subrainband structure and dynamic characteristics in the principal rainband of typhoon hagupit 2008 abstractthe principal rainband in tropical cyclones is currently depicted as a solitary and continuous precipitation region however the airborne radar observations of the principal rainband in typhoon hagupit 2008 reveal multiple subrainband structures these subbands possess many characteristics of the squall lines with trailing stratiform in the midlatitudes and are different from those documented in previous principal rainband studies the updraft and reflectivity cores are upright and elevated the updraft is fed by a low level radial outflow from the inner side the tangential wind speed shows a clear midlevel jet on the inner side of the reflectivity core except for the structural similarities the dynamics of the subbands is also similar to the squall lines the local environment near the subbands shows little convective inhibition modest instability and vertical wind shear the temperature retrieval shows a cold pool structure in the stratiform precipitation region the estimated vertical w

factors controlling geochemical and mineralogical compositions of coals preserved within marine carbonate successions a case study from the heshan coalfield southern china abstract the late permian coals in the heshan coalfield of southern china are preserved within marine carbonate successions and characterized by super high organic sulfur 5 13 10 82 minerals identified in the coals include quartz kaolinite illite mixed layer illite smectite albite pyrite marcasite calcite and dolomite along with trace amounts of smectite fluorite strontianite rey bearing carbonate minerals jarosite and water bearing fe oxysulfate the coals are very rich in trace elements including f up to 3362 g g v up to 270 g g se up to 24 4 g g mo up to 142 g g u up to 111 g g and to a lesser extent sr y zr nb cd cs heavy rare earth elements hf ta w hg and th previous studies attributed the high organic sulfur and elevated trace elements to the seawater influence or the formation of soil horizons before the accumulation of peat in the basin however mineralogical and geochemical data presented in this study have shown that the sediment source region and multi stage hydrothermal fluids are the dominant influences on the mineralogical composition and elevated trace elements in the coal although seawater influence also contributed to the composition of the mineral matter for example a large proportion of the quartz and clay minerals as well as almost all the albite in both the coal benches and the parting mudstones were derived from detrital materials of terrigenous origin in the yunkai upland high concentrations of lithophile trace elements were also derived from the sediment source region minerals including fluorite calcite dolomite strontianite and rey bearing carbonate minerals were derived from multi stage hydrothermal activities high concentrations of v mo and u that occur through the coal seam sections were probably derived from hydrothermal solutions during peat accumulation or at the early diagenetic stages the hydrothermal fluids also corroded the syngenetically formed minerals quartz albite and pyrite and caused re distribution of lithophile elements from partings to the underlying coal benches resulting in higher key element ratios yb la nb ta and zr hf and more abundant heavy rare earth elements in the coal benches than in the immediately overlying partings

origin of minerals and elements in the late permian coals tonsteins and host rocks of the xinde mine xuanwei eastern yunnan china abstract this paper reports the mineralogical and geochemical compositions of the late permian c2 and c3 coals both medium volatile bituminous coal from the xinde mine near xuanwei in eastern yunnan which is located close to the area with the highest female lung cancer mortality in china the two coals are characterized by high ash yields and low sulfur contents three factors including sediment source region multi stage volcanic ash generation and multi stage hydrothermal fluid injections were responsible for variations in the geochemical and mineralogical compositions of the xinde coals trace elements including v sc co ni cu zn se zr nb hf and ta are enriched in the coals and were mainly derived from the sediment source kangdian upland region major minerals in the samples of coal roof floor and non coal sediment partings include quartz kaolinite and chamosite as well as interstratified illite smectite and anatase chamosite in the coal was derived from reactions between kaolinite and fe mg rich hydrothermal fluids however chamosite in the roof strata was directly precipitated from fe mg rich hydrothermal fluids or was derived from the alteration of precursor minerals e g biotite by hydrothermal fluids quartz in some samples is very high especially in the roof strata of the c2 and c3 coal such high quartz along with minor minerals including pyrite chalcopyrite sphalerite calcite celestite vanadinite barite clausthalite and silicorhabdophane were derived from multi stage hydrothermal fluids the floors of both the c2 and c3 coal seams are fully argillized fine grained tuffaceous claystone and the immediate roof of the c2 coal is argillized coarse grained tuff the original materials of the floors and roofs of these coal seams were high ti alkali basaltic volcanic ashes as indicated by high tio 2 nb and siderophile elements and the distribution patterns of rare earth elements two intra seam tonstein layers in the c3 coal were identified based on their lateral persistence mineralogical mode of occurrence and composition as well as their elemental composition the tonsteins are dominated by kaolinite with minor quartz and possibly mixed layer illite smectite both tonsteins were derived from dacitic magma the ratios of nb ta zr hf and u th are much lower in tonsteins than in the adjacent coal benches which is attributed to the hydrothermal leaching

petrology mineralogy and geochemistry of the lower cretaceous oil prone coal and host rocks from the laoheishan basin northeast china abstract the coal and host rocks mainly oil shale partings in the laoheishan basin ne china are oil prone this study uses petrological mineralogical and geochemical analyses to determine the reasons of high oil yield in the coal and the origin and modes of occurrence of the minerals and elements in the coal and oil shale partings the obtained data show that this sub bituminous b coal has higher oil yield av 10 than oil shale partings av 5 7 consistent with a higher hydrogen content in the coal this oil prone coal has potential for comprehensive utilization due to the relatively high gross calorific value av 17 23 mj kg in the semi coke the maceral composition suggests that the relatively high hydrogen content in the coal is mainly caused by higher resinite content palynological analysis of coal and oil shale partings mainly proved the presence of gymnosperms and ferns revealing that the paleovegetation is dominated by lygodiacean osmundacean ground ferns and cupressaceaen taxodiaceaen canopy trees these canopy trees would have provided abundant hydrogen rich components e g resin to the paleomire all the identified sporopollen suggests a warm humid subtropical paleoclimate minerals in the coal include kaolinite quartz illite and or illite smectite chlorite feldspar calcite and traces of pyrite rutile and zircon similar to the oil shale partings most of the minerals quartz feldspar clay minerals rutile and zircon occur in layers within detrovitrinite and probably are of detrital origin pyrite and calcite are of epigenetic origin and probably derived from hydrothermal fluids compared with average chinese coal the laoheishan coal is enriched in zr nb in and sb zirconium and nb mainly occur in zircon indium is both organically and inorganically associated whereas antimony largely occurs in pyrite rey rare earth elements and yttrium distribution patterns of coals and oil shale partings are dominated by heavy rey enrichment whereas roof and floor samples are medium rey enriched the m hrey enrichment is probably caused by low temperature hydrothermal fluids the sedimentary input is the major controlling factor of geochemical patterns in coal and host rocks the source rocks are probably felsic intermediate igneous rocks from the surrounding basement as indicated by relatively high al2o3 tio2 ratios 7 38 cross plot between zr ti and nb y negative eu anomalies 0 28 0 96 the presence of k feldspar and plagioclase and lithic fragment types such as granite and andesite in the samples in addition source rocks of sediments have caused high zr and nb concentrations in the coal

microseimicity and strain pattern in northwestern greece during a 7 week microearthquake experiment conducted in epirus akarnania and the ionian islands of western greece we located approximately 600 earthquakes with magnitudes between 2 and 4 2 no event was deeper than 40 km the seismicity cannot be clearly associated with any single fault except the lixourion right lateral fault located west of the ionian islands focal mechanisms of about 100 earthquakes show for a narrow band of earthquakes located along the coast ene wsw shortening consistent with the surface tectonics farther east focal mechanisms show nnw sse extension beneath the foothills of the pindus mountains which is unrelated to surface faulting but is consistent with the presently subsiding basins this strain pattern is seen far north and south of the lixourion fault and is similar to the one observed in the peloponnese it suggests that a large scale mechanism is responsible for the recent geodynamics of both the northwestern and southwestern aegean

waveform relocation and focal mechanism analysis of an earthquake swarm in trichonis lake western greece abstract in early april 2007 a series of moderate earthquakes m l 4 1 4 8 oc curred in the area of trichonis lake in western greece the earthquake activity waswell recorded by the hellenic broadband seismic network hl operated by the na tional observatory of athens initial locations for 156 events of the swarm showed adiffuse image of seismicity subsequently 101 events are precisely relocated calcu lating source specific station terms and differential travel times from waveform crosscorrelation uncertainties in relocations are estimated with a bootstrap approach byrandomly weighting the original picks and the differential times additionally wave forms of seven out of the eight largest earthquakes of the swarm were inverted inorder to derive regional moment tensor solutions the results showed a tight north northwest south southeast cluster located on an offshore extension of a similarlyoriented fault trace mapped onshore moment tensor solutions indicate normal fault ing with a substantial component of left lateral strike slip motion it is possible thatthis identified fault forms part of a link that connects the gulf of corinth rift system tothe west northwest east southeast fault zone south of trichonis basin online material event catalog and focal mechanism for the eight largest events introduction

along strike changes in the structural evolution over a brittle detachment fault example of the pleistocene corinth patras rift greece abstract the patras corinth and northern saronic gulfs occupy a 200 km long n120 trending pleistocene rift zone where peloponnese drifts away from mainland greece the axes of patras and corinth basins are 25 km apart and linked by two transfer fault zones trending n040 the older one defines the western slope of panachaikon mountain and the younger one limits the narrow rion patras littoral plain between these two faults the ca 4 km thick rion patras series dips 20 30 ssw it is part of the patras gulf synrift deposits which pile in an asymmetric basin governed by a fault dipping ca 25 35 nne located in the southern gulf of patras mapping of this fault to the east in northern peloponnese shows that it is an inactive north dipping low angle normal fault 0 to 30 n called the northern peloponnese major fault npmf the structural evolution of the npmf was different in the gulfs of patras and corinth in the gulf of patras it is still active in northern peloponnese footwall uplift and coeval southward tilting flattened the fault and locked its southern part steeper normal faults formed north of the locked area connecting the still active northern part of the npmf to the surface after several locks the presently active normal faults psathopyrgos aigion helike trend along the southern shore of the gulf of corinth this migration of faults caused the relative 25 km northward shift of the corinth basin and the formation of ne sw trending transfer faults between the corinth and patras gulfs

the occurrence of buddingtonite in super high organic sulphur coals from the yishan coalfield guangxi southern china abstract this paper discusses the identification abundance modes of occurrence and origin of buddingtonite and associated minerals in three lopingian coals from the yishan coalfield guangxi province southern china the coals of this coalfield are preserved within carbonate successions and are characterized by super high organic sulphur contents mostly 6 9 three different types of feldspars have been identified in these coals buddingtonite albite and minor k feldspar both the albite and k feldspar in the coal were largely derived from detrital materials of terrigenous origin although some were authigenically deposited they were subsequently subjected to corrosion dissolution by percolating fluids buddingtonite was derived largely from k feldspar via diffusion mechanisms through the substitution of k by nh4 the latter coming from decomposition of organic matter in the coal or from changes in the organic matter with rank advance a small proportion of the buddingtonite was also derived from albite through the replacement of na by nh4

geochemical and petrographical characteristics of low rank balingian coal from sarawak malaysia its implications on depositional conditions and thermal maturity abstract geochemical and coal petrographical analyses were undertaken on low rank upper pliocene balingian coal from sarawak malaysia in an attempt to reconstruct the conditions during peat accumulation and the subsequent coalification processes chemically the coal in this study is characterised by high moisture low ash yield and low sulphur content the low ash yield and low sulphur content together with the lack of epiclastic partings clearly indicate that it was deposited in ombrotrophic raised bogs the coal was plotted in the type iii terrigenous kerogen zone of the van krevelen diagram with h c value below 0 9 this shows that the coal was derived from plant materials of terrigenous origin and is still immature for petroleum generation the petrographical study reveals nonetheless the expulsion of early generated hydrocarbons from the disintegration of suberinite and also from phlobaphinite and cutinite petrographically the coal is dominated by huminite with low to moderate amounts of liptinite and low amounts of inertinite pointing to predominantly anaerobic deposition conditions in the paleomires with limited thermal and oxidative tissue destruction most of the studied samples are characterised by low tpi and high gi values and are plotted on the marsh field of the diessel s diagram or it could also originate from decomposed wood in forested swamps nevertheless coals originating from both these sources usually generate high ash yield which is not the case for the studied coal this shows that the interpretation as suggested by the diessel s diagram is not valid for the studied coal the coal has a mean random huminite reflectance between 0 26 and 0 35 suggesting a lignite coal rank for the coal nevertheless geochemical classification based on total moisture and calorific value suggests a subbituminous c rank

revisiting the late permian coal from the huayingshan sichuan southwestern china enrichment and occurrence modes of minerals and trace elements abstract the late permian coals from the huayingshan coalfield of southwestern china are significantly enriched in zr 695 g g nb 75 9 g g se 6 99 g g hf 10 1 g g and rare earth elements and y 1423 g g previous studies showed that the sediment source region for these coals was the kangdian upland which was formed at an early stage of the late permian period the source rocks have a basalt composition and those studies attributed the enrichment of the above high field strength elements hfses to derivation from the kangdian upland geochemical and mineralogical data presented in this study show that the dominant sediment source regions for the coal and roof strata of the huayingshan coalfields are the dabashan uplift hannan upland and leshan longnvsi uplift the highly elevated concentrations of hfses in the coals are due to hydrothermal fluids three tonstein layers derived from alkali rhyolite were identified these tonsteins are characterized by highly enriched hfses and by strong negative eu anomalies in the rare earth element distribution patterns the major carriers of the rare earth elements in the coal are rhabdophane and silicorhabdophane the latter of which is also enriched in zr zirconium however mainly occurs in zircon rhabdophane and silicorhabdophane in the coal are mainly distributed along the bedding planes and occur as cell fillings zircon in the coal occurs as cell fillings and is of authigenic origin anatase in the partings and coals contains nb and occurs as fracture filling and colloidal forms the modes of occurrence of the above minerals indicate that they were derived from hydrothermal fluids mercury and se mainly occur in sulfide minerals pyrite and marcasite

3 d p wave velocity structure in western greece determined from tomography using earthquake data recorded at the university of patras seismic network patnet the 3 d p wave velocity structure of the upper crust in the region of western greece is investigated by inversion of about 1500 residuals of p wave arrival times from local earthquake data recorded in the year 1996 by the newly established university of patras seismic network patnet the resulting velocity structure shows strong horizontal variations due to the complicated structure and the variation of crustal thickness relatively low velocity contours are observed in the area defined by cephallonia zakynthos islands and northwestern peloponnesos this is in addition to some well localized peaks of relatively higher values of p wave velocity may be related to the zone of triassic evaporites in the region and correspond to diapirism that breaks through to the uppermost layer finally a low p velocity deeping zone extending from zakynthos to the gulf of patras is correlated with bouguer anomaly map and onshore and offshore borehole drillings which indicate that thick sediments overly the evaporites which exist there at depth greater than 2 km

the oceanic mesoscale convective system observed with airborne doppler radars on 9 february 1993 during toga coare structure evolution and budgets data collected on 9 february 1993 during the tropical ocean and global atmosphere programme coupled ocean atmosphere response experiment toga coare with the doppler radars on board the two national oceanic and atmospheric administration wp 3d and the national center for atmospheric research electra aircraft are analysed to study the structure and evolution of an equatorial oceanic mesoscale convective system mcs observations lasted more than five hours a period during which the cloud cluster characteristics changed from convective to stratiform this mesoscale system was approximately aligned along the tropospheric wind shear but it was nearly perpendicular to the low level shear series of three dimensional fields of reflectivity air velocity components retrieved pressure and temperature perturbations show similarities with previously observed convective systems over the tropical oceans in particular although the cloud top reached 18 km altitude relatively weak vertical motions and temperature perturbations resulted from a moderate convective instability in the low levels a cold front to rear flow intensified and deepened as the overall structure evolved from convective to stratiform the vertical profiles of mean horizontal divergence evolved from low level convergence in the cross line direction for the earliest analyses to mid level convergence from all directions during the later stratiform phase vertical momentum fluxes were important and led to an increase in the cross line wind shear and a decrease in the along line one analysis of radiosounding data from the nearest stations of the toga coare array shows that the period during which airborne doppler observations were conducted was characterized by relatively strong large scale ascent and apparent sources of heat moisture and momentum these diagnosed values and the mean radarderived ones agree fairly well this shows that the early convective and late stratiform phases of the mcs are equally important for the apparent sources of heat and momentum

quaternary tectonics in the gulf of patras western greece abstract air gun seismic and 3 5 khz profiling data from the gulf of patras western greece show that it is occupied by a small asymmetric graben with several geometric similarities to the larger scale graben in the gulf of corinth to the east major listric faulting characterizes the southern flank of the graben whilst the northern flank represents an associated rollover structure affected by antithetic and synthetic faulting the present phase of subsidence is of holocene age but buried growth faults suggest earlier subsidence in the gulf the average rate of subsidence through the holocene is estimated to be 10 mm year the gulf of patras graben together with the gulf of corinth graben and the megara basin represent a continuous system of wnw ese trending grabens in a broad zone of intense seismicity within the aegean domain individual grabens are offset and are interconnected by ne sw trending fault systems

analysis origin and significance of mineral matter in coal an updated review abstract the material classed as mineral matter in coal embraces crystalline mineral materials as well as a range of inorganic elements that occur in non crystalline form this review outlines the methods that may be used to evaluate the percentage of mineral matter for a coal sample as opposed to the ash yield and to identify the minerals their individual percentages and their modes of occurrence within the coal the principal techniques include low temperature oxygen plasma ashing quantitative evaluation of x ray diffraction data observation using optical microscopy and a combination of observation chemical analysis and in some cases mapping based on scanning electron microscopy and related methods a range of other techniques may also be used to provide additional information on particular mineral matter components processes responsible for mineral matter formation include detrital input biogenic activity and authigenic precipitation at different stages of the coal s depositional and post depositional history differential migration of non mineral inorganic elements may also occur in lower rank coals and expulsion of non mineral inorganics may take place with rank advance knowledge of the mineral matter may be of assistance in understanding the modes of trace element occurrence with implications for assessing possible environmental impacts and also the potential for recovery of economic products from coal the behaviour of different mineral matter components at high temperatures is also discussed as well as methods for mineralogical analysis of ashes and other coal utilization products information from mineral matter studies may provide an improved basis for understanding coal formation and for evaluating the response of particular coals to different combustion gasification and coking processes

microearthquake swarms scaling and lacunarity summary this paper suggests that lacunarity latin lacuna hole pool deficiency hence blank empty part should be adopted as an important parameter in the description of the size spacing and rank of the gap texture within an otherwise fractal temporal and spatial distribution of earthquakes distributions of earthquakes with the same or similar fractal dimensions may have different lacunarities because of the differences in their gap textures lacunarity parameters resolve non uniqueness in similar fractals and represent the different degrees of homogeneity and complex natures exhibited by seismic fractals a new expression for the lacunarity of the temporal distribution of earthquakes is proposed taking two microearthquake swarms in central greece as examples we study the characteristics of their temporal distributions and calculate their parameters including lacunarity based on suitable scaling and threshold of earthquake magnitude within the swarms although the two swarms have different tectonic backgrounds and seismicities their distributions exhibit similar fractal dimensions suggesting that the concept of fractal dimension alone has limitations when distinguishing between complex natures of swarms different gap textures in these otherwise similar fractals are then revealed as different lacunarities indeed lacunarity values of one swarm are at least twice those of the other swarm the study thus has important geophysical implications for the appraisal of different types of microearthquake swarms and ultimately for ensuing judgements of seismicity and earthquake risk

coseismic crustal deformation from microseismicity in the patras area western greece summary the patras area lies in the western part of central greece it is an area characterized by high seismicity and complex neotectonics several devastating earthquakes have occurred in the region since 600 bc contemporary crustal deformation is examined in this area using microearthquake data recorded over a lengthy period during 1983 84 by the patras seismic network principally and to a lesser extent by the volos seismic network the microseismicity 1 8 3 9 ml defines a zone deepening to the ne which justifies a possible extension of the gulf of corinth major graben towards the trikhonis lake to the nw spectra of 108 well located microearthquakes are estimated using p waves obtained by selective windowing designed to include only the p phase seismic moments in the range 0 3 45 7 1012 nm are obtained accompanied by estimates of seismotectonic source parameters including source radii average stress drop and average coseismic slip poor correlation is found between seismic moment and magnitude and the likely reason is the complex nature of the neotectonic regime existing in the area two zones differing in crustal deformation characteristics are observed the corinth trikhonis zone reveals two sets of characteristic faults the first set is represented by microearthquakes showing distinctive and relatively higher seismic moments in conjunction with lower stress drops and seismic slips this set of faults shows greater source radius than the second set and therefore the faults are longer the second set is characterized by an almost constant source radius within the range of uncertainty and a wide range of seismic moments stress drops and seismic slips the rio zone is characterized by low seismic slip stress drop and fault radii with the exception of the locality south of the city of patras where relatively higher seismic slip stress drop and fault radius are observed

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

a microseismic study in the western part of the gulf of corinth greece implications for large scale normal faulting mechanisms summary we present the results of a dense seismological experiment in the western part of the gulf of corinth psathopyrgos aigion area one of the most active rifts in the aegean region for which we have precise tectonic information the network included 51 digital stations that operated during july and august 1991 covering a surface of 40 x 40 km2 among the 5000 recorded events with ml ranging between 1 0 and 3 0 we precisely located 774 events we obtained 148 well constrained focal mechanisms using p wave first motions of these 60 also have mechanisms obtained by combining the p wave first motions with the s wave polarization directions the observed seismicity is mainly located between 6 and 11 km depth most of the fault plane solutions correspond to e w striking normal faulting in agreement with the geological evidence most of the well determined mechanisms indicate a nodal plane dipping 10 25 due north and a steep south dipping plane a similar asymmetry is also seen in the seismicity distribution and in the overall geological structure of the corinth rift we discuss this evidence and the inference of a deep detachment zone a structure where the major faults seen at the surface appear to root a large part of the microseismic activity appears to cluster in regions near the junctions of the main faults with the proposed detachment zone this feature of the microseismicity is interpreted in terms of stress transfer and stress concentration in regions of probable nucleation of future large earthquakes

mineralogy and geochemistry of a superhigh organic sulfur coal yanshan coalfield yunnan china evidence for a volcanic ash component and influence by submarine exhalation abstract the mineralogy and geochemistry of a superhigh organic sulfur shos coal of late permian age from the yanshan coalfield yunnan province southwestern china have been studied using optical microscope low temperature ashing plus x ray diffraction analysis scanning electron microscope equipped with energy dispersive x ray spectrometer a sequential chemical extraction procedure and inductively coupled plasma mass spectrometry the m9 coal from the yanshan coalfield is a shos coal that has a total sulfur content of 10 12 11 30 and an organic sulfur content of 8 77 10 30 the minerals in the coal consist mainly of high temperature quartz sanidine albite muscovite illite pyrite and trace amounts of kaolinite plagioclase akermanite rutile and dawsonite as compared with ordinary worldwide bituminous coals and anthracite and chinese coals the m9 coal is remarkably enriched in b 268 g g f 841 g g v 567 g g cr 329 g g ni 73 9 g g mo 204 g g and u 153 g g in addition elements including se 25 2 g g zr 262 g g nb 20 1 g g cd 2 07 g g and tl 2 03 g g are also enriched in the coal occurrence of high temperature quartz sanidine muscovite and illite in the m9 coal is evidence that there is a volcanic ash component in the coal that was derived from acid volcanic ashes fallen into the swamp during peat accumulation occurrence of albite and dawsonite in the coal and strong enrichment of some elements including f s v cr ni mo and u are attributed to the influence by submarine exhalation which invaded along with seawater into the anoxic peat swamp abundances of lithophile elements including rare earth elements nb y zr and tio2 indicate that the silicate minerals in the coal were derived from the northern vietnam upland to the south of the basin

palaeoenvironment of seam i in the marathousa lignite mine megalopolis basin southern greece the present study aims to elucidate the depositional environment of seam i in the megalopolis basin southern greece using existing geological data supported by maceral and mineralogical analyses as well as by natural radioactivity determinations very high pyrite and uranium contents and a very low tissue preservation index usually suggest a marine influence during deposition in seam i however these features are most probably the result of a karstic aquifer supplying the palaeomire with sulphate rich neutral to weakly alkaline water the pyrite formation and the u precipitation are attributed to the anaerobic conditions which prevailed during peat accumulation the petrographic mineralogical and geochemical data of the studied profile point to several changes in the surface runoff and the supply of clastic material during deposition

palynofloral and organic characteristics of a miocene bog forest kalimantan indonesia palynological investigations of a 20 m thick miocene lignite from southeastern kalimantan indonesia reveal that there are distinct vertical variations in palynofloral characteristics three palynofloral zones likely represent large scale successional changes that were a product of long term ecological and depositional changes within the original mire all three zones are represented by palynofloras of both bog forest and mangrove affinity the abundance and diversity of these bog forest palynofloras accompanied by extremely low sulphur contents 0 4 suggests predominantly freshwater terrestrial deposition it is probable that the mangrove pollen is allochthonous and was transported into the mire by winds increasing relative abundances of mangrove pollen within the total palynofloral assemblage suggests encroachment of the mangrove swamp toward the bog forest pollen common and abundant within all assemblages includes that of species of the genera calophyllum melanorrhea and dactylocladus overall the vegetation that formed this miocene lignite is virtually identical to the present day peat forming vegetation of indonesia despite the vertical variations in vegetation within this miocene lignite as deduced from palynology coal petrographic investigations reveal that there is little variation in the organic characteristics within this seam petrographic analyses show that maceral assemblages are similar for most parts of this seam analyses of the plant parts and matrix illustrate that these characteristics are similar for much of the seam and that the composition and grain size of organic components are wholly comparable to results of similar analyses from a holocene mire this suggests that degradation processes during the miocene were similar to processes occurring in present day indonesian mires it further suggests that these degradation processes have homogenized the organic characteristics within the lignite despite original vegetational differences

coseismic crustal deformation on a fault zone defined by microseismicity in the pavliani area central greece summary pavliani is an area of high microseismicity in northern central greece there is no evidence in the historical record of large damaging earthquakes in this area since at least 600 bc we examine contemporary crustal deformation in this area using microearthquake data recorded during 1983 84 by the volos seismic network principally and to a lesser extent by the patras seismic network the microseismicity 1 4 6 ml defines an approximately vertical fault zone trending wsw ene of 55 km length and 25 km depth the fault plane solution for the 4 6 m earthquake shows a strike consistent with the trend of the microseismicity zone and an extension direction consistent with many large earthquakes in central greece associated with the extensional greater aegean spectra of the microearthquakes are estimated using p waves obtained by selective windowing designed to exclude other p phases from the coda seismic moments in the range 1 95 x 10 n m are obtained accompanied by estimates of seismotectonic source parameters including source radii average stress drop and average coseismic slip of prime utility is an excellent correlation found between seismic moment and magnitude and with coseismic slip this allows heterogeneity in the distribution of individual microearthquake source parameters to be mapped onto the vertical fault zone plane and the history of coseismic deformation for the whole seismicity observed during 1983 84 to be examined using cumulative slip and moment release rate peaks of high moment release rate occur in the east and centre of the fault zone that in the east is dominated by a few large moment release events that in the centre by a large number of small events both moment release rate peaks despite their different component seismicity are associated with high cumulative coseismic slip only the eastern peak is also associated with high stress drop it is also shallower and therefore any surficial interaction is less likely to be attenuated the surface projection of this peak is within 3 km of a mapped normal fault coincident with an alpine thrust front delineated by a major scarp of mesozoic limestone surface evidence of recent movement on this normal fault is only slight friable fault gouge is seen at a few localities displacement could not be determined because the limestone surfaces are deeply weathered and lack kinematic indicators however considering the whole fault zone as a cohesive entity and using a brune estimate of slip at the current moment release rate throughout the present extensional tectonic regime suggests a total vertical displacement of order 175 m similar to the elevation of the scarp

some genetic implications of silica and aluminosilicates in peat and coal abstract the inorganic content of okefenokee peat in the absence of a significant detrital contribution is a function of sponge spicule phytolith and diatom abundance in addition to the degree of organic matter decomposition and the frequency of fires the detrital component quartz dominates ash composition where it is present no clear correlation has been observed between the inorganic content of coals examined in this study and their maceral composition vitrinite rich coals have a wide range of ash yield these observations suggest that the minerals have been introduced detritally rather than accumulated as a result of peat degradation quartz in the coals appears to be detrital and the presence of 2m 1 mica indicates that there is also a detrital contribution to the clay minerals present

seismic faults in the aegean area abstract reliable fault plane solutions of shallow earthquakes and information on surface fault traces in combination with other seismic geomorphological and geological information have been used to determine the orientation and other properties of the seismic faults in the aegean and surrounding area thrust faults having an about nw se strike occur in the outer seismic zone along western albania westernmost part of mainland of greece ionian sea south of crete south of rhodes the inner part of the area is dominated by strike slip and normal faulting strike slip with an about ne sw slip direction occurs in the inner part of the hellenic arc along the line peloponnesus cyclades dodecanese southwest turkey as well as along a zone which is associated with the northern aegean trough and the northwesternmost part of anatolia all other regions in the inner part of the area are characterized by normal faulting the slip direction of the normal faults has an about sw ne direction in crete n38 e and an about e w direction n81 e in a zone which trends n s in eastern albania and its extension to western mainland of greece in all other regions central greece southern yugoslavia and bulgaria western turkey the slip of the normal faults has an about n s direction

tectonics and sedimentation in the gulf of corinth and the zakynthos and kefallinia channels western greece abstract single channel seismic reflection profiling data are presented from the gulf of corinth and from the continental margin outside the gulf of patras different tectonic styles are exhibited in the two regions the gulf of corinth is occupied by a complex asymmetrical graben structure with major faults trending nearly perpendicular to the local tectonic zones of the internal hellenides the gulf is interpreted to have formed during the quaternary in response to approximately north south extensional stress the deep floor of the gulf is underlain by a sequence of turbidites up to 1 km thick affected by normal growth faulting that extends up to the sea floor the sea areas inside the ionian islands of zakynthos and kefallinia zakynthos and kefallinia channels occupy a broad structural depression that trends parallel to the local tectonic zones of the external hellenides and is situated on the continental side of the strophades continental margin rise the channels contain local nw se trending structural basins zakynthos and kefallinia basins whose geometry is controlled by reverse faults or thrusts with associated diapirism in triassic evaporites hydra bank is interpreted as a tilted fault block with a diapiric core and its faulted western margin can be traced into the zone of thrusting and diapirism in southeast kefallinia at the boundary between the ionian and pre apulian paxos zones of the external hellinides the zakynthos and kefallinia structural basins are filled with a variety of sediments including prodeltaic deposits in front of the modern delta complex of the acheloos river slumped masses and debris flow deposits and in the zakynthos basin occasional turbidites the boundary separating zones of extensional and compressional focal mechanisms for shallow earthquakes crosses the gulf of patras the inner part of which exhibits wnw ese trending graben tectonics apparently related to the gulf of corinth tectonic province onshore neotectonic studies around the gulf of patras are required in order to understand the nature and cause of the westward tectonic transition from wnw ese graben structures in the gulfs of corinth and patras to nw se oriented zones of subsidence with associated compressional tectonics and diapirism in the zakynthos and kefallinia channels

neotectonic evolution of northwestern continental greece the post miocene sedimentary and structural evolution of nw continental greece changes from west to east

palaeoenvironmental reconstruction of the eastern part of the karapinar ayranci coal deposit central turkey abstract regional tectonic movements during the neogene period resulted in the development of several fault controlled basins in central anatolia many of these basins host economic coal deposits the recently discovered karapinar ayranci coal deposit is the most important one due to its large reserves c 1 8 gt and location in the vicinity of important urban areas the paper aims to reconstruct the palaeoenvironmental conditions before during and after coal formation in the eastern part of karapinar ayranci deposit by means of coal petrography and mineralogical data combined with sedimentological and palaeontological data the basinal infilling consists of mainly lacustrine fluvial and alluvial sediments the coal seams comprise several beds intercalating with claystone mudstone and marl the coal being lignite in rank displays high ash yield 36 4 wt on dry basis and high total sulphur content avg 7 7 wt on dry ash free basis facies diagrams and lithological features of the coal seams suggest that peat was accumulating under pure telmatic to limnotelmatic conditions however peat accumulation ceased several times due to a rise in water level therefore clastic e g quartz clay minerals and authigenic e g pyrite mineral contents are variable along the seam profile gastropod and ostracod fauna points to freshwater conditions in the palaeomire high total sulphur and evaporite mineral e g halite contents usually point to brackish saline conditions during peat accumulation however in case of the karapinar ayranci deposit high sulphur contents can be related to sulphate rich karstic aquifer which contributed to the palaeomire water supply

a microearthquake study in the gulf of patras region western greece and its seismotectonic interpretation summary the seismicity of the gulf of patras region was monitored from 1983 may to 1984 april by a six station microearthquake network with 30 km aperture over 650 events were located using the revised version of the hypo71 computer program for determining hypocentral locations of these a subset of 73 well located events was identified for detailed study analysis of these 73 events reveals a local pattern of seismicity with two main features firstly a gap in seismicity in the central and western parts of the gulf despite the local presence of active faulting affecting the seabed secondly a zone of high seismicity in the northeast part of the gulf where offshore seismic surveys reveal a zone of intense structural complexity a northeast dipping diffuse zone of seismicity extending to a depth of about 25 km has been identified in the northeastern corner of the gulf centred on the rio antirrio channel between the gulfs of patras and corinth it is postulated that the active faults in the central part of the gulf which are apparently aseismic are linked via a shallow decollement surface under the gulf to a deep wnw ese trending fault zone defining the southern margin of the corinth graben and extending westwards to trichonis lake the dipping zone of seismicity is related to the latter fault zone and aseismic faulting in the gulf of patras is attributed to the shallow surface of decollement into which the faults sole a transfer fault zone trending approximately ne sw is postulated to account for the offset of the corinth and patras grabens

a traverse of the ionian islands front with coincident normal incidence and wide angle seismics abstract marine vertical reflection profiling with a powerful airgun source augmented with a few wide angle seismometer stations on land has been applied along a 180 km line across the presently active deformation front of the subduction of the ionian sea plate beneath the western hellenides east of the ionian islands there is limited evidence for reflectivity down to 23 km interpreted as the base of a rather thin continental type crust under the western slope of the islands a major normal incidence reflector dips eastward first gently to the west of the islands then more steeply under them this reflector may be extrapolated southwestwards beneath a bulge that is thought to represent the modern pre apulian front located over the subduction zone the continuity signature and geometry of this reflector suggest that it may act as the lower limit of the western hellenides where they override the ionian sea quasi oceanic crust rather than just an intracrustal interface of a pre apulian crust the location of the previous deformation front the ionian thrust proposed in previous models can be constrained by the new seismic data the new data raise the possibility of a larger area of evaporite mobility than previously considered insofar as active block motion apparently related to halokinesis is recognized west of the zakynthos anticline diapirism decollement and westward directed over thrusting in the pre apulian crust may have been brought on by late pliocene quaternary reactivation of regional extension associated with the separation of the peloponnesus from northern greece as it was captured by the anatolian aegean rotation and associated also with the fast clockwise rotation of the ionian islands as they were sheared off the apulian domain to the southwest by the initiation of the kefallinia transform

the 12 13 january 1988 narrow cold frontal rainband observed during mfdp fronts 87 part i kinematics and thermodynamics abstract the kinematic and thermodynamic structure of a narrow cold frontal rainband ncfr observed during the english french german mfdp fronts 87 experiment is presented radiosonde data indicated a very weak convective instability below 1500 m altitude and a low level jet of 30 m s 1 from ssw before the arrival of the front a cooling of about 1 c associated with an airflow of 13 m s 1 from wsw after its passage a composite of wind and reflectivity fields from 17 dual doppler radar analyses shows high reflectivity values large convergence and relatively intense vertical motions associated with this ncfr at the 1000 m altitude a mean vertical cross section perpendicular to the surface front derived from three successive high resolution dual doppler scans is used to examine the general characteristics of the air circulation a structure apparently similar to that of a density current is observed above the 2 km altitude however air flowing at a speed faster than the surface front appreciably mod

authigenic quartz in the upper freeport coal bed west central pennsylvania cathodoluminescence petrography was used to examine quartz grains contained in facies of the upper freeport coal bed middle pennsylvanian of west central pennsylvania samples included ash concentrates polished blocks of different lithotypes and standard petrographic pellets of specific gravity separates of facies channel samples more than 80 of the quartz in mineral and vitrain rich bands in the polished blocks of the upper freeport coal bed do not exhibit cathodoluminescence in specific gravity separates of the coal 100 of the quartz examined in the lightest gravity separates did not luminesce in the heaviest gravity separates which included shale parting material 60 of the quartz did not luminesce in contrast in a sample of shale directly overlying the coal bed more than 90 of the quartz luminesced on the basis of these cathodoluminescence data and other published data quartz in the upper freeport coal bed is interpreted to be authigenic in origin the authigenic quartz grains are postulated to have been derived from phytoclasts

rupture process and aftershocks relocation of the 8 june 2008 mw 6 4 earthquake in northwest peloponnese western greece on 8 june 2008 at 12 25 gmt an m w 6 4 strong earthquake occurred in the area of northwest peloponnese western greece causing the death of two people and extensive damage to the surrounding area the main event and its aftershocks were recorded by one nationwide and three regional networks equipped with three component broadband seismometers initial locations of the earthquake sequence comprising 438 aftershocks showed a linear northeast southwest trend and that the mainshock was located at 22 km depth after the relocation using catalog and differential travel times most events form three distinct clusters at depths 15 25 km moment tensor solutions for the main event and its largest aftershocks exhibited a pure strike slip mechanism with one nodal plane orientated northeast southwest in accordance with the relocated seismicity a parallel nonnegative least squares inversion technique utilizing multiple time windows was used to derive the spatiotemporal slip distribution of the main event the resulting slip distribution model revealed a large slip patch maximum slip 150 cm between 10 and 20 km depth at the northeast part of the fault that also coincides with the area that suffered most of the damage another patch exhibiting smaller amounts of slip 20 50 cm is located to the southwest direction at the same depth range and smaller patches exist at 25 30 km depth most aftershocks are located in areas of low slip 25 cm filling the regions of slip deficit the 8 june earthquake occurred at an area where no previous seismological or other observations indicated the existence of a seismogenic fault at that depth and with this strike this and the fact that the event nucleated in the middle to lower crust may be interpreted as the reactivation of a fault structure that was inherited from previous tectonic phases

the strain pattern in the western hellenic arc deduced from a microearthquake survey summary than loo0 earthquakes recorded during 7 weeks in 1986 in the peloponnese and surrounding areas show shallow seismicity spread over a wide area bounded by the hellenic trench the highest level in the energy release is for clusters located along the hellenic trench where changes in the morphology are seen a few clusters are also observed as at the intersection between the gulf of corinth and the gulf of patras near the lake trikhonis or between kythira and crete in the peloponnese the shallow earthquakes do not define single faults but are diffusely distributed a higher concentration and a deepening of the foci within the whole crust towards the west seem to reflect a higher strain rate there fault plane solutions exhibit a scattered pattern for earthquakes shallower than 11 km but for earthquakes deeper than 11 km they show some consistency in the orientation of p t and b axes gently dipping nodal planes are seen all over the peloponnese with the conjugate vertical plane striking in various directions and with no consistency in the sense of motion these earthquakes are located between 8 and 18 km deep and could reflect a decoupling between the lower and the upper crust reverse faulting is seen in the gulf of kefallinia and the western peloponnese the p axes trend ne sw to e w normal faulting is seen in the gulf of corinth and in central peloponnese with the t axes trending n s and in the southern peloponnese where the t axes trend nw se the deformation over the western hellenic arc revealed by fault plane solutions of earthquakes with depth between 11 and 40 km appears to be the superposition of two phenomena first throughout the aegean crustal extension with orientation roughly parallel to the trench dominates with crustal shortening and subduction along the aegean arc superimposed on this is a more local effect of the collision between the aegea and apulia which seems to induce horizontal compression roughly perpendicular to the aegean arc west of the peloponnese and epirus the compression due to this decays eastward at a distance comparable with the width of the collision zone the deepening of the brittleductile transition is likely to be due to an increase of the strain field towards the ionian islands

the january 2010 efpalio earthquake sequence in the western corinth gulf greece abstract the january 2010 efpalio earthquake sequence provides some key elements to enhance our view on the western corinth gulf tectonics the sequence lasted almost six months and included two mw 5 strong events both exhibiting normal faulting along e w trending planes this paper attempts to construct a unified seismotectonic model of the sequence jointly interpreting earthquake locations moment tensors and slip inversions in terms of the possible activated fault planes previous studies have connected the prevailing microseismic activity to a major low angle north dipping structure under the corinth gulf and the efpalio sequence favors such a general trend moreover it clearly shows the significance of the shallow activity so far less recognized and possibly connected to the relatively steep faults outcropping on the northern coast the first 18 january 2010 mw 5 event had almost no on fault aftershocks and most likely it occurred on a 55 south dipping nodal plane the early off fault aftershocks formed two clusters roughly e w trending both of which are connected with normal faulting cross sections revealed that the northernmost cluster is connected with a north dipping structure where the second 22 january 2010 mw 5 event occurred in addition the very shallow parts of the faults

coal facies studies in the eastern united states coals in the eastern united states east of the mississippi river have been the subject of a number of coal facies studies going back to the 19th century such studies would not necessarily fall within a strict modern classification of coal facies studies but if a study encompassed some aspects of paleobotany palynology petrology geochemistry or sedimentology we assumed that some data and interpretations may be of use in evaluations of the facies references are presented as a guide for further research with annotation in the tables

palaeoenvironmental reconstruction of the cardak coal seam sw turkey abstract the study focuses on the firstly documented cardak coal seam cored in the neogene acigol basin denizli province being formed in a late stage of alpine orogeny in sw turkey the aim is to contribute reconstructing the palaeoenvironmental conditions before during and after coal formation on the basis of coal petrology mineralogical and palaeontological data combined with the results of previous studies the basin infilling consists of alluvial fluvial and lacustrine sediments their deposition depended on the water level in the basin which in turn was controlled by the interplay between tectonics and climate coal seam was probably formed in latest miocene early pliocene under the influence of basin s fluvial regime in oxbow and terminal lakes the coal seam comprises alternating inorganic and coal layers logged between depths of 599 00 to 627 00 m beneath surface the coal being lignite to subbituminous in rank displays moderate to high ash yield 21 31 46 11 wt on dry basis and high total sulphur content up to 13 30 wt on dry ash free basis the maceral composition points to an origin from mainly herbaceous helophytes along with woody species in the upper part of the core the presence of salinity tolerant ostracod species along with gypsum and halite are documented the palaeontological and mineralogical data obtained imply changes of climate water level and lake chemistry in the basin

the april 2007 earthquake swarm near lake trichonis and implications for active tectonics in western greece abstract we investigate the properties of the april 2007 earthquake swarm mw 5 2 which occurred at the vicinity of lake trichonis western greece first we relocated the earthquakes using p and s wave arrivals to the stations of the hellenic unified seismic network husn and then we applied moment tensor inversion to regional broad band waveforms to obtain the focal mechanisms of the strongest events of the 2007 swarm the relocated epicentres cluster along the eastern banks of the lake and follow a distinct nnw ese trend the previous strong sequence close to lake trichonis occurred in june december 1975 we applied teleseismic body waveform inversion to obtain the focal mechanism solution of the strongest earthquake of this sequence i e the 31 december 1975 mw 6 0 event our results indicate that a the 31 december 1975 mw 6 0 event was produced by a nw se normal fault dipping to the ne with considerable sinistral strike slip component we relocated its epicentre i using phase data reported to isc and its coordinates are 38 486 n 21 661 e ii using the available macroseismic data and the coordinates of the macroseismic epicentre are 38 49 n 21 63 e close to the strongly affected village of kato makrinou b the earthquakes of the 2007 swarm indicate a nnw sse strike for the activated main structure parallel to the eastern banks of lake trichonis dipping to the ne and characterized by mainly normal faulting occasionally combined with sinistral strike slip component the 2007 earthquake swarm did not rupture the well documented e w striking trichonis normal fault that bounds the southern flank of the lake but on the contrary it is due to rupture of a nw se normal fault that strikes at a 45 angle to the trichonis fault the left lateral component of faulting is mapped for the first time to the north of the gulf of patras which was previously regarded as the boundary for strike slip motions in western greece this result signifies the importance of further investigations to unravel in detail the tectonics of this region

the winter 1991 1992 earthquake sequence at cephalonia island western greece properties of the earthquake sequence of the 23 january 1992 5 8 ms earthquake in cephalonia island western greece are investigated the parameter b in the frequency magnitude relation is found equal to 1 084 while the decay parameter p of the time distribution of the aftershock sequence is found equal to 0 991 the principal parameters method is applied to the aftershock sequence and the average strikes of n156 e 20 and n61 e 10 were obtained denoting also very small dips the major strike which resulted from the aftershock epicentre distribution was nw se similar to miocene neogene basins on cephalonia island

stratigraphic and interregional changes in pennsylvanian coal swamp vegetation environmental inferences abstract quantitative analysis of pennsylvanian coal swamp vegetation provides a means of inferring organization and structure of communities distribution of these communities further provides inferences about environmental factors including paleoclimate our observations are based on in situ structurally preserved peat deposits in coal ball concretions from 32 coal seams in the eastern one half of the united states and from several seams in western europe and on spore assemblages from more than 150 seams there were three times of particularly significant and nearly synchronous vegetational changes in the midcontinent and appalachian coal regions during the pennsylvanian period each was different in kind and magnitude the first marked changes occurred during the early part of the middle pennsylvanian with the fluctuating decline in the high level of lycopod dominance the abundance of cordaites increased there was a rise in the occurrences of the lycopod herbs to form intercalated marshlands and an overall increase in floral diversity changes ensuing from this time also include shifts in dominant species of lycopod trees and a sustained rise in abundance and diversity of tree fern spores the next significant time of change was during the middle part of the middle pennsylvanian representing both a culmination of earlier trends and expansions of cordaites in the midcontinent where there was a maximum change in species without net loss of diversity tree ferns and medullosan pteridosperms attained subdominant levels of abundance and diverse lycopod species dominated except in the atokan desmoinesian transition of the midcontinent the third and sharpest break occurred near the middle late pennsylvanian boundary when extinctionsof the dominant coal swamp lycopods allowed development of tree fern dominance the late pennsylvanian coal swamps apparently were colonized or recolonized mainly by species from outside coal swamps rather than by the survivor populations of the middle pennsylvanian swamps paralleling the changes in floras through the pennsylvanian are changes in preservational aspects of the peat these include a decline in shoot root ratios from approximately 1 to

stable isotopic and elemental characteristics of pale and dark layers in a late pliocene lignite deposit basin in yunnan province southwestern china implications for paleoenvironmental changes abstract the carbon and nitrogen stable isotopic compositions and elemental characteristics of pliocene pale and dark lignites in the jinsuo basin yunnan province southwestern china were investigated these data were used to develop paleoenvironmental models and to discuss possible geological driving forces for the formation of pale and dark layers the 13c values of fossil wood av 24 79 and fusain samples av 24 19 are generally higher than the values obtained from bulk pale av 27 01 and dark av 26 38 lignite samples in contrast the 15n values of fossil wood av 0 63 and fusain samples av 1 29 are lower than the average values of bulk pale lignites av 2 17 and dark lignites av 1 79 the difference in the carbon isotopic values between pale and dark lignites can be explained by the very high amount of liptinite and strong degradation of woody material by bacterial activity in pale lignites which resulted in depletion of 13c in pale lignites and the wet humid depositional conditions contributed to the relatively heavy stable carbon isotope compositions of dark layers the higher 13c values in the fossil wood and fusain samples can be explained by the general enrichment of 13c in woody material compared to leaves the weakly negative correlation between the 15n and 13c values indicates that besides bacterial degradation the liptinite content could also influence the carbon and nitrogen compositions of lignites the influence of the original plant community gymnosperms angiosperms on the carbon and nitrogen isotopic compositions of bulk lignites is insignificant in the jinsuo basin the paleoenvironmental model suggests deposition of pale layers under relatively dry cold conditions supporting the expansion of gymnosperms such as pinus yunnanensis the slight stepwise uplift of the tibetan plateau and the approximate co occurrence of the more intense asian monsoon might have supported short periods of a locally dry cold climate resulting in the lowering of water table which was favorable for the formation of pale layers the low 13c values in pale layers further support this the relatively high sio2 al2o3 ratios higher values of the average detrital authigenic index and high levels of tio2 and zr in pale layers suggest an increased detrital input relative to dark layers the dark layers however formed in a tropical subtropical warm humid climate that favored angiosperm dominance of the vegetation the long term geologically stable conditions together with the regionally warm humid climate resulted in a rise in the water table in the basin which led to the formation of dark layers until the subsequent slight uplift of the tibetan plateau this conclusion is also supported by the high 13c values in dark layers and the thickness differences between pale thin and dark thick layers and the changes in major elements and minerals changes between the two types of layer

axisymmetric potential vorticity evolution of hurricane patricia 2015 abstractoperational numerical models failed to predict the record setting rapid intensification and rapid overwater weakening of hurricane patricia 2015 in the eastern north pacific basin result

effects of detrital influx in the pennsylvanian upper freeport peat swamp abstract quartz cathodoluminescence properties and mineralogy of three sets of samples and vegetal and or miospore data from two sets of samples from the upper freeport coal bed west central pennsylvania show that detrital influence from a penecontemporaneous channel is limited to an area less than three km from the channel the sets of samples examined include localities of the coal bed where 1 the coal is thin split by partings and near a penecontemporaneous fluvial channel 2 the coal is relatively thick and located approximately three km from the channel and 3 the coal is thick and located approximately 12 km from the channel samples from locality 1 nearest the channel have relatively high ash yields low temperature ash average 27 3 on a pyrite and calcite free basis and high proportions of quartz and clay minerals the quartz is primarily detrital as determined by cathodoluminescent properties and the ratio of kaolinite to illite is low in addition most of the plant remains and miospores indicate peat forming plants that required low nutrient levels for growth in contrast samples from localities 2 and 3 from the more interior parts of the bed contained predominantly authigenic quartz grains nd yielded low temperature ash values of less than 14 on a pyrite and calcite free basis the low temperature ash contains low concentrations of quartz and clay minerals and the ratio of kaolinite to illite is relatively high although intact core was not available for paleobotanical analyses another core collected within 1 km from locality 3 contained plant types interpreted to have required high nutrient levels for growth these data indicate that mineral formation is dominated by authigenic processes in interior parts of the coal body some of the authigenic quartz may have been derived from herbaceous ferns as indicated by patterns in the palynological and paleobotanical data in contrast detrital processes appeared to be limited to in areas directly adjacent to the penecontemporaneous channel where the coal bed is high in ash split by mineral rich partings and of little or no economic value

ionian sea western greece its structural outline deduced from drilling and geophysical data abstract this paper outlines the preliminary structural results obtained by the compilation of geological drilling and geophysical data in western greece most external geotectonic zones of the hellenides are included in the geological setting of the marine and insular domain of western greece ionian pre apulian and apulian zones the gavrovo and pindus zones make a restricted contribution to the marine geological framework continental shelf of southwest peloponesus besides the geographical setting of the geotectonic units their general tectonic characteristics allow the following remarks to be made the main tectonic events younger than eocene are well marked in both ionian and pre apulian zones the detrital sequence shows a fast pinch out towards the apulian platform where the plio quaternary clastic layers overlap what are probably late mesozoic or early tertiary limestones taking into consideration general tectonic features we can distinguish a northern area and a southern one separated by a fault trending 30 n located on the western margin of kephallinia lefkas islands 1 a in the northern area we observe a strong tangential tectonism decreasing towards the apulian platform with transitional characteristics on the pre apulian zone paxos where asymmetrical folding occurs 2 b in the southern area from lefkas kephallinia islands to the s w cape of peloponesus the tangential tectomism is well masked by strong vertical faulting attributed to young plio quaternary deformations the fast subsidence induces huge diapiric structures in the ionian zone salt walls originating from triassic layers intersect a thick pleistocene sequence

the egion june 15 1995 6 2m l earthquake western greece on june 15 1995 at 00 15 gmt a devastating earthquake 6 2m l occurred in the western end of the gulf of corinth this was followed 15 min later by the largest aftershock 5 4m l the main event was located by the university of patras seismological network patnet at the northern side of the gulf of corinth graben the second event 5 4m l was located also by patnet near the city of egion on a fault parallel to the eliki major fault that defines the south bound of the gulf of corinth graben a seismogenic volume that spans the villages of akrata se and rodini nw and extends to eratini ne was defined by the aftershock sequence which includes 858 aftershocks of magnitude greater than 2m l that occurred the first seventeen days the distribution of hypocentres in cross section does not immediately suggest a planar distribution but rather defines a volume about 15 km depth by 35 km nw se and by 20 km ne sw

a catalogue of seismicity in greece and adjacent areas summary a new earthquake catalogue for greece has been formed to cover the instrumental period 1901 78 in particular 605 earthquakes for the period 1917 63 inclusive are relocated using first arrival data from the international seismological summary these relocations incorporate macro seismically and other well controlled master events into an ensuing joint epicentre determination technique the largest annual average shift is 165 km for 78 earthquakes during the decade after 1917 decreasing to 17 km for the later years 1957 63 magnitudes are redetermined mainly using readings from the swedish network and uppsala since as early as 1908 catalogue completeness exists for magnitudes around 5 5 for at least the last 60 years but magnitudes of about 4 7 are completely reported only during the most recent 15 years the new epicentral positions lead to a better delineation of the seismic zones than has previously been achieved the majority of shallow earthquakes are contained in a belt parallel to the hellenic arc which extends north into albania in the south east the epicentral locations give a more diffuse extension of this zone into the west coast of turkey depths of intermediate earthquakes along the hellenic arc tend to relocate to shallower depths in the south west part of crete no earthquake focus deeper than 100 km is found although in the south eastern section of the arc a tendency to increased depths is observed a second zone starts at leukas island in the west and extends through central greece to near volos on the east coast where it divides into two branches which are less well defined but which eventually join the seismicity of western turkey a third zone follows the saronikos and corinth gulfs

the sedimentary record of carboniferous rivers continuing influence of land plant evolution on alluvial processes and palaeozoic ecosystems abstract evidence from modern rivers and the deep time geological record attests to the fundamental importance of plant life for the construction of physical habitats within fluvial environments data from an extensive literature review and original fieldwork demonstrates that many landforms and geomorphic features of modern river systems appear in the palaeozoic stratigraphic record once terrestrial vegetation had adopted certain evolutionary advances for example stable point bars are associated with the onset of rooted plants in the siluro devonian and avulsive and anabranching fluvial systems become common at the same time as extensive arborescent vegetation in the carboniferous in this paper we demonstrate a correlation between the diversification of physical fluvial environments and the expansion of terrestrial fauna and flora with an emphasis on the culmination of these trends within carboniferous alluvial systems many extrinsic factors have been considered as possible controls on the evolutionary timelines of terrestrialization for organisms however a fundamental prerequisite for achieving terrestrial biodiversity was the variety of physical habitats especially riparian systems available for newly evolved organisms in association with abundant lowland meandering systems the widespread appearance across carboniferous alluvial plains of fixed channel and anabranching reaches created further physical landforms for colonization and would have promoted increasingly complex hyporheic flow regimes furthermore the associated increase in arborescent vegetation and supply of large woody debris to inland and coastal rivers would have created a wealth of microhabitats for continental organisms we argue that the expanding extent and diversity of physical alluvial niches during the palaeozoic is an underappreciated driver of the terrestrialization of early continental life the study of the deep time fossil and stratigraphic record also illustrates that vegetation is a fundamental prerequisite for the creation of biogeomorphic alluvial landforms and physical habitats and microhabitats

northwestern turkey earthquakes and the crustal structure inferred from surface waves observed in western greece records of several earthquakes occurring in turkey in 1999 obtained at broadband seismic stations in western greece have been used to study the dispersion of surface waves mainly love waves the observed group velocity dispersion curves have been inverted into horizontally layered models of the earth s crust by a modified method of the single parameter variation as compared with a previous model for the territory of greece the dispersion data require significantly lower velocities in the uppermost crust and smaller crustal thickness in particular the resulting model displays s wave velocities between 1 3 and 2 4 km sec in the upper 2 km and a crustal thickness of about 33 km manuscript received 31 july 2000

geometry and kinematics of active faults and their seismotectonic significance in the western corinth patras rift greece abstract the western part of the corinth patras rift is formed in an area which is being uplifted rifted domains have subsided relative to the adjacent areas in nw peloponnesus and sterea hellas but subsidence rates rarely exceed uplift rates extension is mainly accomplished by wnw trending active faults with lengths up to 25 km most of these faults show an along strike segmentation and often terminate against transfer faults displacement analysis along 170 mesoscopic faults and 36 mappable faults has been carried out to assess slip rates and to estimate the magnitudes and recurrence time intervals of earthquakes occurring along them earthquake magnitude ranges between 5 and 6 7 only eight faults appear to be capable of producing earthquake magnitudes larger than 6 recurrence times of these large earthquakes vary between 80 and 1690 years upper crustal deformation in the western corinth graben can be described by six large asymmetric grabens which are inferred to bottom out to a n dipping curved ramp the asymmetric shape of most wnw trending rifts in the hellenic peninsula including the corinth patras rift promotes the simple shear model of extension against the pure shear model in the upper crustal layer

the aigion neos erineos coastal normal fault system western corinth gulf rift greece geomorphological signature recent earthquake history and evolution 1 at the westernmost part of the corinth rift greece an area of rapid extension and active normal faulting geomorphological observations reveal the existence and geometry of an active nw se trending coastal fault system which includes the aigion fault we recognize a similar fault pattern on both the coastal range front to the nw of aigion town and the holocene fan deltas in front of it we interpret this as a result of recent migration of faulting to the hanging wall of the fault system differences in the geomorphic expression of the constituent faults provide hints on the possible evolution of the fault pattern during this recent migration a trench excavated across one of the identified coastal fault scarps on a holocene fan delta provides information on the seismic history of the fault system which includes at least four possibly six earthquakes in the past 4000 years a minimum estimate for the slip rate of the trenched fault is 1 9 2 7 mm yr the trench exposed sediments of an uplifted paleolagoon approximate age 2000 years b p inside which the last two earthquakes formed an underwater monoclinal scarp oscillating coastal vertical movements are suggested by the fact that the lagoonal deposits are also uplifted on the trenched fault hanging wall uplift by offshore faults and by the abrupt transition from fluvial to lagoonal deposits subsidence by more landward faults assuming that extensive coastal sediment failure has not taken place in the specific part of the fan delta within the time interval of interest these movements suggest that the proposed migration of activity from the range front faults to those on the fan deltas is probably still ongoing with activity on both sets of faults

mineralogy of the volcanic influenced great northern coal seam in the sydney basin australia abstract the mineralogy of the individual coal plies and intra seam claystone bands in the great northern seam of the sydney basin has been evaluated using optical and scanning electron microscopy and quantitative x ray diffraction techniques the uppermost two claystone bands are tonsteins consisting mainly of well ordered kaolinite with graupen to vermicular textures idiomorphic crystals of k feldspar within these tonsteins may represent members of the anorthoclase sanidine series or a sodic sanidine and indicate an acid to intermediate volcanic ash input in contrast the lowermost parting was largely derived from epiclastic sediment admixed with minor volcanic material such as high temperature quartz and a different type of k feldspar component the mineral fraction of the coals especially in the middle and upper parts of the seam is dominated by authigenic kaolinite with a very low abundance of quartz apart from the tonsteins authigenic processes therefore appear to be the dominant mechanism of mineral matter formation authigenic k feldspar also occurs in the lower few metres of the seam with a variety of modes of occurrence including cell and cleat infillings cross cutting veins and thin laminae parallel to the organic matter and detrital clay bands a late syngenetic low temperature hydrothermal fluid injection process is suggested for formation of the feldspar veins the origin of the fluid is uncertain but is most likely associated with contemporaneous volcanic activity

flexural uplift of rift flanks in central greece uplifts with elevations of up to 2000 m and short wavelengths 30 35 km flank three major grabens in central greece the rio sparta and atalanti grabens they are bordered on their landward sides by narrow basins oriented parallel to the graben axes the manesi and trichonis basins at the rio graben and copais and istiea basins at the atalanti graben the flexural origin of these uplift profiles is investigated here by using thin broken plate models it is demonstrated that the observed topography of the graben flanks is consistent with the upward deflection of elastic and viscoelastic plates in response to upward directed forces applied at the graben flanks in order to evaluate to applicability of each model their predictions are checked against the observations the elastic predictive modeling fits well with the observed flexural wavelengths and the flanking seismicity however it fails to predict the graben widths and the inferred elastic layer thickness in contrast the viscoelastic model successfully explains the graben widths and the back basins as flexural hinterland basins and matches the seismological data and the time constraints of rifting it is therefore suggested that flexural uplift with viscoelastic relaxation accounts for the building of the graben flanks the invoked viscoelastic models constrain the effective elastic thickness of the plates at 10 km for the rio graben and 15 km for the sparta and atalanti grabens suggesting a low viscosity lower crust furthermore they predict low rates of tectonic uplift of the order of 0 1 mm a 1 for the atalanti graben intermediate rates of 0 24 0 37 mm a 1 for the rio graben and high rates of 0 7 0 9 mm a 1 for the sparta graben the latter are quite possibly overestimated since napping events capable of producing high local relief are traced normal to the modeled profiles

comparison of the petrography palynology and paleobotany of the little fire creek coal bed southwestern virginia u s a abstract two continuous cores that penetrated the lower pennsylvanian little fire creek coal bed in the southwestern coal field in southwestern virginia were sampled and x ray radiographed to determine subunit distinctions comparison of petrographic palynologic and paleobotanic data from the same sample sets from the two cores allowed for comparison of compositional data within the little fire creek coal bed the proximate petrographic palynologic and plant tissue data from two sets of samples indicate a high ash gelocollinite and liptinite rich coal consisting of a relatively diverse paleoflora including lycopsid trees small lycopsids tree ferns small ferns pteridosperms seed ferns and rare calamites and cordaites the relatively very high ash yields 3 80 wt the relatively thin subunits 1 28 cm and the large scale vertical variations in palynomorph floras suggest that the study area was at the edge of the paleopea forming environment as a result most of the compositional correspondences are among those components indicative of degradation or decomposition

diagenetic quartz and amorphous silica in new zealand coals new zealand coal seams late cretaceous miocene lignite semi anthracite contain numerous and varied occurrences of diagenetic quartz and amorphous silica early diagenetic silicifications include sub horizontal and laterally extensive quartz mineralized bands micro and megascopic euhedral quartz crystals dispersed or concentrated in layers and silicified in situ tree stumps late diagenetic forms include sub horizontal quartz mineralized bands mostly 1 m in length and fracture infillings the origins of the silica remain uncertain but leached basement rocks and coal measure sediments and siliceous phytoliths within the coal forming plants are possible sources the silicification of coal seams may have significant implications for exploration mining and geological studies

seismotectonics of the aegean region abstract fault plane solutions neotectonic field observations and in situ stress measurements have been used to determine the stress field associated with the active deformation of the lithosphere in the aegean and surrounding regions a stress gradient and a zonal pattern of different tectonism away from the trench axis has been postulated pure thrust faulting occurs in the fore arc side while the back arc side is mainly dominated by almost n s extensional tectonics a narrow belt of strike slip faults with predominantly thrust component separates these tectonic zones this belt seems to represent a transition from the thrust type faults to normal faults fault plane solutions of the whole region in question indicate that both the large and small magnitude shocks are caused by the same regional stress field a body of 33 focal mechanisms indicates that the intermediate depth shocks along the sinking mediterranean slab are associated with thrust type fracturing orientation of kinematic axes favours the suggestion that shear zones within the descending slab cause these shocks the active crustal shortening along the hellenic consuming boundary and the sinking of the mediterranean lithosphere beneath the south aegean area explain satisfactorily the seismotectonic features of the fore arc and the southern back arc sides on the contrary geophysical evidence concerning the cenozoic geodynamic evolution of the aegean is needed to interpret features of the north back arc area

reflection refraction seismics in the gulf of corinth hints at deep structure and control of the deep marine basin abstract the gulf of corinth is a natural laboratory for the study of seismicity and crustal deformation during continental extension seismic profiling along its axis provides a 24 fold normal incidence seismic reflection profile and wide angle reflection refraction profiles recorded by sea bottom seismometers obs and land seismometers at wide angle incidence the land receivers document the moho at 40 km depth under the western end of the gulf north of aigion rising to 32 km depth under the northern coast in the east of the gulf both refraction and normal incidence reflection sections image the basement under the deep marine basin that has formed by recent extension the depth to the base of the sedimentary basin beneath the gulf constrained by both methods is no more than 2 7 km with 1 km of water underlain by no more than 1 7 km of sediment less than what was expected from past modeling of uplift of the south coast in the east of the gulf unlike the flat sea bottom the basement and sedimentary interfaces show topography along this axial line several deeps are identified as depocenters which suggest that this axial line is not a strike line to the basin it appears instead to be controlled by several faults oblique to the s60 e overall trend of the south coast of the gulf their more easterly strikes being consistent with the instantaneous direction of extension measured by earthquake slip vectors and by gps

the evolution of the gulf of corinth greece an aftershock study of the 1981 earthquakes summary a preliminary study of the aftershocks of three earthquakes that occurred near to corinth greece in 1981 is combined with observations of the morphology and faulting to understand the evolution of the eastern gulf of corinth the well located aftershocks form a zone 60km long and 20km wide they do not lie on the main fault planes and are mostly located between the north dipping faulting on which the first two earthquakes occurred and the south dipping faulting associated with the third event a cluster of aftershocks also lies in the footwall of the eastern end of the south dipping fault of the third event morphologically it is observed that in the evolution of the eastern gulf of corinth antithetic faulting apparently predates the appearance of the main faulting at the surface this evolution can be explained by motion on a deep seated shallow angle aseismic normal fault a model based on such a fault also accounts for the aftershock distribution of the 1981 earthquakes

electrical conductivity and crustal structure beneath the central hellenides around the gulf of corinth greece and their relationship with the seismotectonics a deep magnetotelluric sounding mts investigation in the western part of the gulf of corinth has revealed a complex electrical image of the crustal structure the geotectonic structure of the parnassos unit and the transition zone in the central hellenides overthrusting the pindos zone both towards the west and towards the south has been clearly identified by its higher resistivity and its intrinsic anisotropy related to the n s strike of the hellenides range subsequent n s extension of the gulf introduced another heterogeneous anisotropy characteristic that corresponds to e w trending normal faults on both sides of the gulf the 2 d modelling of the mts results reveals the existence of a relatively conductive layer about 4 km thick at a depth greater than 10 km in the middle crust it corresponds to a ductile detachment zone suggested by microseismic and seismic studies king et al 1985 rigo et al 1996 bernard et al 1997a it may be attributed to the phyllite series lying between the allochthonous hellenic nappes and the autochthonous plattenkalk basement towards the east under the pangalos peninsula approaching the internal hellenides the detachment zone could root deeply into the lower crust some strong local electrical anomalies are observed reaching the conductive layer in the middle crust such as that under the mamousia fault and under the front of the overthrust of the transition zone on the pindos zone other anomalies affect only the shallower zones such as that beneath the helike fault and in the psaromita peninsula these shallower anomalies provide complementary information to the study of spatial and temporal variations of the seismic anisotropy in relation to the short and long term tectonic activity of the gulf bouin et al 1996 gamar et al 1999