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1.
用定量的计算方法来模拟碳酸盐台地的二维地层空间，可以预测储层分布，调整井和地震资料的解释，在盆地前期勘探资料不足的情况下，检验勘探方案及估计地层的基本控制因素。该文首先对模拟的数学方法作了详尽的推导及合理假设，提出了碳酸盐台地模拟的主控因素，并将这些因素与数学方程对应起来；其次，对模拟的各主控因素分别加以讨论，明确它们在地层模拟中的地位，检验其对地层几何形态及岩性控制的作用；最后，通过不同参数下的模拟实例，进一步证明其正确性。同时在模拟出的图形中，可以清晰地看到层序地层学中提出的一些地层要素。 相似文献
2.
本文分析了安徽南陵-铜陵地区茅口期的沉积特征。描述和讨论的主要岩石类型有亮晶生物屑灰岩、泥晶海百合丘灰岩、含有机质藻粒泥晶灰岩、放射虫硅质岩及含钙质生物硅质岩。结合古生物和其它各种相标志,共划分出五个微相,即深水盆地、盆地边缘、碳酸盐缓坡、生屑浅滩和泻湖-潮坪相。研究区茅口期的沉积模式是一个被深水盆地包围的碳酸盐孤立台地。其地貌特征可与现代大巴哈马滩类比,所不同的是它发育了布满海百合灰泥丘的缓坡带。该孤立台地的沉积演化表现为向上变浅的海退序列。 相似文献
3.
碳酸盐台地高水位溢流是指在海平面高水位期,台地沉积物被搬运到斜坡及较深水盆地中沉积下来所形成的沉积体。一般发育在镶边陆架型台地或平顶台地低纬度暖水区,它的形成受台地类型、台地斜坡坡度、海平面变化幅度等要素的制约。 相似文献
4.
理论推导结果表明，在无剥蚀且沉积速率(Vs)和压缩比(C)不变的条件下，碳酸盐台地相剖面点处三极相对海平面早期上升速度(VR1)与三级沉积层序厚度(Sd)、海侵体系域及陆架边缘体系域厚度(Td Md)和老空间增量(△k0)之间，具有近似关系式：VR1≈CVs Sd △k0/Td Md．据此，可应用剖面层序地层比值R(=Sd △k0/Td Md)，来定量化评估台地相剖面中无剥蚀、无凝缩段若干三级沉积层序所代表的不同时期相对海平面早期上升的相对快慢；当某个或某些沉积层序的尺值相对于其它沉积层序的尺值较大时，则表明这个或这些沉积层序形成时期的相对海平面早期上升相对较快，反之亦然；尺值相差越大则评估结论越可靠。 相似文献
5.
新生代南海北部碳酸盐岩台地的淹没事件研究 总被引：2，自引：0，他引：2
碳酸盐岩台地广泛发育及其淹没事件是南海新生代地层的重要特征之一。通过钻孔揭示的地层，古生物等资料对位于南海北部的东沙和西沙碳酸盐岩石地发育，演化及其淹没层序进行了分析，首次提出了本区自新生代以来经历了三次大的淹没和若干次小的淹没事件，分别相当于Haq提出的三级和四级层序。 相似文献
6.
四川及邻区上二叠统吴家坪组石灰岩属于碳酸盐缓坡沉积;与北、东及东北方向的同期盆
地相沉积渐变过渡。在西南近滨地区岌育浅水高能带;与同期龙潭组陆源沉积过渡;形成特殊的陆源屑—碳酸盐混合沉积。由于持续的海侵及碳酸盐的快速沉积作用;碳酸盐缓坡逐渐向台地特化.最终形成该区晚二叠晚期的碳酸盐台地。吴家坪碳酸盐缓坡的古地理控制着该区上二叠统不同类型生物油气藏的分布。
相似文献
地相沉积渐变过渡。在西南近滨地区岌育浅水高能带;与同期龙潭组陆源沉积过渡;形成特殊的陆源屑—碳酸盐混合沉积。由于持续的海侵及碳酸盐的快速沉积作用;碳酸盐缓坡逐渐向台地特化.最终形成该区晚二叠晚期的碳酸盐台地。吴家坪碳酸盐缓坡的古地理控制着该区上二叠统不同类型生物油气藏的分布。
相似文献
7.
六盘山地区早中奥陶世马家沟组、平凉组为一套碳酸盐台地-斜坡沉积建造序列,发育碳酸盐开阔台地沉积体系、台地灰泥、碎屑流沉积体系及重力滑塌、碳酸盐浊流等沉积体系。自下而上为一套向上变粗变厚的进积型沉积建造。反映了鄂尔多斯陆块西缘早中奥陶世被动大陆边缘碳酸盐陆棚与台前海盆共存的古地理格局。 相似文献
8.
本文运用系统论的方法,分析了川西北地区早中志留世生物礁系统的组成基本单元。根据耗散结构原理解释了该区生物礁系统的演化机理及其环境对该礁系统所产生的正负效应。 相似文献
9.
利用钻井、测井及地震资料,通过对珠江口盆地(东部)大量的岩心和薄片的观察鉴定以及对地震剖面资料的精细解释,进而探讨珠江组碳酸盐台地的沉积特征与地震响应特征.珠江口盆地(东部)碳酸盐岩由于古地貌及海侵时间的差异性,珠江组沉积序列,特别是碳酸盐台地的沉积厚度及发育时间,存在明显的差异性.碳酸盐台地沉积相带发育齐全,包括:开阔台地、台地边缘及其台地前缘斜坡3类沉积相.碳酸盐台地的地震相特征突出,易于识别. 相似文献
10.
湖南城步白腊铺泥盆纪生物礁曾被认为是一个点礁，发育在浅海台盆中的隆起区之上．本文根据其岩石学和古生物学特征的研究，并对礁进行了长矩离追索，认为该礁应属于提礁，发育在碳酸盐台地边缘斜坡的上部。这种认识扩大了城步一带泥盆纪生物礁中找油的范围。 相似文献
11.
Systematic mass spectrometric 230Th ages are reported for a Porites coral reef terrace from Dengloujiao,Leizhou Peninsula, South China Sea. Seven episodes of coral growth were recognized in this terrace: 7125±96, 6764±29,5826±37, 5006±54, 2543±24, 1915±15, and 1513±22 calendar years before present (cal. aBP). 50% of the coral age population fall between 7200 and 6600 cal. aBP, marking post-glacial stabdization of global sea level. Considering the facts that ( i ) Dengloujiao reef fiat was measured at 1.6-2.5m above modern tidal datum plane; (ii) modern Porites corals in the South China Sea are living at least ～1 m below the modern tidal datum plane; (iii) the top 20-30 cm of the reef was eroded; and (iv) crustal subsidence in the region since mid-Holocene was negligible, we conclude that the above age groups record at least two major periods (7200-5000 and 2500-1500 cal. aBP) of high sea-level at least 2.9-3.8 m above the present-day level. 相似文献
12.
Using 7 years of TOPEX/POSEIDON satellite altimetry data, we have identified a general trend of sea level rising in the South China Sea between January 1993 and December 1999. The estimated bulk rising rate of the entire basin is -1 cm/a. The rise of sea level appears to be spatially non-homogeneous, which shows a highest rate of 2.7 cm/a in the deep basin west of Luzon and generally low (even negative) rates over the shallow continental shelves. It is believed that the observed rapid rising of sea level is a regional phenomenon and is mainly caused by warming of the upper layer of the South China Sea, which showed a bulk warming rate of 0.15℃/a in the same period. It is also suggested that the observed rising trend is mainly a decadal signal, which is possibly associated with decadal variation of the Pacific warm pool region. 相似文献
13.
Coral reef bleaching is usually characterized by expulsion of symbiotic zooxanthellae, loss of zooxanthellae pigmentation, or both. We collected 128 samples comprising 39 species of 21 genera of reef-building corals from Luhuitou and Xiaodonghai in Sanya of Hainan Island and Daya Bay of Guangdong Province, respectively, and analyzed the symbiotic zooxanthellae population density. The results show that： （1） the symbiotic zooxanthella density varies from 0.67×10^6 to 8.48×10^6 cell/cm^2, displaying significant interspecies variability, with branch corals usually having relatively less zooxanthellae （ranging from 0.67×10^6 to 2.47×10^6 cell/cm^2） than massive species （from 1.0×10^6 to 8.48×10^6 cell/cm^2）; （2） corals inhabiting within 4 m water depth have higher levels of symbiotic zooxanthellae than those living at the bottom （-7 m depth） of the reef area; （3） there is no discernable difference in the zooxanthellae density between corals from relatively high latitude Daya Bay （-22°N） and those from relatively low latitude Sanya （-18°N） at comparable sea surface temperatures （SST）; （4） in partially-bleached corals, the density of zooxanthellae shows the following order： healthy-looking part〉 semi-bleached part 〉 bleached part. Based on the above results, we suggest that （1） the zooxanthellae density difference between branching and massive coral species is the main cause that branching corals are more vulnerable to bleaching than massive corals. For example, symbiotic zooxanthellae levels are low in branching Acropora and Pocillopora corals and thus these corals are more susceptible to bleaching and mortality; （2） symbiotic zooxanthellae density can also be affected by environmental conditions, such as sediment loads, diving-related turbidity, and aquaculture-related nitrate and phosphate input, and their increase may reduce symbiotic zooxanthellae density in corals. 相似文献
14.
西科1井为全取心科学钻井。采用定量微相分析方法,通过精细的岩芯观察和系统的薄片分析,对西科1井上新统-全新统碳酸盐岩微相进行精细研究,以阐明各组分类型和微相类型的纵向分布特征。研究表明,研究区碳酸盐岩表现出颗粒含量高,基质和胶结物含量低的特点。根据碳酸盐岩组分的显微特征,识别出19种微相类型,主要为生屑泥粒灰岩、生屑粒泥灰岩、珊瑚骨架灰岩和苔藓动物粘结灰岩。碳酸盐岩微相纵向分布表明:乐东组经历了动荡水沉积-强动荡水与动荡水交互沉积-动荡水与弱动荡水交互沉积。莺歌海组经历了强动荡水沉积、动荡水与弱动荡水交互沉积-动荡水沉积。 相似文献
15.
晚更新世间冰期时的南海海平面 总被引：1，自引：0，他引：1
刘尚仁 《中山大学学报(自然科学版)》1996,35(3):98-103
从海蚀平面，晚更新世海积地面及其沙坝下伏的滨海相粘性土顶界高程等来看，距今约２０３万ａ的间冰段时南海高海面及其北部岸线接近现在的情况。晚更新世与全新世形成的海蚀平台类高，老，新沙坝比邻和类高，这是南海北部海岸的地貌的特色。 相似文献
16.
WEIGangjian YUKefu ZHAOJianxin 《科学通报(英文版)》2004,49(17):1876-1881
High-resolution Sr/Ca ratios of two Porites corals from Leizhou Peninsula were measured using inductively coupled plasma atomic spectrometry (ICP-AES). TIMS U-Th dating reveals that the life-spans of the two corals are 489-500 AD and 539-530 BC, respectively. Monthly sea surface temperatures (SSTs) during these two periods can be reconstructed from their skeletal Sr/Ca ratios. The results reveal that SSTs during 539-530 BC were roughly the same as those during 1990-2000 AD in this area, indicating a relative warm climate period. However, the period of 489-500 AD was significantly cooler, with annual mean SST, the 10-a average of minimum monthly winter SSTs and the 10-a average of maximum monthly summer SSTs being about 2, 2.9 and 1℃ lower than that in the 1990s, respectively. Such climate patterns agree well with the phenological results recorded in the historic documents in other areas of China. 相似文献
17.
The authors analyze the coral growth band from a colony in the northwestern South China Sea. The coral growth band can provide comprehensive environmental information on climate. The trend from the two-century-long annual density of the coral is in a good agreement with that of the global CO2 concentration. Both trends were small prior to the end of the 19th century; after that, trends became clear, more so from the 1960s to the 1990s (the end of the coral record). The overall coral density shows a steady d... 相似文献
18.
LI Li JING ChunSheng ZHU DaYong 《科学通报(英文版)》2007,52(12):1699-1707
The coupling and propagating features of mesoscale sea level variability between the western Pacific (WP) and the South China Sea (SCS) were studied based on time series analyses of satellite altimeter measured, along-track sea surface height anomalies (SSHA) along 21°N and the slope of the northern SCS. The analyses show that mesoscale sea level fluctuations in the WP have rather limited coherent effects on the SCS, and no statistically significant propagation of mesoscale variability through the Luzon Strait was observed except in the 45-day band. Evidence suggests that the 45-day fluctuation is very much likely a character of the Kuroshio originating from its low-latitude beginning. It is also sug- gested that the westward propagating Rossby waves will deform when they encounter the dynamical barrier of the Kuroshio. The Kuroshio will then acts on the SCS in its own way. The SCS is a relatively isolated system in the sense of coupling and propagating of oceanic mesoscale waves. 相似文献
19.
ZHAN Wenhuan YAO Yantao ZHANG Zhiqiang SUN Zongxun ZHAN Meizhen SUN Longtao LIU Zaifeng 《科学通报(英文版)》2006,51(B12):89-94
Coral reefs in the northwest of South China Sea have recorded the information from not only the environmental variation but also the crustal activities there during their development. The main crustal activities correlated with the coral reef development include fault, seismic, and volcano activities, etc. The high-resolution spark seismic profiles in the northwestern South China Sea show that the fault activities in the coral reef region have been clearly recorded, and appear as neonatal faults incising reefs. Earthquakes in the coral reef region are rather intense, especially the two occurring on December, 31, 1994, and January, 10, 1995, around the southwest of Leizhou Peninsula, with the magnitude of 6.1 and 6.2, respectively. They have great influence on the growth of the local coral reefs. Quaternary volcanos are active in the northwestern South China Sea, especially around the southwest of Leizhou Peninsula, and they have obvious control of the coral reef development. Some submarine volcanoes form the substrates of coral reef, while a few emerge above the sea surface and form coral islands. 相似文献
20.
The coast of southern Hainan Island is characterized by wide sandy embayments, which consist of ( i) drowned valleys bounded by steep bedrock hills and only locally receiving sediments, and embayments of various dimensions covered either by (ii) alluvial-deltaic deposits or by (iii) sands of coastal beach ridges/barriers and associated elongated lagoons. During the late Tertiary-Pleistocene the area has experienced isostatic and eustatic movements associated with neotectonics and climatic changes. Such history isrecorded in terraces at various altitudes (SO, 40, 20 m asl) and sequences of coastal sand ridges/baymouth bars. The Holocene variations in sea level and climate are recorded in the dated coastal ridges, coral reef and beachrock. Conditions suitable for reef development started about 8000 a BP. The GPR profiles also show that the internal structures of the sand ridges have composite nature being formed by several superimposed secondary ridges. 相似文献