鄂爾多斯西南緣岐山地區(qū)奧陶紀巖相古地理研究.pdf

1、西北大學碩士學位論文鄂爾多斯西南緣岐山地區(qū)奧陶紀巖相古地理研究姓名：劉溪申請學位級別：碩士專業(yè)：油氣田開發(fā)工程指導教師：林晉炎20100609TheOrdovicianLithofaciespaleogeographicalresearchofQishanregioninsouthwestOrdosAbstractQishanregionliesonthesouthedgeofOrdosTeconicallyitsituatedonth

2、econnexionofHelanaulacogenandQingqigeosyncline，westsectionofWeibeiupliftDuringtheOrdovician，theregiondepositedmarinecarbonaterocksHowever，theformerresearchofthisplacearefaultiness，themainexistingproblemsarelike：Thereason

3、whylithologyofM旬iagouformationandPinglaingformationbetweenQishanregionanditsadjacentstillhavegreaterdifferencesisnotconfirmed；Fromthedataofoverseasanddomestic，itCanbeensuredthatthestratumofMajiagouformationinQishanregion

4、isnotdividedintosectandlithofaciespaleogeographyinthisplaceneedsmoreparticularandsystematicresearchandexpatiationAimingattheseproblems，undertheguidanceofsedimentologytectonics，sequence—stratigraphyandgeophysits，onthebasi

5、cofformerinvestigationandcombinedwithexplorationoffieldsections，sampling，sliceidentificationanddatacollectionofpaleontologyandwelllogging，thepaperdidtheresearchofrockcombination，sedimentaryconstruction，lithofaciespaleoge

6、ographyevolvementanddepositmodeinOrdovicianInOrdovicianperiod，nomattertransgressionorregression，Qishanregionwasalwaysunderthesealevel，belongedtoepicontinentalseadepositionInEarlyOrdovicianYeli—Liangjiashanperiod，theregio

7、nWasinrestrictedmarineplatformfacieswhichWasmainlyofdolomitedepositInMiddleOrdovicianMajiagouperiod，herewasasuitoflimestonebelongedtoopen—seaplatformtoplatformmarineslopezoneThelithologyinthisplacedidn’tcomposesedimentar

8、ycycleslikeotherregionofbaseanditssorthedgeTherefore，thepaperdividedMajiagouformationintolowerMajiagouformation，upperMajiagouformationandFengfengformationInLateOrdovicianPingliangperiod，Huabeimesawaswhollyupliftedbecause

9、ofCaledonianmovementFromthisperiodOrdosancientcontinentbecamemuchlargerterrigenousmattermainlyofcalcareousmudstoneandshaleweremanifoldedinQishanregionSointhisperiod，researchareawasinplatformmarginslopezoneInBeiguoshanper