in situ shear tests of soil blocks with roots in situ shear tests were performed on soil blocks that contained roots to study the contribution of roots to the shear strength in a case where the shear deformation is not constrained to a thin zone the shearing resistance of the soil root system the tensile force in selected roots and the deformation of the soil block were measured the roots were exposed after the test and their positions were determined and used to estimate the initial positions the root force and the shearing resistance of the soil root system were estimated with known solutions and compared with measured root force and shearing resistance none of the roots that passed through the shear zone failed in tension at the maximum displacement as a consequence the root resistance is much less than that found in a case where the failure surface is restricted to the boundary between a weak soil and a firm base and where roots are anchored in the firm base and fail in tension simplified procedures for estimating root forces are suggest

characteristics and origin of the zhulazhaga gold deposit in inner mongolia china abstract the zhulazhaga gold deposit in the northern margin of the north china craton ncc is a large tonnage hydrothermal deposit with a reserve of about 50 t at about 4 g t au the deposit is characterized by an epigenetic style of mineralization in metasedimentary rocks dominated by slates low grade metamorphic clastic rocks and minor volcanic rocks gold mineralization is dominantly controlled by structures manifested by stratabound orebodies located immediately to the east and west of a major n s trending fault and associated extensional fractures and ne trending fault zones the mineralization is also preferentially located in the fourth sub member of first member of the agulugou formation there are many auriferous quartz veins parallel to the bedding of the host rocks which contain the orebodies and high grade ore preferentially occurs near to these quartz veins the structures provided pathways for transportation of gold bearing fluids within the formation that appears to form a particularly favorable host rock and depositional setting hydrogen and oxygen isotope data indicate that ore forming fluids were dominated by magmatic water mixed with minor meteoric water sulfur and lead isotope data indicate that some sulfur and lead came from the magmatic fluid the metallogenic age 280 ma of this deposit and the crystallization age 280 290 ma of the granite porphyry in the district indicate a link between the hercynian magmatism and gold mineralization the hercynian tectono magmatism and associated hydrothermal activity remobilized gold and drove ore forming fluids to the favorable depositional environment the northern margin of the ncc is prospective for gold mineralization hosted in metasedimentary rocks which may be one of the most important deposit types for future gold exploration in northern china

gold mineralization in proterozoic black shales example from the haoyaoerhudong gold deposit northern margin of the north china craton abstract the haoyaoerhudong gold deposit in the northern margin of the north china craton ncc is a large tonnage lower grade deposit with a reserve of about 148 tons of gold gold mineralization is characterized by pyrite and pyrrhotite films and thin veins on the schistosity plane of the proterozoic black shales the orebodies strictly controlled by a near ew trending shear zone are stratabound within carbonaceous phyllite and andalusite garnet schist of the bilute formation hydrogen and oxygen isotopic data show that the ore forming fluid was derived from a magmatic source and mixed with meteoric water sulfur and carbon isotope data indicate that most of the sulfur and carbon came from the black shale strata well defined biotite ar ar plateau age and inverse isochron age show that the deposit formed at ca 270ma which suggests a probable link between hercynian magmatism and gold mineralization studies on regional geology ore geology isotope geochemistry and ore forming age substantiate a complex evolutionary history of the deposit the proterozoic black shales rich in gold sulfur and organic matter which were deposited in the proterozoic continental margin rifts comprised the source bed for gold mineralization ew ene structures products of palaeozoic orogenic process provided pathways and mineralization space for ore forming fluids hercynian tectono magmatism and subsequent hydrothermal events remobilized gold and drove the ore forming fluids to dilatational fracture zones related to postcollisional magmatic hydrothermal events the haoyaoerhudong gold deposit is considered as a special type of orogenic gold deposit formed in the compression extension transition stage

hydrologic and hydraulic effects of riparian root networks on streambank stability is mechanical root reinforcement the whole story abstract riparian vegetation has a number of effects on the mechanisms by which streambanks fail some positive and some negative previous research has shown that the effect of mechanical root reinforcement on soil stability can be considerable and can be successfully quantified and included in streambank stability models root networks contained within a soil matrix however also have effects on the hydrologic and hydraulic processes acting on a streambank and although these effects are often discussed they have generally been difficult to quantify this paper summarizes the results of field data collection laboratory testing and computer simulations carried out to better quantify the effects of riparian vegetation on hydrologic and hydraulic processes occurring along streambanks first the evapotranspiration potentials of different riparian species were isolated by setting up an experiment to grow young riparian trees and switch grass in separate soil columns each instrumented with tensiometers at 30 cm and 70 cm depths and compared against bare control columns the hydrological reinforcement provided to the soil from increased apparent cohesion as a result of enhanced matric suction was estimated to range from 1 0 to 3 1 kpa in spring when bank stability was most critical and up to a maximum of 5 0 kpa in the summer second a vertical jet test device was used to measure rates and volumes of scour in soils permeated by switch grass roots results showed that the volume of soil scoured during a test declined non linearly with increasing root volume per unit volume of soil and with increasing root length density rld and increasing root biomass calculation of relative soil detachment rates rsd showed that with the highest rooting densities measured in the field jet tests eroded soil volume was 10 of that in the tests with no roots third the effects of enhanced matric suction from evapotranspiration and decreased soil erodibility because of the presence of plant roots were modeled using bstem 5 1 to quantify the effects on streambank factor of safety fs and to compare with the effects of mechanical root reinforcement the sensitivity analysis showed that the change in soil matric suction from evapotranspiration provided the greatest potential benefit to fs but only during the summer months during the winter and spring months root reinforcement remained the most important contributor to fs the sensitivity analysis conducted here also showed that whilst roots are capable of reducing the volume of hydraulic scour the resulting effect on streambank geometry did not increase fs as much as changes in soil matric suction and or mechanical root reinforcement

determination of the anisotropic shear stiffness of an unsaturated decomposed soil the shear modulus at very small strains 0 001 or less g0 is one of the most important parameters for predicting ground movements and dynamic responses of many engineering earth structures wit

geological features and genesis of gold deposits hosted by low grade metamorphic rocks in central western inner mongolia the central western inner mongolia area located in the western section of the northern margin of the north china craton is one of the most important gold metallogenic provinces in north china the gold deposits and prospects hosted by low grade metamorphic rocks are widely distributed in two parallel ew trending protrozoic rift belts i e the bayan obo belt in the north and the chaiertaishan belt in the south up till now twenty three ore deposits and prospects have been discovered of which changshanhao zhulazaga and saiyinwusu are the largest ones gold mineralization occurs in proterozoic carbonaceous sandstone siltstone carbonaceous phyllite phyllite slate and schist in the stratoid layer stratiform stockwork and veinlike forms all these gold deposits are characterized by shallow burial large size simple composition and easy mining systematic geological investigations indicate that wall rocks of these deposits and prospects vary from place to place but most of them show an intimate spatial temporal relation with the caledonian ductile brittle fracture zone and the hercynian intrusive dyke swarm geometry of individual ore bodies is mainly controlled by interstratified fracture zones all the geological features of the gold deposits hosted by low grade metamorphic rocks in central western inner mongolia are similar to features of the muruntau gold deposit in uzbekistan the relationship between the regional crustal evolution and gold metallogeny can be summarized as follows middle proterozoic stage tectono magmatism caused by the intense rifting occurring within the early precambrian continent or along its margin resulted in the spatial preparation of gold and other ore forming materials and formed a number of gold source beds and protores along certain strata early paleozoic stage a number of gold prospects were formed by regional metamorphism and its related hydrothermal event caused by regional tectonic movement and magmatic intrusion with middle to large sized gold deposits of this stage also identified late paleozoic stage gold deposits with economic significance are considered to have been caused by the re working of the early formed deep rooted faults and its related hercynian mafic to felsic magmatism the extensional faulting and high alkaline magmatism might have played the key role during the formation of the ore deposits geological and geochemical features of the gold deposit hosted by the low grade metamorphic rocks occurring in central western inner mongolia have aroused much attention among geologists both in china and abroad an integrated analysis of the geological setting and geological and geochemical features of these deposits and their related intrusive rocks will greatly upgrade the understanding of the ore forming processes of the gold deposits and prospects hosted by low grade metamorphic rocks in central western inner mongolia meanwhile the genetic model and mineral exploration criteria of these deposits and prospects can also be used during the comprehensive evaluation of the concealed gold deposits hosted by low grade metamorphic rocks in central western inner mongolia and its neighboring areas

modelling the seismic performance of root reinforced slopes using the finite element method this paper investigates the seismic performance of rooted granular slopes using dynamic finite element analysis validated against recently published centrifuge test data the importance of selecti

occurrence and origin of minerals in a chamosite bearing coal of late permian age zhaotong yunnan china the minerals found in the no 5 coal late permian from the zhaotong coalfield yunnan province southwestern china have been examined and found to consist mainly of kaolinite pyrite chamosite quartz and calcite with trace amounts of illite and mixed layer illite smectite the proportion of chamosite in clay minerals ranges from 32 to 56 wt with an average of 46 wt chamosite is distributed not only in collodetrinite but also occurs as cell fillings in fusinite semifusinite and telinite the high content and mode of occurrence of chamosite in this mine indicate its formation by interaction of kaolinite with fe mg rich fluids during early diagenesis except for a minor amount of terrigenous quartz most quartz is of authigenic origin and formed from kaolinite desilication the calcite content of the no 5 coal is 1 4 6 3 with an average of 3 and is distributed in collodetrinite and as cell fillings of coal forming plants calcite originated from seawater invasion during peat accumulation pyrite occurs in several ways as massive framboidal isolated enhedral anhedral and euhedral forms in addition the presence of a large amount of pyritized red algae provides strong evidence of seawater invasion during peat accumulation the red algae may have played an important role in the enrichment of sulfur in the coal the characteristic assemblage of minerals in this mine resulted from a unique basinal environment in which the mineral matter was derived from a basaltic source region volcanic activity and seawater transgression during coal formation

petrology mineralogy and geochemistry of the ge rich coal from the wulantuga ge ore deposit inner mongolia china new data and genetic implications abstract the early cretaceous wulantuga high ge coal deposit in inner mongolia is one of the major coal hosted ge deposits in china this paper reports new data on the petrological mineralogical and geochemical compositions of 13 bench samples of the high ge no 6 coal from the wulantuga deposit and provides new insight into the origin and modes of occurrence of the minerals and elements present the no 6 coal has a low rank ro max 0 45 and is a low ash coal 8 77 the total content of inertinite 52 5 vol on average in most coal benches is higher than that of huminite 46 8 vol on average the dominant huminite maceral is textinite averages 43 9 and the dominant inertinite macerals are mainly fusinite averages 33 and semifusinite 12 5 along with trace portions of intertodetrinite secretinite funginite and macrinite fungus seen as the maceral funginite played a role in the development of degraded maceral forms in the wulantuga coals funginite is present in samples examined in this study but is not easily extracted during palynological studies recovered fungal taxa are saprophytes indicating woody decomposition prior to incorporation in the mire palynology revealed a sparse flora that is consistent with the early cretaceous age minerals in the coal include quartz kaolinite illite and or illite smectite gypsum pyrite and traces of rutile and anatase a varying proportion of bassanite was observed in the low temperature ashes ltas bassanite in the ltas was derived both from the dehydration of gypsum in the raw coals and from the interaction between organically associated ca and s during the low temperature ashing in addition to a proportion of detrital quartz fine grained and cell filling quartz of authigenic origin is also present pyrite is of syngenetic origin and derived from sulfate rich hydrothermal fluids compared to common chinese and world low rank coals the no 6 coal is enriched in be 25 7 g g f 336 g g ge 274 g g as 499 g g sb 240 g g cs 5 29 g g w 115 g g hg 3 165 g g and tl 3 15 g g germanium in the coal is organically associated and its enrichment is attributed to hydrothermal fluids from the adjacent granitoids beryllium is probably associated with ca and mn bearing carbonate minerals and to a lesser extent with clay minerals rather than with organic matter fluorine largely occurs in clay minerals kaolinite and illite the elevated concentrations of tl hg as and sb are mainly distributed in pyrite and were derived from the same hydrothermal source the high w in the coal occurs in both the organic matter and the authigenic quartz illite is the major carrier of cs in the coal the accumulation of rare earth elements ree in the coals had a polygenetic and multistage nature including two syngenetic stages early hydrothermal and terrigenous and one diagenetic late hydrothermal stage the ree distribution patterns of the early hydrothermal and terrigenous stages were characterized by the enrichment of medium ree m type ree and light ree l type ree respectively a h type ree distribution pattern hree enrichment occurred in the late diagenetic hydrothermal stage the high ge wulantuga coals are also abnormally enriched in precious metals gold pt and pd in the coals calculated from their concentrations in the ltas are 3 5 25 8

mineralogy and geochemistry of al hydroxide oxyhydroxide mineral bearing coals of late paleozoic age from the weibei coalfield southeastern ordos basin north china abstract this paper mainly describes mineralogy and geochemistry of coals from the weibei coalfield in the southeastern ordos basin north china a number of al hydroxide oxyhydroxide minerals were detected in the late carboniferous coals nos 5 10 and 11 coals especially in the no 10 coal aluminum hydroxide oxyhydroxide minerals nordstrandite boehmite and diaspore in the no 10 coal are associated with kaolinite suggesting that these minerals are derived from the breakdown of kaolinite a model in which al hydroxide oxyhydroxide minerals form from the incongruent dissolution of kaolinite is presented nordstrandite and boehmite mainly occur as massive lenses n 2 mainly occurs within al hydroxide oxyhydroxide minerals nordstrandite boehmite and diaspore kaolinite and organic matter

ge distribution in the wulantuga high germanium coal deposit in the shengli coalfield inner mongolia northeastern china abstract the geological and geochemical controls of the ge distribution in the cretaceous wulantuga high germanium coal deposit in the shengli coal field inner mongolia are investigated this paper focuses mainly on the spatial distribution of the ge contents in coal the high ge coals mainly occur in three splits of the 6 coal in the southwestern part of the shengli coal field mean germanium contents in the coal range from 32 to 820 g g with a mean value of 137 g g on a bulk coal basis mean of 939 coal samples from 75 boreholes in the 6 coal seam in an area of 2 2 km 2 the highest ge content occurs sw of 6 coal seam close to the margins of the coal basin decreasing with a fan shaped trend towards nw the direction of the coal basin there is an negative correlation between the mean ge content and the thickness of the coal seam different distribution patterns of ge content were found in vertical profiles high ge concentrations may occur in the middle parts of coal seams at the bottom and or the top of thick coal seams and inconspicuous variation a major organic affinity was determined for ge with a special enriched in the banded bright and semibright coal the high ge coals and the coalified wood in the sandstone overlaying the 6 1 coal highly enriched in ge as sb w cs tl be and hg the late jurassic silicified volcanic rocks in the nw of the ge coal deposit relatively high enriched in ge ga sb as cs be ge and hg the correlation coefficients among the elements enriched showed marked variations at close sites in this deposit suggesting a possible diagenetic origin of the geochemical anomaly the main ge anomaly was attributed to early cretaceous hydrothermal fluids circulating through the fault systems and porous volcanic rocs probably from the subjacent granitoid rocks the fault systems the porous coarse clastic rocks overlying coal seam and the lithotype of coal played an important role in the transport and trapping of ge a main diagenetic origin overlapping a slight synsedimentary accumulation is deduced for the ge anomaly

mineralogical and geochemical compositions of the pennsylvanian coal in the adaohai mine daqingshan coalfield inner mongolia china modes of occurrence and origin of diaspore gorceixite and ammonian illite abstract aluminum hydroxide boehmite rich pennsylvanian coals of high volatile a bituminous rank were found previously in the jungar coalfield inner mongolia china this paper reports new results on 48 bench samples of the cp2 coal from the adjacent adaohai mine daqingshan coalfield inner mongolia and provides new insights into the origin and modes of occurrence of the minerals and elements present in the cp2 coal compared to the same coal in the adjacent mines the cp2 coal in the adaohai mine has a higher rank ro ran 1 58 which is attributed to igneous intrusions during the late jurassic and early cretaceous epochs the proportion of inertinite 35 3 in the coal is higher than that in other late paleozoic coals in northern china but lower than that in the jungar coals minerals in the cp2 coal include diaspore boehmite gorceixite calcite dolomite siderite clay minerals kaolinite and ammonian illite and trace amounts of anatase fluorapatite quartz and pyrite based on mineral proportions in the coal bench samples the cp2 coal may be divided into four zones i to iv from bottom to top the major mineral in zones i and iv is kaolinite zones ii and iii are mainly composed of ammonian illite diaspore boehmite gorceixite calcite dolomite and siderite diaspore boehmite and gorceixite forming materials were derived from oxidized bauxite in the weathered crust of the benxi formation in the sediment source region during peat accumulation however gorceixite may have formed earlier than diaspore the diaspore was derived from gibbsite that was subjected to dehydration by the heat of the igneous intrusions the ammonian illite may have been formed at a relatively high temperature by interaction of kaolinite with nitrogen released from the organic matter in the coal during metamorphism caused by the igneous intrusion the calcite and dolomite occur as epigenetic cell and fracture fillings and were probably derived from the igneous fluids compared to the common chinese and world coals the cp2 coal is enriched in cao 1 69 mgo 0 32 p2o5 0 214 f 207 g g ga 16 3 g g zr 446 g g ba 276 g g hg 0 33 g g and th 12 4 g g but has a lower sio2 al2o3 ratio due to the higher proportions of diaspore boehmite and gorceixite in the coal the f occurs mainly in gorceixite and fluorapatite the major carriers of ga are diaspore and kaolinite but not gorceixite barium mainly occurs in gorceixite and barite mercury was probably derived from the igneous intrusion and is distributed in both the organic matter and the minerals the elements are classified into five associations by cluster analysis groups a b c d and e group a represents a ree be y se ga ge sc in pb bi nb ta tio2 w hg sb zr hf th u association most of the elements in group a are lithophile elements that occur in aluminosilicate minerals group b sn te zn cd v as cr cu mo ni re is weakly correlated with ash yield and is associated with unidentified trace sulfide minerals elements in group c ad na2o al2o3 sio2 li k2o rb cs tl association probably occur in the clay minerals and diaspore group d consists of p2o5 ba f sr s and cl and with the exception of s they occur in minerals gorceixite and fluorapatite oxides of fe2o3 mno cao mgo make up group e and mainly occur in the carbonate minerals the coals are enriched in light rees and the lrees hrees have been highly fractionated with an average la yb n of 8 71 the heavy rees in the coals have a stronger organic affinity than the lrees

solifluction meets vegetation the role of biogeomorphic feedbacks for turf banked solifluction lobe development vegetation is an important factor influencing solifluction processes while at the same time solifluction processes and landforms influence species composition fine scale distribution and corresponding ecosystem functioning however how feedbacks between plants and solifluction processes influence the development of turf banked solifluction lobes tbls and their geomorphic and vegetation patterns is still poorly understood we addressed this knowledge gap in a detailed biogeomorphic investigation in the turtmann glacier foreland switzerland methods employed include geomorphic and vegetation mapping terrain assessment with unmanned aerial vehicle uav and temperature logging results were subsequently integrated with knowledge from previous geomorphic and ecologic studies into a conceptual model our results show that geomorphic and vegetation patterns at tbls are closely linked through the lobe elements tread risers and ridge a conceptual four stage biogeomorphic model of tbl development with ecosystem engineering by the dwarf shrub dryas octopetala as the dominant process can explain these interlinked patterns based on this model we demonstrate that tbls are biogeomorphic structures and follow a cyclic development during which the role of their components for engineer and non engineer species changes our study presents the first biogeomorphic model of tbl development and highlights the applicability and necessity of biogeomorphic approaches and research in periglacial environments copyright 2016 john wiley sons ltd

coal deposits as potential alternative sources for lanthanides and yttrium abstract this paper presents data on widespread abnormal accumulations of lanthanides and yttrium rey in many coal deposits worldwide high rey contents 0 1 have been found in coal seams and coal ashes as well as in the host and basement rocks of some coal basins for a preliminary evaluation of coal ashes as an rey raw material not only the abundance but also the individual rey compositions were taken into account in this paper three rey distribution patterns for high rey coal ashes are fixed with lrey lan lun 1 mrey lan smn 1 and hrey lan lun

mineralogical and geochemical compositions of the coal in the guanbanwusu mine inner mongolia china further evidence for the existence of an al ga and ree ore deposit in the jungar coalfield abstract aluminum hydroxide boehmite and diaspore ga rey rare earth elements and y and al rich pennsylvanian taiyuan formation coals have previously been found in the jungar and daqingshan coalfields inner mongolia china gallium rey and al are potentially extractable and usable elements in combustion residues derived from these coals this paper reports new results on 50 bench samples of the no 6 coal from the guanbanwusu mine jungar coalfield inner mongolia and provides new data and evidence for the existence of an al ga rey ore deposit in the unique jungar coalfield the no 6 coal in the guanbanwusu mine has a low rank ro ran 0 56 and a low sulfur content st d 0 58 the proportion of inertinite in the coal 56 7 mineral free basis is higher than that of vitrinite 31 the minerals in the coal are mainly represented by kaolinite boehmite and chlorite along with variable proportions in some samples of calcite ankerite siderite and goyazite boehmite goyazite and part of the kaolinite were derived from bauxite in the weathered surface of the sediment source region ankerite calcite and siderite in the coal are of authigenic origin the chlorite in the guanbanwusu coals appears to have a chemical composition intermediate between cookeite and chamosite this mineral mainly occurs as cell fillings also indicating an authigenic origin and was probably derived from hydrothermal fluids a new mineral phase mainly composed of ti cl and fe is probably a ti bearing oxychloride or hydroxychloride compared to other chinese coals and to world hard coals the coal from the guanbanwusu mine is enriched in al2o3 9 34 p2o5 0 126 li 175 g g f 434 g g cl 1542 g g ga 12 9 g g sr 703 g g and th 12 9 g g but has a lower sio2 al2o3 ratio 0 74 due to the higher proportions of boehmite and goyazite in the coal the major carrier of p2o5 and sr is goyazite lithium mainly occurs in the chlorite cf cookeite kaolinite and possibly to a lesser extent illite fluorine in the coal has a major boehmite affinity but a small proportion may also occur in the organic matter and chlorite gallium in the coal largely occurs in goyazite chlorine is independent of other elements in the coal associated neither with moisture nor with organic matter but possibly occurring in molecular form cl2 and in the ti bearing oxychloride or hydroxychloride thorium in the coal occurs in the clay and accessory minerals and was mainly derived from detrital materials of the source region rare earth elements and y have a mixed organic and inorganic affinity largely occurring in goyazite group minerals and to a lesser extent boehmite and organic matter most coal benches and partings have either an l type or h type of rey enrichment owing respectively to the weathered bauxite source region and groundwater effects the al2o3 ga rey and possibly li in the guanbanwusu coals like those in coals from the jungar and adjacent daqingshan coalfields are industrially useful metals that could potentially be recovered from the relevant coal combustion residues it is suggested that if ga in ash 50 g g rey 800 900 g g sio2 al2o3 40 in ash and coal thickness 5 m the coal combustion residues would be expected to be suitably enriched in al2o3 and can be considered for al2o3 ga and rey recovery

controls on boron and germanium distribution in the low sulfur amos coal bed western kentucky coalfield usa abstract the duckmantian aged amos coal bed is a thin geochemical analysis of the amos coal bed shows higher concentrations of b and ge than other western kentucky coal beds high total b concentrations as well as high b be both considered to be indicators of marine environments increase toward the top of the coal bed most of the b values for the amos samples range from 66 to 103 ppm whole coal basis indicating deposition in a brackish environment high ge concentrations in coals have been considered to be a function of seam thickness and proximity to the top and bottom of the coal bed thin coals such as the amos are dominated by the coal bed margins and therefore have a tendency to have relatively high ge concentrations in the case of the amos coal bed the lower bench has a higher ge content suggesting that the substrate was a more important source of ge than the roof rock

mineralogy of lignites and associated strata in the mavropigi field of the ptolemais basin northern greece the mineralogy of five lignite layers and the associated roof floor and intercalating strata has been analysed using low temperature oxygen plasma ashing and quantitative x ray diffraction techniques the lignite contains quartz kaolinite illite and smectite and in some cases small proportions of feldspar thought to represent mainly detrital minerals in the original peat deposits one sample also contains crystalline calcium oxalates with weddellite present in the raw lignite and whewellite in the low temperature ash lta of the same lignite sample minor proportions of gypsum are present in some of the raw lignite samples possibly in part derived from precipitation of dissolved ca and so4 in the pore waters on drying all the ltas however contain much higher proportions of bassanite and or gypsum compared to the other minerals present consistent with production of calcium sulphate artefacts from interaction of abundant organically associated ca and s in the lignite during the plasma ashing procedure the inorganic strata are mainly carbonate rocks consisting almost entirely of calcite with minor aragonite small proportions of illite traces of pyrite and in some cases siderite some non carbonate rocks are also associated with the lignite seams these are dominated by plagioclase feldspar and mica along with illite kaolinite and a relatively minor proportion of quartz the mineral assemblages can be related to the palaeoenvironmental conditions under which the various sediments including lignite were deposited comparison of the mineral abundances in the samples to the chemical composition of the materials shows that the quantitative xrd technique provides results consistent with ash analysis data although abundant in the associated rocks calcite does not occur in the lignite samples while part of the relatively abundant ca in the lignite occurs as either gypsum or weddellite most of it appears to be organically bound mine products that incorporate calcareous rocks of the type associated with the lignite may however contain separate calcite phases and display high carbonate co2 contents

a gis based tool for the china national mineral resource assessment initiative a case study of gold deposits in the bayan obo group inner mongolia china abstract this paper describes a software tool and its application to the china national mineral resource assessment initiative cnmrai the initiative was carried out throughout china from 2007 to 2013 creating collaborations among geological societies from institutions such as academies universities companies and local geological surveys a geographic information system gis based tool was designed providing functions for database management of the multiple original spatial datasets modelling targeting estimation and visualization to assist participants in assessing mineral resource potentials during this initiative geologists used the tool to generate mineral potential maps and assess undiscovered resources for the 25 major types of mineral resources in china first the requirements of the tool were introduced second the framework and major functions of the tool were delineated and developed and third a case study of gold resource assessment from a project of the cnmrai in the bayan obo region inner mongolia china was discussed in addition the mineral potential map was displayed by terrain rendering this paper also provides interpretations of the results of a prospectivity analysis based on conceptual geological models discussions of the new requirements and techniques for modelling and assessing will be used to further develop the mineral resources assessment software mras

model for the prediction of shear strength with respect to soil suction experimental studies on unsaturated soils are generally costly time consuming and difficult to conduct shear strength data from the research literature suggests that there is a nonlinear increas

geochemistry of trace elements in chinese coals a review of abundances genetic types impacts on human health and industrial utilization abstract china will continue to be one of the largest coal producers and users in the world the high volume of coal use in china has focused attention on the amounts of toxic trace elements released from coal combustions and also the valuable trace elements extracted or potentially utilized from coal ash compared to world coals chinese coals have normal background values for most trace elements with the exception of higher li 31 8 g g zr 89 5 g g nb 9 44 g g ta 0 62 g g hf 3 71 g g th 5 84 g g and rare earth elements la lu y 136 g g this is not only due to the higher ash yields of chinese coals but also to alkali volcanic ashes found in some southwestern coals the background values of toxic elements of hg 0 163 g g as 3 79 g g and f 130 g g in chinese coals are comparable to coals from most other countries the genetic types for trace element enrichment of chinese coals include source rock controlled marine environment controlled hydrothermal fluid controlled including magmatic low temperature hydrothermal fluid and submarine exhalation controlled subtypes groundwater controlled and volcanic ash controlled the background values of trace elements were dominated by sediment source regions low temperature hydrothermal fluid was one of the major factors for the local enrichment of trace elements in southwestern china serious human health problems caused by indoor combustion of coal in china include endemic fluorosis arsenosis selenosis and lung cancer endemic fluorosis mainly occurring in western guizhou was mostly attributed to the high fluorine in clay that was used as a briquette binder for fine coals in addition to a small quantity of fluorine from coal fluorine in the coal from endemic fluorosis areas of western guizhou is within the usual range found in china and the world endemic arsenosis in southwestern guizhou is attributed to indoor combustion of high as coal endemic selenosis in enshi of hubei was due to high se in carbonaceous siliceous rocks and carbonaceous shales fine particles of quartz released into air during coal combustion are hypothesized as a possible cause for the lung cancer epidemic in xuanwei yunnan china valuable elements including ge ga u ree rare earth element nb zr and re are concentrated to levels comparable to conventional economic deposits in several coals or coal bearing strata in china the ge deposits at lincang yunnan province and wulantuga inner mongolia have been exploited and industrially utilized the enrichment of ge in the two deposits was caused by hydrothermal fluids associated with adjacent granitoids the ga al ore deposit in the jungar coalfield inner mongolia was derived from the neighboring weathered and oxidized bauxite of the benxi formation pennsylvanian the nb ta zr hf ree ga deposits in the late permian coal bearing strata of eastern yunnan and chongqing of southwestern china were attributed to ashes of the alkali volcanic eruptions

some considerations concerning the use of correlation coefficients and cluster analysis in interpreting coal geochemistry data the mode of occurrence of trace elements in coal is important from both scientific and environmental viewpoints because the behavior of trace elements in coal utilization depends not only on their concentration but also on their chemical form or mode of occurrence statistical methods are one of the more commonly used indirect approaches for interpreting element modes of occurrence these methods include correlation coefficients between elements and ash as well among the elements themselves cluster and factor analysis using data sets derived from a suite of 75 samples from a bulgarian lignite deposit we demonstrate that statistical analysis of subsets with different ash ranges and with slightly different suites of elements can lead to substantially different conclusions concerning the element modes of occurrence in this example we assume that direct information on the element modes of occurrence such as mineralogy or selective leaching behavior is absent statistical methods however can provide useful insights into trace element modes of occurrence for properly constrained sample suites

geology geochronology and sulphur isotope geochemistry of the black schist hosted haoyaoerhudong gold deposit of inner mongolia china implications for ore genesis abstract the haoyaoerhudong gold deposit is located in the urad middle banner area of inner mongolia in china and is hosted by black schist of the bilute formation in the mesoproterozoic bayan obo group the gold mineralization is within a 4500 m long and 100 m wide zone associated with sulphide quartz veins following the schistosity and crosscutting fractures in the host rocks locally as disseminated sulphide in altered black schist the sulphide mineral assemblage is pyrrhotite pyrite arsenopyrite chalcopyrite sphalerite and is associated with a weak hydrothermal alteration characterized by a silica halo with variable amounts of biotite sericite and carbonate the bilute formation was intruded by multi stage dykes these include metamorphosed porphyritic diorite that pre dates mineralization unmetamorphosed amphibole olivine gabbro that pre dates mineralization and tourmaline bearing pegmatite that post dates mineralization in order to constrain the timing of the gold mineralization and host rocks zircons from the porphyritic diorite amphibole olivine gabbro and tourmaline bearing pegmatite were extracted for u pb dating gold bearing pyrite samples were analysed for 34 s to help determine the possible source of s in the mineral zones a weighted mean 206 pb 238 u age date of 288 3 ma mswd 2 4 was obtained for the porphyritic diorite a weighted mean 206 pb 238 u age date of 282 1 ma mswd 0 58 was obtained from the amphibole olivine gabbro and a weighted mean 206 pb 238 u age date of 182 1 ma mswd 1 04 was obtained from the tourmaline bearing pegmatite these dates constrain the timing of gold mineralization to between 282 1 and 182 1 ma and are consistent with the hydrothermal alteration ages of ca 267 246 ma reported from the literature these new zircon dates indicate that the regional metamorphism of the bayan obo group ceased by the time the haoyaoerhudong gold mineralization was deposited and the genesis of mineralization is not related to the regional metamorphic event the gold bearing pyrites gave positive 34 s v cdt values between 6 8 and 13 4 and are different from the 34 s widely distributed values for the typical black rocks indicating that the sulphur is not derived from the black bilute formation but sourced from some other relatively uniform reservoir widespread contemporaneous granitic magmatism is developed in the haoyaoerhudong area and we suggest that the sulphur forming the gold bearing sulphides is probably sourced from a carbonate contaminated granitic magma reservoir the new zircon dates for the dykes and the 34 s data for gold bearing sulphides indicate that the gold mineralization did not form from metamorphosed black schist in the bayan obo group but is associated with magmatic hydrothermal activity

quantifying root reinforcement of river bank soils by four australian tree species the increased shear resistance of soil due to root reinforcement by four common australian riparian trees casuarina glauca eucalyptus amplifolia eucalyptus elata and acacia floribunda was determined in situ with a field shear box root pull out strengths and root tensile strengths were also measured and used to evaluate the utility of the root reinforcement estimation models that assume simultaneous failure of all roots at the shear plane field shear box results indicate that tree roots fail progressively rather than simultaneously shear strengths calculated for root reinforced soil assuming simultaneous root failure yielded values between 50 and 215 higher than directly measured shear strengths the magnitude of the overestimate varies among species and probably results from differences in both the geometry of the root system and tensile strengths of the root material soil blocks under a floribunda which presents many well spread highly branched fine roots with relatively higher tensile strength conformed most closely with root model estimates whereas e amplifolia which presents a few large unbranched vertical roots concentrated directly beneath the tree stem and of relatively low tensile strength deviated furthest from model estimated shear strengths these results suggest that considerable caution be exercised when applying estimates of increased shear strength due to root reinforcement in riverbank stability modelling nevertheless increased soil shear strength provided by tree roots can be calculated by knowledge of the root area ratio rar at the shear plane at equivalent rar values a floribunda demonstrated the greatest earth reinforcement potential of the four species studied

determination of the shearing behaviour of root permeated soils with a large scale direct shear apparatus abstract soils with roots or root like inclusions have often been tested in direct shear to quantify the effects of vegetation on the shear strength of soil and in turn the stability of slopes however a straightforward evaluation of root reinforcement is challenging due to the complex nature of roots and the dependency of soil behaviour on many factors an inclinable large scale direct shear apparatus ildsa was built to study the shearing behaviour of root permeated soils planted specimens consisting of two different sets of species were prepared with a moraine sampled from a recent landslide location and tested in direct shear subsequent to saturation relationships of peak stress ratio with dry weight of roots maximum dilatancy angle and void ratio were investigated to evaluate the behaviour of root permeated soil the combined approach of taking both presence of roots and dilatant behaviour of soil into consideration results in a more realistic understanding and quantification of the effects of root reinforcement at least for laboratory testing of root permeated soils

mineral matter and trace elements in coals of the gunnedah basin new south wales australia abstract the concentrations of major and trace inorganic elements in a succession of permian coals from the gunnedah basin new south wales have been determined by x ray fluorescence techniques applied to both whole coal and high temperature ash samples the results have been evaluated in the light of quantitative data on the minerals in the same coals determined from x ray diffraction study of whole coal samples using a rietveld based interpretation program siroquant to determine relationships of the trace elements in the coals to the mineral species present comparison of the chemical composition of the coal ash interpreted from the quantitative mineralogical study to the actual ash composition determined by xrf analysis shows a high degree of consistency confirming the validity of the xrd interpretations for the gunnedah basin materials quartz illite and other minerals of detrital origin dominate the coals in the upper part of the sequence whereas authigenic kaolinite is abundant in coals from the lower part of the permian succession these minerals are all reduced in abundance however and pyrite is a dominant constituent in coals formed under marine influence at several stratigraphic levels calcite and dolomite occur as cleat and fracture infillings mostly in seams near the top and bottom of the sequence the potassium bearing minerals in the detrital fraction are associated with significant concentrations of rubidium and the authigenic kaolinite with relatively high proportions of titanium zirconium is also abundant with associated p and hf in the gunnedah basin coal seams relationships exhibited by ti zr nd and y are consistent with derivation of the original sediment admixed with the seams from an acid volcanic source pyrite in the coals is associated with high concentrations of arsenic and minor proportions of thallium no other element commonly associated with sulphides in coals however appears to occur in significant proportions with the pyrite in the sample suite small concentrations of cl present in the coal are inversely related to the pyrite content and appear to represent ion exchange components associated with the organic matter strontium and barium are strongly associated with the cleat filling carbonate minerals ge and ga appear to be related to each other and to the coal s organic matter cr and v are also related to each other as are ce la nd and pr but none of these show any relationship to the organic matter or a particular mineral component

analysis of a small debris slide in coastal alaska on october 1 1980 a moderately intense storm at trap bay alaska triggered a small debris slide in a forested midslope depression that was instrumented to record the maximum piezometric rise although the return period for the storm was 2 years 54 3 68 cm of the total rain fell during the final 3 h causing the soil mantle to become nearly saturated this resulted in an average maximum pore water pressure of 2 2 kpa at the sliding surface causing failure analysis of the mechanics of the failure showed that an apparent cohesion of 2 0 kpa probably due to rooting strength was acting on the 43 hillslope calculated factors of safety for such thin partially saturated soils are very sensitive to small changes in apparent cohesion and should be used with caution on such sites

determination of the shear strength parameters of an unsaturated soil using the direct shear test multistage direct shear tests have been performed on saturated and unsaturated specimens of a compacted glacial till a conventional direct shear apparatus was modified in order to use the axis tra

mineralogy and geochemistry of the no 6 coal pennsylvanian in the junger coalfield ordos basin china abstract this paper discusses the mineralogy and geochemistry of the no 6 coal pennsylvanian in the junger coalfield ordos basin china the results show that the vitrinite reflectance 0 58 is lowest and the proportions of inertinite and liptinite 37 4 and 7 1 respectively in the no 6 coal of the junger coalfield are highest among all of the late paleozoic coals in the ordos basin the no 6 coal may be divided vertically into four sections based on their mineral compositions and elemental concentrations a high boehmite content mean 6 1 was identified in the no 6 coal the minerals associated with the boehmite in the coal include goyazite rutile zircon and pb bearing minerals galena clausthalite and selenio galena the boehmite is derived from weathered and oxidized bauxite in the weathered crust of the underlying benxi formation pennsylvanian a high pb bearing mineral content of samples zg6 2 and zg6 3 is likely of hydrothermal origin the no 6 coal is enriched in ga 44 8 g g se 8 2 g g sr 423 g g zr 234 g g rees 193 3 g g hg 0 35 g g pb 35 7 g g and th 17 8 g g gallium and th in the no 6 coal mainly occur in boehmite and the pb bearing selenide and sulfide minerals contribute not only to se and pb contents in the coal but also probably to hg content a high zr content is attributed to the presence of zircon and sr is related to goyazite the rees in the coal are supplied from the sediment source region and the rees leached from the adjacent partings by groundwater

minerals in bituminous coals of the sydney basin australia and the illinois basin u s a although other forms of inorganic components may be significant in lower rank coals the mineral matter in most bituminous coals is dominated by silicates carbonates sulphides phosphates and other crystalline mineral groups these may be present in various forms including thin bands and laminae intimately associated with the organic matter as well as lenticles nodules crystal aggregates and cell infillings all of which indicate approximately contemporaneous formation with the peat bed other minerals however occur as veins or cleat and fracture fillings indicating precipitation after most of the compaction and presumably after most of the rank advance ome of the penecontemporaneous mineral matter is of detrital origin representing epiclastic or pyroclastic particles washed or blown into the peat swamp other mineral matter however including much of the pyrite quartz and siderite as well as abundant well crystallized kaolinite appears to have been formed by precipitation processes either within the swamp waters or in the pores of the peat deposit pyrite largely formed by bacterial reduction of dissolved sulphate ions seems to be related in abundance to marine transgressions which allowed permeation of sea water into the swamp and through the peat bed beneath siderite appears to form in the absence of sulphate rich sea water probably from co2 released by organic decay the clay fraction of the noncoal rocks in many coal bearing sequences is typically dominated by illite or interstratified clay minerals with kaolinite chlorite and possibly montmorillonite also present to a variable though typically minor extent although perhaps modified by chemical reactions or ion exchange mechanisms in the peat swamp these clay minerals may also be present in the coal as well especially near the base of top of the seam the kaolinite in the noncoal rocks is usually poorly crystallized and typically a minor constituent but well crystallized kaolinite is characteristically present and often the dominant component in the mineral fraction of bituminous coal beds as well as in some of the lutites including underclays intimately associated with the seams a progressive upward gradation to a particularly kaolinite dominated mineral assemblage occurs in some seams of the sydney basin australia this gradation is thought to be due to either increased blockage of detrital contaminants as the swamp developed or to in situ chemical or biological leaching of the mineral fraction and reconstitution of the residues in the upper parts of the peat bed superimposition of such cycles is also noted within the seam in some instances suggesting repetition of several phases of this type during major peat accumulations

quantification of mineral matter in the argonne premium coals using interactive rietveld based x ray diffraction abstract the mineral matter in the eight reference north american coal samples of the argonne premium coal series has been investigated on a quantitative basis using x ray diffraction xrd techniques x ray diffraction data obtained from electronic low temperature oxygen plasma ash lta residues from ashes produced by heating the coals in air at 370 c and also from the raw coals themselves were evaluated using an interactive data processing system siroquant based on rietveld interpretation methods the results from the three types of material lta 370 c ash and raw coal were compared for each sample this allowed the components present in the raw coals in crystalline form to be recognised separately from mineral artifacts produced particularly in the low rank coals from interaction of organically associated elements ca s etc during the two ashing processes after the allowance for the production of any artifacts the quantitative mineral assemblages identified from xrd of the raw coals were found to be consistent even for coals having a relatively low ash percentage around 5 with the results obtained from the respective mineral concentrates prepared by the ashing methods the effects of heating the coal to 370 c could also be distinguished relative to the raw coal or the lta through changes in components such as pyrite and the clay minerals although some areas of uncertainty exist particularly with magnesium in the low rank coals the calculated chemical compositions of the coal ash derived from the mineral mixtures identified for each coal were also found to be consistent with the results of direct chemical analysis of the respective coal ash materials

geological controls on the mineralogy and geochemistry of the beypazari lignite central anatolia turkey abstract the raw coal from the cayirhan mine beypazari basin turkey contains an average of 28 5 mineral matter consisting up to 80 zeolites the coal seam is split by a 1 m thick tuffaceous siltstone into the upper first tv and lower second tb seams which contain essentially different zeolites the first seam contains ca rich zeolites clinoptilolite heulandite whilst the second seam contains na rich zeolites analcime experimental work has shown that a na rich activation solution will produce na rich zeolites when the original volcanic glass is na rich but will produce ca rich zeolites when the volcanic material is ca rich it is thought that a na rich activation solution derived from contemporaneous volcanics in the beypazari basin reacted with volcanic tuffs of different chemical composition to produce the vertical variability in the mineral matter of the two seams trace element analyses of the raw coal showed that they are enriched in as b cr ni and zr when compared to world wide averages of coal they are also enriched in the major elements na and k these elements are probably also derived from a volcanic source barium and sr show a clear affinity for analcime whilst li cr ni cu zn co and ga show a clear affinity for clinoptilolite heulandite trace elements showing a positive correlation with the organic matter are mn b be ge y zr nb hf w and u manganese u th sc ge and hree heavy rare earth elements show correlations with phosphate trace elements showing correlation with both fe and s contents are co mo ta pb and iree intermediate rare earth elements arsenic and v seem to have mixed affinities with sulphides and zeolites and organic matter and zeolites respectively although a proportion of the as b and s are retained in the ash during coal combustion due to the sorption mechanism of cao derived from the clinoptilolite heulandite decomposition significant emissions of these elements may arise from the cayirhan thermal power station due to the anomalously high concentrations of these elements in the beypazari coal the high total alkali metal content of these coals exceeds the recommended maximum for steam coal but it is believed that sodium occurring in a mineralogical form such as analcime is not as likely to contribute to boiler fouling as organically associated sodium

geochemical and mineralogical changes in a coal seam due to contact metamorphism sydney basin new south wales australia abstract the mineralogical changes in a bituminous coal seam thermally altered by a small basaltic intrusion have been investigated using electronic low temperature oxygen plasma ashing x ray diffraction and other laboratory techniques an assemblage dominated by montmorillonite and well crystallized kaolinite in the area away from the intrusion passes laterally to one dominated by illite and poorly crystallized kaolinite along with abundant dolomite and calcite at the actual contact point geochemical considerations of both the mineral matter and the igneous rock suggest that the changes in the clay fraction were produced by heating to temperatures of between 400 and 650 c for a relatively short period coupled with migration of potassium from the intrusive body into the coal seam heating at lower temperatures although causing an increase in vitrinite reflectance does not appear to have had a particularly significant effect at all on the clay minerals in the coal seam

concentration and distribution of trace elements in lignite from the shengli coalfield inner mongolia china implications on origin of the associated wulantuga germanium deposit abstract the wulantuga germanium deposit wgd hosted in coal seams with ge resources up to 1600 mt is located in the shengli coalfield in xilingol inner mongolia china forty two channel samples of ge bearing lignites of the no 6 1 coal seam in lower cretaceous bayanhua formation were collected and analyzed by inductively coupled plasma mass spectrometry icp ms the mode of occurrence of elements in selected lignite samples were studied by cluster analysis and scanning electron microscope with energy dispersive x ray spectrometer sem edx the lignite samples of wgd are distinctly enriched in be ge sb w and u and depleted in rb nb sn and ta compared with the average composition of upper continental crust the average concentrations of above enriched elements also are higher than those of overlying sandstone of wgd and contemporary ge barren lignite of hongqi coal mine in shenli coalfield as well as the average concentration of elements in the usa coals and worldwide coals with an exception of sr most trace elements and ash yields obey the log normal distribution in all 42 lignite samples collected from wgd the elements in these lignites may be classified into four groups the first group ge mo association contains elements with negative correlation coefficients with ash yields and they show mainly organic affinity the elements in the second group tl ga zn co association show negative to moderate correlation coefficients with ash yields and may also have an organic affinity but most of them are mainly related to mineral matter such as sphalerite the last two groups rb cs and w u cd y pb cu hf zr th sn nb ta tio 2 sb ba sr mno be associations contain elements with moderate to high correlation coefficients with ash yields much of them associated mainly with mineral matter such as anatase manganite zircon and barite as identified by sem edx analysis and show mainly aluminosilicate affinity silver bearing particles or native silver were identified by sem edx in the lignites from wgd and hongqi coal mine germanium and mo can concentrate in different proportion of coal seam in different sections while other elements more or less follow the distribution of ash yield the tio 2 normalized elemental profiles reveal that be tio 2 ge tio 2 w tio 2 u tio 2 mo tio 2 sb tio 2 tl tio 2 and sr tio 2 ratios of the lignite samples in three sections of wgd are generally one or two order of magnitude higher than the reference ratios of sandstone from wgd and lignite from hongqi coal mine much more than 90 of these elements be ge w u mo sb tl and sr may be transported into coal seam by solution the ge bearing lignites from wgd are distinctly characterized by lower rb cs ratios higher u th ratios different from those of the overlying sandstone from wgd and contemporary lignite from hongqi coal mine most trace elements in the ge bearing lignite of wgd may have been derived from a granitic source and the enrichment of be ge sb w and u may be attributed to an epigenetic lateral transferred ge bearing solution that leached these elements from the granitic source and transported them into the lignite

the variability of root cohesion as an influence on shallow landslide susceptibility in the oregon coast range decades of quantitative measurement indicate that roots can mechanically reinforce shallow soils in forested landscapes forests however have variations in vegetation species and age which can dominate the local stability of landslide initiation sites to assess the influence of this variability on root cohesion we examined scarps of landslides triggered during large storms in february and november of 1996 in the oregon coast range and hand dug soil pits on stable ground at 41 sites we estimated the cohesive reinforcement to soil due to roots by determining the tensile strength species depth orientation relative health and the density of roots 1 mm in diameter within a measured soil area we found that median lateral root cohesion ranges from 6 8 23 2 kpa in industrial forests with significant understory and deciduous vegetation to 25 6 94 3 kpa in natural forests dominated by coniferous vegetation lateral root cohesion in clearcuts is uniformly 10 kpa some 100 year old industrial forests have s

rare earth elements and yttrium in lithotypes of bulgarian coals abstract rare earth element and yttrium abundances in vitrain xylain liptain fusain and whole coal samples from bulgarian coal deposits have been studied vitrain xylain and liptain are depleted while fusain is enriched in ree and y as compared to the whole coal samples from which they were selected chondrite normalized patterns show relative enrichment of light lree against heavy hree rare earth elements negative eu anomaly and positive lu anomaly the shale normalized patterns of the lithotypes reveal an increase from lree to hree while those of the whole coal samples and mineral interlayers are less fractionated the petrographic composition of the coals is of secondary importance for the concentration of the ree and y the main factors are the source area and the input of dissolved ree and y into the coal depositional sites

quantification of mechanical and hydric components of soil reinforcement by plant roots the use of vegetation to stabilize slopes with regard to shallow landslides is an ecological and economic alternative to traditional solutions of civil engineering this study aims at quantifying the effect of soil water content on the reinforcement of soil by plant roots and determines how soil water content influences the failure modes of roots during shear direct shear box tests were performed on three species used in hillslope reforestation programs in yunnan china reinforcement was quantified and divided into a hydric component corresponding to the effect of water removal and a mechanical component reflecting the influence of roots on apparent cohesion and friction angle it was shown that the hydric component of reinforcement can be of the same order as the mechanical component and that root system architectural traits influence the type of mechanical reinforcement cohesive or frictional we also demonstrate the potential development of matric suction effects on the shear strength of soil

a new type of nb ta zr hf ree ga polymetallic deposit in the late permian coal bearing strata eastern yunnan southwestern china possible economic significance and genetic implications abstract this paper describes a new type of nb ta zr hf ree ga polymetallic deposit of volcanic origin in the late permian coal bearing strata of eastern yunnan southwestern china well logging data especially natural gamma ray geochemical data high concentrations of nb ta zr hf ree and ga and mineralogical compositions nb ta zr hf or ree bearing minerals rarely observed together with the volcanic lithological characteristics indicate that there are thick 1 10 m mostly 2 5 m ore beds in the lower xuanwei formation late permian in eastern yunann of southwestern china the ore beds are highly enriched in nb ta 2 o 5 302 627 ppm zr hf o 2 3805 8468 ppm ree oxides of la lu y 1216 1358 ppm and ga 52 4 81 3 ppm the ore beds are mainly composed of quartz mixed layer illite smectite kaolinite berthierine and albite four types of ore beds in the study area were identified namely clay altered volcanic ash tuffaceous clay tuff and volcanic breccia preliminary studies suggest that the high concentrations of otherwise rare metals were mainly derived from the alkalic pyroclastic rocks the modes of occurrence spatial distribution and enrichment mechanism of the rare metals however require further study

geochemistry of boron in bulgarian coals a set of 466 individual full channel samples coals coaly shales and partings of thirteen bulgarian coal deposits as well as vitrain lenses gagatite and coalified woods embedded in sedimentary rocks have been analyzed by atomic emission spectroscopy the deposits consist of lignites subbituminous and bituminous coals the average boron content ranges from 15 to 164 ppm in the coals the boron content of the individual coal samples ranges from 2 to 164 ppm about 86 of the samples have a b content from 2 to 110 ppm which corresponds to the most probable interval of concentration for coals worldwide the boron content is not related to rank the lignites have the lowest boron content some of the vitrain and xylain samples studied are enriched in boron in comparison with the whole coal samples boron occurs in both organic borg and inorganic binorg forms excluding one deposit the boron content in the ash correlates negatively with the ash content whereas in coals it usually slightly increases with increasing ash content organically associated b dominates in the low ash coals and in the deposits enriched in boron the coals of the burgas deposit have the highest b content which is in agreement with the geological evidence for marine influence during the early stages of coalification the distribution of b is also independent of other geological factors

factors controlling debris avalanche initiation heavy rainfall during a january 1983 storm triggered numerous debris avalanches and associated debris torrents in the smith creek basin western whatcom county washington united states four classes of debris avalanches are recognized wedges drainage depressions logging roads and discontinuity surfaces nine different debris avalanche headscarps that are representative of these four classes are studied in detail the geometric configuration of each headscarp the properties of soils comprising the headscarps and water tables based on numerical models of hillslope hydrology are used in limit equilibrium slope stability analyses to back calculate root cohesion cr values at failure the calculated values are consistent with those reported by others four groups of cr values are proposed and correlated with forest vegetation group i understory cr range from 1 6 to 2 1 kpa group ii scrub forest cr range from 2 1 to 2 5 kpa group iii mixed forest cr range from 2 5 to 3 0 kpa and group iv old

the effects of volcanic ash on the maceral and chemical composition of the c coal bed emery coal field utah abstract volcanic ash which fell in the peat swamp that formed the upper cretaceous c coal bed ferron sandstone member of the mancos shale utah produced semi impermeable layers that caused the ponding of surface waters coal samples from directly above tonsteins altered volcanic ash partings are enriched in desmocollinite telinite and detrocollinite as a result of poorly drained swamp conditions coal samples from directly below tonsteins are enriched in semifusinite inertodetrinite and fusinite as a result of well drained conditions leaching of the volcanic ash or the incorporation of volcanic ash in peat provided a source for many elements including zr nb th and ce that are enriched in coal samples taken from directly above and below tonsteins

late cretaceous coal overlying karstic bauxite deposits in the parnassus ghiona unit central greece coal characteristics and depositional environment abstract the pera lakkos coal located on top of bauxite deposits in the ghiona mining district central greece is the only known mesozoic late cretaceous coal in the country it was derived from herbaceous plants and algae growing in mildly brackish mires that formed behind a barrier system during a regression of the sea on a karstified limestone partly filled in with bauxitic detritus petrological mineralogical and geochemical data point to the predominance of reducing conditions and intense organic matter degradation in the palaeomires o c vs h c and oi vs hi plots based on elemental analysis and rock eval data characterize kerogen types i ii this reflects the relatively high liptinite content of the coal besides kerogen composition o c vs h c plot for the pera lakkos coals is in accordance with a catagenesis stage of maturation in contrast with vitrinite reflectance and t max from rock eval pyrolysis which indicate the onset of oil window maturation stage suppression of vitrinite reflectance should be considered and the high liptinite content corroborates this hypothesis despite some favourable aspects for petroleum generation presented by the pera lakkos coal its maximum thickness up to 50 cm points to a restricted potential for petroleum generation coal oxidation took place either during the late stage of peat formation due to wave action accompanying the subsequent marine transgression or epigenetically after the emergence of the whole sequence due to percolation of drainage waters both options are also supported by the ree shale normalized profiles which demonstrate an upwards depletion in the coal layer oxidation also affected pyrite included in the coal this led to the formation of acidic sulfate rich solutions which percolated downwards resulting in bleaching of the upper part of the underlying bauxite

lanthanide yttrium and zirconium anomalies in the fire clay coal bed eastern kentucky abstract the fire clay coal bed in the central appalachian basin region contains a laterally persistent tonstein that is found in the coal throughout most of its areal extent the tonstein contains an array of minerals including sanidine quartz anatase and euhedral zircon that constitutes strong evidence for a volcanic origin of the parting for this study five samples of the tonstein and four sets of coal samples underlying the tonstein were collected from five sites in eastern kentucky inductively coupled plasma mass spectroscopy icp ms analysis of the tonstein and underlying coal collected from four sites in eastern kentucky show that although zr concentrations are high in the tonstein 570 1820 ppm on a coal ash basis cab they are highest in the coal directly underlying the tonstein 2870 4540 ppm cab a similar enrichment pattern is observed in the concentration of y plus the sum of the rare earth elements y ree total y ree concentrations in the five tonstein samples range from 511 to 565 ppm cab however y ree contents are highest in the coals directly underlying the tonsteins values range from 1965 to 4198 ppm cab scanning electron microscopy of samples from coal which directly underlies two of the tonstein samples show that ree rich phosphate tentatively identified as monazite commonly infills cracks in clays and cells in clarain and vitrain zircon is rare and commonly subhedral on the basis of coal chemistry and grain morphology we suggest that volcanic components in the tonstein were leached by ground water the leachate rich in y and ree precipitated as authigenic mineral phases in the underlying coal

the origin of tonsteins an overview and links with seatearths fireclays and fragmental clay rocks abstract tonsteins are volcanic ash falls in coal bearing sequences that have altered to kaolinite only in the last twenty years or so has the volcanic origin become firmly established the evidence for the volcanic origin encompasses bed form including lateral extent structures textures volcanogenic mineralogy and geochemistry the lines of evidence are reviewed from a historical perspective tonsteins came to prominence over a hundred years ago because of their stratigraphic value tonsteins continue to be of value in coalfield exploration but their stratigraphic value has been enhanced in recent years with the ability to determine radiometric ages with a high level of accuracy the geochemistry not only provides good evidence for the volcanic origin but also enables tectomagmatic deductions to be made for areas external to the coal basin in addition some tonsteins are the indicators for the discovering of rare metal ore deposits nb rees and ga there is also the potential to use the geochemistry to identify specific tonsteins essentially a chemostratigraphic approach tonsteins are seen as one class of bentonites others include k bentonites metatonsteins and possibly illitic bentonites tonsteins have been linked to seatearths fireclays and fragmental clay rocks although all such rocks contain kaolinite the origins differ the seatearths contain rootlets and were subjected to pedogenic activity alteration of the silicate minerals is limited under conditions of a high water table and in the presence of organic matter reducing conditions prevailed leading to gleization on the other hand the fireclays show extensive alteration to kaolinite there is a link with the major marine bands and this has implications in terms of sequence stratigraphy the fragmental clayrocks have also been linked to soil forming processes but in this case possibly the reworked soil was the product of an open system containing free alumina minerals that reacted with silica in solution during diagenesis

interpretation of direct shear box testing of sands as quasi simple shear interpretation of the direct shear box dsb test implicitly assumes a simple shear mode of deformation but this assumption has not been fully verified in particular in tests on sands this paper describes a laboratory investigation which was commissioned to find an optimum configuration of a dsb apparatus for measuring the strength and dilatancy characteristics in direct simple shear the examination was made in a newly developed dsb apparatus using dry specimens of two standard sands toyoura sand and silver leighton buzzard sand boundary effects such as the wall friction the size of the opening between the two halves of the shear box and the constraint imposed by the loading platen were each independently examined in pilot tests to determine their influence on the measurements of strength and angle of dilatancy the optimum configuration was determined through careful examination of the boundary stresses and strains of rectangular specimens subjected to shearing under drained and constant volume

prediction of rainfall induced shallow landslides in the loess plateau yan an china using the trigrs model in this work a transient rainfall infiltration and grid based regional slope stability model trigrs was implemented in a case study of yan an city northwest china in this area widespread shallow landslides were triggered by the 12 july 2013 exceptional rainstorm event a high resolution dem soil parameters from in situ and laboratory measurements water table depths the maximum depth of precipitation infiltration and rain gauge corrected precipitation of the event were used as inputs in the trigrs model shallow landslides triggered on the same day were used to evaluate the modeling results the summarized results are as follows i the characteristics and distribution of thirty five shallow landslides triggered by the 12 july 2013 rainfall event were identified in the study area and all were classified as shallow landslides with the maximum depth area and volume less than 3 m 200 m2 and 1000 m3 respectively ii four intermediate factor of safety fs maps were generated using the trigrs model to represent the scenarios 6 12 18 and 24 hours after the storm event the area with fs 1 increased with the rainfall duration the percentage of the area with fs 1 was 0 2 3 3 3 8 and 5 1 for the four stages respectively twenty four hours after the rainstorm trigrs predicted that 1255 grid cells failed which is consistent with the field data iii trigrs generated more satisfactory results at a given precipitation threshold than sinmap which is ideal for landslide hazard zoning for land use planning at the regional scale comparison results showed that trigrs is more useful for landslide prediction for a certain precipitation threshold also in the regional scale iv analysis of the responses of loess slope prone to slope failure after different precipitation scenarios revealed that loess slopes are particularly sensitive to extended periods of heavy precipitation copyright 2016 john wiley sons ltd

cleat mineralization of upper permian baralaba rangal coal measures bowen basin australia coals from the permo triassic bowen basin have been investigated using a variety of complementary analytical techniques face cleat minerals in the studied samples are dominated by authigenic clays notably pure illite or illite chlorite mixtures butt cleats and joints are dominated by carbonates mostly calcite with less abundant ferroan calcite ankerite and siderite k ar ages of cleat fill illites and one fracture illite smectite fill indicate three phases of illite formation during the triassic 1 an early phase with ages clustered around 244 ma ago 2 a second phase about 232 ma ago and 3 the latest phase about 219 ma ago thermal modelling of selected boreholes from the study area and other geological data indicate that the first phase of illitization occurred when the coal seams were about 1000m below the surface and at a temperature of between 70 and 80 c at a time when the basin was rapidly subsiding these early illites were stable and retained their 1m polytype even after being exposed to temperatures of 150 190 c during maximum burial in the southeastern bowen basin the second phase of illitization at 232 3 occurred at about the time of maximum burial the latest phase took place between 223 3 and 212 3 ma ago and occurred in a wider temperature range between 170 and 100 c during a rapid uplift in the late triassic the bowen basin area experienced a second cycle of subsidence that commenced in the early jurassic with the formation of the surat basin which overlies the bowen basin and forms part of the great artesian basin system regional uplift and erosion in middle cretaceous times terminated sediment accumulation in the surat basin during the second cycle of burial widespread carbonate mineralization in butt cleats and joints took place calcite fluid inclusions indicate that calcite was precipitated from meteoric water at about 80 c the widespread carbonate mineralization in butt cleats and the near absence of carbonates in the face cleats is here attributed to permeability anisotropy caused by a change in the direction of lateral compressive stress during jurassic cretaceous times relative to that during the triassic hunter bowen orogeny

gallium and germanium in selected indiana coals abstract the distribution of gallium ga and germanium ge was studied in two pennsylvanian high volatile bituminous coals of indiana the springfield coal member of the petersburg formation and the danville coal member of the dugger formation gallium in the springfield and danville coals shows similar ranges from 1 70 to 8 90 ppm averaging 5 06 ppm for the danville coal and 1 40 to 12 30 ppm with an average of 3 39 ppm for the springfield coal for ge these ranges are 2 50 to 26 70 ppm average 14 19 ppm for the danville coal and 1 54 to 38 0 average 9 40 ppm for the springfield coal in the vertical section ga shows a symmetric distribution with the lowest values in the middle part of the seam in the springfield coal and an asymmetric distribution increasing or decreasing upward in the danville coal gallium is dominantly associated with the mineral matter and clay minerals in particular germanium shows a symmetric distribution with the largest enrichment in the topmost and the basal benches of the coal it appears to be associated with either mineral matter dominantly clays occasionally pyrite or organic matter

effects of vegetation type on soil resistance to erosion relationship between aggregate stability and shear strength article i nfo soil water erosion and shallow landslides depend on aggregate stability and soil shear strength we investigated the effect of vegetation on both soil aggregate stability and shear strength through direct shear tests in former croplands converted to vegetated erosion protection areas within the context of china s sloping land conversion programme four treatments were analysed in plots comprised of i 4 year old crop trees vernicia fordii where understory vegetation was removed ii v fordii and the dominant understory species artemisia codonocephala iii only a codonocephala and iv no vegetation soil samples were taken at depths of 0 5 cm and 45 50 cm root length density rld in five diameter classes was measured soil organic carbon soc hot water extractable carbon hwec texture and fe and al oxides were also measured we found that mean weight diameter after slow wetting mwdsw in the a horizon was significantly greater 0 94 1 01 mm when a codonocephala was present compared to plots without a codonocephala 0 57 0 59 mm soc and rld in the smallest diameter class b0 5 mm were the variables which best explained variability in mwdsw a significant positive linear relationship existed between mwdsw and soil cohesion but not with internal angle of friction as herbaceous vegetation was more efficient than trees in improving aggregate stability this result suggests that the mechanisms involved include modifications of the cohesive forces between soil particles adjacent to plant roots and located in the enriched in soc rhizosphere thus also affecting shear strength of the corresponding soil volume thus vegetation stabilised soil under different hierarchical levels of aggregate organisation i e intra and inter aggregate our results have implications for the efficacy of techniques used in land conversion programs dedicated to control of soil erosion and shallow landslides we suggest that mixtures of different plant functional types would improve soil conservation on slopes by reducing both surface water erosion and shallow substrate mass movement planting trees for cropping or logging and removing understory vegetation is most likely detrimental to soil conservation

geochemistry of mineralization with exchangeable rey in the weathering crusts of granitic rocks in south china abstract mineralization with exchangeable rare earth element ree and yttrium mex rey has been recognized in the weathering profiles in south china since the early 1970 s this type of rey mineralization occurs in weathering profiles of parent rocks ranging in composition from granite to acidic volcanic rocks and lamprophyre the majority of the known resources occurring in the weathering profiles of granitic rocks total resources of this type of rey amount to millions tons of rare earth oxides and therefore represent one of the most important types of rare earth resources in china particularly for heavy rare earth elements hree and yttrium accumulation of rey in the weathering profiles of granitic rocks is strongly controlled by the resistance to weathering of the principal rey bearing accessory minerals in the parent rocks only a limited proportion of total rey 4 and na etc in electrolyte solutions and can be removed by complexing agents such as edta are commonly the major form of ree occurrence in the b horizon cerium is enriched in the top layer a horizon and depleted in the subsurface horizons of the weathering profiles most likely due to the oxidation of ce iii to ce iv followed by cerianite formation or absorption onto clays and or fe and al oxyhydroxides

mineralogy and geochemistry of boehmite rich coals new insights from the haerwusu surface mine jungar coalfield inner mongolia china abstract boehmite rich coal of pennsylvanian age was discovered earlier at the heidaigou surface mine jungar coalfield inner mongolia china this paper reports new results on 29 bench samples of the no 6 coal from a drill core from the adjacent haerwusu surface mine and provides new insights into the origin of the minerals and elements present the results show that the proportion of inertinite in the no 6 coal is higher than in other late paleozoic coals in northern china based on mineral proportions boehmite to kaolinite ratio and major element concentrations in the coal benches of the drill core the no 6 coal may be divided into five sections i to v major minerals in sections i and v are kaolinite sections ii and iv are mainly kaolinite with a trace of boehmite and section iii is high in boehmite the boehmite is derived from bauxite in the weathered surface benxi formation in the sediment source region the no 6 coal is rich in al2o3 8 89 tio2 0 47 li 116 g g f 286 g g ga 18 g g se 6 1 g g sr 350 g g zr 268 g g rees 172 g g pb 30 g g and th 17 g g the elements are classified into five associations by cluster analysis i e groups a b c d and e group a ash sio2 al2o3 na2o li and group b ree sc in y k2o rb zr hf cs u p2o5 sr ba ge are strongly correlated with ash yield and mainly have an inorganic affinity the elements that are negatively or less strongly correlated with ash yield with exceptions of fe2o3 be v and ni are grouped in the remaining three associations group c se pb hg th tio2 bi nb ta cd sn group d co mo tl be ni sb mgo re ga w zn v cr f cu and group e s as cao mno fe2o3 aluminum is mainly distributed in boehmite followed by kaolinite the high correlation coefficients of the li ash li al2o3 and li sio2 pairs indicate that li is related to the aluminosilicates in the coal the boehmite rich coal is high in gallium and f which occur in boehmite and the organic matter selenium and pb are mainly in epigenetic clausthalite fillings in fractures the abundant rare earth elements in the coal benches were supplied from two sources the bauxite on the weathered surface of the benxi formation and from adjacent partings by groundwater leaching during diagenesis the light rare earth elements lrees are more easily leached from the partings and incorporated into the organic matter than the heavy rees leading to a higher ratio of lrees to hrees in the coal benches than in the overlying partings