Long-term fluid circulation in extensional faults in the central Catalan Coastal Ranges: P–T constraints from neoformed chlorite and K-white mica     

Irene Cantarero  Pierre Lanari  Olivier Vidal  Gemma Alías  Anna Travé  Vinyet Baqués 《International Journal of Earth Sciences》2014,103(1):165-188

The neoformation of chlorite and K-white mica in fault rocks from two main faults of the central Catalan Coastal Ranges, the Vallès and the Hospital faults, has allowed us to constrain the P–T conditions during fault evolution using thermodynamic modeling. Crystallization of M1 and M2 muscovite and microcline occured as result of deuteric alteration during the exhumation of the pluton (290 °C > T > 370 °C) in the Permian. After that, three tectonic events have been distinguished. The first tectonic event, attributed to the Mesozoic rifting, is characterized by precipitation of M3 and M4 phengite together with chlorite and calcite C1 at temperatures between 190 and 310 °C. The second tectonic event attributed to the Paleogene compression has only been identified in the Hospital fault with precipitation of low-temperature calcite C2. The shortcut produced during inversion of the Vallès fault was probably the responsible for the lack of neoformed minerals within this fault. Finally, the third tectonic event, which is related to the Neogene extension, is characterized in the Vallès fault by a new generation of chlorite, associated with calcite C4 and laumontite, formed at temperatures between 125 and 190 °C in the absence of K-white mica. Differently, the Hospital fault is characterized by the precipitation of calcite C3 during the syn-rift stage at temperatures around 150 °C and by low-temperature fluids precipitating calcites C5, C6 and PC1 during the post-rift stage. During the two extensional events (Mesozoic and Neogene), faults acted as conduits for hot fluids producing anomalous high geothermal gradients (50 °C/km minimum).  相似文献   

Fluid–rock interactions associated with regional tectonics and basin evolution     

Simone Fontana  Fadi Henri Nader  Sadoon Morad  Andrea Ceriani  Ihsan Shakir Al‐Aasm  Jean‐Marc Daniel  Jean‐Marie Mengus 《Sedimentology》2014,61(3):660-690

An integrated approach consisting of fracture analysis, petrography, carbon, oxygen and strontium‐isotope analyses, as well as fluid‐inclusion micro‐thermometry, led to a better understanding of the evolution of fluid–rock interactions and diagenesis of the Upper Permian to Upper Triassic carbonates of the United Arab Emirates. The deposited carbonates were first marked by extensive early dolomitization. During progressive burial, the carbonates were affected by dolomite recrystallization as well as precipitation of vug and fracture‐filling dolomite, quartz and calcite cements. After considerable burial during the Middle Cretaceous, sub‐vertical north–south oriented fractures (F1) were cemented by dolomite derived from mesosaline to hypersaline fluids. Upon the Late Cretaceous maximum burial and ophiolite obduction, sub‐vertical east–west fractures (F2) were cemented by dolomite (Dc2) and saddle dolomite (Ds) derived from hot, highly saline fluids. Then, minor quartz cement has precipitated in fractures from hydrothermal brines. Fluid‐inclusion analyses of the various diagenetic phases imply the involvement of increasingly hot (200°C) saline brines (20 to 23% NaCl eq.). Through one‐dimensional burial history numerical modelling, the maximum temperatures reached by the studied rocks are estimated to be in the range of 160 to 200°C. Tectonically‐driven flux of hot fluids and associated diagenetic products are interpreted to have initiated during the Late Cretaceous maximum burial and lasted until the Oligocene–Miocene compressional tectonics and related uplift. The circulation of such hydrothermal brines led to partial dissolution of dolomites (Dc2 and Ds) and to precipitation of hydrothermal calcite C1 in new (mainly oriented north–south; F3) and pre‐existing, reactivated fractures. The integration of the obtained data confirms that the diagenetic evolution was controlled primarily by the interplay of the burial thermal evolution of the basin and the regional tectonic history. Hence, this contribution highlights the impacts of regional tectonics and basin history on diagenetic processes, which may subsequently affect reservoir properties.  相似文献   

Impact of the geomorphology and soil management on the development of waterlogging in closed drainage basins of Egypt and Saudi Arabia   总被引：1，自引：0，他引：1  

Mohammed El Bastawesy  Rafat Ramadan Ali  Khalid Al Harbi  Abdallah Faid 《Environmental Earth Sciences》2013,68(5):1271-1283

This paper investigates the interplay of the catchment geomorphology, hydrology and soil properties on the development of waterlogging and land degradation within different dry land catchments in Egypt and Saudi Arabia. Multi-temporal remote sensing data of the Landsat Thematic Mapper and Enhanced Thematic Mapper were collected and processed to detect the land cover changes and development of cultivations within the two areas. The Shuttle Radar Topography Mission Digital Elevation Model were hydrologically processed to delineate the catchment morphometrical parameters and to examine the spatial distribution of cultivated fields and their relation to the extracted drainage networks. The fluvial channels of the Farafra Oasis have largely been obliterated by the prevailing aridity and often buried under aeolian deposits. The soil of these areas are mainly lithic with a high calcium carbonate content, thus limiting the downward percolation of excess irrigation water and therefore develop perched water table and seepage through the buried fluvial channels. On the other hand, the cultivations of Tabuk catchment (which has similar geomorphologic setting to the Farafra Oasis) have shown no signs for waterlogging. This situation is could be related to the different soil properties; the spatial distribution of cultivated areas and the adopted irrigation methods via pivots. The inactive alluvial channels, landforms and irrigation methods have to be considered when planning for a new cultivation in dry land catchments to better control waterlogging hazard. The ‘dry-drainage’ concept can be implemented as the drainage and seepage water, which can be conveyed into certain abandoned playas for evaporation.  相似文献   

Assessment of extraction drainage pattern from topographic maps based on photogrammetry     

Samih B. Al Rawashdeh 《Arabian Journal of Geosciences》2013,6(12):4873-4880

The extraction of the water hydrographical pattern and watershed and subwatershed boundary is very important for many types of study. In Jordan the topographic map scale 1:25,000 produced at the Royal Jordanian Geographic Center is considered the most important source of contour lines and drainage pattern; therefore, it is imperative to estimate the accuracy of these types of data extracted from the previous topographic maps. In this project we aim to extract the hydrographical pattern of the Humrat Assahn basin in two methods: (1) an orthophoto based on aerial photographs using Socetset as photogrammetric software and (2) topographic maps at scale 1:25,000. A precise Digital Terrain Model (DTM) was built from stereoscopic aerial photographs using Socetset software. As we know, the quality of DTM is imperative to assure precise results and depends on the method of creation of this DTM besides other factors. A complete data base for the necessary information for achieving this objective was built. The obtained results were evaluated using GPS points and photo-interpretation. The results show that the drainage pattern extracted from DTM using photogrametric software was very accurate; meanwhile, the accuracy of the drainage pattern extracted from topographic maps has some flaws.  相似文献   

Strategic groundwater resources planning in arid regions     

Zekai Şen  Saleh A. Al Sefry  Saleh A. Al Ghamdi  Wahib A. Ashi  Wael A. Bardi 《Arabian Journal of Geosciences》2013,6(11):4363-4375

A strategic approach is presented for future groundwater reservoir planning in arid regions where the evaluation of groundwater resources is restricted by scarcity of rainfall, data paucity, restrictive and unrepresentative methodologies, weak economies, almost nonexisting management and optimization programs, frequent groundwater quality variables along short distances, etc. This paper explains the necessary steps in preparing an effective strategic planning program that is expected to provide all the necessary data for identifying alternative solution scenarios especially in arid regions. It is shown on the basis of available scarce data that the risk model of these factors appears as the logarithmic normal probability distribution. The basic decision variables in groundwater storage and recharge planning are furnished with application to Wadi Fatimah in the western central part of the Kingdom of Saudi Arabia along the Red Sea coast. The approach given in this paper provides a basic example for future groundwater reservoir strategic use and management studies in the Kingdom in particular and in any part of the arid regions of the world, in general.  相似文献   

Determination and applications of chemical analysis to evaluate Jurassic hydrocarbon potentiality in Northern Iraq   总被引：1，自引：1，他引：0  

Ahmed Asker Najaf Al Ahmed 《Arabian Journal of Geosciences》2013,6(8):2941-2949

Chemical analysis was carried out to evaluate the potentiality of rock samples having hydrocarbon characteristics, identified by chemical methods as one of the approaches to evaluate the source rocks encountered from Sehkanian, Sargelu, Naokelekan, Sarmord and Ghia Gara of (Middle to Upper Jurassic–Lower Cretaceous) stratigraphic sequence of Iraq, representing source rocks, which are recovered from oil exploratory wells Butmah-15, Ajeel-8, Makhul-2, Qarachuq (1 and 2) and TaqTaq-1 (Bm-15, Aj-8, Mk-2, Qc-1,Qc-2 and Taq-1) alternatively, located in the northern part of Iraq and also the outcrop samples extracted from the type locality at Surdash Anticline. Additional samples were taken from another exposure section of the Jurassic rocks from Banik village, those various samples represent Varity of palynofacies. The bulk of chemical analysis enables to enhance the potentiality of the source rocks, leading to believe generating tremendous amount of oil and subordinate gas promising more than earlier predictions for forming super giant oil and thermogenic gas fields in this area. The value of the production indices determines that the system of the oil in Iraq is not widely different from the depocenters of the surrounding countries. Accordingly Iraq is considered as an ideal and systematic basin that all the total petroleum system elements are available, giving indications of good source rocks, extensive reservoirs and excellent seals. Typical oil fields, which as determined by the remarkable total organic carbon exceeds 20 %, and maturation evidences accompanied with maximum temperature up to 450°C indicate obviously various values of the hydrogen and oxygen indices, kerogen type II and type III, of marine to mixed to terrestrial origin that lead to determine that the oil and gas prone Sargelu, Naokelekan and Ghia Gara were good source rocks. Meanwhile Barsarin and Sarmord were reservoir rocks. The area of study is widely promising to produce oil with condensed gas.  相似文献   

Remote sensing in hydrology   总被引：4，自引：0，他引：4  

Thomas J. Schmugge  William P. Kustas  Jerry C. Ritchie  Thomas J. Jackson  Al Rango 《Advances in water resources》2002,25(8-12)

Remote sensing provides a means of observing hydrological state variables over large areas. The ones which we will consider in this paper are land surface temperature from thermal infrared data, surface soil moisture from passive microwave data, snow cover using both visible and microwave data, water quality using visible and near-infrared data and estimating landscape surface roughness using lidar. Methods for estimating the hydrometeorlogical fluxes, evapotranspiration and snowmelt runoff, using these state variables are also described.  相似文献   

Where do the progenitors of millisecond pulsars come from?     

A. Taani  C.M. Zhang  M. Al‐Wardat  Y.H. Zhao 《Astronomische Nachrichten》2012,333(1):53-59

Observations of a large population of millisecond pulsars (MSPs) show a wide divergence in the orbital periods (from approximately hours to a few months). In the standard view, low‐mass X‐ray binaries (LMXBs) are considered as progenitors for some MSPs during the recycling process. We present a systematic study that combines different types of compact objects in binaries such as cataclysmic variables (CVs), LMXBs, and MSPs. We plot them together in the so called Corbet diagram. Larger and different samples are needed to better constrain the result as a function of the environment and formations. A scale diagram showing the distribution of MSPs for different orbital periods and the aspects for their progenitors relying on accretion induced collapse (AIC) of white dwarfs in binaries. Thus massive CVs (M ≥ 1.1 M_⊙) can play a vital role on binary evolution, as well as of the physical processes involved in the formation and evolution of neutron stars and their magnetic fields, and could turn into binary MSPs with different scales of orbital periods; this effect can be explained by the AIC process. This scenario also suggests that some fraction of isolated MSPs in the Galactic disk could be formed through the same channel, forming the contribution of some CVs to the single‐degenerate progenitors of Type Ia supernova. Furthermore, we have refined the statistical distribution and evolution by using updated data. This implies that the significant studies of compact objects in binary systems can benefit from the Corbet diagram.Observations of a large population of millisecond pulsars (MSPs) show a wide divergence in the orbital periods (from approximately hours to a few months). In the standard view, low‐mass X‐ray binaries (LMXBs) are considered as progenitors for some MSPs during the recycling process. We present a systematic study that combines different types of compact objects in binaries such as cataclysmic variables (CVs), LMXBs, and MSPs. We plot them together in the so called Corbet diagram. Larger and different samples are needed to better constrain the result as a function of the environment and formations. A scale diagram showing the distribution of MSPs for different orbital periods and the aspects for their progenitors re  相似文献   

Food and the city: urban agriculture and the new food revolution     

Md Rajibul Al Mamun 《Urban geography》2013,34(1):152-153

  相似文献   

Hydrogeological condition and assessment of groundwater resource using visual modflow modeling,Rajshahi city aquifer,Bangladesh     

M. Al Mamunul Haque  C. S. Jahan  Q. H. Mazumder  S. M. S. Nawaz  G. C. Mirdha  P. Mamud  M. I. Adham 《Journal of the Geological Society of India》2012,79(1):77-84

The Rajshahi city is the fourth largest metropolitan city in Bangladesh on the bank of the River Padma (Ganges). Here an upper semi-impervious layer overlies aquifer — the source for large-scale groundwater development. The groundwater resource study using Visual MODFLOW modeling shows that recharge occurs mainly due to infiltration of rainfall and urban return flow at low rate, and water level fluctuates seasonally in response to recharge and discharge. Hydraulic connection between river and aquifer which indicates inflow from high river water levels beyond its boundaries. The total groundwater abstraction in 2004 (15000 million liters) is lower than total input to aquifer reveals an ample potentiality for groundwater development with increasing demand. But groundwater shortage (1000 million liter/year) especially in the vicinity of the River Padma in dry season happens due to its increasing use and fall of river water level resulting in reduced inflows and hence decline in groundwater level. The conjunctive use of surface water-groundwater and its economic use will help for sustainable groundwater supply to avoid adverse impact.  相似文献