Chalcophile elements in western Canadian coals     

F. Goodarzi  D.J. Swaine 《International Journal of Coal Geology》1993,24(1-4)

Concentrations of chalcophile elements (As, Co, Cu, Hg, Mo, Ni, Pb, Sb and Zn) in western Canadian coals were determined using INAA and AAS. The concentrations of these elements in western Canadian coals are within the range for most world coals. However, there are some high values for coals from outcrops and from areas which are not currently being mined.Arsenic content in the majority of western Canadian coals, particularly those currently being mined, is low (0.2–3 ppm). However, there are coals with high arsenic content; for example, lignites from Hat Creek A zone contain between 4.0 and 14.0 ppm As. In some samples from Comox and Suquash, the As concentration is as high as 240 ppm and 1400 ppm, respectively. The enrichment of As in high arsenic coals is related to the geology and nature of country rocks associated with the coal seams. The concentration of other elements for most western Canadian coals, particularly those being mined, are within the range for most world coals. In these coals, the concentration ranges (in ppm) of chalcophile elements are 0.3-3.6 for Sb, 0.8-4.6 for Co, 7–35 for Cu, <0.1 for Hg, 2–6 for Mo, 4–94 for Ni, 6–22 for Pb, 2–7 for Se and 7–110 for Zn.  相似文献   

Petrology, rank and evidence for petroleum generation, Upper Triassic to Middle Jurassic coals, Central Alborz Region, Northern Iran     

L.D. Stasiuk  F. Goodarzi  H. Bagheri-Sadeghi 《International Journal of Coal Geology》2006,67(4):249-258

Upper Triassic to Middle Jurassic coals from the Alborz region of northern Iran were analyzed by reflected light-fluorescence microscopy and Rock Eval 6® pyrolysis to evaluate their regional rank variation, degree of hydrothermal alteration, and petroleum generative potential. The coal ranks in the region range from a low of 0.69%Ro_R in the Glanddeh-Rud area to a high of 1.02%Ro_R in the Gajereh area. T_max (°C) values (Rock Eval 6 pyrolysis) also increase progressively with increasing vitrinite %Ro values, however T_max is suppressed lower than would be expected for each rank ranging from 428 °C for the Glandeeh coal to 438 °C for the Gajereh coal. T_max suppression may be caused by maceral composition and soluble organics within the coal. Moderately high hydrogen indices, persistent and oily exudations from the coals during UV exposure, and traces of hydrocarbon fluid inclusions suggest that liquid petroleum was likely generated within some of the coals.  相似文献   

Exploring the sample size and replications scenarios effect on spatial prediction of flood,using MARS and MaxEnt methods case study: saliantape catchment,Golestan, Iran     

Rajabi  Ahmad  Shabanlou  Saeid  Yosefvand  Fariborz  Kiani  Afshin 《Natural Hazards》2021,109(1):871-901

Flood has always been a destructive natural hazard during the recent years. Hence, this research aimed to predict the potentiality and probability of flood phenomenon by using the two well-known models, i.e., the MARS algorithm (multivariate adaptive regression splines) and MaxEnt (maximum entropy) method in the Saliantapeh catchment, Golestan province, Iran, covering 4515.47 km². First, documentary sources report and field surveys were used to provide a flood database map. Then, to prepare the flood spatial potentiality map (FSPM), we select sixteen influential variables as predictors. Furthermore, the relative contributions of predicting factors are estimated using the MaxEnt method. For the analysis of data sensitivity and the uncertainty of the proposed models, different scenarios including the sample size (50%/50%, 80%/20%, and 70%/30%, respectively, for training and validation), and the number of replications (5, 10, and 20) were used. Along with the area under the ROC curve (AUC), the highest accuracy for both models corresponds to the first scenario of sample size (80/20%). Contrarywise, it can be concluded that for this scenario, the MARS technique indicated higher predictive skill (AUC?=?98.51%). Regarding the second scenario, which is corresponding to the replicate, the MARS model with 20 replications still has the highest accuracy (94.70%) compared to the other scenarios and the MaxEnt model. The findings of robustness demonstrated that the scenarios with the greatest AUC value have the highest robustness. This work demonstrates that the utilization of the best accurate model with high certainty along with FSPM may be useful to identify and manage the areas that are most susceptible to flood.

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Coalbed methane producibility from the Mannville coals in Alberta, Canada: A comparison of two areas   总被引：2，自引：1，他引：1  

T. Gentzis  F. Goodarzi  F.K. Cheung  F. Laggoun-Dfarge 《International Journal of Coal Geology》2008,74(3-4):237-249

Selenium concentrations were measured in five rock cores from a mine in Boone County, West Virginia to determine their relationship to sulfur, rock type and stratigraphic location. The samples spanned the Winifrede and Coalburg coal beds of the Middle Pennsylvania upper Kanawha Formation and included coals and clastic lithologies. The coals generally contained the highest concentrations of Se and the sandstones the lowest. No correlation was observed between total Se and sulfur concentrations for either the entire data set or for individual lithologies. Better correlations were identified for log concentrations between total Se and total organic carbon. Principal component analysis identified a strong sulfur–acid component, interpreted to be due to sulfide mineral presence, which correlates well with S but not with Se. Coal sample chemistry is more likely to load onto this component while clastic rock chemistry is more likely to load onto the second, non-sulfur component. Se concentrations load onto both components indicating they are not controlled by a single overriding chemistry. Selective extractions indicate that Se is distributed between both sulfide and organically-bound fractions, as defined by the test. Overall, the lack of correlation between Se and S, the distribution of Se among extracted fractions, and the loading of Se onto both sulfur and non-sulfur components support that the Se in these rock layers is distributed in more than one chemically-bound form. Non-coal rock units with the highest concentrations of Se were found adjacent to coal beds, suggesting that redistribution of Se may have occurred post-deposition. The acidic domed swamps that formed these coals were low in sulfur and a reasonable chemical setting to accumulate Se if it were introduced. The preservation of Se in the domed swamp peat coupled with post-depositional redistribution may partly explain the data presented.  相似文献   

Magmatic and metamorphic history of the Deh-Salm metamorphic Complex, Eastern Lut block, (Eastern Iran), from U–Pb geochronology     

Shahryar Mahmoudi  Fariborz Masoudi  Fernando Corfu  Behzad Mehrabi 《International Journal of Earth Sciences》2010,99(6):1153-1165

The Deh-Salm metamorphic Complex (DMC) of the Lut block in East Iran consists of metapelites, amphibolites, marbles, and metasandstones intruded by granite and pegmatites. U–Pb dating of zircon, monazite, xenotime, and titanite by ID-TIMS show that the granitic rocks were emplaced at 166–163 Ma, confirming that the high temperature metamorphism was synchronous with the intrusive activity, and that the region cooled rapidly thereafter. Late- to post-magmatic hydrothermal activity was probably responsible for the late crystallization, at 159.5 Ma, of zircon and titanite in an amphibolite and of monazite in granite. Xenocrystic zircons yield indications for a Carboniferous component in the source, together with a variety of Precambrian ages, which indicate a provenance of the sedimentary protolith from mature continental crust. The timing and rapidity of the events are consistent with evolution of the DMC in a back-arc environment during the Jurassic subduction of the Neotethys Ocean.  相似文献   

Thermal maturation, potential source rocks and hydrocarbon generation in Mesozoic rocks, Lougheed Island area, Central Canadian Arctic archipelago     

Thomas Gentzis  Fariborz Goodarzi  Ashton F. Embry 《Marine and Petroleum Geology》1996,13(8):879-905

Significant oil and gas accumulations occur in and around Lougheed Island, Arctic Canada, where hydrocarbon prospectivity is controlled by potential source rock distribution and composition. The Middle to Upper Triassic rocks of the Schei Point Group (e.g. Murray Harbour and Hoyle Bay formations) contain a mixture of Types I and II organic matter (Tasmanales marine algae, amorphous fluorescing bituminite). These source rocks are within the oil generation zone and have HI values up to 600 mg HC/g Corg. The younger source rocks of the Lower Jurassic Jameson Bay and the Upper Jurassic Ringnes formations contain mainly gas-prone Type II/III organic matter and are marginally mature. Vitrinite reflectance profiles suggest an effective geothermal gradient essentially similar to the present-day gradient (20 to 30°C/km). Maturation gradients are low, ranging from 0.125 to 0.185 log%Ro/km. Increases in subsidence rate in the Early Cretaceous suggest that the actual heat flow history was variable and has probably diminished from that time. The high deposition rates of the Christopher Formation shales coincide with the main phase of rifting in Aptian-Albian times. Uplift and increased sediment supply in the Maastrichtian resulted in a new sedimentary and tectonic regime, which culminated in the final phase of the Eurekan Orogeny. Burial history models indicate that hydrocarbon generation in the Schei Point Group took place during rifting in Early Cretaceous, long before any Eurekan deformation.  相似文献   

Regional maturity as determined by organic petrography and geochemistry of the Schei Point Group (Triassic) in the western Sverdrup Basin, Canadian Arctic Archipelago     

F. Goodarzi  P.W. Brooks  A.F. Embry 《Marine and Petroleum Geology》1989,6(4)

Maturity and source rock potential of organic rich beds in the Triassic Schei Point Group in the Sverdrup Basin, Arctic Canada have been investigated using reflected light microscopy and the results are compared with other maturity parameters determined geochemically (i.e. Rock Eval, and biomarker maturation parameters). The samples evaluated belong to the Eden Bay Member of the Hoyle Bay Formation and contain a predominance of marine algal material, in the form of Tasmanales, and dinoflagellates, along with mixed terrestrial organics.The rock matrix is dominantly carbonate with some shaly input, indicating that the rocks were deposited in an iron-poor highly euxinic environment. With few exceptions there is good agreement between parameters,determined using microscopy; namely %R_o, λ_max and and geochemical parameters, T_max, HI, steranes, C₂₉ steranes. The ternary diagram showing the abundance of normalized C₂₇, C₂₈ and C₂₉ regular steranes indicates a mostly marine depositional environment for the Schei Point source rock. This is confirmed by the abundance of marine fauna and flora in these samples.Analytical results from several different techniques indicate that the source rocks become more mature from the margin towards the axis of the Sverdrup Basin. This is due, in part, to the increase in overburden of sediments in the axis of the basin. Also the high thermal conductivity of salt has strongly influenced the maturity of Schei Point source rocks over the crest of the salt cored structures, i.e. Well Hazen F-54, and the proximity of salt has enhanced maturation levels at Well Rock Point J-43. The sections investigated were also considered to have an excellent gas potential due to their higher than average TOC content.  相似文献   

Preservation and characteristics of plant remains in Iranian natural bitumens     

Fariborz Goodarzi 《International Journal of Coal Geology》1985,4(4):321-334

Gell preserved monocotyledon and peeridophyta remains were found in natural bitumen frrm Iranian, tar pit and oil seeps, using reflected and fluorescence light microscopy. The plant tissue are impregnated or partially replaced by bitumens the extent of this replacement is noted.  相似文献   

Effect of maceral subtypes and mineral matrix on measured reflectance of subbituminous coals and dispersed organic matter     

Fariborz Goodarzi  Thomas Gentzis  Shimon Feinstein  Lloyd Snowdon 《International Journal of Coal Geology》1988,10(4)

The variability in reflectance of huminite (texto-ulminite, eu-ulminite A and B, different types of corpohuminite) and liptinite groups of macerals in subbituminous coals was examined using reflected light microscopy. All macerals were selected from coal and interbedded carbonaceous shale and carbonate sediment samples from the 515-m-thick coal deposit No. 2 located in the Hat Creek valley of south-central British Columbia. The measurements obtained reveal that, in addition to burial depth, reflectance distribution depends on maceral subtypes and associated mineral matrix.Huminite in the coals and sediments (kerogen) consists mainly of humotelinite, with eu-ulminite B being the dominant maceral sub-type. Reflectance values determined on huminite in coals and Type IIIb kerogen increase from eu-ulminite A and phlobaphinite type 1 through eu-ulminite B and phlobaphinite type 2 to gelinite. The reflectance of all five huminite maceral subtypes studied increases with depth. However, the increase of phlobaphinite type 1 and gelinite reflectance with depth is irregular.A comparison of the reflectance values obtained for the same maceral subtype (eu-ulminite B) from the interbedded coal, shale and carbonate samples records consistent differences, implying some dependence of the reflectance (and perhaps rate of organic maturation) on the mineral matrix. Generally, the highest eu-ulminite B reflectance was recorded from carbonate rocks and the lowest from shale, whereas coal matrix produced intermediate values.At present, it is not known whether differences in reflectance of eu-ulminite found in the above lithologies are due to differential retention, efficiency of reaction products removal, thermal conductivity of the lithologies, or existence of a calcium carbonate catalyst.  相似文献   

Rhönite in undersaturated alkaline gabbroic rocks,Central Alborz,North Iran: petrography and mineral chemistry     

Roghieh?DorooziEmail author  Carmela?Vaccaro  Fariborz?Masoudi 《Arabian Journal of Geosciences》2016,9(15):665

The Kamarbon alkaline gabbroic intrusion crops out in Central Alborz, north Iran, along the northern margin of the Alpine-Himalayan belt. The gabbroic intrusion includes theralites at margins which replace with teschenites toward the center. In teschenitic rocks, the main minerals are diopside, clinopyroxene, and rhönite. In this research, the occurrence of rhönite is reported in Kamarbon teschenitic gabbros, and also its mineralogical properties, paragenesis, and source magma are investigated. Based on whole rock and microprobe analysis data, we try to clarify the formation of Kamarbon gabbro and the crystallization condition of rhönite. In teschenitic gabbros, rhönite reveals the composition (Na, Ca)_1.97(Ti, ^VIAl, Fe⁺³, Fe⁺², Mn, Mg)_5.99(Si, ^IVAl)_6.02O₂₀. On the basis of petrographical observations and mineral chemistry, we suggest that the teschenites were formed in distinctive lower pressures and temperatures than theralites, below 1.9 kbar and 1075 °C. Rhönite was crystallized (at the mentioned P-T condition) as a primary phase, in the late stage of crystallization at shallow depth corresponding with 6–10 km, in teschenites. Important factors of the rhönite crystallization in undersaturated magmas can be regardarded as Al and Ti enrichment and Si depletion; the same enrichment and depletion are also observed in the associated clinopyroxenes.  相似文献