the kerogen type depositional environment and maturity of the irati shale upper permian of parana basin southern brazil abstract two samples from the upper and lower horizons of the irati oil shale of the parana basin brazil were sampled in a single borehole and analysed using organic petrography and geochemistry the results are interpreted in terms of the kerogen type maturity and depositional environment of the two horizons organic petrography shows the oil shales to be composed of a mineral groundmass mainly clay minerals carbonate and pyrite associated and sometimes impregnated with fluorescing organic material and disseminated phytoclasts humic material is fairly rare and mostly present as very small particles the liptinitic particles are mostly alginite a and b sporinite and more rarely resinite reflectance measurements upper seam 0 34 r0 lower seam 0 40 r0 indicate an equivalent rank of lignite sub bituminous coal astm i e immature with respect to oil and gas generation different organic geochemical methods rock eval pyrolysis solvent extraction gc and gc ms demonstrate both samples to be immature rich oil shales 100 114 kg ton containing type i kerogen of a dominantly bacterially degraded algal origin deposited in a lacustrine environment the presence of botryococcus suggests deposition under fresh brackish water conditions a tentative interpretation of the extract and vitrinite reflectance data suggests a maximum paleo burial of between 1 3 and 2 8 km for the analysed section of the irati formation

supposed permo triassic megashear between laurasia and gondwana a consensus has emerged that during the palaeozoic several landmasses progressively collided to form the supercontinent pangaea which subsequently split up in the mesozoic and tertiary to produce the present array of continents but whereas there is a high measure of agreement about the general shape of the early jurassic pangaea shortly before the initial atlantic opening three very different reconstructions of the end palaeozoic supercontinent have recently been proposed these differences which involve the relative positions of the northern and southern sectors of pangaea known respectively as laurasia and gondwana relate to the interpretation of palaeomagnetic data the three constructions are here tested with reference to geological and palaeobiogeographic data and arguments

contrasting eastern pacific and central pacific types of enso abstract surface observations and subsurface ocean assimilation datasets are examined to contrast two distinct types of el nino southern oscillation enso in the tropical pacific an eastern pacific ep type and a central pacific cp type an analysis method combining empirical orthogonal function eof analysis and linear regression is used to separate these two types correlation and composite analyses based on the principal components of the eof were performed to examine the structure evolution and teleconnection of these two enso types the ep type of enso is found to have its sst anomaly center located in the eastern equatorial pacific attached to the coast of south america this type of enso is associated with basinwide thermocline and surface wind variations and shows a strong teleconnection with the tropical indian ocean in contrast the cp type of enso has most of its surface wind sst and subsurface anomalies confined in the central pacific and tends to onset develop and decay in situ

the vertical and spatial structure of enso in the upper troposphere and lower stratosphere from gps radio occultation measurements 1 the vertical and spatial structure of the atmospheric el nino southern oscillation enso signal is investigated using radio occultation ro data from august 2006 to december 2010 due to their high vertical resolution and global coverage ro data are well suited to describe the full 3 dimensional enso structure in the troposphere and lower stratosphere we find that interannual temperature anomalies in the equatorial region show a natural decomposition into zonal mean and eddy deviations from the zonal mean components that are both related to enso consistent with previous studies we find that during the warm phase of enso zonal mean temperatures increase in the tropical troposphere and decrease in the tropical stratosphere maximum warming occurs above 8 km and the transition between warming and cooling occurs near the tropopause this zonal mean response lags sea surface temperature anomalies in the eastern equatorial pacific by 3 months the atmospheric eddy component in contrast responds rapidly within 1 month to enso forcing this signal features a low latitude dipole between the indian and pacific oceans with off equatorial maxima centered around 20 to 30 latitude in both hemispheres the eddy response pattern attains maximum amplitude in the upper troposphere near 11 km and with opposite polarity in a shallow layer near the tropopause at approximately 17 km the eddy enso signal tends to be out of phase between low and middle latitudes in both the troposphere and lower stratosphere citation scherllin pirscher b c deser s p ho c chou w randel and y h kuo 2012 the vertical and spatial structure of enso in the upper troposphere and lower stratosphere from gps radio occultation measurements geophys res lett 39 l20801 doi 10 1029 2012gl053071

paleoreconstruction by biological markers abstract during diagenesis and conversion of the original lipid fraction of biological systems to petroleum hydrocarbons the following four basic events needed for paleoreconstruction can be monitored by biological markets 1 sourcing 2 maturation 3 migration and 4 biodegradation actual cases of applying biological markers to petroleum exploration problems in different parts of the world are demonstrated cretaceous and phosphoria sourced oils in the wyoming thrust belt can clearly be distinguished from one another by high quality source fingerprinting of biomarker terpanes using gas chromatography mass spectrometry identification of recently discovered biological markers head to head isoprenoids allows subtle source differentiation between oils from sumatra the degree of crude oil maturation in basins from california alaska russia wyoming and louisiana can be assessed by specific novel biomarker ratios 20s 20r sterane epimers field evidence from such interpretation is confirmed by laboratory pyrolysis of the rock an example of immature sumatra rock is given extensive migration is documented by biomarkers in several oils the effect of biodegradation on biomarker steranes and terpanes is exemlified in a california basin all biological marker results are consistent with the geological setting and add a new dimension in assisting the petroleum explorationist toward paleo reconstruction

aspects of interannual and intraseasonal variability of the tropopause and lower stratosphere radiosonde and national centers for environmental prediction national center for atmospheric research reanalysis data are utilized to consider aspects of large scale variability in tropopause height temperature and pressure this variability is related to coherent dynamical fluctuations in the troposphere and lower stratosphere through the use of linear correlation and regression on interannual time scales significant global scale tropopause fluctuations are tied to variability in sea surface temperature sst associated with the el ni o southern oscillation phenomenon when sst is anomalously high in the central tropical pacific tropopause height pressure is high low throughout the tropics with largest perturbation amplitudes in the subtropical pacific at the same time the tropopause is cold over the tropical and subtropical pacific sector but warm elsewhere in the tropics over the extratropics wave like perturbations in the tropopause are seen with anomalous cyclonic flow corresponding to a lower tropopause height and higher tropopause temperature and pressure and vice versa the sign of the temperature anomalies in the lower stratosphere tends to match that at the tropopause over much of the globe with opposite signed anomalies in the upper troposphere the vertical structure of these perturbations is consistent with the expected potential vorticity anomalies induced by quasi stationary rossby waves and vertically propagating gravity waves forced by displacements of tropical convection similar relationships are associated with the eastward propprotion of tropical convection due to the madden julian oscillation on intraseasonal time scales

a warming tropical central pacific dries the lower stratosphere the amount of water vapor in the tropical lower stratosphere tls which has an important influence on the radiative energy budget of the climate system is modulated by the temperature variability of the tropical tropopause layer ttl the ttl temperature variability is caused by a complex combination of the stratospheric quasi biennial oscillation qbo tropospheric convective processes in the tropics and the brewer dobson circulation bdc driven by mid latitude and subtropical atmospheric waves in 2000 the tls water vapor amount exhibited a stepwise transition to a dry phase apparently caused by a change in the bdc in this study we present observational and modeling evidence that the epochal change of water vapor between the periods of 1992 2000 and 2001 2005 was also partly caused by a concurrent sea surface temperature sst warming in the tropical central pacific this sst warming cools the ttl above by enhancing the equatorial wave induced upward motion near the tropopause which consequently reduces the amount of water vapor entering the stratosphere the qbo affects the tls water vapor primarily on inter annual timescales whereas a classical el nino southern oscillation enso event has small effect on tropical mean tls water vapor because its responses are longitudinally out of phase this study suggests that the tropical central pacific sst is another driver of tls water vapor variability on inter decadal timescales and the tropical sst changes could contribute to about 30 of the step wise drop of the lower stratospheric water vapor from 1992 2000 to 2001 2005

property changes of oil shale during artificial maturation the irati formation from the parana basin brazil abstractacquiring elastic property information from oil shale during pyrolysis remains a difficult endeavor we subject oil shale samples from the irati formation in the parana basin brazil to high temperature high pressure hydrous and anhydrous pyrolysis while simultaneously acquiring p and s waveform data we present elastic properties as a function of temperature at constant differential pressure using samples cored in three different directions relative to the bedding plane hydrous pyrolysis decreased total organic carbon toc in samples from 25 wt to 20 wt whereas anhydrous pyrolysis had no significant change in toc the cores experienced higher strain hysteresis up to 0 094 residual axial strain after hydrous pyrolysis compared to after anhydrous pyrolysis 0 56 residual axial strain the larger residual strain was accompanied by a larger increase in shear velocity up to 35 after hydrous pyrolysis as compared to the 3 shear velocity increase after anhydrous pyrolysis the change coul

contrasting effects of central pacific and eastern pacific el nino on stratospheric water vapor 1 targeted experiments with a comprehensive chemistry climate model are used to demonstrate that seasonality and the location of the peak warming of sea surface temperatures dictate the response of stratospheric water vapor to el nino in boreal spring el nino events in which sea surface temperature anomalies peak in the eastern pacific lead to a warming at the tropopause above the warm pool region and subsequently to more stratospheric water vapor consistent with previous work however in fall and in early winter and also during el nino events in which the sea surface temperature anomaly is found mainly in the central pacific the response is qualitatively different temperature changes in the warm pool region and specifically over the cold point region are nonuniform and less water vapor enters the stratosphere the difference in water vapor in the lower stratosphere between the two variants of el nino approaches 0 3 ppmv while the difference between the winter and spring responses exceeds 0 5 ppmv

small meanders of the kuroshio extension and associated northward spreading of warm water three vessel simultaneous observations and an eddy resolving ocean model simulation

linear trends in sea surface temperature of the tropical pacific ocean and implications for the el nino southern oscillation a principal component decomposition of monthly sea surface temperature sst variability in the tropical pacific ocean demonstrates that nearly all of the linear trends during 1950 2010 are found in two leading patterns the first sst pattern is strongly related to the canonical el nino southern oscillation enso pattern the second pattern shares characteristics with the first pattern and its existence solely depends on the presence of linear trends across the tropical pacific ocean the decomposition also uncovers a third pattern often referred to as enso modoki but the linear trend is small and dataset dependent over the full 61 year record and is insignificant within each season enso modoki is also reflected in the equatorial zonal sst gradient between the nino 4 region located in the west central pacific and the nino 3 region in the eastern pacific it is only in this zonal sst gradient that a marginally significant trend arises early in the northern hemisphere spring march may during el nino and la nina and also in the late summer july september during el nino yet these sst trends in the zonal gradient do not unequivocally represent an enso modoki like dipole because they are exclusively associated with significant positive sst trends in either the eastern or western pacific with no corresponding significant negative trends insignificant trends in the zonal sst gradient are evident during the boreal wintertime months when enso events typically mature given the presence of positive sst trends across much of the equatorial pacific ocean using fixed sst anomaly thresholds to define enso events likely needs to be reconsidered

decadal changes of enso persistence barrier in sst and ocean heat content indices 1958 2001 decadal changes of el nino southern oscillation enso persistence barriers in various indices of sea surface temperature sst and ocean heat content ohc are examined in this study using observations and ocean data assimilation products for the period 1958 2001 it is found that the sst indices in the eastern and central equatorial pacific exhibit very different decadal barrier variability the variability is large for the eastern pacific sst indices nino1 2 and nino3 whose persistence barriers shifted abruptly in 1976 1977 and 1989 1990 in contrast the central pacific sst indices nino3 4 and nino4 experienced little decadal barrier variability and have had their persistence barriers fixed in spring in the past four decades the zonal mean ohc index averaged over the equatorial pacific shows decadal barrier changes similar to those in the eastern pacific sst indices and always leads the nino3 sst barrier by about one season it is noticed that the sst persistence barrier appeared first in the eastern pacific before 1976 1977 first in the central pacific between 1976 1977 and 1989 1990 and almost simultaneous in both the eastern and central pacific after 1989 1990 these timings coincide with the westward propagating eastward propagating and standing pattern of enso sst anomalies observed in these three periods these results suggest that enso sst anomalies in the equatorial pacific can be considered to consist of two different processes a central pacific process whose phase transition such as onset and barrier always happen in spring and an eastern pacific process whose phase transition and barrier change from decade to decade and are influenced by changes in the mean thermocline depth along the equatorial pacific

two types of el nino events cold tongue el nino and warm pool el nino abstract in this study two types of el nino events are classified based on spatial patterns of the sea surface temperature sst anomaly one is the cold tongue ct el nino which can be regarded as the conventional el nino and the other the warm pool wp el nino the ct el nino is characterized by relatively large sst anomalies in the nino 3 region 5 s 5 n 150 90 w while the wp el nino is associated with sst anomalies mostly confined to the nino 4 region 5 s 5 n 160 e 150 w in addition spatial patterns of many atmospheric and oceanic variables are also distinctively different for the two types of el nino events furthermore the difference in the transition mechanism between the two types of el nino is clearly identified that is the discharge process of the equatorial heat content associated with the wp el nino is not efficient owing to the spatial structure of sst anomaly as a result it cannot trigger a cold event it is also demonstrated that zonal advective feedback i e zonal adve

occurrence of organic matter rich deposits middle jurassic to lower cretaceous from qalikuh locality zagros basin south west of iran a possible oil shale resource abstract organic rich deposits of qalikuh locality zagros basin southwest of iran are unconventional hydrocarbon resources considered as an oil shale which is hosted within a carbonate succession with the age range of middle jurassic to lower cretaceous leco carbon rock eval vi and modified fischer assay analysis were performed on some outcrop samples of these resources to investigate the occurrence of oil shale in the studied samples mean total organic carbon toc is 17 3 wt and the average of petroleum genetic potential s1 s2 is 98 kg hc t rock furthermore toc has direct relationship with petroleum genetic potential hydrogen index hi tmax diagram indicates that the organic matter corresponds to type ii kerogen of probable marine origin with high quality of oil generation according to rock eval data and bitumen reflectance brr the samples are thermally early mature based on the studied samples oil yield of the qalikuh oil shales ranges from 6 1 to 7 9 wt mean oil gas ratio is 2 7 and mean oil yield is 56 7 l t rock according to the observations the production value of qalikuh oil shale is more or less similar in the entire studied regions whereas the total production is below the expected values the produced oil is considerably lighter higher api than that of most other known oil shales

the effects of the indo pacific warm pool on the stratosphere sea surface temperature sst in the indo pacific warm pool ipwp plays a key role in influencing east asian climate and even affects global scale climate change this study defines ipwp nino and ipwp nina events to represent the warm and cold phases of ipwp sst anomalies respectively and investigates the effects of these events on stratospheric circulation and temperature results from simulations forced by observed sst anomalies during ipwp nino and nina events show that the tropical lower stratosphere tends to cool during ipwp nino events and warm during ipwp nina events the responses of the northern and southern polar vortices to ipwp nino events are fairly symmetric as both vortices are significantly warmed and weakened however the responses of the two polar vortices to ipwp nina events are of opposite sign the northern polar vortex is warmed and weakened but the southern polar vortex is cooled and strengthened these features are further confirmed by composite analysis using reanalysis data a possible dynamical mechanism connecting ipwp sst to the stratosphere is suggested in which ipwp nino and nina events excite teleconnections one similar to the pacific north america pattern in the northern hemisphere and a rossby wave train in the southern hemisphere which project onto the climatological wave in the mid high latitudes intensifying the upward propagation of planetary waves into the stratosphere and in turn affecting the polar vortex

a classification of petroleum on the basis of the ratio of sulfur to nitrogen abstract examination of the ratio of organic sulfur to organic nitrogen s n in 455 petroleums shows that individual petroleum families selected geographically stratigraphically and by source exhibit distinctive limited ranges of the value of this ratio commonly observed values in petroleums are between 1 and 20 the coefficient of variation within a family is frequently 100

el nino modoki and its possible teleconnection 1 using observed data sets mainly for the period 1979 2005 we find that anomalous warming events different from conventional el nino events occur in the central equatorial pacific this unique warming in the central equatorial pacific associated with a horseshoe pattern is flanked by a colder sea surface temperature anomaly ssta on both sides along the equator empirical orthogonal function eof analysis of monthly tropical pacific ssta shows that these events are represented by the second mode that explains 12 of the variance since a majority of such events are not part of el nino evolution the phenomenon is named as el nino modoki pseudo el nino modoki is a classical japanese word which means a similar but different thing the el nino modoki involves ocean atmosphere coupled processes which include a unique tripolar sea level pressure pattern during the evolution analogous to the southern oscillation in the case of el nino hence the total entity is named as el nino southern oscillation enso modoki the enso modoki events significantly influence the temperature and precipitation over many parts of the globe depending on the season the impacts over regions such as the far east including japan new zealand western coast of united states etc are opposite to those of the conventional enso the difference maps between the two periods of 1979 2004 and 1958 1978 for various oceanic atmospheric variables suggest that the recent weakening of equatorial easterlies related to weakened zonal sea surface temperature gradient led to more flattening of the thermocline this appears to be a cause of more frequent and persistent occurrence of the enso modoki event during recent decades

indices of el nino evolution abstract to characterize the nature of el nino southern oscillation enso sea surface temperature sst anomalies in different regions of the pacific have been used an optimal characterization of both the distinct character and the evolution of each el nino or la nina event is suggested that requires at least two indices i sst anomalies in the nino 3 4 region referred to as n3 4 and ii a new index termed here the trans nino index tni which is given by the difference in normalized anomalies of sst between nino 1 2 and nino 4 regions the first index can be thought of as the mean sst throughout the equatorial pacific east of the date line and the second index is the gradient in sst across the same region consequently they are approximately orthogonal tni leads n3 4 by 3 to 12 months prior to the climate shift in 1976 77 and also follows n3 4 but with opposite sign 3 to 12 months later however after 1976 77 the sign of the tni leads and lags are reversed

gc ms characterisation of c27 and c28 triterpanes in sediments and petroleum abstract earlier studies have shown that an unusual c 27 triterpane is abundant in sediments from the norwegian continental shelf and the north sea this compound was assigned the tentative structures 24 28 30 trisnormoretane or 25 28 30 trisnormoretane but we have now shown from detailed retention time measurements and a reinterpretation of the mass spectral data that its correct structure is 17 h 18 h 21 h 25 28 30 trisnorhopane two other triterpanes 25 28 30 trisnormoretane and 28 30 bisnormoretane have also been identified as minor constituents of extracts of sediments from the north sea possible origins for these compounds are discussed

patterns of late paleozoic glacial sedimentation on the southeast side of the parana basin brazil abstract during the late paleozoic glaciation glaciers moved from southern africa over a platform composed of crystalline and sedimentary rocks into the subsiding parana basin of southeastern brazil in each successive glacial advance the platform was eroded and is marked by crescentic gouges striae roches moutonnees grooves and glacially modified valleys the glacial sediments which are found on the platform in southeastern brazil and margins of the parana basin were deposited from grounded ice and are termed terrestrial these sediments which are best exposed in the northern part of the study area are composed of supraglacial deposits such as layers of diamictite flow tillite interbedded with sandstones and minor amounts of lodgement tillite the supraglacial deposits are frequently faulted and the sandstones show pull apart structures and abnormal dips these features and others suggest that ice retreat in the terrestrial environment was primarily by down wasting the glaciogenic sediments found within the subsiding parana basin are termed basinal even though it is not certain that they were all deposited in a subaquatic environment they are composed primarily of sandstones siltstones shales and mudstones interbedded with massive and laminated diamictites it is suggested that the massive diamictite was deposited from the base of the advancing glaciers by basal melting during ice retreat from water filled parts of the basin unstable masses of glaciogenic debris flowed down slope resulting in layered debris flows and in some instances chaotic debris flows which may have been triggered by subaquatic slupms and slides as the ice continued to retreat to the margin of the basin a complex of subaquatic outwash including deltaic sands was deposited minor varvites were deposited in shallow restricted embayments in the shoreline which were flooded with fresh glacial meltwaters deposits of retreat including the varvites interfinger with marine fossiliferous sediments which suggests that the water level in the basin was rising during deglaciation it is not known how may times glaciers advanced into the parana basin but recent studies show that there were at least nine glaciations in the northern part of this study area covering a time span of from 10 to 35 million years

paleotemperatures and paleofluids recorded in fluid inclusions from calcite veins from the northern flank of the ponta grossa dyke swarm implications for hydrocarbon generation and migration in the parana basin abstract the parana basin southern brazil has an atypical thermal and fluid history due to the occurrence of an episodic continental flood volcanism during the early cretaceous so far there are few data about the influence of this volcanic event on the paleotemperatures and paleofluids of the parana basin sedimentary rocks the teresina formation in the northern flank of the ponta grossa dyke swarm hosts high concentration of subsurface igneous rock bodies sills and dykes besides its covering by a hundreds meter thick volcanic rock cap in this study we used fluid inclusion analysis performed in horizontal and vertical calcite veins from the teresina formation and from a late cretaceous basic dyke to estimate paleotemperatures and to characterize the composition of diagenetic paleofluids homogenization temperatures of requilibrated fluid inclusions show that the teresina formation reached temperatures above 200 c horizontal parallel bedding calcite veins from the teresina formation record low to high salinity 2 26 wt nacl eq aqueous paleofluids the prevalence of high salinity fluid inclusions associated with light hydrocarbon fluid inclusions indicates deep buried fluids fluid inclusions in vertical calcite vein from basic dyke comprise only low salinity aqueous fluids 0 3 wt eq nacl interpreted as dominated by meteoric water the recorded paleotemperatures are attributed to the heating by the parana volcanic event during the early cretaceous with the thermal effect of the volcanic rock cap surpassing the effect of nearby sills and dykes estimated paleotemperatures higher than 200 c would allow the generation of light liquid and gaseous hydrocarbons overpressured compartments in the teresina formation allowed the expulsion of buried pore fluids high salinity aqueous fluids and hydrocarbons to fracture systems where they mixed with meteoric water the input of meteoric water through fracture systems connected with the surface favored hydrocarbons degradation in the early stages of source rock maturation during the early cretaceous