Relative contributions of crust and mantle to generation of Oligo-Miocene medium-K calc-alkaline I-type granitoids in a subduction setting—a case study from the Nabar Pluton,central Iran

The Nabar pluton with the age of Oligo-Miocene located northwest of Isfahan, the Urumieh-Dokhtar magmatic belt, is composed of gabbro, gabbro diorite, diorite, quartz diorite, tonalite, and quartz monzonite. These rocks contain plagioclase, quartz, alkali-feldspar, magnesiohornblende, actinolite, tremolite-hornblende, actinolite-hornblende, anthophyllite, biotite, and Na-poor pyroxene. Application of the Al-in-hornblende barometry indicates pressures of 2–2.15 kbar, whereas the clinopyroxene barometry shows a pressure of 5 kbar. The temperature (i.e., 750–800°C) is estimated using the amphibole-clinopyroxene thermometry in a dioritic sample. Magmatic water content was greater than 10% at the time of formation of dioritic rocks in the Nabar pluton. Based on chemistry of mafic minerals and geochemical data, the Nabar plutonic complex comprises medium-K, calc-alkaline, and I-type granitoid. The rocks are characterized by enrichment of lithophile elements (LILEs) and depletion of high-field-strength elements (HFSEs). The Nabar rocks have weak concave-upward rare earth element (REE) patterns, suggesting that amphibole played a significant role in their generation during magma segregation. Low (Al₂O₃/(FeO + MgO + TiO₂) and (Na₂O + K₂O)/(FeO + MgO + TiO₂) ratios, and the patterns of trace and rare earth elements suggest that these rocks formed along a destructive plate margin and were derived from a lower crustal source. The magma probably formed by partial melting of lower crustal protoliths (amphibolites). Lower crust contamination with magma derived from partial melting of the upper mantle has an important role in the formation of this intrusive body, and a fractional crystallization of melts in higher crustal levels generated this spectrum of rock types. Mantle-derived gabbroic magmas emplaced into the lower crust are the most likely heat sources for partial melting.     

Numerical study of soil heterogeneity effects on contaminant transport in unsaturated soil (model development and validation)

The movement of chemicals through soil to groundwater is a major cause of degradation of water resources. In many cases, serious human and stock health implications are associated with this form of pollution. The study of the effects of different factors involved in transport phenomena can provide valuable information to find the best remediation approaches. Numerical models are increasingly being used for predicting or analyzing solute transport processes in soils and groundwater. This article presents the development of a stochastic finite element model for the simulation of contaminant transport through soils with the main focus being on the incorporation of the effects of soil heterogeneity in the model. The governing equations of contaminant transport are presented. The mathematical framework and the numerical implementation of the model are described. The comparison of the results obtained from the developed stochastic model with those obtained from a deterministic method and some experimental results shows that the stochastic model is capable of predicting the transport of solutes in unsaturated soil with higher accuracy than deterministic one. The importance of the consideration of the effects of soil heterogeneity on contaminant fate is highlighted through a sensitivity analysis regarding the variance of saturated hydraulic conductivity as an index of soil heterogeneity. Copyright © 2011 John Wiley & Sons, Ltd.     

Wildfire impacts on education and healthcare: Paradise,California, after the Camp Fire

Natural Hazards - The 2018 Camp Fire caused significant damages to the education and healthcare systems in the town of Paradise, CA. This paper presents the findings of a qualitative case study...     

Genealogical concordance,comparative species delimitation,and the specific status of the Caspian pipefish Syngnathus caspius (Teleostei: Syngnathidae)

To evaluate the specific validity of the Caspian pipefish Syngnathus caspius, we used a comparative molecular species delimitation method on a COI barcode library of Syngnathus, as well as principles of genealogical concordance. Comparative species delimitation allowed us to delineate putative species without a priori assignment of individuals to nominal species, while genealogical concordance extended our species delimitation results to multiple genes, multiple codistributed species, and comparisons with biogeographic evidence. All species delimitation analyses including two topology‐based, one network‐based, and one distance‐based analysis showed genetically isolated lineages of pipefish in the Black and Caspian Sea, corresponding to S. abaster and S. caspius, respectively. Mean evolutionary divergence between the two lineages (0.029) was within the range separating species of Syngnathus (0.024–0.217). The interclade/intraclade ratio of variation was comparable to the operational criterion of divergence between clades greater or equal to 10 × the level within clades to recognize separate species. Our argument on taxonomic validity of S. caspius is also supported by the principles of genealogical concordance as a conceptual basis for recognition of biological species. As a second objective, using a limited number of S. caspius specimens from two semi‐confined water bodies along the Caspian Sea south coastal zone (i.e., Anzali Wetland in the west and Gorgan Bay in the east), we searched for a possible matrilineal structure. The retrieved phylogeographic pattern was characterized by a shallow genealogy and lineage distributions varied, most probably caused by low to modest contemporary gene flow between populations of S. caspius across the southern Caspian Sea that are linked tightly through history.     

A Closed Loop Wastewater Biorefinery Based on the Recently Introduced SHEFROL Reactor and Two Freely Available Macrophytes

With an objective to develop a closed loop wastewater biorefinery, the performance of two free floating aquatic weeds water hyacinth (Eichhornia crassipes, Mart, Solms) and salvinia (Salvinia molesta, Mitchell) is explored when either is used as the main bioagent for treating sewage in “sheet flow root level” (SHEFROL) bioreactors. Both the macrophytes prove to be easy to propagate and maintain while they are able to help in achieving significant primary, secondary, and tertiary treatment steps of greywater in a single step. Water hyacinth is able to remove suspended solids, chemical oxygen demand (COD), biological oxygen demand (BOD), total Kjeldahl nitrogen, soluble phosphorous, zinc, copper, nickel, and manganese to the average extents of 81%, 79%, 43%, 41%, 40%, 36%, 34%, and 29%, respectively. The reduction in COD and BOD levels achieved by salvinia is marginally lesser than by water hyacinth but in terms of the removal of other pollutants, the performance of salvinia is comparable to that of water hyacinth. It is possible to convert the dead or harvested plants to organic fertilizer thus making it a closed-loop system with no waste of its own.     

Recent developments of the Middle East catalog

This article summarizes a recent study in the framework of the Global Earth model (GEM) and the Earthquake Model of the Middle East (EMME) project to establish the new catalog of seismicity for the Middle East, using all historical (pre-1900), early and modern instrumental events up to 2006. According to different seismicity, which depends on geophysical, geological, tectonic, and seismicity data, this region is subdivided to nine subregions, consisting of Alborz–Azerbaijan, Afghanistan–Pakistan, Saudi Arabia, Caucasus, Central Iran, Kopeh–Dagh, Makran, Zagros, and Turkey (Eastern Anatolia; after 30° E). After omitting the duplicate events, aftershocks, and foreshocks by using the Gruenthal method, and uniform all magnitude to Mw scale, 28,244 main events remain for the new catalog of Middle East from 1250 B.C. through 2006. The magnitude of completeness (Mc) was determined as 4.9 for five out of nine subregions, where the least values of Mc were found to be 4.2. The threshold of Mc is around 5.5, 5.0, 4.5, and 4.0, for the time after 1950, 1963, 1975, and 2000, respectively. The average of teleseismic depths in all regions is less than 15 km. Totally, majority of depth for Kopeh–Dagh and Central Iran, Zagros, and Alborz–Azerbaijan, approximately, is 15, 13, and 11 km and for Afghanistan–Pakistan, Caucasus, Makran, Turkey (after 30° E), and Saudi Arabia is about 9 km.     

New climatic zones in Iran: a comparative study of different empirical methods and clustering technique

Theoretical and Applied Climatology - Recently in agricultural and industrial sectors, researchers have started to classify the climate of a region using empirical methods and clustering. This...     

Eocene continental dyke swarm from Central Iran (Khur area)

The Eocene dyke swarm with east-west general trend intrudes the Cretaceous sedimentary rocks in ～25 km north of the Khur city (Central Iran). Some of the studied dykes can be followed for over 7 km, but the majority of exposures in the area are less than 5 km long. The dykes commonly exhibit a chilled contact with the wall rocks. These dykes are trachybasalt and basalt in composition. The trachybasalt dykes are much more abundant. The basaltic dykes cross cut the trachybasalt dykes in some locations, indicating that trachybasalt dykes are older than the basaltic ones. Primary igneous minerals of the basaltic dykes are olivine (chrysolite), clinopyroxene (diopside, augite), plagioclase (labradorite), sanidine, magnetite, orthopyroxene (enstatite), spinel and phlogopite, and secondary minerals are zeolite (natrolite and mesolite), chlorite (diabantite), calcite and serpentine. The trachybasalt dykes are composed of clinopyroxene (diopside), plagioclase (labradorite), sanidine, mica (biotite and phlogopite), amphibole (magnesio-hastingsite) and magnetite as primary minerals, and chlorite and calcite as secondary ones. Whole rocks geochemical data of the studied dykes indicate their basic and calc-alkaline nature and suggest that these two set of dykes were derived from the same parental magma. The chondrite-normalized REE patterns and the primitive mantle-normalized multi-elemental diagram of the Khur dykes show enrichment of light rare earth elements (LREE) relative to heavy rare earth elements (HREE), and negative anomalies of high field strength elements (HFSE) (e.g. Ti, Nb and Ta). These rocks show enrichment of the large ion lithophile elements (LILE) (e.g. Cs, Ba, Th and U) and depletion of the HREE and Y relative to MREE, Zr and Hf. In the chondrite-normalized REE diagram, the basalts show elevated REE abundances relative to the trachybasalt samples. Geochemical analyses of the studied samples suggest a spinel lherzolite from the mantle as the source rock and confirm the role of subduction in their generation. The chemical characteristics of the Khur dykes resemble those of continental arc rocks, and they were possibly formed by subduction of the Central-East Iranian microcontinent (CEIM) confining oceanic crust and decompression melting of a lithospheric subcontinental mantle spinel lherzolite enriched by subduction.     

Ecohydrological responses to surface flow across borders: Two decades of changes in vegetation greenness and water use in the riparian corridor of the Colorado River delta

Hydrological and bioclimatic processes that lead to drought may stress plants and wildlife, restructure plant community type and architecture, increase monotypic stands and bare soils, facilitate the invasion of non-native plant species and accelerate soil erosion. Our study focuses on the impact of a paucity of Colorado River surface flows from the United States (U.S.) to Mexico. We measured change in riparian plant greenness and water use over the past two decades using remotely sensed measurements of vegetation index (VI), evapotranspiration (ET) and a new annualized phenology assessment metric (PAM) for ET. We measure these long-term (2000–2019) metrics and their short-term (2014–2019) response to an environmental pulse flow in 2014, as prescribed under Minute 319 of the 1944 Water Treaty between the two nations. In subsequent years, small-directed flows were provided to restoration areas under Minute 323. We use 250 m MODIS and 30 m Landsat imagery to evaluate three vegetation indices (NDVI, EVI, EVI2). We select EVI2 to parameterize an optical-based ET algorithm and test the relationship between ET from Landsat and MODIS by regression approaches. Our analyses show significant decreases in VIs and ET for both the 20-year and post-pulse 5-year periods. Over the last 20 years, EVI _Landsat declined 34% (30% by EVI_MODIS) and ET_Landsat-EVI declined 38% (27% by ET_MODIS-EVI), overall ca. 1.61 mm/day or 476 mm/year drop in ET; using PAM ET_Landsat-EVI the drop was from 1130 to 654 mm/year. Over the 5 years since the 2014 pulse flow, EVI_Landsat declined 20% (13% by EVI_MODIS) and ET_Landsat-EVI declined 23% (4% by ET_MODIS-EVI) with a 0.77 mm/day or a 209 mm/year 5-year drop in ET; using PAM ET_Landsat-EVI the drop was from 863 to 654 mm/year. Data and change maps show the pulse flow contributed enough water to slow the rate of loss, but only for the very short-term (1–2 years). These findings are critically important as they suggest further deterioration of biodiversity, wildlife habitat and key ecosystem services due to anthropogenic diversions of water in the U.S. and Mexico and from land clearing, fires and plant-related drought which affect hydrological processes.     

Effect of spatial resolution of satellite images on estimating the greenness and evapotranspiration of urban green spaces

Urban green spaces (UGS), like most managed land covers, are getting progressively affected by water scarcity and drought. Preserving, restoring and expanding UGS require sustainable management of green and blue water resources to fulfil evapotranspiration (ET) demand for green plant cover. The heterogeneity of UGS with high variation in their microclimates and irrigation practices builds up the complexity of ET estimation. In oversized UGS, areas too large to be measured with in situ ET methods, remote sensing (RS) approaches of ET measurement have the potential to estimate the actual ET. Often in situ approaches are not feasible or too expensive. We studied the effects of spatial resolution using different satellite images, with high-, medium- and coarse-spatial resolutions, on the greenness and ET of UGS using Vegetation Indices (VIs) and VI-based ET, over a 780-ha urban park in Adelaide, Australia. We validated ET with the ground-based ET method of Soil Water Balance. Three sets of imagery from WorldView2, Landsat and MODIS, and three VIs including the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI) and Enhanced Vegetation Index 2 (EVI2), were used to assess long-term changes of VIs and ET calculated from the different imagery acquired for this study (2011–2018). We found high correspondence between ET-MODIS and ET-Landsat (R² > 0.99 for all VIs). Landsat-VIs captured the seasonal changes of greenness better than MODIS-VIs. We used artificial neural network (ANN) to relate the RS-ET and ground data, and ET-MODIS (EVI2) showed the highest correlation (R² = 0.95 and MSE =0.01 for validation). We found a strong relationship between RS-ET and in situ measurements, even though it was not explicable by simple regressions; black box models helped us to explore their correlation. The methodology used in this research makes a strong case for the value of remote sensing in estimating and managing ET of green spaces in water-limited cities.