Multiple statistical approaches for the discrimination of mangrove species of Rhizophoraceae using transformed field and laboratory hyperspectral data

This study aims at discriminating eight mangrove species of Rhizophoraceae family of Indian east coast using field and laboratory spectra in spectral range (350–2500 nm). Parametric and non-parametric statistical analyses were applied on spectral data in four spectral modes: (i) reflectance (ii) continuum removed, (iii) additive inverse and (iv) continuum removed additive inverse. We introduced continuum removal of inverse spectra to utilize the advantage of continuum removal in reflectance region. Non-parametric test gave better separability than parametric test. Principal component analysis and stepwise discriminant analysis were applied for feature reduction and to identify optimal wavelengths for species discrimination. To quantify the separability, Jeffries–Matusita distance measure was derived. Green (550 nm), red edge (680–720 nm) and water absorption region (1470 and 1850 nm) were found to be optimal wavelengths for species discrimination. The continuum removal of additive inverse spectra gave better separability than the continuum removed spectra.     

Quantification of LST and CO2 levels using Landsat-8 thermal bands on urban environment

Land surface temperature (LST) is an important aspect in global to regional change studies, for control of climate change and balancing of high temperature. Urbanization is one of the influencing factors increasing land surface and atmospheric temperature, by the emission of greenhouse gases (e.g. CO₂, NO and methane). In the present study, LST was derived from Landsat-8 of multitemporal data sets to analyse the spatial structure of the urban thermal environment in relation to the urban surface characteristics and land use–land cover (LULC). LST is influenced by the greenhouse gases i.e. CO₂ plays an important role in increasing the earth’s surface temperature. In order to provide the evidence of influence of CO₂ on LST, the relationship between LST, air temperature and CO₂ was analysed. Landsat-8 satellite has two thermal bands, 10 and 11. These bands were used to accurately to calculate the temperature over the study area. Results showed that the strength of correlation between ground monitoring data and satellite data was high. Based on correlation values of each month April (R² = 0.994), May (R² = 0.297) and June (R² = 0.934), observed results show that band 10 was significantly correlating with air temperature. Relationship between LST and CO₂ levels were obtained from linear regression analysis. band 11 was correlating significantly with CO₂ values in each of the months April (R² = 0.217), May (R² = 0.914) and June, (R² = 0.934), because band 11 is closer to the 15-micron band of CO₂. From the results, it was observed that band 10 can be used for calculating air temperature and band 11 can be used for estimation of greenhouse gases.     

Application of Zn isotopes in environmental impact assessment of Zn–Pb metallurgical industries: A mini review

Zn and Pb smelters are the major contributors to Zn and Pb emissions among all anthropogenic sources, thus, it is essential to understand Zn isotopic variations within the context of metallurgical industries, as well as its fractionation in different environments impacted by smelting activities. This mini review outlines the current state of knowledge on Zn isotopic fractionation during the high-temperature roasting process in Zn and Pb refineries; δ⁶⁶Zn values variations in air emissions, slags and effluents from the smelters in comparison to the geogenic Zn isotopic signature of ores formation and weathering. In order to assess the environmental impact of these smelters, the available and measured δ⁶⁶Zn values are compiled for smelter impacted natural water bodies (groundwater, stream and river water), sediments (lake and reservoir) and soils (peat bog soil, inland soil). Finally, the discussion is extended to the fractionation induced during numerous physicochemical reactions and transformations, i.e. adsorption, precipitation as well as both inorganic and organic surface complexation.     

Late Oligocene–Early Miocene palaeoecology based on pollen data from the Kalkım-Gönen Basin (Northwest Turkey)

Radiometric and palynological data of the Upper Oligocene–Lower Miocene Soma Formation from the Kalk?m-Gönen Basin yield new results related to age and palynological contents. In this study, Upper Oligocene strata from the Dani?ment and Linfa areas and Lower Miocene strata from the Bengiler area were sampled palynologically and for radiometric dating. The Dani?ment assemblage, which is older than the Linfa assemblages, mainly contains coniferous and evergreen to deciduous mixed mesophytic forest elements. Relatively high quantities of the altitudinal plants Picea and Abies, indicate a cooler palaeoclimate. The Linfa associations mainly include coniferous and riparian elements. Pollen of the riparian plant Alnus and Taxodiaceae indicative for the swamp forest community was predominant, probably as a result of a high lake level. There is a hiatus during the Oligocene–Miocene transition, probably showing a non-depositional phase and sea-level fall indicating the Mi-1 glaciation event. Higher in the sequence, the Aquitanian Bengiler sediments include high amounts of coniferous forest elements as well as components indicative for the evergreen and deciduous mesophytic forest and also riparian forest and swamp forest. Due to presence of thermophilous taxa Reveesia, Mastixiaceae and Arecaceae, a warm and humid palaeoclimate is inferred according to quantitative analyses using the Coexistence Approach.     

A note on “Origin of components in Chilean thermal waters” by

Risacher et al. (2011) have presented voluminous data on thermal waters of Chile that is quite appreciable; however, their work still falls short on several counts. The most notable shortcoming of the work is the presentation and treatment of data. The interpretations are based on questionable premises (viz., extent of seawater intrusion) and considerations (viz., using average chemical composition of rock types for geochemical modeling, considering volcanic rocks as the only rock type in contact with the geothermal fluids) and assumptions not always substantiated by facts (with proper references) could have been corroborated. Use of Cl/Br ratio for discrimination purpose is unconvincing, considering the uncertainty in the measurement of low (<1 mg/L) Br concentration.     

Geochemistry of Paraná-Etendeka basalts from Misiones,Argentina: Some new insights into the petrogenesis of high-Ti continental flood basalts

The Early Cretaceous (∼135–131 Ma) Paraná-Etendeka continental flood basalts, preserved in bulk in the Paraná basin of southern Brazil and vicinity, have been divided into low-Ti and high-Ti types that govern the southern and northern halves of the basin, respectively. We have examined a new sample set from the southern margin of the northern high-Ti segment of Paraná basalts in Misiones, northeastern Argentina. These basalts are strongly to moderately enriched in TiO₂ (2–4 wt.%), have relatively high Ti/Y (300–500), low MgO (3.5–6.5 wt.%), and high Fe (FeO(tot) 12–14 wt.%) and belong to the Pitanga and Paranapanema magma types of Peate et al. (1992). Nd and Sr isotope compositions are quite unvarying with ε_Nd (at 133 Ma) values of −4.6 to −3.6 and initial ⁸⁷Sr/⁸⁶Sr of 0.7054–0.7059 and show no variation with fractionation. Compared to high-Ti lavas in the central and northern parts of the Paraná high-Ti basalt segment, the lavas from Misiones are similar to those in the northeastern magin of the basin but less radiogenic in initial Nd isotope composition than those in the central part. This variation probably reflects mixed EM1-EM2 source components in the sublithospheric mantle. A polybaric melt model of a sublithospheric mantle source at the garnet lherzolite-spinel lherzolite transition is compatible with the observed Ti budget of the Pitanga and Paranapanema lavas, regardless of the Nd isotope composition of their purported source.     

冀北中低级变质表壳岩的年代学特征及其对华北克拉通构造演化的约束

华北克拉通在新太古代末期发生克拉通化,形成了现今规模的古陆,大量的太古宙岩石均经历了~2500Ma左右的区域高级变质作用(高角闪岩相-麻粒岩相)。而华北克拉通北部冀北地区出露一套中低级变质(绿片岩相-角闪岩相)的火山-沉积岩系,主要包括胡麻营地区红旗营子表壳岩和大阴山地区单塔子表壳岩中变质程度较低的部分。胡麻营地区红旗营子表壳岩系主要岩石组合为变基性火山岩、绿帘角闪岩、斜长角闪岩、含石榴石斜长角闪岩、角闪斜长片麻岩、黑云斜长片麻岩、黑云角闪斜长片麻岩、黑云二长片麻岩、石英片岩、磁铁石英岩等,SIMS锆石U-Pb定年结果表明斜长角闪岩形成于2486±18Ma(MSWD=1.4),而黑云斜长片麻岩形成于2507±37Ma(MSWD=2.0)。大阴山地区单塔子中低级变质表壳岩系主要由浅变质火山岩、云母石英片岩、斜长角闪岩、磁铁石英岩和大理岩等组成,SHRIMP锆石U-Pb定年结果显示,浅变质火山岩中的变玄武岩形成于2490±19Ma(MSWD=2.0),而变英安岩形成于2502±8Ma(MSWD=0.83)。因此,冀北中低级变质的表壳岩系主要形成于新太古代末期,形成年龄为2507~2486Ma;结合冀东青龙地区新太古代末期(2511~2503Ma)的浅变质火山-沉积岩系(青龙表壳岩),我们认为新太古代末期,中低级变质表壳岩系广泛分布于华北克拉通的核部和边缘地区,此套岩系覆盖在太古宙高级变质杂岩之上,代表华北克拉通化之后的稳定盖层,是克拉通化的主要标志之一。     

鞍山地区东鞍山花岗岩年代学、地球化学特征及成因研究

鞍山地区位于华北地台东北部辽宁省,区内保留有3.8~2.5Ga连续的地质记录。对位于鞍山市南侧的东鞍山花岗岩进行了SHRIMP锆石U-Pb同位素分析、白云母Ar-Ar同位素分析及岩石地球化学分析。SHRIMP测年结果为3004±7Ma,代表岩石的形成年龄,Ar-Ar测年结果为2545±16Ma,代表岩石受到构造热事件扰动的时间。岩体地化特征为富硅(Si O2=72.95%~75.37%,平均值为74.18%)、富碱(K2O+Na2O=7.05%~8.45%)、富铝(Al2O3=12.95%~15.44%),低钙(Ca O=0.13%~0.66%)。在稀土元素配分图上,曲线呈明显的右倾趋势,且有较明显的负Eu异常,重稀土分馏不明显。在微量元素洋中脊玄武岩标准化蛛网图上可以看出,东鞍山花岗岩强烈亏损Nb、P、Sr、Ti,富集大离子亲石元素Rb、K、Nd和高场强元素Th、U。岩石地球化学特征表明东鞍山花岗岩岩浆来源为壳源,残留相可能由石榴石+辉石+角闪石+斜长石组成。将鞍山-本溪地区3个3.0Ga花岗岩(东鞍山花岗岩岩体、铁架山二长花岗岩岩体以及弓长岭片麻状花岗岩)的地球化学数据进行对比,发现三者的地球化学存在较大差异,为三个独立的岩体。三个岩体最初可能发育在一个陆块之上,然后在25.5亿年左右分离开来,最后在25亿年左右再次拼贴到一起。     

肥东花岗质岩脉的变形及年代学特征对郯庐断裂带早白垩世构造活动的指示

郯庐断裂带肥东段位于大别造山带与苏鲁造山带之间。在肥东段西韦采石场内发育了大规模的北北东向左行走滑韧性剪切带和一条低角度的韧性滑脱正断层。走滑韧性剪切带为郯庐断裂带走滑活动的产物,低角度滑脱正断层则代表了伸展背景下的构造活动。低角度滑脱正断层上、下盘发育未变形和变形的岩脉,走滑韧性剪切带内外也发育有受剪切带活动而变形的岩脉。对采石场内岩脉的构造和同位素年代学研究表明,低角度韧性滑脱正断层在129~126Ma之间发生过剪切活动,走滑韧性剪切带的活动时间在125Ma之后。综合研究认为,郯庐断裂带的伸展活动可能开始于早白垩世早期(130Ma),但在早白垩世并非一直处于伸展活动之中,125Ma之后的左行走滑活动很可能发生在早白垩世的晚期。     

新疆西天山铁木里克铁矿床火山岩锆石U-Pb年代学、岩石地球化学特征及地质意义

铁木里克铁矿位于西天山阿吾拉勒铁铜成矿带中段,矿床围岩为一套以粗面安山岩、安山岩和流纹岩为主的连续变化的中酸性火山岩。本文通过对铁木里克铁矿床火山岩进行LA-ICP-MS锆石U-Pb定年,并且结合Hf同位素和岩石地球化学研究,对火山岩的形成时代以及大地构造背景进行探讨。锆石LA-ICP-MS测年结果显示,粗面安山岩、安山岩以及流纹岩的测年结果分别是318.8±2.3Ma、320.8±2.5Ma和319.1±3.5Ma。地球化学分析表明该套火山岩属于高钾钙碱性-钾玄岩系列,富集轻稀土元素(LREE)和大离子亲石元素(LILE;如Rb、Th、K),重稀土元素(HREE)配分平坦,同时具有Nb、Ta的强烈亏损,具有明显的岛弧火山岩地球化学特征。在火山岩的大地构造判别图解上,样品点都落在了大陆弧部分。锆石的Hf同位素显示εHf(t)具有一致的变化范围(+6.2~+12.0),指示火山岩具有相同的岩浆来源,都是来源于早古生代新生陆壳的重熔,形成于相同的构造岩浆背景下。结合区域地质资料,本文认为铁木里克铁矿床出露的这套高钾钙碱性-钾玄岩系列火山岩可能是南天山洋闭合末期到陆陆碰撞早期大陆弧岩浆作用的产物。