Tertiary coal geology and stratigraphy of the Port Phillip Basin,Victoria     

G. R. Holdgate  S. J. Gallagher  M. W. Wallace 《Australian Journal of Earth Sciences》2013,60(3):437-453

Results from coal‐exploration drilling in the onshore part of the Port Phillip Basin, Victoria, have established stratigraphic and age correlations of the Lower Miocene Werribee Formation brown coal deposits at Bacchus Marsh to similar brown coals at Altona. The coal deposits occur in a northwest‐southeast structural depression (the Parwan Trough) that appears to be a southeast continuation of the Ballan Graben. Recent drilling for potential coal‐bed methane in the trough has provided new data on the deeper stratigraphy not penetrated by earlier drilling, including recognition of an Upper Cretaceous to Eocene Yaloak Formation coal‐bearing interval, similar to the Anglesea area, Ballan Graben and Lal Lal Basin. Up to 200 m of coal‐bearing sediment and minor volcanics underlie the Miocene coal measures. A marine facies transition takes place between the Miocene coal swamps of the Parwan Trough, through barrier sands west of Werribee, to carbonate facies near Geelong. To the south beneath Port Phillip Bay, a similar transition probably occurs between coal swamps of the Parwan Trough and fully marine carbonate environments of the contiguous Sorrento Graben. The palaeogeographical reconstructions suggest a similar coal‐to‐carbonate facies transition as in the adjacent onshore Gippsland Basin.  相似文献   

Neoproterozoic (Cryogenian) stromatolites from the Wolfe Basin,east Kimberley,Western Australia: Correlation with the Centralian Superbasin     

K. Grey  D. H. Blake 《Australian Journal of Earth Sciences》2013,60(3):329-341

Linella avis, an early to middle Neoproterozoic (Tonian to Cryogenian) stromatolite, occurs in the Eliot Range Dolomite, part of the Ruby Plains Group in the Wolfe Basin, east Kimberley. Previously, this dolomite was assigned to the Mesoproterozoic Bungle Bungle Dolomite in the Osmond Basin, which contains a different suite of stromatolites. Linella avis, which also occurs in the Neoproterozoic Bitter Springs Formation of the Amadeus Basin, central Australia, appears to be restricted to rocks aged around 850 to 800 Ma. The presence of L. avis indicates that the Ruby Plains Group is a probable correlative of the Heavitree Quartzite and Bitter Springs Formation, and is probably much younger than the Bungle Bungle Dolomite. If the correlation suggested here is correct, the Wolfe Basin, together with the Amadeus and Ngalia Basins, formed part of the Centralian Superbasin.  相似文献   

Thermal history of the Hodgkinson Province and Laura Basin,Queensland: Multiple cooling episodes identified from apatite fission track analysis and vitrinite reflectance data     

S. J. Marshallsea  P. F. Green  J. Webb 《Australian Journal of Earth Sciences》2013,60(4):779-797

Apatite fission track analysis and vitrinite reflectance data from outcrop and well samples in the Hodgkinson Province and Laura Basin reveal regional Cretaceous cooling. Apatite fission track analysis appears to define two discrete cooling episodes, in the mid‐Cretaceous (110–100 Ma) and Late Cretaceous (80–70 Ma), although in most samples data allow only definition of a single episode. Rocks now at outcrop cooled from Cretaceous palaeotemperatures generally between 50 and 130°C in the south of the region, and from >100°C in the north. Some samples from the Hodgkinson Province also show evidence for an Early Jurassic cooling episode, characterised by maximum palaeotemperatures varying from at least 95°C (from apatite fission track analysis) to ～200–220°C (from vitrinite reflectance), with cooling beginning at around 200 Ma. Apatite fission track analysis data do not reveal the earlier event in the Laura Basin, but on the basis of vitrinite reflectance data from Permian? units this event is also inferred to have affected the pre‐Jurassic basin units in this region. The regional extent of the Cretaceous cooling episode in the Hodgkinson Province suggests that the elevated palaeotemperatures in this region were most likely due to greater depth of burial, with subsequent cooling due to kilometre‐scale denudation. For a palaeogeothermal gradient of 30°C/km and a palaeosurface temperature of 25°C the total degree of Cretaceous cooling experienced by the samples corresponds to removal of between ～0.8 and >3.0 km of Triassic and younger section removed by denudation, beginning some time between ca 110 and 80 Ma. Higher palaeogradients would require correspondingly lower amounts of removed section. The geology of the Laura Basin suggests that an explanation of the observed Cretaceous palaeotemperatures in this region in terms of deeper burial may be untenable. Heating due to hot fluid flow may be a more realistic mechanism for producing the observed Cretaceous palaeothermal effects in the Laura Basin.  相似文献   

A 44-year high-resolution ocean and atmospheric hindcast for the Mediterranean Basin developed within the HIPOCAS Project     

A.W. Ratsimandresy  M.G. Sotillo  J.C. Carretero Albiach  E. Álvarez Fanjul  H. Hajji 《Coastal Engineering》2008

A set of 44-year (1958–2001) homogeneous and high-resolution hindcasts of atmospheric, sea level residuals, and wave states was performed for the Mediterranean Basin within the framework of the HIPOCAS European Project. To this aim, different numerical models were used. As a first step, a Mediterranean high-resolution atmospheric database, suitable to provide realistic and homogeneous forcing for ocean hindcast runs was generated. The HIPOCAS atmospheric database was created by means of dynamical downscaling from the global reanalysis NCEP, using for that the limited area model SN-REMO along with a spectral nudging technique. In a second stage, different Mediterranean oceanic hindcasts were performed. On one hand a long-term database of sea state over the western Mediterranean was generated by means of the wave model WAM and on the other hand a sea level residual database containing storm surge events was obtained from a long-term integration of the HAMSOM model over the entire basin. The three different hindcast runs have been exhaustively validated. On that score, various simulated parameters have been compared to both satellite and in situ measurements. Such comparisons provide a measure of the skills of the different simulated fields to realistically reproduce the observed features. Once these skills are evaluated, a study of the ocean and atmospheric climate trends as well as the interannual variability for the whole 44-year period was carried out with the hindcasted data. The reliability of the data as shown by its comparison to measurements and a proven temporal homogeneity over the 44 years of simulation make the Mediterranean HIPOCAS ocean–atmosphere hindcasted database a useful tool for studies focused on regional climatic variability, as well as for further applications in coastal and environmental decision processes in the Mediterranean area.  相似文献   

Geological environment conflicts of Kunming Basin and its urban sustainable development     

Jianhua FAN  Bingfei SHI 《世界地质(英文版)》2006,9(2)

Kunming Basin locates middle of Yunnan altiplano and has a particularity in geography, topographic and geological environment. With the urban dilation quickly, add the reason of the unreasonable city layout, conflicts between environment and urban resources consumption become shrill increasingly. It is human being activities that lead to vulnerability and depravation of geological environment in local. Take a few examples on geological environment to expatiate relationship between urban construction and geological environment carrying capacity, and find a way how to make a better plan for urban sustainable development to achieve new balance between man and nature in local.  相似文献   

Geochemical and isotopic evidence of a groundwater source in the Corral Canyon meadow complex,central Nevada,USA     

Eliot A. Atekwana  Dorothea S. Richardson 《水文研究》2004,18(15):2801-2815

Major inorganic ions and stable carbon and oxygen isotopes in stream water, groundwater, groundwater seeps and springs were measured in the Corral Canyon meadow complex and watershed in the Toquima Mountains of central Nevada, USA. The purpose of the study was to determine whether stream water or groundwater was the source of water that supports vegetation in the meadow complex. Water samples from the watershed and meadow complex were mixed cation–HCO₃ type. Stream water sampled at different locations in the meadow complex showed variations in temperature, pH and specific conductance. The cation–anion proportions for stream water were similar to groundwater, groundwater seeps and runoff from the meadow complex. Stable oxygen isotope ratios for stream water (?17·1 to ?17·6‰ versus VSMOW) and groundwater and groundwater seeps in the meadow site (?17·0 to ?17·7‰ versus VSMOW) were similar, and consistent with a local meteoric origin. Dissolved inorganic carbon (DIC) and the δ ¹³C_DIC for stream water (?12·1 to ?15·0‰ versus VPDB) were different from that of groundwater from the meadow complex (?15·3 to ?19·9‰ versus VPDB), suggesting different carbon evolution pathways. However, a simple model based on cation–δ ¹³C_DIC suggests that stream water was being recharged by shallow groundwater, groundwater seeps and runoff from the meadow complex. This leads to the conclusion that the source of water that supports vegetation in the meadow complex was primarily groundwater. The results of this study suggest that multiple chemical and stable carbon isotope tracers are useful in determining the source of water that supports vegetation in meadow complexes in small alpine watersheds. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Comparison of Kuqa foreland basin with Persian Gulf Basin in salt tectonics     

Guimei WAN  Liangjie TANG  Wenzheng JIN 《世界地质(英文版)》2007,10(2)

Compared Kuqa foreland basin with Persian Gulf Basin in development of salt layers, salt tectonics, and the relation between salt tectonics and hydrocarbon, it is concluded that the salt diapirs are relative to hydrocarbon. Searching salt diapirs and related traps in Kuqa foreland basin is important. The forming mechanism of salt tectonic in Kuqa foreland basin is different from that of Hormuz Series, but similar to that of Lower Fars Series/Gachsaran Formation. Inspired by the role of salt tectonics of Lower Fars Series/Gachsaran Formation in hydrocarbon accumulation, the authors considered that the exploration below salt layer should be enforced, and the traps below salt layer in the southern part of the Kuqa foreland basin would be found where salt layer is thicker. On the contrary, the traps should be found both above and below the salt layer in front of the northern mountain where salt layer is thin. The Triassic and Jurassic source rocks are rich in this area with great exploration prospective.  相似文献   

关中盆地潜水化学特征及其变化趋势     

田春声  王丽艳 《地球科学与环境学报》1993,(Z2)

本文在阐明关中盆地环境水文地质条件的基础上,论述了关中盆地潜水化学特征及其成因,并着重对盆地潜水化学变化的几个主要问题,诸如常规组份的升高及水化学类型的改变、潜水硬度的升高、硝酸盐的富集及微量重金属元素的污染等进行了分析。讨论了上述问题的因果及今后工作意见。  相似文献   

柴达木盆地察尔汗古湖贝壳堤剖面粒度特征及其沉积环境   总被引：15，自引：2，他引：13  

雷国良  张虎才  张文翔  常凤琴  樊红芳  杨明生  陈玥  牛洁 《沉积学报》2007,25(2):274-282

通过对柴达木察尔汗盐湖贝壳堤剖面沉积物粒度、碳酸盐和磁化率的对比,结合沉积物粒度频率曲线与多种粒度参数分析,详细讨论了研究剖面形成过程中物质搬运和沉积作用以及所反映的环境变化。结果表明沉积物粒度特征指示了湖泊水位的相对变化。在距今约38.2 ka BP（14-C年代,未校正。下同）左右,沉积记录指示古湖泊的范围和水位已达到剖面位置,之后湖泊继续扩张、水位波动上升;在距今约35.5 ka BP,粒径有一突然变细又变粗的过程,可能为一次较快速的湖面波动;在距今约35.5 ～ 33.3 ka BP之间,沉积物颗粒较粗,碳酸盐含量和磁化率值低,揭示湖泊水位较低。距今约33.3 ～ 27.1 ka BP之间,沉积物颗粒较细,碳酸盐含量较前一阶段高,表明此阶段湖泊水位相对较深,但粒度、碳酸盐和磁化率等指标也记录了三次较明显的湖泊快速但短暂的退缩过程;在距今约29.7～28.3 ka BP,沉积物颗粒最细,指示了此时期可能为湖泊水位最高期。从距今约27.1 ka BP开始,沉积积物颗粒明显变粗,揭示湖泊进入到退缩期,距今约18.1 ka BP,粒度指标的变化和上层的盐壳指示湖泊进入快速盐化阶段,之后湖泊退出剖面所在的位置,此后研究区湖泊水位再也没有达到这个高度。  相似文献   

塔里木盆地志留纪沉积层序构成及充填响应特征   总被引：9，自引：2，他引：7  

施振生  杨威  郭长敏  朱筱敏  张林  陈刚 《沉积学报》2007,25(3):401-408

塔里木盆地志留系是由角度不整合面所限定的一个区域性（二级）的沉积层序,其内可划分出5个三级沉积层序。总体上显示一个从水进到水退的沉积旋回,可识别出曲流河三角洲—辫状河三角洲、滨外陆棚及较深水盆地、无障壁碎屑滨岸—无障壁碎屑潮坪沉积体系组合,它们代表了二级沉积层序中相对低位、海侵和高位的3个沉积体系组合。研究区构造、沉积、古生物和古气候资料表明,层序1底界面和层序5顶界面是塔里木周缘板块构造挤压、盆地隆升作用的结果;层序2底界面是周缘板块强烈挤压、盆地挠曲下降作用结果,同期全球海平面快速上升;层序3、层序4和层序5的底界面是在构造作用稳定、全球海平面下降背景之上由相对海平面次一级旋回变化形成的,是古气候变化、沉积物供给及构造沉降共同作用的结果。  相似文献