airborne biogeophysical mapping of hidden mineral deposits three mapping surveys of cotter basin montana and spirit lake washington the tree cover with widespreading and deeply penetrating root systems is turned to an advantage in the airborne biogeophysical technique by detecting metal induced changes in the chlorophyll reflectance spectrum modified journal abstract

mineral mapping and ore prospecting using landsat tm and hyperion data wushitala xinjiang northwestern china abstract the southern tianshan area situated in central asia is one of the most important gold belts identified by many world class superlarge and large gold deposits the wushitala area located in the eastern part of southern tianshan xinjiang china has a strong potential for gold and other metallic mineral deposits however no metallic mineral deposit or occurrence has been reported in detail for the wushitala area in the past apparently due to poor exploration this study attempts to map alteration zones and acquire ore prospecting targets in the wushitala area by integrating landsat tm and hyperion data with the aster spectral library mineral spectra the crosta technique and the anomaly overlaying selection method were combined to process four temporal landsat tm data acquired in the same season in different years so as to eliminate the random interference caused false anomalies of alteration minerals iron oxides and hydroxyl bearing minerals and carbonates while retaining the real anomalies the matched filtering method was applied on hyperion data for the detailed identification of hydrothermally altered minerals surrounding the granites in the north the results of hyperion data are spatially consistent with those of landsat tm data furthermore the results of hyperion data show that the alteration minerals associated with the potash feldspar granite are dominated by muscovite and goethite in our field campaign fourteen sites eleven acid intrusion related and three structure associated distributed throughout the study area were inspected all of which proved to be of geological genesis our study led to the discovery of three mineralization sites associated with acid intrusions and structures that were not previously documented due to the extensively distributed acid intrusions and structures along the southern tianshan belt several other gold iron copper mineralized locations could be found with more detailed investigations our mineral prospecting methodology proved effective in the study area and is hereby suggested for application in similar geological settings

incremental growth of an upper crustal a type pluton argentina evidence of a re used magma pathway abstract carboniferous igneous activity in the sierra de velasco nw argentina led to the emplacement of several magmas bodies at shallow levels t 5 8 and ehf t in zircon 2 9 to 4 5 the second group comprises the metaluminous to peraluminous granitic rocks of the youngest units san blas and hualco which were formed by a heterogeneous mixture between mantle and crustal sources end t 0 6 to 4 8 and ehf t in zircon 3 to 6 our results provide a comprehensive view of the evolution of an intrusive complex formed from multiple non consanguineous magma intrusions that utilized the same magmatic plumbing system during downward transfer of host materials as the plutonic system matures the ascent of magmas is governed by the visco elastic flow of host rock that for younger batches include older hot magma mush the latter results in ductile downward flow of older during rise of younger magma such complexes may reflect the plutonic portion of volcanic centers where chemically distinct magmas are erupted

detection of hydrothermal alteration zones in a tropical region using satellite remote sensing data bau goldfield sarawak malaysia abstract remote sensing for geology in tropical environments is very challenging because of the dense vegetation cover and the problem of persistent cloud cover in this research paper we have investigated and demonstrated the detection of hydrothermal alteration zones and structural elements associated with intrusion related gold mineralization using various types of remote sensing data in the bau gold mining district in the state of sarawak east malaysia on the island of borneo the climate of bau is tropical with persistent cloud cover and very dense vegetation ground geological analyses coupled with remote sensing data were used to detect hydrothermally altered rocks and structural elements associated with gold mineralization in the bau area landsat enhanced thematic mapper etm hyperion and phased array type l band synthetic aperture radar palsar data were used to carry out lithological structural mapping of the mineralized zones in the study area and surrounding terrain hydrothermal alteration zones were detected along the ssw to nne structural trend of the tai parit fault that corresponds with the occurrence of other gold mineralization in the bau limestone the results show that the known gold prospects and potential areas of mineralization are recognizable by the methods used despite limited bedrock exposure the approach used in this study is broadly applicable to the detection of gold mineralization using etm hyperion and palsar data in tropical sub tropical regions

integrated method of rs and gpr for monitoring the changes in the soil moisture and groundwater environment due to underground coal mining mining affects the environment in different ways depending on the physical context in which the mining occurs in mining areas with an arid environment mining affects plants growth by changing the amount of available water this paper discusses the effects of mining on two important determinants of plant growth soil moisture and groundwater table gwt which were investigated using an integrated approach involving a field sampling investigation with remote sensing rs and ground penetrating radar gpr to calculate and map the distribution of soil moisture for a target area we initially analyzed four models for regression analysis between soil moisture and apparent thermal inertia and finally selected a linear model for modeling the soil moisture at a depth 10 cm the relative error of the modeled soil moisture was about 6 3 and correlation coefficient 0 7794 a comparison of mined and unmined areas based on the results of limited field sampling tests or rs monitoring of landsat 5 thermatic mapping tm data indicated that soil moisture did not undergo remarkable changes following mining this result indicates that mining does not have an effect on soil moisture in the shendong coal mining area the coverage of vegetation in 2005 was compared with that in 1995 by means of the normalized difference vegetation index ndvi deduced from tm data and the results showed that the coverage of vegetation in shendong coal mining area has improved greatly since 1995 because of policy input rmb 0 4 per ton coal production by shendong coal mining company the factor most affected by coal mining was gwt which dropped from a depth of 35 41 m before mining to a depth of 43 38 m after mining at the bulianta coal mine based on water well measurements ground penetrating radar at frequencies of 25 and 50 mhz revealed that the deepest gwt was at about 43 4 m there was a weak water linkage between the unsaturated zone and groundwater and the decline of water table primarily resulted from the well pumping for mining safety rather than the movement of cracking strata this result is in agreement with the measurements of the water wells the roots of nine typical plants in the study area were investigated populus was found to have the deepest root system with a depth of about 26 m based on an assessment of plant growth demands and the effect of mining on environmental factors we concluded that mining will have less of an effect on plant growth at those sites where the primary gwt depth before mining was deep enough to be unavailable to plants if the primary gwt was available for plant growth before mining especially to those plants with deeper roots mining will have a significant effect on the growth of plants and the mechanism of this effect will include the loss of water to roots and damage to the root system

hydrothermal altered serpentinized zone and a study of ni magnesioferrite magnetite awaruite occurrences in wadi hibi northern oman mountain discrimination through aster mapping abstract economic important minerals and ore deposits are common in hydrothermal altered serpentinized zone advanced spaceborne thermal emission and reflection radiometer aster satellite sensor is capable of discrimination of such hydrothermal mineralized zone and detection of hydrothermal altered minerals in the present study the hydrothermal altered serpentinized harzburgites of wadi hibi area of northern oman mountains have been discriminated by using aster vnir swir spectral bands by image processing methods and the occurrences of ni magnesioferrite magnetite awaruite in the rocks are studied the color composite rgb image developed using aster spectral bands 8 4 and 1 mapped well the occurrence of weathered peridotites by pale green to dark blue in colors and discriminated the hydrothermally altered serpentinized rocks by pale brown to dark blue colors due to the strong absorption of oh and mg oh molecules that occurred in the serpentine minerals of the rocks in the study area the aster band ratios 4 7 4 1 and 2 3 4 3 rgb images studied are capable of discrimination of hydrothermal mineralized areas more clear by pale blue to purple colors due to the strong absorption of such hydroxyl bearing serpentine minerals the studied image processing methods are evaluated by applying to the region of wadi sarami situated in the semail ophiolite oman in addition to that the occurrence of serpentine minerals namely lizardite and antigorite in the hydrothermally altered serpentinized region are detected qualitatively and quantitatively using spectral angle mapper sam supervised classification image processing method and studied the interpreted images are verified in the field and checked for the occurrences of minerals including ni magnesioferrite magnetite pentlandite and awaruite and are confirmed through laboratory studies petrographic study of serpentinized harzburgites shows that the rocks consist predominantly of antigorite and lizardite serpentines olivine and have the opaque minerals assemblage of ni magnesioferrite magnetite awaruite pentlandite developed during serpentinization of the rock the occurrences of such minerals are confirmed by xrd electron microprobe analyses and spectral measurements in the laboratory aster sensor proved its capability in discriminating the hydrothermal altered serpentinized zone and detecting the mineral occurrences and thus the study recommends the technique to the exploration geologists scientists and mining geologists for mapping of such rocks and minerals in the similar arid region

measuring rock microstructure in hyperspectral mineral maps abstract a novel method is presented to measure rock microstructure in hyperspectral mineral maps of rock specimens shape parameters were calculated from rock objects in segmented mineral maps object area object perimeter object hull perimeter and fitted ellipses were used to calculate shape parameters such as compactness convexity and a cookie cutter parameter shape parameters were used to describe a variety of microstructures and microstructural elements the parameters were tested on microstructures in artificial imagery and subsequently applied to hyperspectral mineral maps of rocks analyses of parameters calculated on artificial imagery showed that object shapes could be measured by the flattening of fitted ellipses as a measure of sphericity and elongation together with the cookie cutter parameters that measured angularity compactness and convexity could differentiate between euhedral subhedral and anhedral crystal shapes aphanitic phaneritic and porphyritic igneous microstructures could be identified and differentiated by homogeneity and relative object size parameters the degree of sorting of sedimentary rocks was measured by the distribution of object sizes and statistical parameters describing the distribution orientation of single objects was measured by the angle between the major axis of a fitted ellipse and the vertical of the image preferred orientations in the rock microstructure were determined by calculation of a standardized resultant of orientation vectors and a mean angle layering and banding of the rock was identified by the length of major axes of fitted ellipses relative to the image dimension the shape parameters calculated on objects in segmented hyperspectral mineral maps of rock specimens were able to discriminate between sedimentary and volcanic microstructures using the size distribution of mineral objects the presence of a preferred orientation of the rock and a layered microstructure the volcanic microstructures could be differentiated by the size distribution of amygdales phenocrysts and xenocrysts in the rock shape parameters could be used to differentiate between xenocrysts and phenocrysts the latter being more elongated in the studied samples the study shows that object shape parameters can be used to measure microstructure and microstructural elements in mineral maps and subsequently discriminate between different rock types and microstructures the expression of microstructure into numeric parameters is a first step towards quantification of microstructures in mineral maps of rocks further development of the methodology could contribute to the creation of unbiased classification scheme of rocks improved statistical modeling of compositional rock parameters such as mineral ore grades and the automated recognition of microstructures in large image databases of rocks and drill core

characterization of the hydrothermal systems associated with archean vms mineralization at panorama western australia using hyperspectral geochemical and geothermometric data abstract airborne hyperspectral imagery was used to study the distribution of white mica minerals in archean 3 2 ga submarine hydrothermal systems associated with volcanogenic massive sulfide mineralization in a well exposed volcanic sequence of the soansville greenstone belt in the pilbara western australia white mica mineral abundance and distribution maps were compared with published hydrothermal alteration maps and differences were interpreted using whole rock geochemistry and temperature estimates from oxygen isotope geothermometric studies of hydrothermally altered rocks three different zones were identified from the hyperspectral imagery 1 al rich white mica zones in the upper parts of the volcanic sequence which are related to recharge of unevolved seawater 2 al poor white mica zones at middle and upper levels of the volcanic sequence predominantly related to k alteration by more evolved hydrothermal fluids and 3 high to intermediate al content white mica zones in lower levels of the sequence and in cross cutting zones related to intense alteration by laterally flowing and upwelling evolved fluids the integrated study of the spatial distribution of hyperspectrally detected white mica minerals together with published maps and rock analyses allowed characterization of the hydrothermal systems and reconstruction of paleo fluid pathways

an evaluation of short wave infrared swir data from the aviris and geoscan instruments for mineralogical mapping at cuprite nevada an evaluation was performed on swir 2000 2400 nm data from two airborne remote sensing systems for discriminating and identifying alteration minerals at cuprite nevada the data were acquired by the nasa airborne visible infrared imaging spectrometer aviris and the geoscan mk ii multispectral scanner the evaluation involved comparison of processed imagery and image derived spectra with existing alteration maps and laboratory spectra of rock samples from cuprite results indicate that both the aviris and geoscan data permit the discrimination of areas of alunite buddingtonite kaolinite and silicification using color composite images formed from three swir bands processed with either the decorrelation stretch or a log residual algorithm the laboratory spectral features of alunite kaolinite and buddingtonite could be seen clearly only in the log residual processed aviris data however this does not preclude their identification with the geoscan data

controls on porphyry cu mineralization around hanza mountain south east of iran an analysis of structural evolution from remote sensing geophysical geochemical and geological data abstract hanza mountain in urmia dokhtar magmatic arc southeast of iran consists of monocline of eocene volcanic rocks into which the oligocene granitoid rocks have been intruded this area has excellent potential for economic porphyry copper deposits with bondar hanza daralu and sarmesk deposits among them hanza mountain is located between nw se horsetail thrust faults derived from the gowk and sabzevaran strike slip faults the analysis of the kinematics of these strike slip faults shows that they were not the cause of the formation of the pull apart basin thus they have not directly played any effective role in localizing the final emplacement of porphyries responsible for the formation of these copper deposits but the cu mineralization occurred mainly within a set of normal and thrust faults in the region the alteration types and faults in bondar hanza were distinguished using detailed local geology including distribution of known mineralization supported by remote sensing aster airborne geophysics and topography the relationship between mineralization and faults was examined using rose diagrams and fry analysis this investigation of bondar hanza deposit has revealed that the trend of faults and dykes as well as the distribution of copper analyses within drill cores is aligned with the main trend of mineralization the nw se trending faults in the urmia dokhtar magmatic arc are effective in localizing the emplacement of porphyry copper ore deposits and those that trend between n125 n145 are key to further exploration

hydrothermally altered mineral mapping using synthetic application of sentinel 2a msi aster and hyperion data in the duolong area tibetan plateau china abstract the duolong area is in a strong potential copper mineralization zone associated with felsic intrusions and several porphyry copper deposits pcds have been identified the pcds are characterized by hydrothermal alteration zones in this study sentinel 2a multispectral instrument msi advanced spaceborne thermal emission and reflection radiometer aster and hyperion data are combined to map hydrothermally altered minerals three temporal sentinel 2a msi images are processed by integrating the crosta technique and the anomaly overlaying selection method to map iron oxides and hydroxyl bearing minerals these approaches are implemented to omit interference induced false anomalies the six shortwave infrared swir bands of aster are used to extract information on al oh and mg oh group minerals the distribution of al oh minerals in the aster image map corresponds to that of hydroxyl bearing minerals in the msi image map a combination of minimum noise fraction mnf pixel purity index ppi n dimensional visualizer n d visualizer and matched filtering mf is adopted to process the hyperion image to obtain accurate hydrothermal alteration mapping results the overall accuracy for mineral mapping is 92 75 and the kappa coefficient is 0 89 the results of the hyperion image are spatially consistent with those of the sentinel 2a msi and aster images the image processing results were validated by field investigations and spectral reflectance measurements hydrothermally altered rocks correspond well with the five pcds in the duolong area three mineralization prospects associated with felsic intrusions are discovered in accordance with the results the methodologies and data are effective in detecting porphyry copper mineralization in other arid areas

detection of hydrothermal mineralized zones associated with listwaenites in central oman using aster data abstract listwaenites are highly altered ultramafic rocks that are potentially associated with economic mineralization and research on these is extremely important worldwide in the present study the classification of mineralized listwaenites developed along the serpentinite amphibolite interface of the semail ophiolite its associated lithology and the zones of alteration and mineralization in the fanjah saddle of the central oman mountains region of the sultanate of oman are carried out using advanced spaceborne thermal emission and reflection radiometer aster satellite data the developed band ratioing principal component analysis pca and the spectral angle mapper sam supervised classification and image processing techniques applied on the aster data set have proved their capability for better interpretation and identification of hydrothermally altered rocks and associated mineralization the hyperspectral tools minimum noise fraction mnf pixel purity index ppi and nd visualizer extracted end member spectra and sam classification clearly show the occurrence of minerals and their spatial distributions the promising results are verified and confirmed in the field by identification of alteration and mineralization such as listwaenites silicification serpentinization and talc alteration and are validated further through laboratory analysis the confirmation of the occurrence of base metal mineralization along the serpentinite amphibolite interface in listwaenites suggests that detailed investigation in this and other arid regions which have similar geological conditions may locate mineral deposits the hyperspectral tools applied on aster satellite data show that these can be used as a powerful tool to explore the listwaenites and the potential associated mineralization in other arid geographical regions worldwide

a novel approach for extraction of gaoshanhe group outcrops using landsat operational land imager oli data in the heavily loess covered baoji district western china abstract we studied the applicability of landsat operational land imager oli data for extraction of gaoshanhe group outcrops in a heavily loess covered area in the northern baoji district of china which is always a crucial but challenging issue in geological remote sensing mapping an integrated approach was employed to process the remote sensing data first the interpretation target area of interest was clipped using certain slope and elevation difference thresholds topographical analysis second band ratio b4 b2 and fractal summation algorithms were conducted in succession to extract the bedrock induced anomalies third spatial clumping and hot spot analysis were performed in order to eliminate residual false anomalies and finally we introduced high resolution worldview 2 data for visual interpretation and further spectral analysis the findings show that the rocky outcrops were somewhat spectrally indistinguishable and they were identified mainly due to their generally moderate degree of spatial clustering thirteen anomalous pixels were extracted from nearly 200 000 pixels covering the study area and our field reconnaissance verified the results this research constitutes the first useful case study on the applicability of landsat data derived lithology interpretation in china s loess plateau region

the application of advanced space borne thermal emission and reflection aster radiometer data in the detection of alteration in the chadormalu paleocrater bafq region central iran abstract ore deposits are often produced by fluid flow processes that alter the mineralogy and chemistry of the country rock one of the main objectives in developing a multi spectral and hyperspectral sensor is to detect the optical characteristics of the earth s surface using hundreds of spectral bands all previous studies show that remote sensing can recognize alteration to different degrees using different spatial and spectral resolution sensors the aster sensor measures reflected radiation in vnir swir and tir electromagnetic energies it is cheap and easily available the alteration minerals in the precambrian chadormalu area chadormalu paleocrater and the related iron oxide deposit have been investigated in the field and have been successfully detected by applying iarr internal average relative reflectance fcc false color composite decorrelation stretch mnf minimum noise fraction transform correlated filter and mem mathematical evaluation method techniques on aster imageries sodic potassic and silicic phyllic alteration patterns can be distinguished this study shows that the capability and accuracy of the mem method is better than 2 2 correlated filter techniques results indicate that pervasive hydrothermal ore forming processes were important in the study area judging from the assemblage of alteration minerals the chadormalu iron deposit is an end member of the kiruna type iron oxide cu au ore deposit continuum

spaceborne mapping of hydrothermal alteration zones associated with the mundiyawas khera copper deposit rajasthan india using swir bands of aster implications for exploration targeting abstract this paper discusses the effectiveness of spectroscopic techniques for identifying hydrothermal alteration zones associated with the mundiyawas khera copper deposit alwar basin western india and assesses implications for mineral exploration targeting in the greater alwar basin mineral specific swir bands of aster were spectrally enhanced to highlight areas of anomalous al oh and mg oh responses representing key mappable expressions of the mundiyawas khera copper deposit the hydroxyl bearing mineral zones were identified at 98 and 95 threshold pixels respectively kaolinite scapolite sericite muscovite tremolite and dolomite contained in the felsic volcanic and dolomitic copper host rocks were identified from spectroscopic data and corroborated with petrographic and xrd data on this basis distinct argillic phyllic and propylitic hydrothermal alteration zones could be identified at mundiyawas khera the integrated approach presented here i identified a well defined phyllic alteration pattern in the felsic volcanic rocks ii resulted in a comprehensive remotely sensed hydrothermal alteration map illustrating the spatial distribution of the copper related hydrothermal alteration zones i e an eastern argillic a central phyllic and a western propylitic zone iii helped to delineate potential copper rich zones coincident with a known lithostructural trend and iv has implications for copper exploration in the greater alwar basin

thermal infrared analysis of weathered granitic rock compositions in the sacaton mountains arizona implications for petrologic classifications from thermal infrared remote sensing data 1 critical to spectral interpretations of geologic surfaces on the earth and mars is an understanding of the relationship between the composition of weathered rock surfaces and whole rock mineralogy in this study thermal infrared spectroscopic and remote sensing analyses were used to determine the composition of weathered granitoid rock surfaces in the sacaton mountains arizona a linear spectral deconvolution approach was employed to determine the mineralogies of naturally exposed weathered surfaces and artificially exposed fresh rock surfaces deconvolution results from fresh rock surfaces yield similar bulk mineralogy to results from point counting of rock slabs and thin sections deconvolution of weathered rock spectra indicate that compared to fresh samples weathered surfaces are deficient in plagioclase feldspar and are enriched in clay minerals the differential weathering of feldspar minerals impacts the interpretation of whole rock mineralogy and the spectral classification of bedrock geology which for plutonic rocks is dependent on the relative proportions of different feldspars deconvolutions of multispectral remote sensing or laboratory data show a deficiency of total feldspar in the weathered rock units but lack sufficient spectral resolution for the discrimination between different feldspars these results demonstrate that the differential breakdown and removal of primary minerals in rock surfaces due to weathering can affect the interpreted rock petrology from remote sensing studies the relationships observed in our granitic samples could be applied to any rock type and may be important to consider for remote sensing of mars

geology structure geochemistry and aster based mapping of neoproterozoic gebel el delihimmi granites central eastern desert of egypt abstract the gebel el delihimmi granite intrusion located in the central eastern desert of egypt cuts the core of a major anticlinal structure of calc alkaline metavolcanics and ophiolitic melange rocks the intrusion is microscopically differentiated into granodiorite monzogranite syenogranite and alkali feldspar granite decorrelation stretch and band ratio techniques were applied to advanced spaceborne thermal emission and reflection radiometer data processing of aster swir bands enabled discrimination of el delihimmi granite phases and generation of a detailed lithologic map of the study area the structural and microfabric data suggest that the el delihimmi granite underwent at least two phases of deformations the first was related to the najd fault system during which the older granodiorite phase of the intrusion was affected by sinistral ductile shearing during the second phase monzogranite and syenogranite in the intrusion were affected by brittle e w compressional deformation geochemical data reported here reveal that the granodiorite phase has k 2 o na 2 o ratio 2 o na 2 o ratio 1 the granite phases are generally i type metaluminous to slightly peraluminous and are interpreted as formed above subducted slabs of oceanic lithosphere rather than in continental collision zones

comparative alteration mineral mapping using visible to shortwave infrared 0 4 2 4 spl mu m hyperion ali and aster imagery advanced land imager ali advanced spaceborne thermal emission and reflection radiometer aster and hyperion imaging spectrometer data covering an area in the central andes between volcan socompa and salar de llullaillaco were used to map hydrothermally altered rocks associated with several young volcanic systems six ali channels in the visible and near infrared wavelength range 0 4 1 0 spl mu m were useful for discriminating between ferric iron alteration minerals based on the spectral shapes of electronic absorption features seen in continuum removed spectra six aster channels in the short wavelength infrared 1 0 2 5 spl mu m enabled distinctions between clay and sulfate mineral types based on the positions of band minima related to al oh vibrational absorption features hyperion imagery embedded in the broader image coverage of ali and aster provided essential leverage for calibrating and improving the mapping accuracy of the multispectral data this capability is especially valuable in remote areas of the earth where available geologic and other ground truth information is limited

predicting vertical accretion rates at an archaeological site on the mississippi river floodplain effigy mounds national monument iowa abstract the sny magill unit of effigy mounds national monument iowa contains the largest cluster of prehistoric effigy mounds on public land in north america the mounds are situated atop a low terrace of the upper mississippi river where they are slowly being buried by overbank deposition during floods the terrace surface includes forest soils with argillic bt or cambic bw horizons developed in up to 1 m of loamy overbank deposits on top of pleistocene sand and gravel radiocarbon evidence suggests that overbank deposits have accumulated since the end of the mound building period about 700 years bp yielding a vertical accretion rate of about 0 6 mm yr 1 on the basis of 137cs analysis accretion rates over the past 40 50 years average 1 25 2 07 mm yr 1 with some evidence for a decreasing rate since 1964 if these accretion rates are projected forward several of the effigy mounds could be buried by flood deposits within 150 300 years this 137cs derived estimate agrees closely with an estimate of burial times based on flood frequency and observed flood deposit thickness during recent floods however the floodplain and backwater environments of the upper mississippi river are aggrading much more rapidly than the sny magill terrace surface suggesting that burial of the entire terrace could occur within 80 400 years and the entire mound group could be buried within 150 850 years the projected accretion rates and time to burial are subject to large uncertainties because of environmental change in the watershed including recent trends toward increasing flood stages and decreasing suspended sediment loads

mapping proterozoic unconformity related uranium deposits in the rockhole area northern territory australia using landsat etm abstract the rockhole area northern territory australia hosts a number of proterozoic unconformity related uranium deposits the geology of the area features within paleoproterozoic rocks of the pine creek orogen near the unconformity with overlying platform cover sandstone of the paleo to mesoproterozoic mcarthur basin landsat enhanced thematic mapper plus etm data was used in the rockhole area to assist in mapping geological structures and lithology and to identify anomalous concentrations of ferrous minerals the product of alteration which can be indicators of buried uranium mineralization several image processing procedures were applied to the etm data to identify isolate and enhance mineralogical information as simple and complex false color composites etm 754 shown as red green and blue respectively was the best simple image overall complex images based on principal component analysis proved to be the most useful products sandstone shale and siltstone the target lithologies koolpin formation the target stratigraphic unit and bleaching pattern due to the removal of iron ii compounds the target alteration pattern were confidently mapped to provide information required by the mineral emplacement model which ultimately identified areas of likely uranium mineralization thus the contrasting behavior of the two principle oxidation states of uranium and iron can be utilized to map delineate bleached alteration zones associated with economic concentrations of uranium using multispectral sensors like landsat or better hyperspectral sensors

quartzose mafic spectral feature space model a methodology for extracting felsic rocks with aster thermal infrared radiance data abstract the original spectral features of felsic rocks are often intermingled with other surface objects which results in difficulty of detecting felsic rocks using remote sensing techniques few felsic rock indices were proposed and visual interpretation with rgb false color composition is widely used to detect felsic rocks this paper aims to construct a two dimensional spectral feature space model to extract felsic rocks using aster thermal infrared radiance data the study area is located in northern qinghai province western china with average altitude of approximately 4200 m a large number of training pixels of mafic ultramafic rock quartz rich rock felsic rock carbonate rock and vegetation were selected from the aster images as samples of these surface objects then we used a quartz rich rock index qi qi band14 0 844 band12 1 897 and a mafic ultramafic rock index mi mi 0 915 band10 band13 1 437 to generate a two dimensional scatter plot the plot was named after quartzose mafic spectral feature space qmfs the samples show an approximate triangular shape in the qmfs mafic ultramafic rock quartz rich rock and carbonate rock are located in separate locations in the three vertex regions respectively while felsic rock is located in the central region of the triangle next we calculated a linear belt of silicate rocks in which silicate rocks vary regularly by using a linear regression analysis in the qmfs statistical characteristics of the felsic rock samples are analyzed afterwards a polygon which delineates the distribution of felsic rock samples was constructed from the linear belt of silicate rocks then we generated a system of inequalities based on the equations of the edges of the polygon the application of the inequalities to the aser images shows a good performance of the qmfs for extracting felsic rocks

geomorphic and tectonic process rates effects of measured time interval analysis of the original numerical components of diverse geomorphic and tectonic process rates indicates that process rate is not independent of measured time interval this implies that direct comparison of geologic process rates measured over variable time intervals may not be valid and that conclusions based on those comparisons regarding changes in rates through geologic time may be misleading in some cases calculation of statistically derived scaling functions is one approach that can be used to account for this measurement interval bias and to improve comparisons of geologic process rate data when this approach is used a 10 4 or 10 5 yr variation in the measured time interval accounts for approximately one order of magnitude change in the measured process rate the magnitude of the correction can substantially affect conclusions of studies that compare uncorrected process rates calculated from variable time intervals

the application of aster remote sensing data to porphyry copper and epithermal gold deposits abstract this paper reviews the performance characteristics of the advanced spaceborne thermal emission and reflection radiometer aster remote sensor the standard data products and applications of the most recently developed image processing methods applied to aster data as a tool for mapping hydrothermal alteration mineral zones associated with porphyry copper and epithermal gold mineralization and related host rock lithology hydrothermal alteration zones associated with porphyry copper deposit such as phyllic argillic and propylitic mineral assemblages can be discriminated from one another by virtue of their spectral absorption features which are detectable by aster swir spectral bands the identification of the phyllic zone is important in the initial stages of porphyry copper exploration as an indicator of high economic potential for copper mineralization two new crosstalk corrected aster swir reflectance products including ast 07xt and refl1b are more reliable than previous aster data products for regional mineral mapping without use of additional spectral data from the site for calibration four types of algorithms were used to extract spectral information of aster data 1 band ratio indices and logical operator based methods 2 principal components and enhancement based methods such as principal component analysis pca and minimum noise fraction mnf 3 shape fitting based algorithms such as spectral angle mapper sam matched filtering mf and mixture tuned matched filtering mtmf and 4 partial unmixing methods such as linear spectral unmixing lsu and constrained energy minimization cem this review emphasizes that the logical operator algorithms can be best suited for hydrothermal alteration mineral mapping including phyllic and argillic zones associated with porphyry copper mineralization in a regional scale shape fitting based and partial unmixing algorithms are robust and reliable for detecting particular mineral and mineral assemblages in hydrothermal alteration zones in a district scale consequently the integration of the results derived from the logical operator shape fitting based and partial unmixing algorithms can produce comprehensive and accurate information for the reconnaissance stages of copper and gold exploration at both regional and district scales all of the methods and applications reviewed in this paper demonstrate the utility of aster data for exploration of the porphyry copper and epithermal gold deposits around the world

analysis of hot springs and associated deposits in yellowstone national park using aster and aviris remote sensing the advanced spaceborne thermal emission and reflection radiometer aster and the airborne visible ir image spectrometer aviris data were used to characterize hot spring deposits in the lower midway and upper geyser basins of yellowstone national park from the visible near infrared vnir to thermal infrared tir wavelengths field observations of these basins provided the critical ground truth for comparison with the remote sensing results fourteen study sites were selected based on diversity in size deposit type and thermal activity field work included detailed site surveys such as land cover analysis photography global positioning system gps data collection radiometric analysis and vnir spectroscopy samples of hot spring deposits geyser deposits and soil were also collected analysis of aster data provided broad scale characteristics of the hot springs and their deposits including the identification of thermal anomalies aviris high spectral resolution short wave infrared swir spectroscopy provided the ability to detect hydrothermally altered minerals as well as a calibration for the multispectral swir aster data from the image analysis differences in these basins were identified including the extent of thermal alteration the location and abundance of alteration minerals and a comparison of active near extinct and extinct geysers we determined the activity level of each region using a combination of the vnir swir tir spectral differences as well as the presence of elevated temperatures detected by the tir subsystem of aster the results of this study are applicable to the exploration of extinct mineralized hydrothermal deposits on both earth and mars

thermal infrared exploration in the carlin trend northern nevada experimental thermal infrared multispectral scanner tims aircraft data have been acquired for the rodeo creek ne 7 1 2 minute quadrangle eureka county northern nevada covering the carlin gold mine a simple model has been developed to extract spectral emissivities for mapping surface lithology and alteration based on the physical properties of geologic materials emissivity ratio images were prepared that allow generalized lithologic discrimination identification of areas with high silica content and the first reported detection of the carbonate secondary reststrahlen feature together with thermal inertia images they permit identification of areas of subtle lithologic variation not shown on conventional geologic maps emissivity ratio spectra extracted from the data compare favorably with modeled laboratory spectra and establish for the first time the link among theory measured physical properties and color composited tims images identification of previously unknown silicification in the terti

underwater hyperspectral imaging using a stationary platform in the trans atlantic geotraverse hydrothermal field underwater hyperspectral imaging is a relatively new method for characterizing seafloor composition to date it has been deployed from moving underwater vehicles such as remotely operated vehicles and autonomous underwater vehicles while moving vehicles allow relatively rapid surveying of several 10 1000 m2 they are subjected to short term variations in vehicle attitude that often compromise image acquisition and quality in this study we tested a stationary platform that was landed on the seabed and used an underwater hyperspectral imager uhi on a vertical swinging bracket the imaged seafloor areas have dimensions of 2 3 m times 1 m and are characterized by very stable uhi data of high spatial resolution the study area was the trans atlantic geotraverse hydrothermal field at the mid atlantic ridge 26 n in water depths of 3530 3660 m uhi data were acquired a 12 stations on an active and an inactive hydrothermal sulfide mound based on supervised classification 24 spectrally different seafloor materials were detected including hydrothermal and non hydrothermal materials and benthic fauna the results show that the uhi data are able to spectrally distinguish different types of surface materials and benthic fauna in hydrothermal areas and may therefore represent a promising tool for high resolution seafloor exploration in potential future deep sea mining areas

quantitative estimation of granitoid composition from thermal infrared multispectral scanner tims data desolation wilderness northern sierra nevada california we have produced images that quantitatively depict modal and chemical parameters of granitoids using an image processing algorithm called minmap that fits gaussian curves to normalized emittance spectra recovered from thermal infrared multispectral scanner tims radiance data we applied the algorithm to tims data from the desolation wilderness an extensively glaciated area near the northern end of the sierra nevada batholith that is underlain by jurassic and cretaceous plutons that range from diorite and anorthosite to leucogranite the wavelength corresponding to the calculated emittance minimum min varies linearly with quartz content sio2 and other modal and chemical parameters thematic maps of quartz and silica content derived from min values distinguish bodies of diorite from surrounding granite identify outcrops of anorthosite and separate felsic intermediate and mafic rocks

recent morphological evolution of the lower mississippi river abstract this study documents slope and stream power changes in the lower mississippi river during the pre cutoff 1880s 1930s and post cutoff 1943 1992 periods the study reach extends from new madrid mo to natchez ms a distance of about 900 km analyses for six major reaches and 13 sub reaches for the pre and post cutoff periods indicate that the river presently has a much larger slope and stream power than prior to the cutoffs the largest increases have occurred between fulton tn and lake providence la where slope and stream power increases range from about 27 to 36 and 20 to 38 respectively increases in slope and stream power in reaches upstream and downstream have also occurred but to a lesser degree previous investigations have shown that no coarsening of the bed material has occurred since 1932 and that the bed material may actually be somewhat finer overall as the lower mississippi river is not a sediment starved system an increase in stream power with no change in d50 would be expected to be offset by an increase in the bed material load as the river adjusts towards equilibrium previous investigators have inferred a reduction in the sediment loads on the mississippi river this century based on analyses of total measured suspended loads however these results should be viewed as primarily representing the changes in wash load and should not be taken to imply that bed material loads have also decreased therefore the bed material loads in the study reach should be greater than in the pre cutoff period excess stream power in the sub reaches directly affected by cutoffs resulted in scour that increased downstream bed material load these elevated sediment loads play a key role in driving morphological adjustments towards equilibrium in the post cutoff channel the stability status of the channel in the study reach currently ranges from dynamic equilibrium in the farthest upstream reaches through severe degradation to dynamic equilibrium in the middle reaches and aggradation in the lowest reaches these evolutionary trends cannot be explained by consideration of changes in slope and stream power alone changes in the incoming bed material load to each reach generated by upstream channel evolution must also be considered

characterization of indicator tree species in neotropical environments and implications for geological mapping abstract geobotanical remote sensing gbrs in the strict sense is an indirect approach to obtain geological information in heavily vegetated areas for mineral prospecting and geological mapping using ultra and hyperspectral technologies the goals of this research comprise the definition and mapping of neotropical tree species that are associated with geological facies here called geo environments as well as their spectral discrimination at leaf and crown scales this work also aims to investigate the possible relationship between leaf and crown spectral and chemical properties the study was developed at the mogi guacu ecological station in the cerrado domain southeastern brazil data from 70 sample units such as sediment texture and species from inventories were first analyzed through vectorial quantization using self organizing maps som principal component analysis and spearman s ranked correlation coefficients were used to define geo environments and target species respectively biochemical and visible to shortwave infrared vswir point spectral data 350 2500 nm were collected from the leaves of the target species during both rainy and dry seasons spectral data from target species crowns were obtained from hyperspectral images 530 2 532 nm prospectir vs sensor with 1 m spatial resolution and acquired in the beginning of the dry season these spectra were classified using multiple endmember spectral mixture analysis mesma with two endmembers ems based on the mesma results with two ems the best dataset per target species was chosen for pixel based image unmixing with three ems target species other vegetation types and shade from 121 species sampled in the field two proved to be associated with floodplains alluvial deposits sequence two with hills and plateaus of the aquidauna formation carboniferous sedimentary rocks parana basin and two more with a specific facies of the aquidauna formation that has a distinctive presence of coarse and very coarse sand five target species were well discriminated at the leaf scale reaching 90 0 and 85 0 of global accuracies in the rainy season and in the dry season respectively accurate spectral discrimination appears to be linked to the considerable biochemical variability of their leaves in both seasons three species were discriminated at the crown scale with 70 6 of global accuracy when eight other landscape scale vegetation classes were included in the analyses only qualea grandiflora mart produced a satisfactory accuracy 61 1 and 100 of producer and user s accuracies respectively the spatial distribution of its fraction in the unmixed image particularly matches with the geological facies to which it was associated in the field ecological requirements for successfully mapping indicator species include broad and random distribution of the target species population and singular physiological phenological and spectral behavior at the imagery acquisition date our study shows that even in tropical conditions it is possible to use plant species mapping to support geological delineation where rock exposures are typically rare

first hyperspectral imaging survey of the deep seafloor high resolution mapping of manganese nodules abstract hyperspectral seafloor surveys using airborne or spaceborne sensors are generally limited to shallow coastal areas due to the requirement for target illumination by sunlight deeper marine environments devoid of sunlight cannot be imaged by conventional hyperspectral imagers instead a close range sunlight independent hyperspectral survey approach is required in this study we present the first hyperspectral image data from the deep seafloor the data were acquired in approximately 4200 m water depth using a new underwater hyperspectral imager uhi mounted on a remotely operated vehicle rov uhi data were recorded for 112 spectral bands between 378 nm and 805 nm with a high spectral 4 nm and spatial resolution 1 mm per image pixel the study area was located in a manganese nodule field in the peru basin se pacific close to the discol disturbance and recolonization experimental area to test whether underwater hyperspectral imaging can be used for detection and mapping of mineral deposits in potential deep sea mining areas we compared two supervised classification methods the support vector machine svm and the spectral angle mapper sam the results show that svm is superior to sam and is able to accurately detect nodule surfaces the uhi therefore represents a promising tool for high resolution seafloor exploration and characterisation prior to resource exploitation

analyses and monitoring of lignite mining lakes in eastern germany with spectral signatures of landsat tm satellite data abstract coal mining activities cause an increased acidity and an associated decrease of the ph value in mine waters this process is also known as acid mine drainage amd due to amd lakes that were formed in the post mining landscapes in the lignite mining area of central germany are characterized by specific limnological development changes remote sensing is a time and cost saving technique that enables the observation of the hydrological and limnological development of the lakes ranging from a small to a mid size scale the current research was based on landsat tm5 etm 7 satellite data collected between 1999 and 2004 in combination of satellite data surface waters of the post mining lakes in central germany were sampled and analyzed for their physicochemical properties the objective of this approach was to evaluate the environmental conditions and to develop a monitoring system on the other hand the research was conducted to assess the potential of the use of satellite data and to calibrate its content for monitoring the geochemistry of mining lakes correlation of hydrochemical parameters of lake water to spectral signatures detected by satellites was performed with multivariate statistical analysis methods the five determined clusters of spectral partitions described the actual data ground truth data within the visible range the statistically identified clusters were combined with expert knowledge in limnology geology and water chemistry of large scale lakes in open cast mining areas in order to analyze the spectral information of the satellite images scientifically the utilization of spectral signatures revealed an acceptable classification of hydrological and hydrochemical properties of mining lakes and established the basis for further investigation of open cast lignite mining concerning the environmental impact particularly in areas where lignite mining lakes usually form

aster spectral analysis for alteration minerals associated with gold mineralization abstract this study presents classifications of advanced spaceborne thermal emission and reflection radiometer aster imagery based on spectral analysis of alteration minerals associated with gold mineralization in abo marawat area which is located in the central eastern desert of egypt spectral analysis of continuum removed reference spectra of alteration minerals alunite kaolinite sericite and calcite from usgs and jpl spectral libraries show shifts in position shape and strength most probably related to changes in sample purity and particle size of analyzed samples spectral information divergence sid classification method proved successful for mapping sericite calcite and clay minerals spectral angle mapper sam classification identified only sericite and calcite alteration minerals the identified alteration zones are coincidence with the field sampling and geological map of the study area the microscopic examination of samples collected from the quartz veins and hydrothermally altered wall rocks from near surface and subsurface at abu marawat gold mine shows sericitization argillaceous and carbonatization alteration zones gold occurs as very fine inclusions in pyrite chalcopyrite and sphalerite and also found filling the fractures between chalcopyrite grains this study concludes that aster image classifications using reference spectra are a stable and reproducible technique for mapping gold related hydrothermal alteration zones in areas with no dominant vegetation cover

integration of k ar geochronology and remote sensing mapping volcanic rocks and constraining the timing of alteration processes al lajat plateau syria abstract the al lajat plateau southern syria is a quaternary volcanic field hosting numerous historical and archaeological sites based on the integration of k ar geochronology and remote sensing methods a new map is presented for al lajat plateau volcanic field and a chronological model for alteration processes such as weathering in relation to quaternary paleoclimatic changes potential use of the geological data in archaeological investigations is discussed the alteration patterns of ferric ferrous and clay minerals were identified by using landsat enhanced thematic mapper data etm methods and ratio images of 3 1 5 4 and 5 7 principal components analysis pca combined with crosta technique interpretation was used to gauge the response of weathered minerals using this technique high concentrations of ferrous minerals appear brightly colored in the third axis of the principal components analysis pc3 while oxides show the opposite in pc4 composite images consisting of ratio images 3 1 4 5 and 5 7 shown in blue green and red respectively appear to be the most useful for mapping the lithologic boundaries of the main lava flows based on new k ar ages the timing of the volcanic activity appears to have been between 56 9 ka and 266 6 ka three distinct groups of ages can be identified confirming the sequence of the basaltic units defined by remote sensing 1 the youngest unit belongs to tyrrhenian between 71 ka and 56 ka 2 the intermediate unit pre tyrrhenian to tyrrhenian between 114 ka and 139 ka and 3 the oldest basaltic unit surrounding the al lajat plateau is dated to at least 266 ka a chrono alteration model highlights the role of climatic changes in the distribution of the minerals at the surface of the volcanic rocks as a function of the ages weathering conditions during the post glaciation phase are responsible for clay removal in the study area integrating dating and remote sensing data are important for mapping the location and timing of past volcanic activity but can also be used to identify the sources of archaeological tools and architecture in volcanic areas such as the al lajat plateau

recent advances in the use of public domain satellite imagery for mineral exploration a review of landsat 8 and sentinel 2 applications abstract thanks to their wide coverage and the valuable spectral information remote sensing data constitute a popular instrument in the mineral exploration toolbox in recent times the remote sensing community has witnessed the launch of the new and improved landsat 8 and sentinel 2 multispectral sensors the former constitutes the eighth sensor of the landsat series launched by the national aeronautics and space administration nasa while the latter is linked to the sentinel mission launched by the european space agency esa the main objective of our contribution is to provide a comprehensive review of the use of the landsat 8 and sentinel 2 multispectral sensors in mineral exploration the free and open access to these data and their enhanced spectral and spatial characteristics compared to the existing multispectral sensors has clearly promoted the use of remotely sensed in mineral exploration in addition as illustrated by the case studies presented in this paper landsat 8 and sentinel 2 data present effective and accurate mapping tools for mineral exploration both sensors identified iron oxides and al oh absorption features in addition to silicate and carbonate minerals our review indicated that landsat 8 is by far the more popular sensor in mineral exploration applications greater uptake of sentinel 2 and further case studies will be necessary to better demonstrate its capabilities and potential

remote sensing of damavand volcano iran using landsat imagery implications for the volcano dynamics abstract remote sensing techniques are applied to retrieve land surface temperature lst radiative heat flux rhf geothermal heat flux ghf and to map hydrothermal alteration zones around the damavand stratovolcano iran landsat enhanced thematic mapper plus etm day and nighttime images are used and merged to available geological data to identify thermal anomaly areas rhf is determined using the stefan boltzmann equation after preprocessing geometric radiometric and atmospheric correction and processing emissivity calculation and lst retrieval of thermal infrared bands in order to estimate ghf from daytime image solar radiation and albedo maps are generated to minimize these effects the ghf values are derived from nighttime image using the background subtraction technique using boolean operation only those pixels with the ghf values greater than 30 w m 2 obtained from daytime image and the ghf values greater than 10 w m 2 estimated from nighttime image are identified as thermal anomalies the geothermal areas are identified by combining the thermal anomaly map and other geological information thermal anomalies have close spatial correlation to faults thermal springs and high heat flow measurements from subsurface data and lithology some of the thermal anomalies and hydrothermal alteration areas also overlap active deformation areas this suggests role of heat and hydrothermal alteration on flank instability processes the thermal anomaly areas show an arc shaped pattern this pattern and the concentration of higher ghf areas in the eastern sector of the volcano are consistent with a release of fluids in a transition zone between a transpressional and a transtensional tectonic regime the combination of thermal infrared data with other geological information layers can be used to detect geothermal areas as well as to analyze the complex relationships among geothermal activity active tectonics and gravity instability processes on volcanoes

rapid determination of coalbed methane exploration target region utilizing hyperspectral remote sensing abstract this study reveals the common surface mineral characteristics over coalbed methane cbm enrichment regions from spaceborne hyperion images and the possibility of hyperspectral remote sensing for prospecting coalbed methane exploration target region with an inexpensive large scale rapid and convenient way for this study a typical scheme including bands removal atmospheric correction snr estimation minimum noise fraction mnf pixel purity index ppi and n dimensional visualization was applied on hyperion image in qinshui basin china to accurately extract mineral endmembers the endmember spectra of carbonate and clay mineral were identified based on the diagnostic absorption feature while no endmember of ferrous iron mineral was found the absorption feature parameters of carbonate absorption position and especially asymmetric factor and clay mineral absorption position left and right shoulder positions were quantitatively estimated which showed the endmember spectra of carbonate and clay mineral from hyperspectral images in this paper were correct in addition this study proposed an interesting research direction measuring the asymmetric absorption factor to facilitate the identification of carbonates furthermore spectral angle mapper sam and spectral feature fitting sff were used to map carbonates and clay minerals two assessment methods visual interpretation based on field spectra and x ray diffraction xrd analysis were utilized to evaluate the mapping accuracy which showed total agreements of 84 03 and 72 58 respectively the results in this paper suggested that both carbonates and clay minerals were rich while there was hardly any ferrous iron mineral on the surface of cbm enrichment regions in addition another similar experiment was carried out in ordos basin and also showed similar surface mineral characteristics on cbm enrichment region

regional scale demarcation of alteration zone using aster imageries in south purulia shear zone east india implication for mineral exploration in vegetated regions abstract regional scale demarcation of alterations is an important preliminary step in mineral exploration advanced spaceborne thermal emission and reflection radiometer aster imageries here have been used for alteration mapping and iron rich e g gossans area demarcation in a highly vegetated and relatively unexplored part of eastern india namely south purulia shear zone spsz the area is surrounded by mineral rich singhbhum shear zone ssz but the mineral potentiality of spsz has not yet been proven alteration mineral assemblages are comprise of iron rich alteration gossan clay alteration with varying amounts of iron content sericitization ferruginization and chloritization in this paper we discuss a few advantages and limitations of commonly used satellite image processing techniques for mineral mapping we integrate the outputs of band ratio principal component analysis pca pca loading and thresholding termed as directed pca dpca for delineating mineral potential areas our approach mapped the alteration zones with overall 74 accuracy our study leads to demarcation of 28 alteration area within a 10 km wide and 60 km long stretch of spsz two areas namely lawa 23 1 39 31 n 86 4 2 55 e and sindurpur 23 4 38 30 n 86 5 3 99 e were identified as mineral potential zone samples from those areas were studied using xrf microscope and sem with the conclusive presence of mineralization lawa is potential for hydrothermal polymetallic sulfides along with gold mineralization sindurpur is potential for secondary iron and manganese mineralization the study shows that dpca is a useful tool for aster data processing for narrowing target area in preliminary stages of exploration in vegetated zones

temporal merging of remote sensing data to enhance spectral regolith lithological and alteration patterns for regional mineral exploration abstract remote sensing has been widely used to map geological structure regolith materials and hydrothermal alteration minerals in different regions of the world based largely on the spectral characteristics of clay carbonate and iron oxide minerals given that features related to minerals may form very subtle patterns in landsat imagery finding suitable methods for enhancing the spectral information due to alteration minerals has been the subject of much research since the satellites were launched although multispectral sensors such as landsat do not have enough spectral resolution to distinguish between specific minerals effective processing of the data does yield useful images for regional exploration and targeting when combined with a good understanding of the associated landforms aster and various airborne systems can now provide useful high resolution mineral information however the cost and time taken to acquire and process good resolution spectral data should now be balanced against the enhanced spectral discrimination possible using temporal merging or data stacking from the existing landsat data archive dating back to 1972 one critical characteristic of the spectra related to surface mineral composition is its persistence over time this study proposes a further enhancement to the data using temporal merging to create images that are both easier to interpret and more reliable indicators of lithology and alteration the new approach is to select a large number of scenes typically separated by two or more years and to merge the data for each band to give a cumulative spectral signature the technique of stacking landsat data to create a new dataset with much greater spectral depth is termed landsat tm3 or landsat tm temporal merge for terrain mapping this emphasises not only the process used to create the dataset but also the dominant use to which these data are ideally suited namely mapping geological and mineral related terrains

how can satellite imagery be used for mineral exploration in thick vegetation areas the hokuroku district northern japan is globally recognized for rich ore deposits kuroko and vein types which have been thoroughly explored under thick vegetation cover this situation is ideal to evaluate the effects of ore deposits on vegetation anomalies through geobotanical remote sensing here we present novel methods to detect vegetation anomalies caused by ore deposits and verify their usefulness by comparing the anomalies with a deposit potential map produced from multiple geological data we use the reflectance spectra of landsat etm images acquired in summer and autumn to calculate a vegetation index for plant physiological activity a key variable to detect the anomalies is a variation of vegetation index with time at each pixel difference in variation is enlarged by a sequence of image enhancement methods for the detection we find that the vegetation anomalies defined by the large ratios correspond well to the high potential zones of ore deposits and known major deposits consequently our methods can extend the applicability of remote sensing based mineral exploration to the areas covered by thick vegetation in addition to traditional arid and semi arid areas this article is protected by copyright all rights reserved

mineralization controls and source of metals in the lufilian fold belt shaba zaire zambia and angola the pan african lufilian fold belt hosts extensive and rich polymetallic mineralization dominated by cu co and zn pb sulfides u oxides and noble metals stratiform vein and skarn deposits are present in the late proterozoic rocks of the katangan supergroup mineralization is regionally widespread the sedimentary basin evolution included three phases the first two characterized by rift fault controlled rapid subsidence followed by slower thermal subsidence were associated with bimodal magmatism and probably related to two thermal events the third phase reflects the onset of tectonic deformation and uplift in the southern part of the basin the stratiform mineralization emplaced before the folding of the basin is concentrated in lithologically varied permeable rocks of the roan group that underlie the impermeable rocks of the lower kundelungu group the stratiform mineralization was emplaced by convective circulation of basinal brines forced by a thermal gradient created by a wedge shaped lithosome of lower kundelungu pelitic rocks with low thermal conductivity hypabyssal igneous intrusions and volcanic and volcaniclastic rocks were the source of metals the metals were introduced to the aquifer horizons saturated with basinal brines by hydrothermal circulation associated with the hypabyssal intrusions and by compactional dewatering of a 5 000 m thick body of pelitic rocks rich in volcaniclastic material vein mineralization located on major late faults resulted from regional metamorphism driven dewatering of the folded basin the skarn metasomatic mineralization is associated with small post katangan acid intrusions and blocks of thermally rejuvenated basement details of the distribution of mineralization are stratigraphically and structurally controlled

regional mineral mapping of island arc terranes in southeastern mongolia using multi spectral remote sensing data abstract over the last few decades many porphyry cu deposits have been discovered in southeastern se mongolia in particular the gurvansayhan and mandalovoo island arc terranes have high potential for ore deposits regional mineral mapping of these terranes using data from the landsat enhanced thematic mapper plus etm and the advanced spaceborne thermal emission and reflection radiometer aster have provided new geological information on the metallogenic province revealing potential mineral deposits for future explorations iron oxides hydroxides with high etm band 1 3 ratio values occur extensively in quaternary deposits located at the boundary between the gurvansayhan and mandalovoo island arcs terranes and basins the high average band ratios 1 35 registered for the porphyry cu and au deposits and their occurrences are associated with iron oxidation which originates from the erosion and weathering of ore zones regional mapping of the island arc terranes using the aster shortwave infrared swir logical operators showed circular or semicircular alteration patterns which usually cluster along faults the mineral assemblages mapped by the aster swir analysis in five major porphyry cu districts can be divided into two types the first type includes argillic phyllic and propylitic mineral assemblages as exemplified by the shuteen ikh shankhai and oyu tolgoi deposits the second type of assemblage includes phyllic and propylitic mineral assemblages as exemplified by the kharmagtai and tsagaan suvarga deposits within the deposits of the first type quartz was also mapped using the aster thermal infrared tir mineral index the difference between the two types may be related to the presence of a lithocap the results of a field survey including spectral reflectance measurements in the ikh shankhai porphyry cu district showed a good correlation with the image analysis results

recognizing propylitic alteration associated with porphyry cu mo deposits in lower greenschist facies metamorphic terrain of the collahuasi district northern chile implications of petrographic and carbon isotope relationships the collahuasi district is a porphyry cu mo subprovince located on the andean high plateau of northern chile late eocene early oligocene mineralization in the district involved hydrothermal alteration of the upper paleozoic to lower triassic collahuasi group granodiorites diorites andesites dacites and rhyolites which had previously experienced regional lower greenschist facies metamorphism as well as uneconomic porphyry style mineralization and associated sericitic alteration alteration mapping represents an effective technique for prospecting for hydrothermal deposits but in low grade metamorphic terrains recognition of propylitic assemblages that represent the boundary of the mineralizing system is hampered by their resemblance to metamorphic mineral assemblages our results from collahuasi indicate that petrographic criteria can distinguish propylitic alteration from the effects of lower greenschist facies metamorphism but distinctions vary with rock type mafic intermediate and felsic rocks with varying degrees of propylitic alteration can be distinguished from background metamorphism mainly by the presence of calcite however propylitic alteration can also be distinguished by high whole rock 13c values and carbon contents 19 1 to 1 4 and up to 0 79 wt respectively that result from the incorporation of magmatic co2 during the mineralizing events lower 13c values 32 7 to 13 1 and carbon contents 0 09 wt were recorded in other types of hydrothermal alteration intermediate argillic sericitic and potassic alteration and associated with background metamorphism they reflect a dominantly 13c depleted carbon component that remains in the rocks after extensive co2 degassing during emplacement alteration by hydrothermal fluids or contamination by organic carbon carbon and oxygen isotope compositions of calcite from propylitic alteration which range from 12 to 0 3 and 6 6 to 25 9 respectively are consistent with a predominantly magmatic origin for the carbonates although subsequent resetting of the oxygen isotopes by local ground water and minor contributions of organic carbon are recorded in some samples spatial variation in 13c values and carbon contents of outcrop samples from the collahuasi district delineate zones of high magmatic co2 component that correspond exclusively to propylitic alteration surrounding economic deposits

determining hematite content from nuv vis nir spectra limits of detection hematite occurs in various geologic settings including igneous metamorphic and sedimentary rocks as well as in soils however it frequently occurs at low concentrations especially in soils where it may be 1 by weight because hematite has the potential to be an indicator of oxidizing and climatic conditions in soils and paleosols it is important to understand its limit of detection in this paper we examine the limits of detection of hematite visually and with diffuse reflectance spectrophotometry drs and x ray diffraction xrd to accomplish this we used a sample set consisting of knowns or calibration samples these known samples consisted of 15 different matrices of varying mineral composition into which hematite in 7 different concentrations ranging from 0 01 to 4 by weight were mixed including the 0 hematite our calibration data set consisted of 120 samples visually hematite can be detected at a concentration of 0 01 by weight in a light matrix and 0 5 in the darkest of our matrices however because of metamerism visual techniques cannot specifically identify hematite we find that for both drs and xrd the limit of detection is also dependent on the matrix for xrd the limit of detection for hematite in bulk samples is about 1 for drs the limit of detection depends on the data reduction technique used the commonly used kubelka munk remission function and its first and second deriva tives can easily identify hematite at the 0 5 level however the first derivative of the percent reflectance curve can detect hematite at 0 01 by weight in a light matrix and 0 05 in a dark matrix we suggest that the first derivative of drs curves is the best currently available method for qualitatively detecting the mineral hematite at low concentrations found in soils sediments and rocks work described in this paper may be applied in several situations our study of visual limits of hematite detection should aid field geologists in assessing hematite content analysis of color wave length bands may also have application in remote sensing by indicating which bands are most sensitive to hematite reported to be an important constituent of the martian surface furthermore this study could help clarify remotely sensed terrestrial albedo changes especially the sahara sahel transition where the sediments change from light quartz dominated to dark hematite dominated our study also points out that with laboratory based spectra the first derivative of the reflectance curve is the most sensitive transform for processing spectral data for hematite thereby allowing concentrations as low as 0 01 to be detected

structural mapping using palsar data in the central gold belt peninsular malaysia abstract the central gold belt cgb of peninsular malaysia has been investigated to map structural elements associated with gold mineralization using the phased array type l band synthetic aperture radar palsar satellite remote sensing data gold mineralization in this belt is structurally controlled and associated with steeply dipping faults and fold hinges adaptive local sigma and directional filters were applied to palsar data for tracing structural elements associated with gold mineralization structural features along the bentong raub suture zone have been identified as highly potential areas for gold prospecting four sets of lineaments trending n s ne sw nnw sse and ese wnw were identified results of this study demonstrate the applicability of palsar remote sensing data to assist gold exploration in the cgb particularly in reducing costs related to exploration for epithermal and polymetallic vein type mineralization in tropical environments

comparison of remote sensing observations of planetary wind streaks abstract wind streaks are common aeolian features observed on terrestrial planets they were first identified on mars thus the associated terminology is based on mars related observations usually describing surface patterns with distinct albedos however terms related to reflected tones are only relevant to past knowledge for mars and not necessarily suitable for description of radar visible streaks located on venus titan or earth furthermore the sensor type used to observe wind streaks can influence the subsequent data analysis the purpose of this study was to examine the effects of sensor type on wind streak identification and interpretation six case studies featuring wind streaks on earth were performed using imaging by both radar and optical sensors the results indicate that wind streak identification is constrained to a specific combination of sensor settings appropriate for the local surface properties only half the optically visible wind streaks considered in this study were also radar visible but all the wind streaks observable in the radar images also appeared in the optical images furthermore bright and dark reflectance and backscatter are relative terms and should be used with caution these results suggest that the venusian wind streak database is most likely far from complete and that many more streaks exist

laser scanning and digital outcrop geology in the petroleum industry a review abstract the use of lidar light detection and ranging systems for modelling petroleum reservoir analogues has become increasingly popular over the past few years and there has been a proliferation of articles on the subject both on techniques and applications a review of the literature of recent years has been conducted focussing on the use of lidar data not only in petroleum geology related projects but also looking to the wider field of lidar usage to examine what other approaches may be of use to the petroleum geologist benefits of digital data acquisition are considered as well as a basic overview of data collection approaches use of a variety of attributes intensity colour dip azimuth co linearity co planarity among others is discussed as an aid to both manual and automated interpretation approaches integration of lidar data with other data types from traditional field data sedimentary logs for example and other digital data types such as multispectral and hyperspectral imagery and ground penetrating radar are discussed as a way of increasing the amount of information in the digital dataset the application of artificial intelligence approaches such as smart swarms and neural networks are considered as well as current developments in both hardware and software a variety of examples are given where lidar has been used in an innovative or interesting way showing the strength of this data acquisition approach when combined with appropriate interpretation and modelling techniques

detecting subtle alteration information from aster data using a multifractal based method a case study from wuliang mountain sw china abstract remote sensing has been widely used to interpret hydrothermal alteration zones and it can support the geological field mapping which is very useful for mineral exploration in inaccessible regions however the alteration information in covered terrains is usually not strong enough to be detected using traditional remote sensing methods so how to efficiently detect subtle alteration information remains a challenging task in this study the multifractal theory based spectrum area s a method is used for the processing of remote sensing data and the new method of principal component analysis pca s a is proposed as a tool to interpret hydrothermal alteration beneath covered areas in order to test the efficiency of this method the pca s a method was compared with the traditionally used pca method based on advanced spaceborne thermal emission and reflection radiometer aster data the wuliang mountain in the yunnan province of sw china a rugged terrain with high altitudes and dense vegetation coverage was selected as a case study to detect information on chlorite epidote biotite and muscovite alteration respectively the following field survey and petrographic studies reveal that 1 the average detection accuracy of the pca s a method is 90 80 9 34 higher than that of the pca method 2 in the covered areas where the traditional pca method cannot detect any subtle hydrothermal alteration the pca s a method can be successfully applied and 3 in those areas where the fractional vegetation cover fvc is greater than 0 8 the detection of subtle hydrothermal alteration using the proposed method is inefficient which requires further studies

geologic interpretation of space shuttle radar images of indonesia the national aeronautics and space administration nasa space shuttle mission in november 1981 acquired images of parts of the earth with a synthetic aperture radar system at a wavelength of 23 5 cm 9 3 in and spatial resolution of 38 m 125 ft this report describes the geologic interpretation of 1 250 000 scale images of irian jaya and eastern kalimantan indonesia where the all weather capability of radar penetrates the persistent cloud cover the inclined look direction of radar enhances subtle topographic features that may be the expression of geologic structures on the indonesian images the following terrain categories are recognizable for geologic mapping carbonate clastic volcanic alluvial and coastal melange and metamorphic as well as undifferentia ed bedrock regional and local geologic structures are well expressed on the images in the vogelkop region of irian jaya the major tectonic elements tamrau mountains sorong fault kemum block bintuni basin and lengguru foldbelt are readily mapped on the image of the sorong fault geomorphic features offset drainage shutterridges aligned notches provide clear evidence for left lateral strike slip displacement several lineaments on the image correlate with previously mapped faults other lineaments may be the expression of previously unrecognized faults on the image of the mainland of irian jaya a belt of metamorphic and melange terrain marks the zone of collision between the pacific plate and the australian plate the high central range of irian jaya is located south of the metamorphic and melange belt the generally homoclinal structure of the central range is interrupted in the paniai lake region by a series of southward directed thrust plates indicated by belts of carbonate terrain new guinea limestone group that alternate with belts of clastic terrain kembelangan formation in the image of eastern kalimantan several major foldbelts are clearly expressed these limited examples of space shuttle radar images demonstrate their value for geologic interpretation of indonesia it is recommended that future shuttle missions acquire complete radar coverage of the main islands of indonesia for use in geologic mapping and energy exploration shuttle radar images would also be valuable for other cloud covered forested regions

remote sensing detection of heavy oil through spectral enhancement techniques in the western slope zone of songliao basin china landsat 7 enhanced thematic mapper plus etm imagery was used to identify anomalous areas caused by hydrocarbon leakage in fula erji in the western slope of songliao basin china three image enhancement techniques including principal component analysis pca band ratioing and false color composition fcc were used based on the spectral characteristics of hydrocarbon induced minerals and the eigenvectors of pca the best four principal components pcs 1345 pc3 the third component of the pca on bands 1 3 4 and 5 1357 pc3 3457 pc4 and 123457 pc4 were selected for fcc combined with band ratios of 3 1 4 3 and 7 5 according to the tonal characteristics of the surface near wells and their visual expression four fcc images were acquired for hydrocarbon induced area delineation the result indicates that anomalies are expressed as a faint tone blob and are mostly located in the holocene sediments an analysis of two cross sections traversing the identified anomalies suggests that they are closely related to the anomalous area interpreted from the four fcc images field data of magnetic susceptibility and delta carbonate are consistent with the distribution of the tonal anomalies and suggest a positive spatial association between the identified anomalous area and the hydrocarbon leakage environment

aster detection of chromite bearing mineralized zones in semail ophiolite massifs of the northern oman mountains exploration strategy abstract economically viable chromite deposit occurrences are widespread in the ultramafic rocks of semail ophiolite massifs of the northern oman mountains particularly in the basal dunite and harzburgite unit of the mantle section geological mapping of this region is challenging primarily due to difficult access complexity of structures and lack of resolution and areal integrity of lithological differentiation using conventional mapping techniques the present research study evaluates the discrimination and occurrence of chromites bearing mineralized zones within ophiolites by analyzing the capabilities of landsat tm and advanced spaceborne thermal emission and reflection radiometer aster satellite data using a number of selected methods including decorrelated stretching different band rationing and principal component analysis image processing techniques exist in the scientific literature the study results show that the processed vnir and swir spectral wavelength regions are promising in detecting the areas of potential chromite bearing mineralized zones within the ophiolite region and proved to be successful for mapping of serpentinized harzburgite containing chromites exploration geologists industrialists and mine owners are advised to adopt this technique and avoid the limits in filed data alone for more exploration and exploitation of areas having chromite deposits in arid region elsewhere

hydrothermal alteration mapping at bodie california using aviris hyperspectral data abstract aviris data covering the bodie and neighboring paramount mining districts eastern california were used to map hydrothermal alteration minerals two spectral analysis algorithms were used spectral angle mapper sam and tricorder the objective was to compare the performance of the two algorithms where no a priori ground or atmospheric information is available aviris data were calibrated to apparent surface reflectance using a modified modtran radiative transfer model in conjunction with laboratory and in flight calibration data both algorithms appear to produce satisfactory results for geologic reconnaissance and mapping applications but tricor der generally classified more pixels and identified more mineral species than sam for some minerals such as na montmorillonite results from tricorder and sam matched reasonably well but major differences appeared in how the two algorithms classified kaolinite group minerals and ferric oxides laboratory spectra of rock samples from five localities were compared to reference spectra of minerals identified by the classification algorithms for corresponding pixels with the results matching to some extent

controls on mineral deposit occurrence inferred from analysis of their spatial pattern and spatial association with geological features in this paper point pattern analysis fractal analysis and fry analysis were employed to study the spatial pattern of known occurrences of mineral deposits of the type sought whereas distance distribution method was applied to study the spatial associations between various geological features and known occurrences of mineral deposits of the type sought in the aroroy district philippines the results of the applications of these spatial analytical techniques support a conceptual model of district scale mechanism of geologic controls on low sulphidation epithermal au mineralization which involves a more or less regular mesh of interlinked zones of extension faults fractures at and or around intersections of nnw and nw trending strike slip faults fractures integration of spatial evidential data layers representing these structural controls and surficial geochemical anomalies via knowledge guided application of data driven evidential belief functions results in delineation of prospective areas occupying about 25 of the district in which there is about 70 likelihood of undiscovered occurrences of low sulphidation epithermal au deposits

geological control of massive sulfide mineralization in the neoproterozoic wadi bidah shear zone southwestern saudi arabia inferences from orbital remote sensing and field studies abstract this study combines new field and orbital remote sensing data to determine geologic controls on sulfide mineralization in the wadi bidah mineral district wbmd located in the neoproterozoic 900 550 ma arabian shield of southwestern saudi arabia the brittle and ductile deformation of these massive sulfide deposits and host rock reflect tectonic events occurring in the arabian shield during the neoproterozoic 900 550 ma remote sensing data were used in conjunction with gis software arcview to map lithologic units and mineral deposits analyze and define regional structural trends and establish geologic controls on sulfide mineralization orbital remote sensing data sets include scenes from landsat 7 and aster the sulfide deposits of the wbmd are found within a group of felsic volcaniclastics a marble unit within the felsic volcaniclastic group is used as a marker horizon based on the distribution of the sulfide deposits relative to the marble unit all sulfide deposits appear to be stratabound deposits have been folded and faulted into their present positions structural control of mineralization appears to be limited to post mineralization folding and shearing

remote sensing for mineral exploration abstract remote sensing is the science of acquiring processing and interpreting images and related data acquired from aircraft and satellites that record the interaction between matter and electromagnetic energy remote sensing images are used for mineral exploration in two applications 1 map geology and the faults and fractures that localize ore deposits 2 recognize hydrothermally altered rocks by their spectral signatures landsat thematic mapper tm satellite images are widely used to interpret both structure and hydrothermal alteration digitally processed tm ratio images can identify two assemblages of hydrothermal alteration minerals iron minerals and clays plus alunite in northern chile tm ratio images defined the prospects that are now major copper deposits at collahuasi and ujina hyperspectral imaging systems can identify individual species of iron and clay minerals which can provide details of hydrothermal zoning silicification which is an important indicator of hydrothermal alteration is not recognizable on tm and hyperspectral images quartz has no diagnostic spectral features in the visible and reflected ir wavelengths recorded by these systems variations in silica content are recognizable in multispectral thermal ir images which is a promising topic for research

remote sensing for porphyry copper deposits in southern arizona landsat multispectral scanners landsat 4 thematic mapper three porphyry copper deposits used as test sites landsat data useful for delineating areas of iron oxide on the surface limited spatial resolution of mss hampered mapping of some critical geologic relationships synoptic view well suited for examining regional tectonic patterns landsat 4 thematic mapper is an improved mapping tool compared to the previous landsat scanners modified journal abstract

forest savanna boundary shift on the plateau of serra sul dos carajas southeastern amazonia since the mid holocene driving forces and limiting factors abstract the vegetation history of the savanna on the plateau of serra sul dos carajas pssc is well studied by three palynological records nonetheless there is no record from the forests around this plateau so that the long term forest savanna boundary shift can be investigated in this study a sediment core taken from the forests on the slopes of the plateau is studied using a multi proxy analysis the palynological result is compared with the records from adjacent savanna this study reveals that well established forests have been present around the plateau during the last 6600 cal yr bp since the mid holocene owing to a change to favorable climatic conditions forests started to move toward the savanna and after 3400 4000 years reached their modern borders in the savanna region because during this long period forest borders moved horizontally a relatively short distance ca 250 m we concluded that there might be limiting factors that delayed forest expansion among different possible factors fire and human may play an important role however the evidence suggests that the slow process of soil formation to produce a soil layer with sufficient depth is the main limiting factor that delayed the forest expansion according to the previous hydroclimatic and palaeo ecological studies the southward displacement of inter tropical convergence zone itcz is more likely the trigger of forest expansion in the area since the mid holocene

prospectivity for epithermal gold silver deposits in the deseado massif argentina previous prospectivity modelling for epithermal au ag deposits in the deseado massif southern argentina provided regional scale prospectivity maps that were of limited help in guiding exploration activities within districts or smaller areas because of their low level of detail because several districts in the deseado massif still need to be explored prospectivity maps produced with higher detail would be more helpful for exploration in this region we mapped prospectivity for low and intermediate sulfidation epithermal deposits liseds in the deseado massif at both regional and district scales producing two different prospectivity models one at regional scale and the other at district scale the models were obtained from two datasets of geological evidence layers by the weights of evidence wofe method we used more deposits than in previous studies and we applied the leave one out cross validation loocv method which allowed using all deposits for training and validating the models to ensure statistical robustness the regional and district scale models were selected amongst six combinations of geological evidence layers based on results from conditional independence tests the regional scale model 1000 m spatial resolution was generated with readily available data including a lithological layer with limited detail and accuracy a clay alteration layer derived from a landsat 5 7 band ratio and a map of proximity to regional scale structures the district scale model 100 m spatial resolution was generated from evidence layers that were more detailed accurate and diverse than the regional scale layers they were also more cumbersome to process and combine to cover large areas the evidence layers included clay alteration and silica abundance derived from aster data and a map of lineament densities the use of these evidence layers was restricted to areas of favourable lithologies which were derived from a geological map of higher detail and accuracy than the one used for the regional scale prospectivity mapping the two prospectivity models were compared and their suitability for prediction of the prospectivity in the district scale area was determined during the modelling process the spatial association of the different types of evidence and the mineral deposits were calculated based on these results the relative importance of the different evidence layers could be determined it could be inferred which type of geological evidence could potentially improve the modelling results by additional investigation and better representation we conclude that prospectivity mapping for liseds at regional and district scales were successfully carried out by using wofe and loocv methods our regional scale prospectivity model was better than previous prospectivity models of the deseado massif our district scale prospectivity model showed to be more effective reliable and useful than the regional scale model for mapping at district level this resulted from the use of higher resolution evidential layers higher detail and accuracy of the geological maps and the application of aster data instead of landsat etm data district scale prospectivity mapping could be further improved by a a more accurate determination of the age of mineralization relative to that of lithological units in the districts b more accurate and detailed mapping of the favourable units than what is currently available c a better understanding of the relationships between liseds and the geological evidence used in this research in particular the relationship with hydrothermal clay alteration and the method of detection of the clay minerals and d inclusion of other data layers such as geochemistry and geophysics that have not been used in this study

multispectral remote sensing mapping for hydrocarbon seepage induced lithologic anomalies in the kuqa foreland basin south tian shan abstract the mineralogy of oil and gas reservoirs can be altered through the effects of hydrocarbon seepage mapping this mineral alteration is thus a potential tool for hydrocarbon exploration hydrocarbons that escape from underground reservoirs can cause oxidation reduction reactions in situ or along vertical migration pathways they can also produce anomalies in surface sediments and soils the surface changes can potentially be detected by various techniques including geochemical geophysical and remote sensing methods in this study satellite multi spectral data combined with field spectrometry geochemical and mineralogical information were evaluated for mapping areas of known hydrocarbon seepages from the qiulitage thrust and fold belt in the southern tian shan northwest china this study found that aster band ratios of 2 1 and 4 9 reveal mineral signatures related to alterations induced by hydrocarbon seepages such as bleached red bed and secondary carbonates respectively in the qiulitage thrust and fold belt these overly known hydrocarbon seepages and thus provide a targeting tool for similar styles of hydrocarbon elsewhere in addition given that hydrocarbon seepages are also one of the non negligible sources for emission of greenhouse gases multispectral remote sensing system can thus potentially be used to map and monitor emission of greenhouse gas emissions from hydrocarbon accumulations

potential of esa s sentinel 2 for geological applications abstract sentinel 2 is esa s medium spatial resolution 10 60 m super spectral instrument aimed at ensuring data continuity for global land surface monitoring of landsat and spot several simulation studies have been conducted that show the potential of sentinel 2 for estimating biophysical and biochemical parameters such as leaf area index chlorophyll and nitrogen and spectral products such as the red edge position and ndvi time series providing data continuity for a number of other operational sensors this paper aims at simulating sentinel 2 products that are relevant to the geology and soil science community and we compare these to well established band ratio products from aster as the basis for the simulation we use airborne hyperspectral imagery from the hymap sensor which were spectrally and spatially resampled to the resolutions of aster and sentinel 2 using actual spectral response functions and pixel aggregate respectively the simulated image products demonstrate a good correspondence between aster and sentinel 2 vnir and swir bands a number of band ratios are proposed for sentinel 2 to derive the following products ferric iron ferrous iron laterite gossan ferrous silicate and ferric oxides these are compared to established band ratios of real aster data as well as simulated from hymap aster data and they correlate favourably investigating the spatial patterns reveals that there is a good match between the proposed sentinel 2 band ratio products and those of aster the resulting band ratio products are compared to the local geologic map of the imaged hydrothermal area the rodalquilar mining area cabo de gata volcanic field se spain it is shown that they support the existing conceptual geologic model of the epithermal deposit

change detection and visualization of acid mine lakes using time series satellite image data in geographic information systems gis can canakkale county nw turkey can a county in the province of canakkale is one of the most prominent coal mining districts in turkey many mining companies have been operating coal deposits for power generation and district heating in this region since 1980 generally small and medium scale mining companies operate for short periods and abandon the operational land without providing any rehabilitation human intervention in the natural structure and topography of the earth surface causes large holes and deterioration in these areas artificial lakes occur because of surface discharge and underground leakage into abandoned open pit mines with high lignite sulfur content 0 21 14 36 wt furthermore these lakes gain acidic character due to acid generation from pyrite oxidation acid mine lakes are highly acidic ph 3 05 and have elevated concentrations of text so 4 2 fe and some metals the main objective of this study is to evaluate the environmental conditions and demonstrate the development of a monitoring system for their possible changes in the acid mine lakes of the open cast lignite mining area on a regional scale for this purpose the data received from remote sensing satellites were used areal change detection and perimeter changes of nine acid mine lakes caused by coal mining companies in can from 1977 to 2011 were determined using landsat quickbird and worldview satellite images as a case study an area of 9 km2 was chosen for the variety of acid mine lakes using gis software satellite images were analyzed in time series borders of acid mine lakes were digitized and converted into vector data format at this stage prior to the digitization in order to create contrast on the satellite images stretch type and stretch values were changed the areal and perimeter changes were computed and presented via tables and graphics in addition thematic maps of the acid mine lakes were created and visualized the results show that the number of acid mine lakes increased and these caused environmental risks due to their hydrochemical properties and areal increments

remote sensing based approach for mapping of co2 sequestered regions in samail ophiolite massifs of the sultanate of oman abstract documentation of chemical weathering and co 2 sequestration in the samail ophiolite massifs of the sultanate of oman represents an important case study for geological carbon capture and storage system gccss the present research study demonstrates the capability of remote sensing technique for mapping of weathered zones and potential co 2 sequestration area abundances at different scales within peridotites in the northern mountain region of the samail ophiolite massifs the carbonate mineral index ci applied with other mineral indices to the tir wavelength region of advanced spaceborne thermal emission and reflection radiometer aster tir spectral bands 13 and 14 mapped co 2 sequestered minerals along the structural and wadi controlled co 2 flowing regions peridotites the source rocks of co 2 sequestration in the study area were mapped using an aster 8 3 and 1 band combinations the decorrelated landsat tm image discriminated the rock types associated with peridotites of ophiolite sequences and delineated the region of weathered and altered serpentinized peridotites in the zone of co 2 sequestration co 2 sequestration mapping was carried out using landsat tm satellite data that span 20 years 1986 1998 2000 2003 and 2006 to assess the present status of co 2 sequestration in this region the image interpretations are verified with existing geological maps and through field and laboratory studies the spectral measurements of carbonate minerals at 1300 to 2500 nm with the spectral resolution of 7 nm using a pima sp infrared spectrometer in the field and laboratory show the presence of hydroxyl bearing minerals and carbonates that have spectral absorption features around 1 4 m 1 9 m and 2 35 m the strong absorptions around 2 35 m are mainly due to c o bonds in carbonate minerals such as calcite caco 3 dolomite camg co 3 2 magnesite mgco 3 aragonite caco 3 and siderite feco 3 which form 15 to 57 12 to 53 9 to 38 11 to 21 and 3 to 8 respectively in the samples the absorptions around 1 4 m and 1 9 m are caused by hydration effects of hydroxyl minerals including antigorite and montmorillonite present at 10 to 21 and 37 to 81 respectively in the samples the alterations of serpentinite are evidenced by the presence of antigorite and lizardite minerals x ray powder diffraction analyses further confirms the occurrence of co 2 sequestered major carbonate minerals such as aragonite calcite and dolomite in the samples the study demonstrates that the aster and landsat tm satellite multispectral sensors are useful to detect the carbonate minerals to delineate the peridotites and to discriminate the areal abundance of potential co 2 sequestration this technique is a useful tool to map and monitor the region of co 2 sequestration in well exposed arid and semi arid regions and to analyze and understand this aspect of the world geological carbon capture and storage system

identification of hydrothermal alteration minerals for exploring of porphyry copper deposit using aster data se iran the nw se trending central iranian volcanic belt hosts many well known porphyry copper deposits in iran it becomes an interesting area for remote sensing investigations to explore the new prospects of porphyry copper and vein type epithermal gold mineralization two copper mining districts in southeastern segment of the volcanic belt including meiduk and sarcheshmeh have been selected in the present study the performance of principal component analysis band ratio and minimum noise fraction transformation has been evaluated for the visible and near infrared vnir and shortwave infrared swir subsystems of aster data the image processing techniques indicated the distribution of iron oxides and vegetation in the vnir subsystem hydrothermal alteration mineral zones associated with porphyry copper mineralization identified and discriminated based on distinctive shortwave infrared swir properties of the aster data in a regional scale these techniques identified new prospects of porphyry copper mineralization in the study areas the spatial distribution of hydrothermal alteration zones has been verified by in situ inspection x ray diffraction xrd analysis and spectral reflectance measurements results indicated that the integration of the image processing techniques has a great ability to obtain significant and comprehensive information for the reconnaissance stages of porphyry copper exploration in a regional scale the results of this research can assist exploration geologists to find new prospects of porphyry copper and gold deposits in the other virgin regions before costly detailed ground investigations consequently the introduced image processing techniques can create an optimum idea about possible location of the new prospects

geological methods in mineral exploration and mining second edition roger marjoribanks pp 238 2010 springer heidelberg isbn 978 3 540 74370 5 price us 129 00 marjoribanks has updated one of the handiest and most readable books ever written for the exploration community exploration managers should be handing copies of it to all their new hires and aspiring explorationists should be reading it before their first interview let alone camp job geared to the entry levels of the profession it s also a handy reference for old hands it covers the basics of the full gamut of modern exploration methods and techniques ranging from mapping through sampling and drilling into geophysics and geochemistry and thence to image analysis and gis examples drawn from real life are very well chosen and the book is larded with designs for handy field apparatus that can significantly streamline cumbersome tasks in the bush marjoribanks focus always seems to be on how to wring as much information out of your exploration activities and data as possible the book starts by examining the underlying philosophy of how one explores and what techniques work when and why and passes on to consideration of

combining digital elevation data srtm aster high resolution satellite imagery quickbird and gis for geomorphological mapping a multi component case study on mediterranean karst in central crete abstract remote sensing data have become more and more popular for geomorphological investigations because their steadily increasing level of detail and accessibility opens up new potentials in this context this paper examines the application and quality of digital elevation models srtm and aster dems high resolution satellite imagery quickbird and gis techniques for the detection and mapping of karst landforms mainly enclosed depressions at different scales in the ida mountains of central crete besides discussing methodological issues and evaluating suitability potentials we conducted an exemplary case study based on spatial analysis of the regional karst morphology different input datasets and processing methods are applied gis based analysis land cover classification raster calculations etc in order to carry out an area wide surveying and mapping of karst depressions the findings are supported and validated by auxiliary field studies due to the level of detail and occasional data errors an exclusive use of satellite imagery or digital elevation models for automatic karst landform detection performs insufficiently our results demonstrate that mapping karst features through remote sensing is significantly dependent on scale of interest existing environmental conditions and data quality a semi automatic data integration approach on the basis of digital datasets generated by combined satellite image processing and dem analysis yields the best results especially when indirect karst indicating variables like iron oxide rich sediments are included as detection criteria the multi component application presented in this paper provides a time saving and effective tool for meso to macro scale object detection and extensive study areas however the potential of fully automated karst feature mapping still needs to be explored in future work concerning the spatial dimension of karstification in central crete the gis based results allow differentiating further geomorphological characteristics e g by indicating a significant altitudinal change of karst forms within the study area size and shape of depressions dolines uvalas and poljes vary considerably due to the geological setting climatic impacts neotectonics and elevation

mapping of salt structures and related fault lineaments based on remote sensing and gravimetric data the case of the monte real salt wall onshore west central portugal the monte real mr salt wall mr structure is a salt structure located in the monte real pombal subbasin onshore west central portugal the mr structure was emplaced during post triassic mesozoic extensional and tertiary compressional tectonics and is now partially buried under miocene to pliocene pleistocene sediments the region is dominated by ns 20 n45 10e n30 10w and n70 10w trending main tectonic systems remote sensing data constrained by gravimetric data allowed the recognition of the two dimensional surface geometry of this salt structure and its associated structural features the use of remote sensing images optical and microwave data allow mapping the mr structure based on the heat radiated from rocks and soils changes in vegetation cover and texture analysis of synthetic aperture radar imagery in addition remote sensing data combined with modeled topographic data also allowed recognition of a lineament pattern consistent with the fracture pattern of the region probably related to the implantation and deformation of this salt body the crosscut behavior of the identified structural lineaments can justify the north northwestern elongated arcuate shape of the mr structure and the corresponding gravimetric anomaly this work shows that remote sensing techniques are a powerful tool to study buried salt domes even in the absence of detailed geophysical data

the sandstone hosted stratiform copper mineralization at mwitapile and its relation to the mineralization at lufukwe lufilian foreland democratic republic of congo abstract the lufilian foreland is a triangular shaped area located in the se of the democratic republic of congo and to the ne of the lufilian arc which hosts the well known central african copperbelt the lufilian foreland recently became an interesting area with several vein type e g dikulushi and stratiform e g lufukwe and mwitapile copper occurrences the lufilian foreland stratiform cu mineralization is to date observed in sandstone rock units belonging to the nguba and kundelungu groups katanga supergroup the mwitapile sandstone hosted stratiform cu prospect is located in the north eastern part of the lufilian foreland the host rock for the cu mineralization is the sonta sandstone of the ngule subgroup kundelungu group a combined remote sensing petrographic and fluid inclusion microthermometric analysis was performed at mwitapile and compared with similar analysis previously carried out at lufukwe to present a metallogenic model for the mwitapile and lufukwe type stratiform copper deposits interpretation of etm satellite images for the mwitapile prospect and the surrounding areas indicate the absence of ne sw or ene wsw faults similar to those observed controlling the mineralization at lufukwe faults with these orientations are however present to the nw w sw and e of the mwitapile prospect at mwitapile the sonta sandstone host rock is intensely compacted arkosic to calcareous with high silica cementation first generation of authigenic quartz overgrowths in the sonta sandstone feldspar and calcite are present in disseminated banded and nodular forms intense dissolution of these minerals caused the presence of disseminated rectangular pipe like and nodular dissolution cavities sulfide mineralization is mainly concentrated in these cavities the hypogene sulfide minerals consist of two generations of pyrite chalcopyrite bornite and chalcocite separated by a second generation of authigenic quartz overgrowth the hypogene sulfide minerals are replaced by supergene digenite and covellite fluid inclusion microthermometry on the first authigenic quartz phase indicates silica precipitation from an h 2 o nacl cacl 2 fluid with a minimum temperature between 111 and 182 c and a salinity between 22 0 and 25 5 wt cacl 2 equiv microthermometry on the second authigenic quartz overgrowths and in secondary trails related to the mineralization indicate that the mineralizing fluid is characterized by variable temperatures th 120 to 280 c and salinities 2 4 to 19 8 wt nacl equiv and by a general trend of increasing temperatures with increasing salinities comparison between mwitapile and lufukwe indicates that the stratiform cu mineralization in the two deposits is controlled by similar sedimentary diagenetic and structural factors and likely formed from a similar mineralizing fluid a post orogenic timing is proposed for the mineralization in both deposits the main mineralization controlling factors are grain size clay and pyrobitumen content the amount and degree of feldspar and or calcite dissolution and the presence of ne sw to ene wsw faults the data support a post orogenic fluid mixing model for the mwitapile and lufukwe type sandstone hosted stratiform cu deposits in which the mineralization is related to the mixing between a cu rich hydrothermal fluid with a temperature up to 280 c and a maximum salinity of 19 8 wt nacl equiv with a colder low salinity reducing fluid present in the sandstone host rock the mineralizing fluid likely migrated upwards to the sandstone source rocks along ne sw to ene wsw orientated faults at lufukwe the highest copper grades at surface outcrops and boreholes were found along and near to these faults at mwitapile where such faults are 2 to 3 km away the cu grades are much lower than at lufukwe copper precipitation was possibly promoted by reduction from pre existing hydrocarbons and non copper sulfides and by the decrease in fluid salinity and temperature during mixing based on this research new cu prospects were proposed at lufukwe and mwitapile and a set of recommendations for further cu exploration in the lufilian foreland is presented

structure of the nemrut caldera eastern anatolia turkey and associated hydrothermal fluid circulation abstract plio quaternary volcanism played an important role in the present physical state of eastern anatolia mount nemrut situated to the west of lake van is one of the main volcanic centers in the region with a spectacular summit caldera 8 5 7 km in diameter the most recent eruptions of the volcano were in 1441 1597 and 1692 nemrut lake covers the western half of the caldera it is a deep half bowl shaped lake with a maximum depth of 176 m numerous eruption centers are exposed within the caldera as a consequence of magma water interaction current activity of nemrut caldera is revealed as hot springs fumaroles and a small hot lake self potential and bathymetric surveys carried out in the caldera were used to characterize the structure of the caldera and the associated hydrothermal fluid circulation in addition analyses based on digital elevation models and satellite imagery were used to improve our knowledge about the structure of the caldera according to sp results the flanks of the volcano represent the hydrogeologic zone whereas the intra caldera region is an active hydrothermal area where the fluid circulation is controlled by structural discontinuities there is also a northern fissure zone which exhibits hydrothermal signatures nemrut caldera collapsed piecemeal with three main blocks stress controlling the collapse mechanism seems to be highly affected by the regional neotectonic regime in addition to the historical activity current hydrothermal and hydrogeologic conditions in the caldera in which there is a large lake and shallow water table increase the risk of the quiescent volcano

relations of ammonium minerals at several hydrothermal systems in the western u s abstract ammonium bound to silicate and sulfate minerals has recently been located at several major hydrothermal systems in the western u s utilizing newly discovered near infrared spectral properties knowledge of the origin and mineralogic relations of ammonium minerals at known hydrothermal systems is critical for the proper interpretation of remote sensing data and for testing of possible links to mineralization submicroscopic analysis of ammonium minerals from two mercury and gold bearing hot springs deposits at ivanhoe nevada and mclaughlin california shows that the ammonium feldspar buddingtonite occurs as fine grained euhedral crystals coating larger sulfide and quartz crystals ammonium feldspar seems to precipitate relatively late in the crystallization sequence and shows evidence for replacement of nh4 by k or other monovalent cations some buddingtonite is observed in close association with mercury but not with gold ammonioalunite is found in a variety of isolated crystal forms at both deposits nitrogen isotopic values for ammonium bearing minerals show a 14 range in composition precluding assignment of a specific provenance to the nitrogen the correlations of nitrogen isotopic values with depth and ammonium content suggest some loss of nitrogen in the oxidizing supergene environment possibly as a metastable mineral the high ammonium content in these hydrothermal systems the close association to mercury and the small crystal size of the ammonium bearing minerals all suggest that ammonium may be transported in a late stage vapor phase or as an organic volatile such a process could lead to the formation of a non carbonaceous organic aureole above a buried geothermal source the discovery of a 10 km outcrop of ammonium minerals confirms that significant substitution of ammonium in minerals is possible over an extensive area and that remote sensing is a feasible means to detect such aureoles

spectral discrimination of contact metamorphic zones and its potential for mineral exploration province of salamanca spain abstract in the mineralized contact aureole of los santos spain contact metamorphic grade of rocks and the mineralogical composition of overlying soils correlate systematically from the exocontact towards the granite intrusion the proportions of kaolinite illite and free iron in soils increase while the proportions of chlorite and smectite decrease laboratory reflectance spectra of soil samples demonstrate that with the increase of the proportion of kaolinite illite and free iron and the decrease of chlorite ratios of band 2 band 3 band 2 band 5 and band 2 band 7 decrease while ratios of band 3 band 4 band 4 band 7 and band 5 band 7 increase soil reflectance is significantly affected if more than 1 5 organic carbon is present a procedure is presented that enables mapping of soils overlying contact metamorphic rocks in thematic mapper tm imagery using these variations in the tm image pixels that correspond with kaolinitic soils are identified by elimination of other pixels during a process of stepwise masking various band ratio images the first step was to eliminate the effect of vegetation and organic material by masking high values of the ratio of tm5 tm7 tm3 tm4 the second step was to eliminate chloritic soils by masking the ratio of tm2 tm7 the third step was to isolate the most kaolinitic and limonitic soils using the ratio of tm3 tm4 finally a maximum likelihood classification was performed on original band ratio images using the result of the masking as training set in order to optimize the classification results

data fusion and porphyry copper prospectivity models southeastern arizona abstract mineral exploration programs commonly use a combination of geological geophysical and remotely sensed data to detect sets of optimal conditions for potential ore deposits prospectivity mapping techniques can integrate and analyse these digital geological data sets to produce maps that identify where optimal conditions converge three prospectivity mapping techniques weights of evidence fuzzy logic and a combination of these two methods were applied to a 32 000 km 2 study area within the southeastern arizona porphyry cu district and then assessed based on their ability to identify new and existing areas of high mineral prospectivity validity testing revealed that the fuzzy logic method using membership values based on an exploration model identified known cu deposits considerably better than those that relied solely on weights of evidence and slightly better than those that used a combination of weights of evidence and fuzzy logic this led to the selection of the prospectivity map created using the fuzzy logic method with membership values based on an exploration model three case study areas were identified that comprise many critical geological and geophysical characteristics favourable to hosting porphyry cu mineralisation but not associated with known mining or exploration activity detailed analysis of each case study has been performed to promote these areas as potential targets and to demonstrate the ability of prospectivity modelling techniques as useful tools in mineral exploration programs