Oligocene erosion had truncated the sediments draped over the dome . 覆盖于穹丘上的沉积岩为渐新世侵蚀所截削。
2.
In the ostra field, venezuela, oil is produced from lenticular sandstone beds of the oligocene oficina formation . 委内瑞拉奥斯特拉油田的产油层，为渐新世奥菲西那组透镜状砂岩层。
3.
Carbonate reservoir of the oligocene member 1 , shahejie formation , dongxin oilfield 东辛油田沙一段碳酸盐岩储集层研究
4.
Oligocene mineral component inversion based on geophysical well logs from odp hole 1148a , south china sea 测井资料反演南海北部陆坡渐新统的矿物组分
5.
Fan delta deposits of sha - 3 and sha - 4 members at oligocene shahejie formation at yong 921 area in the north of dongying depression 东营凹陷北部永921地区渐新世沙三段和沙四段扇三角洲沉积
6.
They have also unearthed some clues from the ensuing oligocene , when the modern suborders of cetaceans ? the mysticetes ( baleen whales ) and the odontocetes ( toothed whales ) ? arose 在随后的渐新世地层中，他们也找到了一些线索；须鲸亚目（有鲸须的鲸鱼）与齿鲸亚目（有齿的鲸鱼）就是在那时候分化的。
7.
The sedimentary systems were alluvial fan - braided fluvial river - lacustrine depositional systems during the paleocene - eocene , and braided fluvial river - lacustrine depositional systems during the oligocene - miocene 古新世始新世发育冲积扇辫状河湖泊沉积体系，渐新世中新世发育辫状河湖泊沉积体系。
8.
( 4 ) the formation and growth of structural traps and stratigraphic - unconformity traps in the area is controlled by three compressive stages of silurian - devonian , late permian - tertiary and oligocene - quaternary ; non - structural and compound traps mainly grew in the early paleozoic . structural traps mostly grew in the late paleozoic and the cenozoic and mostly grew on the north and south belts ; non - structural traps mostly grew in the northern area of the hetian concave . most traps in the area formed or typed at last in the himalayan episode , dispersed on the north and south belts ( 4 )研究区构造与地层不整合圈闭的形成和发育受志留-泥盆纪、晚二叠世-第三纪、渐新世-第四纪三个挤压阶段的控制；早古生代主要发育非构造圈闭和复合圈闭，晚古生代和新生代则主要发育构造圈闭：构造圈闭主要发育在南北两带上，其次为中带；非构造圈闭主要发育在和田凹陷以北的地区；研究区内大多数圈闭是喜山期形成或最终定型的，在南北两带都有分布，而海西期圈闭主要分布于研究区中带玛南构造带处。
9.
The study results can be summerized as following aspects : ( 1 ) the basic settling curve of this basin was broken - line shape of seven sections in which upper jurassic , lower cretaceous , eocene , oligocene and neogene corresponded with the decline ones representing five episodic clear subsidences of this basin , late cretaceous to paleocene and early miocene corresponded with the rising ones reflecting the uplift and denudation of this basin . ( 2 ) the subsidence of this basin migrated from the east to the west , from mesozoic to cenozoic 研究表明： ( 1 )北黄海盆地的基本沉降曲线型式为7段折线状，其中晚侏罗世、早白垩世、始新世、渐新世、新近纪为曲线下降段，代表盆地5幕较明显的沉降；晚白垩世古新世以及中新世早期为曲线上升段，反映盆地的抬升剥蚀。
10.
Based on available data , the study on regional structure , sedimentary reservoir and source rock characteristics shows that the basins in south china sea had experienced sedimentary evolution in faulting period and depression period , deposited thick cenozoic formation , upwardly developed alluvial fan facies , river - lake facies coastal swamp facies coastal facies , neritic facies and bathyal deposit system , regionally had 3 source rocks of eocene , oligocene and miocene , 3 reservoirs of pre - cenozoic basement buried bill , oligocene sandstone and miocene reef , with pliocene and pleistocene neritic facies and bathyal shale as regional caprock 摘要以现有资料为基础，通过对区域构造、沉积储层、烃源岩特征等基础石油地质条件研究，认为南海海域各盆地经历了断陷期和坳陷期沉积演化，沉积了巨厚的新生代地层，自下而上发育了冲积扇相、河湖相、滨岸沼泽相、滨海相、浅海相、半深海相沉积体系，区域上存在始新统、渐新统和中新统3套烃源岩，前新生代基岩潜山、渐新统砂岩、中新统生物礁3套储层，区域盖层为上新统和更新统浅海半深海相泥岩。
