Freshwater Limestone Research Articles

A Pliocene lacustrine system in the Nellis basin, southern Nevada, USA: implications for the Colorado River drainage system

ABSTRACT Lacustrine basins and the sediments in them provide a critical component of regional tectonic development and climate history. Each sub-basin in the landscape records the interplay between active tectonism and shifting climate. Many of the basins in southern Nevada that contain deposits of the Muddy Creek Formation were closed fluvio-lacustrine systems during the latest Miocene and into the Pliocene. They were subsequently integrated into the regional Colorado River system. Lacustrine deposits of the Muddy Creek Formation are exposed along the trace of the Las Vegas Valley shear zone in the Nellis Dunes Recreation Area (NDRA), northeast of Las Vegas, Nevada. The Muddy Creek Formation in NDRA consists of approximately 130 m of mixed carbonates and clastics, and new tephrochronology suggests an early to late Pliocene age (∼ 4.7 to ∼ 2.6 Ma) for the lowermost lacustrine deposits and an unknown, but younger, age for the uppermost spring-fed lacustrine deposit. These sediments were deposited in an arid to semiarid lake (Lake Nellis) and alluvial floodplain system based on the interpretation of lithologies and facies associations. The stratigraphic succession coarsens upward and reflects establishment of a lacustrine carbonate system overlain by a clastic succession of peripheral lake sediments of alluvial and floodplain origin. The peripheral lake deposits consist of spring-fed and fluvial wetland mudflats of brown claystone and siltstone. This brown claystone is capped by a succession of yellow and red sandstones deposited by fluvial and minor eolian processes. The second, and youngest, freshwater limestone, likely disconformably, overlies the yellow and red sandstones, and is thought to be temporally and depositionally distinct from the underlying Muddy Creek deposits. The transition from the lower lacustrine carbonates to clastic fluvial channel and flood-plain deposits indicates desiccation of Lake Nellis and possibly occurs soon after ∼ 2.7 to ∼ 2.6 Ma based on the ages of tuffs occurring in the uppermost limestone and marl beds. This is consistent with an interpreted increase in regional aridity after ∼ 2.8 Ma (Smith et al. 1993). The second limestone deposit at the top of the section represents an even younger spring-fed lacustrine deposit of unknown age. Throughout the lower carbonate section, three tuffs were identified, and geochemically correlated, using a discriminant-function analysis, to the tuff of Napa (≤ 4.70 ± 0.03 Ma), the Putah Tuff (∼ 3.3 Ma), and the lower tuffs of the Badlands (∼ 2.7 to ∼ 2.6 Ma). The timing of deposition of Lake Nellis sediments postdates the integration of the three major lake systems in this region (Lake Grand Wash, Lake Hualapai, and Lake Las Vegas) into the Colorado River drainage (5.6–4.9 Ma), and also postdates the full integration of the river to sea level (4.8–4.63 Ma) (Howard et al. 2015; Crow et al. 2021). Lake Nellis represents an isolated lake basin that was one, and maybe the last, lacustrine system to be fully integrated into the Colorado River drainage in this region.

Durability of freshwater limestones tenelija, miljevina and muljika - Built-in factors as causes of changes in the stone

Durability of freshwater limestones tenelija, miljevina and muljika - Built-in factors as causes of changes in the stone

Influence of environmental (external) factors on durability of freshwater limestones tenelija, miljevina and muljika

Influence of environmental (external) factors on durability of freshwater limestones tenelija, miljevina and muljika

Stratigraphic and Paleoecological Significance of the Early/Middle Pleistocene Vertebrate Fauna of the Süttő 21 Site

The Süttő 21 site is a fissure fill of the freshwater limestone of the Gazda quarry in Süttő. The material was collected between 2017 and 2019, and the results are summarised in this article, with a special focus on the small vertebrate fauna of the site and its stratigraphic and paleoecological significance. The fissure fill can be placed around the Early/Middle Pleistocene boundary (ca. 1.1 and 0.77 Ma). The paleoecological analysis of the herpeto- and mammal fauna of the sequence indicates the proximity of a permanent water body. The lower part of the sequence is dominated by open habitat indicator taxa indicating a cool, dry climate. Towards the upper part of the sequence, the climate remained cool, but became wetter, and the vegetation gradually changed to forest-steppe/open forest. The fauna of the Süttő 21 site can be compared with the material of sites that are of a similar age, thus revealing taxonomic and paleoecological differences between different areas of the country. While a warm, dry climate and open vegetation can be reconstructed in the Villány Hills around the Early/Middle Pleistocene boundary, the Northern Hungarian areas had a cooler, wetter climate and a slightly more closed (sparse forest, forest-steppe) vegetation during this period.

Two new marsupial lion taxa (Marsupialia, Thylacoleonidae) from the early and Middle Miocene of Australia

Five species of marsupial lions (Thylacoleonidae) have been documented from the Oligo-Miocene freshwater limestone deposits of the Riversleigh World Heritage Area in northwestern Queensland, significantly altering understanding of the evolution of this extinct family. This paper presents a further two new thylacoleonid taxa from this fossil-rich region: Lekaneleo myersi sp. nov., from middle Miocene deposits, and Enigmaleo archeri gen. et sp. nov., from early Miocene deposits. Lekaneleo myersi is described from a dentary, partial maxilla and isolated teeth. It is approximately 10% larger in most linear dental dimensions than its sister taxon L. roskellyae. In this feature, it echoes the morphological cline shown by members of the Wakaleo lineage of marsupial lions, which increase their size through the Miocene. Although the first upper molar of L. myersi exhibits a tall metacone, a feature normally characteristic of species of Wakaleo, other features of its upper and lower molars support its attribution to Lekaneleo. Enigmaleo archeri gen. et sp. nov. is described from an isolated upper third premolar. This species is smaller than those of Lekaneleo, but larger than Microleo attenboroughi, the smallest known thylacoleonid. This premolar exhibits an intriguing combination of features, some of which are seen in Microleo and others in Lekaneleo, and on this basis is attributed to a new genus. It is the fourth thylacoleonid taxon from early Miocene deposits, making this time the most diverse period in thylacoleonid evolution. Phylogenetic analysis of 53 dental and 16 cranial characters recovers Enigmaleo as the sister taxon to Microleo, with this clade forming the sister group to the rest of the thylacoleonid family; however, the relationships among species of Lekaneleo was not resolved in this analysis. Comparisons of the morphology of the upper third premolars of all thylacoleonid taxa indicate that the evolution of the Thylacoleo form is more likely to have been derived from a Microleo or Enigmaleo form, and on this basis it is postulated that one of these groups may have provided the ancestor of the Thylacoleo lineage.Anna Gillespie [a.gillespie@unsw.edu.au], Earth and Sustainability Science Research Centre, School of Biological Earth and Environmental Science. University of New South Wales 2052, Sydney, Australia.

Influence of planes of anisotropy on physical and mechanical properties of freshwater limestone (Mudstone)

The formation of the freshwater lakes and travertine limestone was caused by the tectonic depression, which occurred in the Dinarides during the Miocene. This stone has been exploited and used since far back on the territory of Bosnia and Herzegovina as a building stone and for different architectural purposes. Most of the investigations were concentrated on the “tenelija” stone due to its massive use and construction of the famous Stari Most (Old Bridge) in Mostar. Not much investigation was devoted to “miljevina” (mudstone) which belongs to the same petrographic type. This is a soft carbonate rock that is highly porous, has small density, relatively low strengths, poor wear resistance, and low resistance to frost. In this paper, the influence of layers (planes of anisotropy - foliation) of the mudstone was investigated. Within an experimental campaign, numerous sets of tests were performed on different samples. Tests include uniaxial compressive strength (UCS) on cube and cylinder specimens, flexural strength under concentrated load and constant moment, tensile strength based on Brazilian tests, determination of Young’s modulus, modulus of deformations, and Poisson ratio. Prediction of UCS and Young’s modulus, as elastic mechanical characteristics, represent the main goal in engineering projects. Additionally, the influence of sample conditions and planes of anisotropy was investigated. Results have been compared and correlations are established. As a result, a new relation between uniaxial compressive strength obtained on cube and cylinder samples for a stone of low compressive strength is proposed.

Tectono-Sedimentary Evolution of the Madrid Basin (Spain) during the Late Miocene: Data from Paleokarst Profiles in Diagenetically-Complex Continental Carbonates

An intra-Vallesian (Upper Miocene) paleokarst developed at the top of the Intermediate Miocene Unit in the continental intracratonic Madrid Basin is recognized. This paleokarst is an early shallow, tabular-shaped karst that shows a marked control by the depositional facies pattern and lithologies. By integrating morphological, petrological, and geochemical data, three hydrogeological zones were established throughout the paleokarstic profiles: (i) a paleo-vadose zone, characterized by vertically elongated caves and vadose cementation; (ii) a 3–7 m thick paleo-epiphreatic zone (paleo-water table fringe), with development of stratiform breccia bodies, the superimposition of both vadose and phreatic features, and the lowest Fe and Mn contents in host-rock carbonates; and (iii) a paleo-phreatic zone characterized by an increase in δ13C values and the predominance of phreatic cementation. The paleogeographic reconstruction for the intra-Vallesian paleokarst using profiles revealed relative topographic highs to the north and topographic lows to the south, drawing the paleokarst landscape. Immediately overlaying the paleokarst surface are fluvio-lacustrine facies belonging to the Miocene Upper Unit (Late Vallesian to Late Turolian). Their lowermost deposits consist of fluvial terrigenous facies deposited by approximately N–S fluvial streams, and pass upward into fluvio-lacustrine fresh-water limestones. This paleokarstic surface represents a major change in the evolution of sedimentary patterns of basin, from endorheic to exorheic conditions, as the result of a change from compressive to extensional conditions in the tectonic regime.

A zsámbéki Strázsa-hegy és környékének kainozoos képződményei

A Zsámbéki-medence földtani térképezése során részletesen felvettük a Strázsa-hegy kőfejtője által feltárt kainozoos rétegsort, valamint elvégeztük az őslénytani, rétegtani és tektonikai adatok elemzését. A középső-triász dolomitra viszonylag vékony és hézagos középső–felső-miocén rétegsor települ, amelynek alsó szakaszát felső-badeni, középső szakaszát szarmata finomszemcsés sziliciklasztitok (kőzetliszt–középszemcsés homok) és karbonátok alkotják. Az e fölött üledékhézaggal települő édesvízi mészkő a Zsámbéki-medence felső-miocén (pannóniai) rétegsorának bázisképződménye. A Zsámbéki-medencében általános elterjedésű pannóniai üldékek a Strázsa-hegyen lepusztultak, az algás édesvízi mészkőre közvetlenül pleisztocén alluviális-proluviális rétegsor települ. A szedimentológiai jellegek és az ősmaradványok elemzése alapján rekonstruált neogén üledékképződési környezet több vonatkozásban is egyéni jellegeket mutat. A késő-badeni során kezdetben csökkent sótartalmú, partmenti védett lagúnában zajlott az üledékképződés a Vértessomló–Nagykovácsi-zóna mentén kiemelkedő paleomorfológiai hát (sziget vagy félsziget) mögött, amelybe jelentős mennyiségű finomszemcsés törmelék áramlott. Ezzel egy időben a sziget déli oldalán sziklás abráziós part rekonstruálható. A lagúnába a késő-badeni során édesvízi hozzáfolyás zajlott, ami a szarmata során elzáródott, végül a késő-miocén elejére tavi környezet jött létre. A Strázsa-hegyen keresztülhaladó Ny–K-i csapású Vértessomló–Nagykovácsi-zóna neogén–kvarter szerkezetfejlődésén belül több szerkezeti fázist sikerült azonosítani. Ezek közül a legidősebb a triász dolomit kismértékű rátolódása a középső-miocén rétegsorra, amely a késő-badeni sziliciklasztos rétegsor leülepedésével egyidős lehet. A tektonikai zóna szarmata aktivitására utal a rétegsor szélsőségesen vékony kifejlődése és diszkordáns települése. A következő szerkezeti fázist a pannóniai édesvízi mészkövön észlelt oldalirányú vetőkarcok jelzik, ez a fázis megfeleltethető a Gerecse D11-es transzpressziós szerkezeti fázisának. A szerkezeti zóna legfiatalabb deformációja során zajlott kiemelkedés a pannon rétegsor lepusztulását eredményezte, amely a pliocén–kora-pleisztocénre tehető.

Nové poznatky o terciéru a kvartéru získané geologickým mapováním okolí Lipníka nad Bečvou

Detail geological survey of the Lipník nad Bečvou surroundings brought new geological informations about the area, where Variscan and Carpathian orogens touch each other by their allochthonous nappe units. Detail mapping supported by micropaleontology enabled to fix the spatial extent of the nappe remnants of the Ždánice Unit in poorly exposed areas. Southeastern outskirts of Lipník nad Bečvou are part of the type area of the Menilite Formation defi ned by Glocker (1844) and one of his historical type localities near situated Símře was rediscovered. Lower Miocene strata were subdivided to the Stryszawa and Kroměříž formations based on the provenience of clastic material: Bohemian Massif for the Stryszawa Fm. and Carpathian nappes for the Kroměříž Fm. A new occurrence of rhyolitic fine-grained volcaniclastics was discovered in the Carpathian Foredeep in Lipník nad Bečvou. Quaternary sediments are represented, first of all, by complex fluvial terrace system of the Bečva River that illustrates the evolution of landscape since the latest Early Pleistocene. Remarkable local curiosity is fresh-water limestone (travertine) in Tučín, formed at the spring of thermal mineral water.

Late Maastrichtian small-sized herpetofauna from Valencia province, eastern Spain

A Late Maastrichtian microvertebrate assemblage which includes amphibian remains was recovered from continental deposits of the palaeontological site of La Solana, Valencia Province, Spain. This site is composed of variegated mudstones, pedogenically modified, interbedded with fluvial sand bodies and freshwater limestones lenses, and has also yielded plant debris, freshwater and oligohaline invertebrates, abundant fish remains (isolated bones and scales), turtle plates and archosaur bones. This fossil assemblage, dominated by aquatic forms, also includes semiaquatic and terrestrial elements, and may be interpreted as the palaeofauna of a wetland environment with terrestrial environs. The new material described here consists of fragmentary remains of an indeterminate albanerpetontid, a salamandrid and two anuran taxa (an alytid and a palaeobatrachid). The amphibians from La Solana are typical Laurasiatic taxa. This faunal association shows broad similarities to other coeval faunas of the Iberian Peninsula and contrasts with the Upper Campanian–Lower Maastrichtian sites where Gondwanan elements are frequent.

Going underground: postcranial morphology of the early Miocene marsupial mole Naraboryctes philcreaseri and the evolution of fossoriality in notoryctemorphians

We present the first detailed descriptions of postcranial elements of the fossil marsupial mole Naraboryctes philcreaseri (Marsupialia: Notoryctemorphia), from early Miocene freshwater limestone deposits in the Riversleigh World Heritage Area, northwestern Queensland. Qualitative functional analysis of these elements suggest that Na. philcreaseri was very well-adapted for burrowing, albeit somewhat less so than the living marsupial moles Notoryctes typhlops and N. caurinus. Quadratic discriminant analysis of limb measurements suggests that Na. philcreaseri was subterranean, and its Index of Fossorial Ability is almost identical to that of Notoryctes species, being among the highest known for any mammal. These results suggest that notoryctemorphians evolved their specialised, “mole-like” subterranean lifestyle prior to the early Miocene. Given that forested environments predominated in Australia until the middle-late Miocene, this transition to subterranean behaviour may have occurred via burrowing in forest floors, in which case fossorial mammals that live in tropical rainforests today (such as the placental golden moles Chrysospalax trevelyani and Huetia leucorhina) may represent reasonable living analogues for early notoryctemorphians. However, alternative scenarios, such as a cave-dwelling or semi-aquatic ancestry, should be considered. Phylogenetic analysis using a Bayesian total evidence dating approach places Naraboryctes as sister to Notoryctes with strong support (Bayesian posterior probability = 0.91), and indicates that Naraboryctes and Notoryctes diverged 30.3 MYA (95% HPD: 17.7-46.3 MYA). The age and known morphology of Na. philcreaseri does not preclude its being ancestral to Notoryctes. Using estimates of divergence times and ratios of nonsynonymous to synonymous substitutions per site, we infer that the nuclear gene “Retinol-binding protein 3, interstitial” (RBP3), which plays a key role in vision, became inactive in the Notoryctes lineage ~5.4 MYA (95% HPD: 4.5-6.3 MYA). This is much younger than previous published estimates, and postdates considerably the age of Na. philcreaseri, implying that RBP3 was active in this fossil taxon; hence, Na. philcreaseri may have retained a functional visual system. Our estimate for the inactivation of RBP3 in the Notoryctes lineage coincides with palaeobotanical evidence for a major increase in the abundance of grasses in Australia, which may indicate the appearance of more open environments, and hence selection pressure on notoryctemorphians to spend less time on the surface, leading to relaxed selection on RBP3. Ultimately, however, a fuller understanding of the origin and evolution of notoryctemorphians-including when and why they became “mole-like”-will require improvements in the Palaeogene fossil record of mammals in Australia

Comparison of lacustrine successions and their palaeohydrological implications in two sub‐basins of the Triassic Cuyana rift, Argentina

AbstractContinental carbonates are rich in palaeoclimatic, palaeoenvironmental and palaeontological information. While carbonate accumulation mechanisms have been described for many types of continental environments, especially in extensional basins, there are still uncertainties that existing facies models fail to address. The Triassic Cerro de las Cabras and Cerro Puntudo formations are alluvial–fluvial–lacustrine sequences that represent a part of the sedimentary infill of two sub‐basins of the Cuyana Basin during the early stages of the Triassic rift in west‐central Argentina. Previous work has provided absolute dates, confirming that these deposits are coeval (Anisian) allowing a comparative study of carbonate sedimentation in an extensional tectonic context. The description and origin of freshwater carbonate deposits and their surrounding siliciclastic sediments in specific areas of the Cuyana rift, gives insight into the major factors that control carbonate precipitation in all rift basins, including the characterization of the palaeohydrology and the importance of provenance. The Cerro de las Cabras Formation represents an ephemeral, playa‐lake depositional system with subaerial exposure and pedogenesis. Its aggradational succession corresponds to the evaporative facies association lake type, diagnostic of underfilled lake basins where persistently closed surface hydrology can lead to thick evaporites. However, this formation lacks thick evaporites and has microbialitic limestones, pointing to an open groundwater supply. The Cerro Puntudo Formation represents an alkaline playa‐lake system fed by groundwater and ephemeral surface‐water input. The unit is an aggradational–minor progradational succession, pointing to a fluctuating profundal facies association, suggesting a balanced‐filled lake type. These two synchronous, lacustrine depositional systems were influenced by tectonics and climate. Provenance and hydrology are key controls in carbonate accumulation in continental rift basins that must be included in future facies models for continental carbonates. Comparison with other rift basins suggests that application of lake‐type characterizations coupled with palaeohydrology and provenance patterns will aid in developing new sedimentation models for freshwater limestones in extensional settings.

A new species of the basal "kangaroo" Balbaroo and a re-evaluation of stem macropodiform interrelationships.

Exceptionally well-preserved skulls and postcranial elements of a new species of the plesiomorphic stem macropodiform Balbaroo have been recovered from middle Miocene freshwater limestone deposits in the Riversleigh World Heritage Area of northwestern Queensland, Australia. This constitutes the richest intraspecific sample for any currently known basal “kangaroo”, and, along with additional material referred to Balbaroo fangaroo, provides new insights into structural variability within the most prolific archaic macropodiform clade – Balbaridae. Qualitative and metric evaluations of taxonomic boundaries demonstrate that the previously distinct species Nambaroo bullockensis is a junior synonym of B. camfieldensis. Furthermore, coupled Maximum Parsimony and Bayesian phylogenetic analyses reveal that our new Balbaroo remains represent the most derived member of the Balbaroo lineage, and are closely related to the middle Miocene B. camfieldensis, which like most named balbarid species is identifiable only from isolated jaws. The postcranial elements of Balbaroo concur with earlier finds of the stratigraphically oldest balbarid skeleton, Nambaroo gillespieae, and suggest that quadrupedal progression was a primary gait mode as opposed to bipedal saltation. All Balbaroo spp. have low-crowned bilophodont molars, which are typical for browsing herbivores inhabiting the densely forested environments envisaged for middle Miocene northeastern Australia.

Mapping Freshwater Carbonate Deposits by Using Ground-Penetrating Radar at Lake Kolon, Hungary

Abstract Freshwater carbonate deposit, as a special phenomenon in the Danube-Tisza Interfluve, located in the centre of Hungary, is a significant geological heritage in the Carpathian Basin. At present there is not any applicable method to investigate the presence of carbonate layers in an undisturbed way, as neither vegetation nor morphological characteristics indicate unambiguously these formations. Ground-penetrating radar technology is widely used in various earth science related researches, and the number of applications is steadily increasing. The aim of the study was to determine the spatial extension of freshwater limestone using geophysical methods near Lake Kolon, Hungary. The lake, which is now a protected wetland area with opened water surfaces, was formed in the paleo-channel of the River Danube. Measurements were performed with the help of ground-penetrating radar, the results were calibrated by high spatial resolution drillings. Investigations have been made since 2012, and freshwater limestone was detected at several locations determining the more exact extension of the formation. Ground-penetrating radar proved to be an appropriate method to detect the compact and fragmented freshwater limestone layers in such an environment. However, based on the results the method can be best applied under dry soil or sediment conditions while the uncertainty of the results increases significantly as a matter of higher soil moisture. Further control measurements are necessary verified by several drillings in order to give an exact method to determine freshwater limestone.

Freshwater Limestone In An Arid Rift Basin: A Goldilocks Effect

Abstract The Olduvai Basin (3° S), situated just west of the East African Rift System in northern Tanzania, contains a two-million-year record of paleoclimate and paleoenvironmental change, as well as a rich archive of vertebrate paleontology (including hominins). Milankovitch precession cycles (∼ 20 kyr) regulate the mean annual precipitation (250–700 mm/yr), and the ∼ 2500 mm/yr evapotranspiration results in a negative hydrologic balance. Despite persistent aridity, extensive deposits of freshwater limestone punctuate the stratigraphic record. Between 2 and 1 Ma, Lake Olduvai occupied the basin, and its sediments are a proxy for climate-driven cycles. Three limestones (1.84, 1.80, and 1.36 Ma in age), which formed within lake-margin floodplains adjacent to the lake, were studied to determine their depositional environment using field relations, sedimentary structures, fossils, petrography, and stable-isotope and major-element geochemistry. The three limestones are similar in that they contain peloidal micrite, siliciclastic detrital grains, and rhizoconcretions. Abundant faunal remains (gastropods, ostracods, Charaphytes, and fish) indicate that ponded water was relatively fresh and alkaline. Geochemical and stable-isotope data indicate two types of groundwater-sourced carbonate-producing waters: a deeper-sourced fluid that was enriched in iron and manganese due to extended water–rock interactions, and a shallower groundwater that traveled through alluvial-fan deposits. Regional faults tapped the deeper groundwater, producing carbonate at spring sites, while seeps associated with basinward changes in alluvial-fan slopes drew on shallower groundwater sources. Isotope compositions indicate that fault-related waters experienced some evaporation as water moved away from the spring sites while compositions of the seep-related carbonate remained relatively constant. Pedogenic alteration and meteoric calcite cementation affected the carbonate when the spring and seep sites dried out. Secondary strontium-rich dolomite precipitated within the limestones during burial under paleo–Lake Olduvai sediments and fluids during periods of lake expansion. Integrating these data within the geological context of regional paleoclimatic and local environmental change indicates that the freshwater carbonates formed periodically when the conditions were just right, i.e., a “Goldilocks Effect.” Carbonates near the basin center formed from groundwater flowing under a hydraulic head from faults or fractures during the falling limbs of Milankovitch cycles when the lake was in recession. Carbonates near the basin margin formed from an increased rate of groundwater seepage that occurred only on the rising limbs of cycles. In both contexts, the continuous flow of groundwater with surface evaporation and CO2 degassing optimizes the conditions for limestone formation in this arid environment. These results help explain the formation of freshwater limestones in the rift basin, link the carbonates to specific portions of Milankovitch cycles, and document that localized sources of potable water were present for use by hominins in Olduvai Gorge during an important period of human evolution.

New material referable to Wakaleo (Marsupialia: Thylacoleonidae) from the Riversleigh World Heritage Area, northwestern Queensland: revising species boundaries and distributions in Oligo/Miocene marsupial lions

Gillespie, A.K., Archer, M., Hand, S.J. & Black, K.H., 2014. New material referable to Wakaleo (Marsupialia: Thylacoleonidae) from the Riversleigh World Heritage Area, northwestern Queensland: revising species boundaries and distributions in Oligo/Miocene marsupial lions. Alcheringa 38, 513–527. ISSN 0311–5518.New material of Wakaleo oldfieldi and W. vanderleueri from the Miocene freshwater limestones of the Riversleigh World Heritage Area, northwestern Queensland, is described. This material includes the first known upper dentition of W. oldfieldi and dentaries of both species bearing the previously undescribed and morphologically distinct M3. Previously, the two species were distinguished only by size differences in P3 and the size of P3 relative to M1. Wakaleo oldfieldi exhibits a more plesiomorphic M3 that retains a well-developed talonid basin in contrast to W. vanderleueri, which has lost this structure. The phyletic succession and geological occurrences of Wakaleo species make this genus an important taxon in biochronological analyses of Australian Cenozoic assemblages. At Riversleigh, W. oldfieldi is found in deposits allocated to Faunal Zone B and Faunal Zone C, which are regarded as early and middle Miocene in age, respectively. The presence of this species in the Kutjamarpu Local Fauna of central Australia suggests that fauna may be of a similar age. Broader faunal correlations have suggested Faunal Zone C correlates with the middle Miocene Bullock Creek Local Fauna, which contains the more derived W. vanderleueri. Based on stage-of-evolution arguments, W. oldfieldi should occur in older deposits than those yielding W. vanderleueri. The presence of both species of Wakaleo in Faunal Zone C assemblages at Riversleigh suggests that current presumptions about the contemporaneity of the many Faunal Zone C Sites should be examined more rigorously.Anna K. Gillespie [a.gillespie@unsw.edu.au], Michael Archer [m.archer@unsw.edu.au], Suzanne J. Hand [s.hand@unsw.edu.au] and Karen H. Black [k.black@unsw.edu.au] School of Biological Earth and Environmental Science, UNSW 2052, Sydney, Australia. Received 3.1.2014, revised 21.2.2014, accepted 21.3.2014.

Reconstructing a Miocene pitfall trap: Recognition and interpretation of fossiliferous Cenozoic palaeokarst

The middle Miocene cave deposit at AL90 Site in the Riversleigh World Heritage Area of Queensland, Australia, is the largest excavated palaeokarst deposit within the extensive Cenozoic freshwater limestones of the region. Stratigraphic relationships between various lithological components of the cave deposit indicate a dynamic, complex depositional history including dissolution, infill and reworking of cave materials. Euhedral spar, shelf-stone, calcite rafts and desiccation cracks on cave sediments suggest standing water was variably present in the cave environment. The AL90 Local Fauna is moderately diverse comprising at least 20 vertebrate families and 32 species, yet is taphonomically biased towards large marsupial herbivores (families Diprotodontidae, Macropodidae, and Balbaridae) and cave-dwelling hipposiderid bats. Fossil material is generally exceptionally well-preserved with, in many cases, articulated skeletons recovered. The cave entrance appears to have acted as a natural pit-fall trap. The complex (unconformable) depositional structure and lithology, vertebrate taphonomy and faunal composition at AL90 Site are typical of deposits and assemblages formed in the inner environment of the upper vadose zone. In the past, some similar unroofed cave deposits have been interpreted as clastic fluvio-lacustrine sedimentary deposits formed by surface processes. Analysis of characteristic palaeokarst features at AL90 Site has enabled the identification of other less well-preserved, poorly-exposed or relict cave deposits at Riversleigh and has facilitated interpretation of the depositional and palaeoenvironmental history of those deposits. The findings presented here confirm earlier interpretations that specific, highly-fossiliferous early Miocene to early Pliocene fossil deposits at Riversleigh represent relict caves whose roofs and walls are no longer intact.

PHYTODIVERSITY AND SOIL STUDY OF SHIWALIK HILLS OF ILAM, NEPAL: AN ECOLOGICAL PERSPECTIVE

The Siwalik range (locally known as Churia hills) in Nepal comprise a total area of 1,886,000 ha, equivalent to 13% of the country’s total area and consists of hills, steep land slopes, gorges, large spans of river and temporary streams. Study of different kinds of plants, soil and climate and the quantitative analysis of vegetation structure and composition as well as soil analysis at three Village Development Committees (VDCs) of Siwalik hills of Ilam was undertaken. A total number of 137 flowering plants and 8 pteridophytes are reported in the present study. Shorea robusta, Terminalia alata and Semecarpus anacardium are the most dominant species of the entire study area. The Siwalik range with late tertiary exposed rocks consists of fine grained sandstone with pockets of clay, shale, conglomerate and freshwater limestone. The vegetation is much more diverse and intact ecologically than expected from a distant observation. DOI: http://dx.doi.org/10.3126/eco.v18i0.9414Ecoprint: An International Journal of EcologyVol. 18, 2011 Page: Uploaded date: 12/22/2013

GEOCHEMISTRY OF FRESHWATER CALCAREOUS SEDIMENTS AND LONGEVITY IMPACTS OF THEIR APPLICATION TO ACIDIC SOILS OF EASTERN LITHUANIA / GEOCHEMINĖ GĖLAVANDENIŲ KALKINGŲJŲ NUOSĖDŲ SUDĖTIES VARIACIJA IR JŲ NAUDOJIMO PALIKIMAS RŪGŠTIEMS RYTŲ LIETUVOS DIRVOŽEMIAMS

Numerous investigations on the quaternary depositions of natural calcareous sediments and their use for soil conditioning have been carried-out in the Baltic region. Locally sourced freshwater limestone were formerly introduced (1950s) for soil liming, due to the absence or limited availability of appropriate industrial materials. Nowadays, with a greater awareness and understanding of the CO2 issues surrounding the production of industrial lime (intensively heated during manufacture), together with increasing costs of its production and transport, attention has returned to previous approaches. The main aim of this study was the identification of geological distribution peculiarities of freshwater limestone depositions, spatial and vertical geochemical variation and modelling of their previous agricultural use in acid soils regions. Geochemical composition data of local lake limestone has been lacking in Lithuania. Studies reveal that the quality parameters of sediments mostly align with the minimum for standard lime requirements (EN ISO 12945:2008), but materials are geochemically diverse even between layers of the same deposit. Tests show calcareous materials are especially rich in total manganese (3500 ppm) and slightly lower was total barium concentrations (490 ppm). Just a few mg kg−1 less were total concentrations of silver, boron, cobalt, chromium, copper, gallium, nickel, lead and vanadium. Former use of these sediments for liming purposes with regard to the national hygiene norm (HN 60:2004) controlled elements disclaim direct risks of soil pollution by higher heavy metals and rare elements accumulation. Previous liming studies indicate natural limes offer slow acting degradability compared to industrial products (dust limestone) and longer lasting liming effect. However, heavy metals and rare elements applied to soils are locked in topsoil (diffusion is mainly limited to depth of soil tillage). Unfortunately, cessation of liming and accelerated soil acidification promotes increased element mobility, which raises the risk of higher accumulations in crops, and their transfer to the food chain and/or their transport to groundwater. Santrauka Baltijos jūros regione atlikta nemažai tyrimų, kurių sudėtinė dalis – kalkingųjų kvartero nuosėdų tyrimai ir jų naudojimas dirvai gerinti. Gėlavandenės klintys buvo naudojamos dirvožemiams kalkinti trūkstant pramoninių kalkinių medžiagų. Šiuo metu jomis vėl domimasi, nes jos leidžia išvengti CO2 emisijų, susidarančių gaminant pramonines kalkines medžiagas (kaitinant klintis), jų naudojimas yra ekonomiškai patrauklus. Pagrindinis atliktų tyrimų tikslas – nustatyti geologinio paskirstymo ypatumus gėlavandenėse kalkingosiose nuosėdose, horizontalųjį bei vertikalųjį geocheminį pasiskirstymą ir ankstesnio šių medžiagų naudojimo žemės ūkio paskirties rūgščių dirvožemių regionuose išliekamąjį poveikį. Geocheminė gėlavandenių klinčių sudėtis anksčiau Lietuvoje nebuvo tirta. Atliekant tyrimus nustatyta, kad kalkingosios nuosėdos dažniausiai atitiko minimalių standartinių kalkinių medžiagų reikalavimų kokybės rodiklius (EN ISO 12945:2008), bet geocheminė šių medžiagų sudėtis yra labai įvairi net skirtinguose to paties klodo sluoksniuose. Buvo nustatyta, kad išanalizuotose kalkingosiose nuosėdose yra ypač daug suminio Mn (3500 ppm) ir šiek tiek mažesnė Ba koncentracija (490 ppm). Tik keli mg kg−1 ar mažiau buvo rasta suminių Ag, B, Co, Cr, Cu, Ga, Ni, Pb ir V. Modeliuojant buvusį šių nuosėdų naudojimą kalkinimo tikslais, vertinant pagal higienos normoje (HN) kontroliuojamų elementų koncentracijas, paneigtas tiesioginis dirvožemio taršos pavojus sunkiaisiais metalais ir retaisiais elementais. Šiomis medžiagomis kalkintuose dirvožemiuose sunkiųjų metalų ir retųjų elementų atsargos yra ilgam imobilizuotos (mobilesnės iš esmės yra tik armens sluoksnyje). Tačiau dėl nutrauktų kalkinimo darbų spartėjant dirvožemio rūgštėjimui, šių elementų mobilumas didėja, taip pat padidėja grėsmė susikaupti augaluose, patekti į mitybos grandinę ir užteršti gruntinius vandenis.

Geological evolution of the Iraqi Mesopotamia Foredeep, inner platform and near surroundings of the Arabian Plate

Geological evolution of the Iraqi Mesopotamia Foredeep, inner platform and near surroundings of the Arabian Plate