济阳地区深部结构与含油气性讨论

Oil and gas exploration of marine strata in China's Pre-Cenozoic residual basins is regarded as a worldwide puzzle because of existent problems and cruxes. Objectively speaking, the subsurface geologic structure is complicated, and the surface conditions of some areas are tough. On the other hand, there are still many problems to be solved in oil and gas exploration technologies of Pre-Cenozoic marine fades, and theoretic cognition about petroleum geology is not profound yet. Therefore, it is principal to explore integrated geophysical research ways of Pre-Cenozoic residual basins. Seismic prospecting and geophysical integrated interpretation technologies aimed at middle Paleozoic marine facies with deeper burial and complicated geologic conditions have not formed due to bad quality of deep strata data. Pre-Cenozoic strata, and especially extension, thickness and internal structure of Paleozoic strata can not be recognized from seismic profiles, so it is hard to systematically cognize structural features and oil-gas resources prospect of Pre-Cenozoic basins. To further investigation of fabric and structural features, basin prototype, formation and evolution pattern of Pre-Cenozoic basins, and also their control over formation, migration and aggregation of oil and gas, will play a guiding and promotive role in developing new surveying areas, selecting advantageous zones and predicting oil-gas resources.This paper follows the modem macrocontrol theory of "Region constrains local, deep strata controls shallow ones", and uses the integrated geophysical method of "One guide, two hinges, three combinations and multi feedbacks'*. Based on several years of geological and geophysical results of the Shengli Oilfield, and 14 newly-joint regional seismic profiles, deep structure and oil-gas bearing capacity of the Jiyang area are discussed and new cognitions are drawn as below.Seismic identification marks Tr, Tg, Tgl and Tg2 are established for importantPre-Cenozoic geological interfaces, and promoted to the whole Jiyang area.Through area-wide tracking and clogging of important seismic reflection marker,the isochronic framework of pre-Tertiary basin is set up in the Jiyang area for the firsttime, which is vital for basin research.Integrated with geological and geophysical research results, the Jiyang area isdivided into four first-order tectonic sequences- basement, lower tectonic layer,upper tectonic layer, and top tectonic layer. The basement and lower tectonic sequence which are related to Pre-Cenozoic are studied with emphasis.Through the research of regional seismic profiles, the point of view is given thatthe Kongdian Formation of Jiyang is structural transition period. The top-bottomunconformable interface of the Kongdian Formation is found out for the first time,and the basin model is determined primarily, which lay a basis for prototype basinresearch of the Jiyang Kongdian Formation.The distribution status of Middle-Paleozoic is delineated in the Jiyang area.The maximum thickness of Paleozoic lies in the top of the south declivity of half-graben. The thickness gets thinner towards the center of Mesozoic and Cenozoic half-graben basin, and even disappears. Structural action in the west-north affects the distribution of Paleozoic residual strata.6. The features of second-order tectonic sequence of the Jiyang depression isstudied and its evolution history of is rebuilt.Combined with the 5-stage evolution history of the China continent and structure evolution features of the Jiyang area, the structure sedimentary process since Paleozoic is divided into 5 periods - basement forming , Indosinian orogenic, Yanshan negative reversal, Himalayan extension and Neogene subsidence period.Combined with the research results of gravity, magnetic surveying and regionalprofiles, this paper brings forward the idea for the first time that the western boundaryof the Jiyang depression is the Ningjin-Yangpan fracture zone, and forms aside-column assemblage with the Wudi fracture zone.The opinion that under Middle-Cenozoic basins in the middle Jiyang area theremight superimpose an old residual basin is given for the first time. And if it is provedto be true, a new exploration space will be pioneered for Jiyang and even north China.There exists many types of tectonic-stratigraphic traps formed under piezotropy,extension and compound action in Pre-Cenozoic Jiyang. Therein all kinds of burialhills are the most important oil-gas trap type of Pre-Cenozoic, which should besurveyed layeredly according to the layout of oil sources.As such a new challenging project and field, the paper systematically analyses different geophysical responses of the Jiyang area, frames the deep structure of the area, and preliminarily recognizes the Pre-Cenozoic residual basins. It breaks through to a certain extent in both theory and practice, and is expected to provide new geophysical and geotectonic clues for deep exploration in Shengli.

中国东南部晚中生代以来的基性岩脉（体）的地质地球化学特征及其地球动力学意义初探-以江西省为例

基性岩脉具有特殊的地球动力学意义，一直是近十年来国际上研究的热点和重点。至今共举办过四次关于岩脉的国际专题大会，掀起了基性岩脉的研究高潮，分别从其分布、形态、古地磁、岩石学、地球化学、年代学和构造演化等方面进行了系统的研究。由于出露面积的关系，岩脉或岩脉群往往容易被人忽略，直到最近五年来中国东部中新生代基性岩脉的地球动力学意义才引起地质学者的关注，甚至有些学者指出中国东部中生代基性岩脉的研究可以填补国际上对此方面的空白。对中国东南部中生代基性岩脉的系统研究主要集中在粤北地区，琼南、福建沿海一带、湘东南、某些热液矿床的矿区的基性岩脉得到零星的研究，缺少对中国东南部更大范围的和系统的研究。另外，中国东南部晚中生代部分基性岩体与地壳拉张有关，但研究多集中于沿海一带，对于内陆基性岩体的构造应力体制是否与基性岩脉类似。本论文选择了江西省晚中生代以来的基性岩脉（体）为研究对象，运用矿物学、元素和同位素地球化学及K-Ar测年等研究方法，首次较为系统地研究了江西省晚中生代以来的基性岩脉、与地壳拉张有关的基性侵入岩体的地质地球化学特征，并利用对其形成时代、源区性质的研究来探讨中国东南部地壳拉张期次、地幔性质等地球动力学背景中的关键性问题。通过研究取得了以下几点初步认识：1系统地进行野外地质考察和采样，并收集前人的研究资料，发现江西省的基性岩脉的岩石类型主要为煌斑岩、辉-长辉绿岩、辉绿岩、辉绿（珍）岩等，相对较多，主要呈三条北北东向带状分布，分别为星子-上高-萍乡、德兴-余江-相山-吉安-上犹、草桃背-岩背-大吉山。2对江西省的基性岩脉和部分与地壳拉张有关的墓性岩体进行全岩K-Ar定年，结果表明，基性岩脉的形成时代为140-50Ma，再结合中国东南部发育的富碱侵入岩（包括A型花岗岩）和已发表的基性岩脉的年代学资料，作者认为中国东南部地壳拉张可能共有六期，分别为50-6OMa、90士Ma、100-11OMa、125士Ma、140士Ma、165～180 Ma。3对赣南车步辉长岩类的地质特征、矿物学和地球化学特征进行了研究，着重讨论它与沿海辉长岩类构造环境和源区性质的不同，研究表明它可能是中国东南部中侏罗世软流圈上涌、岩石圈伸展和地壳裂解的产物，而沿海白至纪辉长宕类的构造环境是弧后拉张盆地；车步辉味岩类的源区可能是未受到明显俯冲组分影响的富集地幔，而沿海白翌纪辉长岩类的源区可能包含较多俯冲组分。4对赣南大吉山地区和赣北地区早白圣世基性岩脉的地质地球化学特征进行了系统的研究，表明它们可能代表中国东南部早白至世初存在一次重要的岩石圈伸展和地壳拉张事件。但两者在岩石序列、微量元素、同位素方面存在明显不同，结合区域地质背景，认为造成赣南和赣北地区早白坐世的基性岩脉源区不同的可能原因是岩石圈地慢组成不同和／或形成基性岩脉的岩浆深度不同。5通过对江西省早白至世欧特里夫期（125士Ma）基性岩脉的地质、矿物学和地球化学特征进行研究，发现中国东南部的确存在早白至世欧特里夫期（125士Ma）基性岩脉，代表一次重要地壳拉张事件，其源区可能由亏损地幔、EMI和EMII地幔组成，后面两种类型地幔可能是先前受俯冲流体影响的成分不均一的富集岩石圈地幔。6通过对江西省早白至世未期（100-11oMa）和晚白至世（90士Ma）的基性岩脉（体）的地质地球化学特征进行研究，强有力的表明江西省存在100-110Ma、90士Ma两期地壳拉张，与粤北地区类似。本论文研究表明晚白至世的地壳拉张除了形成基性岩脉外，还形成同时代的基性岩体。这两期的基性岩脉（体）的源区可能由亏损地幔、EMI和EMll地幔组分组成，与（125士Ma）基性岩脉类似，但早白至世未期（100-110Ma）基性岩脉的源区可能含有相对较高的亏损地幔组分。7通过对江西省中部古新世的基性岩脉（体）的地质地球化学特征进行研究，发现了江西省中部的确存在50-60Ma地壳拉张事件。本期的基性岩脉（体）微量元素含量、MORB标准化模式和同位素与前面白至纪的基性岩脉（体）明显不同，软流圈参与其源区明显增多。8通过对中侏罗世以来基性岩脉（体）地质地球化学的系统研究，表明中国东南部晚中生代以来地幔性质发生了明显变化，总体变化趋势为亏损地幔代替富集地幔，这种过程与软流圈上涌、岩石圈伸展和地壳拉张有关：主要机制可能为岩石圈减薄，当然不排除其他机制。

Tecttôniica póss--riifftte na Baciia Pottiiguar

The study of Brazilian sedimentary basins concentrates on their rift phase, whereas the Post-rift phase has been considered a tectonic quiescent period. The post-rift sequence of the Potiguar Basin, in the far northeastern Brazil, was once considered little deformed, however several studies have shown how that it was affected by major fault systems. The purpose of this thesis is to characterize the post-rift tectonic. The specific objectives are: to characterize the Neogene and Quaternary sedimentary units that outcrop of the Potiguar Basin; to show how the NW-SEtrending Afonso Bezerra Faults System deformed outcrop rocks in the Basin; to describe soft-sediment deformation in gravels of the Quaternary Alluvial Deposits from Açu River. Facies analyses, grain-size studies, luminescence dating, remote sensing, structural mapping, shallow geophysics (georadar), paleostress and petrography were carried out. The structural mapping and the georadar sections indicated that the Carnaubais and Afonso Bezerra fault systems formed fractures, silicified and non-silicified faults or deformation bands, affecting mainly the Açu, Jandaíra and Barreiras formations. The petrographic data indicate that the strong silicification resulted in a sealant character of the faults. Paleostress analysis indicates that two stress fields affected the Basin: the first presented N-S-trending compression, occurred from the Neocretaceous to the Miocene; the second stress field presents E-W-trending compression, acts from the Miocene to the present. It was verified once the Afonso Bezerra System Faults was reactivated in periods post-Campanian and affects all post-rift lithostratigraphic units of Potiguar Basin, including Quaternary sedimentary covers. The study about soft-sediment deformation structures indicates that they are similar in morphology and size to modern examples of seismically-induced deformation strutures in coarse sediments. TL and OSL ages indicate that sediment deposition and associated soft-sediment deformation occurred at least six times from ~352 Ka to ~9 Ka. Finally these studies demonstrate how recent is tectonics in the Basin Potiguar

Isótopos de Nd na proveniência de rochas e sedimentos da bacia potiguar, ne do Brasil

Nd ISOTOPES IN THE PROVENANCE OF TERRIGENOUS AND CARBONATE ROCKS AND SEDIMENTS OF THE POTIGUAR BASIN, NORTHEASTERN BRAZIL. Mesozoic and Cenozoic rocks from the Potiguar Basin, including terrigenous and carbonate sediments have been investigated to identify their isotopic signature and source areas. Additionally, this study aims to determine the provenance of terrigenous and carbonate sediments on the Brazilian Continental shelf adjacent to Potiguar Basin. The Sm-Nd isotopic signatures of the rocks yielded model ages (TDM) in the range of 2,19- 2,88 Ga, indicating archean to paleoproterozoic sources from the basement. The terrigenous sediments yielded model ages (TDM) in the range of 2,31-2,26 Ga, from 17,5 to 0 cm depth. Despite the small number of samples, limited variations of provenance ages indicates the homogenization of the sediments, probably due to the strong influence of the basement, as the main source of sediments to the shelf. The Sm-Nd isotopic signatures of the carbonate sediments yielded model ages (TDM) in the range of 2,09-2,61 Ga, indicating archean to paleoproterozoic sources from the basement. The results also indicate that the shelf sediments are mainly derived from the Açu River or other small rivers from the Setentrional Sector of Rio Grande do Norte State. The littoral drift doesn´t seem to contribute with sediments from the Oriental Sector since isotopic signatures from this sector were not detected.

Compartimentação morfotectônica da Alta Mogiana Paulista (Nordeste do Estado de São Paulo)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Difusão de conhecimentos geocientíficos por meio de web-mapping: ensaio de aplicação temática com geoturismo em uma região da borda leste da bacia do Paraná

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Neotectônica do baixo vale do rio Jaguaribe - Ceará

Pós-graduação em Geologia Regional - IGCE

Estudo das feições lineares observadas em dados aeromagnéticos da Bacia do Solimões a partir de imagens digitais de sombreamento do relevo anômalo total

A Bacia do Solimões é caracterizada por um padrão magnético complexo, expresso ao longo de toda sua extensão, e produzido pela superposição de anomalias magnéticas que se apresentam sob a forma de feições lineares. Tais feições refletem as diferentes atividades tectônicas que atuaram na Região Amazônica através do Pré-Cambriano e Fanerozóico. Neste trabalho, foi aplicado nos dados aeromagnéticos da Bacia do Solimões um método de processamento de imagens digitais de sombreamento do relevo magnético anômalo total que, dadas suas características metodológicas, permitindo utilizá-lo como um filtro direcional, possibilitou a definição de aspectos relevantes no contexto das relações entre os lineamentos magnéticos E/W, NE/SW, e NW/SE. Nesse sentido, foram identificados padrões de lineamentos magnéticos que refletem a existência de zonas de cisalhamento transcorrentes dextrais, orientadas preferencialmente na direção E/W. A interação entre os diversos segmentos transcorrentes promoveu o desenvolvimento de um regime predominantemente transpressivo, representado por falhas reversas associadas aos lineamentos magnéticos E/W e NE/SW; e duplexes direcionais formando falhas em flor positivas e negativas associadas, respectivamente, aos lineamentos magnéticos orientados na direção N70-80E e N70-80W. A análise quantitativa permitiu explicar dois aspectos importantes em relação às feições lineares observadas nas imagens digitais. O primeiro mostra, através de modelamentos baseados na superposição de prismas bidimensionais, que estas feições lineares magnéticas podem ser explicadas pela superposição de fontes profundas intraembasamento altamente magnéticas, e fontes rasas de alta frequência, sendo estas associadas a falhas reversas ao longo dos níveis de diabásio, presentes em forma de intrusões nos sedimentos paleozóicos da Bacia do Solimões. O segundo aspecto, baseado na utilização dos conceitos da cross-covariância, constata a presença de 'offsets' dextrais, associados aos lineamentos magnéticos NE—SW, ao longo da direção E—W. Este fato mostra, quantitativamente, que o padrão magnético desta região pode ser explicado pela presença de zonas de cisalhamento transcorrestes dextrais, cujos processos tectônicos associados foram fortemente condicionados por zonas de fraquezas pré-existentes (Pré-Cambrianas, Paleozóicas) durante o Mesozóico e Cenozóico.

A species-level supertree of Crocodyliformes

With fossils found worldwide, Crocodyliformes stands as one of the best documented vertebrates over the Mesozoic and Cenozoic. The multiple phylogenetic hypotheses of relationship proposed for the group allow plenty of space for contentious results, partially due to the small overlapping of taxa and disagreeing homology statements among studies. We present two supertrees of Crocodyliformes, based on different protocols of source tree selection, summarising phylogenetic data for the group into a 'synthetic consensus'. The consensus of the most parsimonious trees, containing 184 terminal taxa, has a remarkably well-resolved branching structure, which may serve as a framework for further macroevolutionary studies. In addition, the IterPCR script was for the first time used in the supertree context to build a reduced consensus tree with the pruning of unstable taxa.

Oligocene-Miocene calcareous nannofossils in ODP Leg 149 holes

During Ocean Drilling Program (ODP) Leg 149, five sites were drilled on the Iberia Abyssal Plain in the northeastern Atlantic Ocean. Both Mesozoic and Cenozoic sediments were recovered. Oligocene to Miocene sediments were cored at deepwater Sites 897, 898, 899, and 900. Except for a few intervals, occurrences of generally abundant and well-preserved calcareous nannofossils suggest that the deposition of the turbidite-type sediments occurred above the calcite compensation depth (CCD). One major unconformity in the middle late Miocene is present. Detailed quantitative analyses of calcareous nannofossils are used to determine the changes occurring among the nannoflora in relation to sea-level variation. A succession of 89 biohorizons from the early Oligocene to the late Miocene are defined by combining the biostratigraphic results of the four sites studied in the Iberia Abyssal Plain. One new genus and eight new species are described: Camuralithus, Camuralithus pelliculatus, Ericsonia detecta, Helicosphaera limasera, Sphenolithus akropodus, Sphenolithus aubryae, Sphenolithus cometa, Reticulofenestra circus, and Syracosphaera lamina. Two new variations and seven new combinations are also introduced.