥粉晶白云巖的同位素值均偏正。

4.2 鍶同位素比值

表3為泥粉晶白云巖及細、中晶白云巖87Sr/86Sr值分布范圍及平均值。泥粉晶白云巖的87Sr/86Sr分布范圍為0.708 92～0.713 31,平均值為0.710 64,比細、中晶白云巖87Sr/86Sr值明顯偏高。這也反映形成泥粉晶白云巖的水體鹽度較高。

表3 不同粒度白云巖87 Sr/86 Sr值分布范圍及平均值Table3 Distribution range and average of 87 Sr/86 Sr of dolom ite w ith different crystal diam eter

5 深水準同生白云巖化機理

深水泥粉晶白云巖成因模式如圖7。海盆局限階段,海水蒸發(fā)導致鹽度升高,使得位于斜坡和盆地的松軟沉積物發(fā)生白云巖化形成深水準同生白云巖。

圖6 塔東地區(qū)不同粒徑白云巖的碳、氧同位素分布Fig.6 Distribution ofδ13 C andδ18 O value of dolomite with different crystal diameter in the eastern Tarim Basin

圖7 塔東地區(qū)深水準同生白云巖化模式圖Fig.7 Mode of deepwater penecontemporaneous dolomitisation in the eastern Tarim Basin

白云巖化作用主要取決于兩方面:一是Mg2+的來源;二是動力學機制。濃縮的海水是Mg2+離子的主要來源。當海盆局限時,海水蒸發(fā),鹽度變高,海水稍加濃縮就會成為白云巖化的有效流體[10]。當海底松軟的灰泥沉積物還未固結(jié)成巖時比較疏松,具有較高的孔隙度和滲透率。只要海水水體能夠進入并保證一定的時間,這種快速的準同生白云化作用就能發(fā)生。海水濃縮時,盆地底部的熱量加劇海水的循環(huán)流動,在流動的過程中,高鹽度的海水在疏松的灰泥沉積物中通過保證了準同生白云化作用的發(fā)生。

6 結(jié)論

(1)塔東地區(qū)寒武紀-奧陶紀混積盆地相以及斜坡相海盆局限期發(fā)育深水準同生白云巖,巖性主要為泥晶白云巖以及泥質(zhì)泥晶白云巖,厚度不大,呈夾層狀分布于頁巖、頁巖-硅巖中。

(2)深水準同生白云巖晶體粒級和潮坪準同生白云巖一樣,為泥粉晶白云巖;地化特征相同,具有低有序度、高碳氧同位素值、高鍶同位素比值等,但是不具潮坪環(huán)境標志,如鳥眼構(gòu)造、石膏鑄?？紫丁⒃寮y層等。

(3)海盆局限期深水準同生白云巖的識別標志主要為其與沉積相的伴生關(guān)系,如塔東地區(qū)呈夾層狀分布于盆地及下斜坡等深水環(huán)境。

References)

1 Feng Zengzhao,Jin Zhenkui.Types and origin of dolostones in the Lower Palaeozoic of the North China Platform[J]。Sedimentary Geology,1996,94(3-4):279-290

2 Feng Zengzhao,Zhang Yongsheng,Jin Zhenkui.Type,origin,and reservoir characteristics of dolostones of the Ordovician Majiagou Group,Ordos,North China Platform[J]。Sedimentary Geology, 1998,118(1-4):127-140

3 鄭榮才,耿威,鄭超,等。川東北地區(qū)飛仙關(guān)組優(yōu)質(zhì)白云巖儲層的成因[J]。石油學報,2008,29(6):816-821[Zheng Rongcai,Geng Wei,Zheng Chao,etal.Genesis of dolostone reservoir of Feixianguan Formation in Lower Triassic of northeast Sichuan Basin[J]。Acta Petrolei Sinica,2008,29(6):816-821]

4 金振奎。華北地臺東部下古生界白云巖的類型及儲集意義[J]。沉積學報,1993,11(2):11-19[Jin Zhenkui.Significance and types of lower-paleozoic dolomite in eastern North China Platform[J]。Acta Sedimentologica Sinica,1993,11(2):11-19]

5 王家生,甘華陽,魏清,等。三峽“蓋帽”白云石的碳、硫穩(wěn)定同位素研究及其成因探討[J]?，F(xiàn)代地質(zhì),2005,19(1):11-19[Wang Jiasheng,Gan Huayang,Wei Qing,etal.Stable isotopes of carbon and sulfur of cap dolomite in the Three Gorges and itsmechanism discussion [J]。Geoscience,2005,19(1):11-19?

6 顧炎午,李國蓉,李宇翔,等。塔中地區(qū)中下奧陶統(tǒng)白云巖特征及成因[J]。天然氣技術(shù),2009,3(1):19-22[Gu Yanwu,Li Guorong,Li Yuxiang.Characteristics ofmiddle to lower Ordovician dolomite in central Tarim Basin and its origin[J]。Natural Gas Technology,2009,3(1):19-22]

7 金振奎,馮增昭。滇東-川西下二疊統(tǒng)白云巖的形成機理-玄武巖淋濾白云化[J]。沉積學報,1999,17(3):383-389[Jin Zhen Kui, Feng Zeng zhao.Origin of dolostones of the Lower Permian in East Yunnan-West Sichuan:Dolomitization through leaching of basalts [J]。Acta Sedimentologica Sinica,1999,17(3):383-398]

8 孫健,董兆雄,鄭琴。白云巖成因的研究現(xiàn)狀及相關(guān)發(fā)展趨勢[J]。海相油氣地質(zhì),2005,10(3):25-30[Sun Jian,Dong Zhaoxiong,Zheng Qin.Study actuality and trend on origin of dolostone[J]。Marine Petroleum Geology,2005,10(3):25-30]

9 韓林。白云巖成因分類的研究現(xiàn)狀及相關(guān)發(fā)展趨勢[J]。中國西部油氣地質(zhì),2006,2(4):400-405[Han Lin.Study actuality and trend on classification of dolomite origin[J]。West China Petroleum Geosciences,2006,2(4):400-405]

10 張學豐,胡文瑄。白云巖成因相關(guān)問題及主要形成模式[J]。地質(zhì)科技情報,2006,25(5):32-39[Zhang Xuefeng,Hu Wenxuan, Zhang Juntao.Critical problems for dolomite formation and dolomitization models[J]。Geological Science and Technology Information, 2006,25(5):32-39]

11 計雄飛。塔里木盆地主干斷裂特征及其演化過程研究[D]。碩士論文,成都理工大學,2008[Ji Xiongfei.The study in characters and evolution process of main faults in Tarim Basin[D]。Chengdu Univesity of Technology,2008]

12 尹微。塔里木盆地中央隆起帶寒武系構(gòu)造-沉積作用及響應(yīng)特征[D]。中國地質(zhì)大學(北京)博士論文,2007[Yin Wei.The process of structure-sedimentary and their correlation of the Cambrian Period in the central uplift belt Tarim Basin[D]。China University of Geosciences(Beijing),2007]

13 王鳳俊,塔里木盆地塔東地區(qū)構(gòu)造特征研究及區(qū)帶評價[D]。吉林大學,2005[Wang Fengjun.The structural characteristics research and structural zones evaluation of Tadong Area in Tarim Basin[D]。Jilin Univesity,2005]

14 馬鋒,許懷先,顧家裕,等。塔東寒武系白云巖成因及儲集層演化特征[J]。石油勘探與開發(fā),2009,36(2):144-155[Ma Feng, Xu Huaixian,Gu Jiayu,etal.Cambrian dolomite origin and reservoir evolution in east Tarim Basin[J]。Petroleum Exploration and Development,2009,36(2):144-155]

15 郭成賢,王正允,王方平。深水碳酸鹽巖成巖作用的穩(wěn)定同位素特征[J]。石油與天然氣地質(zhì),1999,20(2):144-147。[Guo Chengxian,Wang Zhengyun,Wang Fangping.Stable isotopic characteristics of diagenesisin deep water carbonate rocks[J]。Oil&Gas Geology, 1999,20(2):144-147]

16 曾理,萬茂霞,彭英。白云石有序度及其在石油地質(zhì)中的應(yīng)用[J]。天然氣勘探與開發(fā),2004,27(4):64-72[Zeng Li,Wan Maoxia,Peng Ying.Dolomite sequentiality and its application to petroleum geology[J]。Natural Gas Exploration&Development,2004, 27(4):64-72]

Dolom itization in Deepwater Environment of Cambrian in Penecontemporaneous Diagenetic Stage,Eastern Tarim Basin

YU Kuan-hong JIN Zhen-kui ZHOU Yong LIPeng LINa GUAN Quan-sheng
(Faculty of Geoscience,China University of Petroleum,Changping,Beijing 102249)

In the Cambrian formation of basin facies in the eastern Tarim Basin,thin bedded dolomicrites,argillaceous dolomicrites and siliceous dolomicrites are distributed in thick formations of siltymudstone,siliceousmudstone and silicalite.There is no obvious evidence of tide-flat where evaporative pumping dolomicrites can be formed,like bird's eye structure,pores formed by gypsum disolution,cryptalgalaminite and mudcracks,while there aremany evidence of deepwater environments,such as Radiolaria,colour of strong oxygen-free environment.As a result,the mechanism forming these dolomicrites can not be interpreted by evaporative pumping.Studies are carried on by petrologic characteristics,degree of order,isotope ratio of13C,18O and87Sr/86Sr.Dolomicrites studied in this article appear in basin facies,composed bymicrite dolomites,withmud intervals and siliceousmetasomatism.In basin facies, the thickness of dolomicrites is small,while in ramp,they are distributed in dolomite with saccharoidal texture.Colour of cathodoluminescence of dolomicrites ismaroon,which is characteristic of high quantity of Mn2+and Fe2+,indicating that dolomicriteswere formed in strong oxygen-free environment.Distribution range and average of degree of order of dolomite show that dolomicrites have lower value of degree of order than other dolomites.The average value of degree of order of dolomicrites is 0.749 8,with 48 samples,while that is 0.948 8(17 samples)of other dolomites, whichmeans that dolomicriteswere formed in relative short time.In deepwater environments,dolomicrites formed rapidly,there was no time to form big and euhedral-granular texture.Distribution range and average ofδ13C andδ18O of dolomite shows that dolomicrites have higher value than other dolomites.The average value ofδ13C of dolomicrites is 1.2,while that of finely crystalline dolomite is-0.4‰and that ofmedium-macrocrystalline dolomite is-0.6‰。The average value ofδ18O of dolomicrites is-5.8‰,while thatof finely crystalline dolomite is-8.8‰and thatofMediummacrocrystalline dolomite is-12.1‰。The characteristics ofδ13C andδ18O show that dolomicriteswere formed in circumstance with high salinity.The average value of87Sr/86Sr of dolomicrites is 0.710 64,while that of finely crystalline and Medium-macrocrystalline dolomite is 0.709 34,which is another evidence of circumstance with high salinity.Mechanism of dolomitization was proposed based on above evidences.Dolomicriteswas formed in the period of restricted sea basin.When there was not sufficient supplement of freshwater into the sea and with strong evaporation, The salinity of seawaterwent high,with Mg2+and Ca2+concentrated.As a result,there is enough Mg2+for dolomitization.For therewere enough interspaces in the fluffy calcium carbonate sediments and seawaterwith high salinity can flows and stays sufficiently so that dolomitization occurred in penecontemporaneous diagenetic stage.

dolomicrites;deepwater;basin facies;ramp;penecontemporaneous diagenetic stage;dolomitization

余寬宏 男 1983年出生 博士研究生 儲層地質(zhì)學 E-mail:yukuanhong1983@126。com

金振奎 E-mail:jinzhenkui@188。com

P588.24+8

A

1000-0550(2011)06-1041-07

2010-10-11;收修改稿日期:2011-03-02