Magnetic polarity stratigraphy and ages of Siwalik group rocks of the potwar plateau,Pakistan

Six magnetic polarity sections have been established over the Potwar Plateau region of Pakistan, including the major stratotypes of the Siwalik Group. In all six sections the dominant feature of the magnetic polarity stratigraphy is a long normal polarity zone, which is contained within the Nagri Formation. This conspicuous normal polarity zone has been radiometrically dated at 9.5 ± 0.6 m.y., which identifies it as magnetic Chron 9. Radiometric dates from the Upper Siwalik Formation have also been used to identify the Chron 2–3 boundary in two of the sections. The magnetic polarity stratigraphy of three of the sections has been correlated securely with the accepted magnetic polarity time scale, so that the ages of the local stratigraphy are indexed accordingly. Based exclusively on data from stratotype sections, the Chinji, Nagri and Dhok Pathan Formations have nominal age ranges of 10.1–13.1, 7.9–10.1 and 5.1–7.9 m.y. Age fluctuations on the order of 10⁵ years may be anticipated for these formational boundaries within radius of some 20 km of the designated stratotype. Mean sediment accumulation rates during the Chinji, Nagri and Dhok Pathan interval range from 13 to 52 cm/10³ yr.Essentially linear sediment accumulations are locally maintained over time intervals of several million years. The Chinji-Nagri lithofacies boundary marks a transition from slow to faster sediment accumulation over much of the Potwar Plateau, indicating a fundamental sedimentary-tectonic change at this time.     

Herpetofaunistic zonation of Northern Eurasia

Distributions of herptile faunas were delimited on a 1:20 000 000 World Phytogeographic Map of Northern Eurasia divided into 245 10-degree longitudinal segments of the native subzone within the former USSR borders (1990). All herptile species recorded in every segment were listed, the Jaccard indices were calculated, and the similarity matrix was studied with cluster analysis. A hierarchic classification was made, composed of 3 herpetofaunistic regions divided into 5 subzones, some of the subzones subdivided into 13 biologic provinces, with some of the provinces broken down into 32 districts. Environmental factors correlating with faunistic nonuniformity were revealed. This division is 2 to 4 times more informative than the schemes proposed earlier and explain 73% of variance in the faunal similarity coefficient of specific areas (multiple correlation coefficient 0.85). Environmental factors can explain 84% of faunistic nonuniformity (correlation coefficient 0.92).     

Early Eocene orthophragminids from the Lower Indus Basin,Pakistan, and their biostratigraphic implication

Orthophragminids are a key biostratigraphic proxy for Paleocene–Eocene sequences in western Tethys, but poorly known in eastern Tethys. The orthophragminids were previously misinterpreted as Paleocene's orbitoidiform foraminifera in the Indus Basin, Pakistan. This study focuses on detailed taxonomy and biostratigraphy of orthophragminids. Nine species/subspecies of orthophragminids are identified, including Discocyclina ranikotensis, D. archiaci bakhchisaraiensis, D. a. ex. interc. staroseliensis bakhchisaraiensis, D. dispansa hungarica, D. d. taurica, D. d. broennimanni and Orbitoclypeus schopeni ramaraoi, and two new species Discocyclina pseudoranikotensis n. sp. and Discocyclina debalensis n. sp. are described. The identified orthophragminid taxa represent the orthophragminid zones OZ2-3, corresponding to the shallow benthic zones SBZ5-7 of early Ypresian (early Eocene), which are correlated with those in western Tethys. However, we found that the first appearances of D. d. hungarica and D. d. taurica occur in the OZ3 or SBZ7 in this study instead of the OZ5 or SBZ10 as in western Tethys. The possible paleoecological setting for the occurrences of recognized species is interpreted as inner to middle shelf.     

Calcareous nannofossil biostratigraphic framework for middle Eocene sediments from ODP Hole 1260A, Demerara Rise

Ocean Drilling Program (ODP) Site 1260 recovered a near-continuous and expanded (187-m thick) middle Eocene carbonate sequence at mid-bathyal depths on Demerara Rise off Suriname, South America. A calcareous nannofossil biostratigraphic framework has been established for the sequence to aid multi-proxy cyclostratigraphic analyses. The diversity of calcareous nannofossils is reasonably high and preservation moderate throughout most of the section, and the proximity to the continent is indicated by the occurrence of braarudosphaerids in the lower three quarters of the section. The species richness of sphenoliths is particularly high, and our data confirm the occurrence of new sphenoliths during the middle Eocene as shown recently by Bown and Dunkley Jones (2006). In particular we corroborate the occurrences of Sphenolithus strigosus and S. runus that these authors found in their Zone NP16 Tanzania sediments, however we extend the ranges of these taxa down into Zone NP15 (CP13). Moreover we document the occurrence of Bramletteius serraculoides in Zone NP15 (CP13b) and the occurrence of Sphenolithus predistentus in NP16 (CP14a), extending their known ranges down column.     

A time framework based on magnetostratigraphy for the siwalik sediments of the Khaur area,Northern Pakistan

The magnetostratigraphy of eleven new sections in the Khaur area of northern Pakistan is presented. All specimens have been subjected to thermal demagnetization. The sections, taken in adjacent ravines incising the Siwalik formations nearly penpendicular to strike, form a temporal framework in which to interpret the biological and lithological information. A composite section is constructed from several long sections and is correlated to the magnetic polarity time scale (Chron 6 to Chron 15), providing absolute age information for the biostratigraphic zonations of Barry et al. (1982). Detailed sections along the strike of major stratigraphic marker beds document an isochronous horizon and form the basis for paleoenvironmental reconstructions. The preservation of a polarity transition in fluvial sediments suggests continuity of sedimentation on a time scale of 10³–10⁴ years.     

Fossil insects of the middle and upper Permian of European Russia

Fossil insects of European Russia from the Urzhumian to Vyatkian stages are reviewed, new taxa are described, and dynamics of insect taxonomic diversity around the Permian-Triassic boundary in light of the Paleozoic-Mesozoic boundary global extinction problem is analyzed. Traces of interactions between arthropods and plants are analyzed. Insect-bearing deposits of the Late Paleozoic found in the northern and eastern areas of the East European Platform are unique on the global scale in their completeness and continuity, allowing us to trace especially comprehensively the biotic processes that occurred around the boundary described as the time of the greatest biotic catastrophe of the Phanerozoic. A total of 28 genera and 111 species are newly described. Within the range from the Urzhumian to the Permo-Triassic boundary, 15 representative successive assemblages, including 112 families, are recognized (seven in the area in question and eight in other regions of Asia, Australia, and Africa). New tools are developed for the analysis of the dynamics of diversity. These tools show an approximately equilibrium (slightly positive) dynamics in the Urzhumian and Severodvinian and a drop in diversity during the Vyatkian Age. It is shown that Permian insect assemblages acquired a substantially post-Paleozoic pattern much earlier than the end of the Paleozoic. The character of changes that took place in the Induan and Olenekian remains uncertain, but a large-scale extinction event did not occur here: most families that have not been recorded at the beginning of the Triassic are recorded again in the Middle and Upper Triassic. Nevertheless, a biotic crisis probably actually took place, but was reduced to reorganization of the biota’s structure, which provided enormous growth of biodiversity over subsequent hundreds of millions of years, rather than resulted in catastrophic extinction. This study is intended for entomologists, stratigraphers, and all readers interested in the biotic events that took place around the Permian-Triassic boundary.     

Exploration and local utilization of medicinal vegetation naturally grown in the Deusai plateau of Gilgit,Pakistan

In the study area, the traditional knowledge regarding the uses of local wild medicinal plants for the health care of human and domestic animals is totally in hold of old people. The young ones are unaware about such an indispensable practices. The objective of the current study was to transfer this sort of precious knowledge from old members of the community to young generations in documented form.     

Paleomagnetism of the middle siwalik formations of northern Pakistan and rotation of the salt range decollement

Sampling for paleomagnetic study has been carried out at seven localities in the Potwar Plateau region of Pakistan in the vicinity of the Salt Range. In all, 253 sites, consisting of three samples per site, were studied. The sites were taken from the Chinji, Nagri, Dhok Pathan and Upper Siwalik formations which span the last 14 m.y. of Earth history. The formations have been deformed in the ongoing Himalayan orogeny and are exposed today in sections which dip at angles of from 10° to 90° in different directions.A characteristic direction of magnetization was isolated at all sections by thermal demagnetization at temperatures of from 550° to 650°C. The sediments have been folded within the last 2 m.y. and because of a positive fold test it can be shown that the characteristic magnetization of these sediments was acquired before folding. Four of the sections have directions of magnetization which have been rotated in a counter-clockwise fashion up to 40°; however, sections taken along the Indus River, the north flank of the Soan syncline and the south flank of the Salt Range show small counter-clockwise rotations of under 10°. These observations are in agreement with previous suggestions that strata in the Salt Range have been moved to the south and rotated in a counter-clockwise fashion. The observations reported here indicate that the paleomagnetic poles derived from Cambrian and Permian formations within the Salt Range have probably also suffered rotation and should be removed from consideration in Gondwanaland reconstruction of the Paleozoic.     

A transect study of the Eucalyptus forests and woodlands of a dissected sandstone and laterite plateau near Darwin,Northern Territory

Tabletop Mountain in the Northern Territory is a sandstone plateau topped in part by a residual laterite soil. The vegetation of the plateau was mapped and transects placed to cover the mapping units in which eucalypts were dominant or shared dominance. A polythetic divisive classification of the transect floristic data was largely congruent with the mapping units, which also differentiated the dominants. Topography and soils have an apparently strong influence on the nature of the vegetation through their influence on the periodicity and intensity of drought and Waterlogging. However, differences in soil fertility and understorey flammability are postulated to be important in discriminating several of the mapped vegetation types. The flora of Tabletop more closely resembles that of the Alligator Rivers region than that of the Mitchell Plateau or Weipa. Some of the communities differentiated at Tabletop are related floristically to some of the communities differentiated in the Alligator Rivers region and at Gove.     

A revision of fossil Rhizomyid rodents from Northern India and their correlation to a Rhizomyid biochronology of Pakistan

Based on the biochronology of rhizomyid rodents of Northern Pakistan, fossil horizons in the Siwaliks of Northern India can be correlated to the late Neogene sequence of Pakistan with greater precision than previously possible. The indian Siwaliks do not include records of the most primitive Rhizomyidae, but rhizomyid faunas of India display strong affinity with those of Pakistan in the late Miocene. Pliocene differentiation of rhizomyid faunas in India and Pakistan may reflect ecological partitioning within the Indian subcontinent. Use of the term «Nagri for deposits at Haritalyangar suggests an erroneous equivalence in age to the Nagri stratotype in Pakistan.     

Past and current status of sturgeons in the upper and middle Danube River

Of the six species of sturgeons native to the Danube basin, five occurred in the upper and middle Danube. Among anadromous sturgeons were the large winter races of beluga, Huso huso, Russian sturgeon, Acipenser gueldenstaedtii, and stellate sturgeon, A. stellatus, which ascended the middle, and sometimes also the upper Danube, to spawn. Due to overfishing, followed by severe habitat alteration including damming and pollution, these anadromous sturgeons are critically endangered or extirpated from the upper and middle Danube. Acipenser gueldenstaedtii and A. nudiventris are represented only as resident non-migratory races with very small populations. The most abundant and widely distributed species is the sterlet, A. ruthenus, although it is presently limited to the middle Danube. Its population increased in some sections of the middle Danube during the past 15 years, presumably because of improving water quality, but this species remains at risk because of continuing habitat degradation.     

A new subdivision of the Albian spore-pollen zonation of Australia

The Albian spore-pollen zonation of Australia is used to date terrestrial sequences from Antarctica to New Zealand. A detailed qualitative and quantitative study of the Albian Crybelosporites striatus and Coptospora paradoxa Zones in the Gippsland Basin confirms many of the published zone indicator taxa are reliable. The first and last appearance datums can be further refined quantitatively based on the upward reduction in the abundance of seed fern produced pollen. Three subzones are defined in the C. paradoxa Zone using a combination of presence/absence range and abundance data. These are (from oldest to youngest): the Trilobosporites trioreticulosus, Pilosisporites grandis and Cicatricosisporites cuneiformis Subzones. This latter subzone presents a new subdivision of this zone in the Gippsland Basin in southeast Australia. All these subzonal divisions have sufficient resolution to facilitate reservoir-scale correlation of fluvial strata confined to the C. paradoxa Zone in the Gippsland Basin. This study has the first record of Taxodiaceaepollenites hiatus in the Early Cretaceous of Australia and a new species Aequitriradites burgerii is described. A re-examination of the chronology of the zones in the Cretaceous marine basins confirms a 103.5 Ma age for the top of the C. paradoxa Zone, however the chronology of the base of this zone is unclear in the Albian.     

Lilliputian bottom fish fauna of the Hatteras upper middle continental slope

Submersible data from two areas along the Carolina-Virginia continental slope reveal a Hatteras upper middle slope (HMS) (35.30'N, 74.50'W) demersal fish fauna remarkable for diminutive size of individuals within and across species, a fauna which is accordingly termed 'Lilliputian'. Contrast of HMS submersible data with Virginia trawl and submersible data support this finding. The four top-ranking HMS fishes, Lycenchelys verrillii, Glyptocephalus cynoglossus, Myxine glutinosa and Nezumia bairdii , are all significantly smaller than on the Virginia upper middle slope. Also peculiar to the HMS is the dominance of sedentary benthic species, rarity of active benthopelagic foragers, and markedly elevated fish population density. Species composition of the HMS fauna differs from that of the general Middle Atlantic Bight fauna; notably absent are species of otherwise continuous distribution along the U.S. East Coast (e.g. Synaphobranchus affinis, Nezumia aequalis ). Since HMS megafaunal and macrofaunal invertebrate communities are also anomalous, the Lilliputian phenomenon among HMS bottom fishes provides a characteristic biotic signature of a pervasively re-structured benthic boundary layer community. The authors hypothesize that the HMS faunal anomaly reflects a limiting factor, episodic sediment surface hypoxia, peculiar to this region of high particulate organic carbon flux from surface waters. Results indicate that substantial changes in fish faunal composition and structure can occur on a small geographic scale on the open soft-Substrate continental slope.     

Middle Telychian (upper Llandovery, Silurian) graptolites from boreholes of northwestern Libya: Their biostratigraphic significance and palaeogeographical implication

A low-diversity but stratigraphically and palaeobiogeographically important graptoloid association comprising Metaclimacograptus flamandi (Legrand), Parapetalolithus meridionalis (Legrand), and Torquigraptus australis Štorch was identified in the core samples of wells A1-66, F1-66 and A1-43 in the Ghadamis Basin of Libya. The former two species have been originally recovered from Algeria. All three taxa are common and widespread in the middle Telychian strata of Spain (Central Iberian Zone and western Iberian Cordillera) and France (Brittany). In European sections, the species are associated with other, moderately diverse graptoloid fauna, which enables a more precise and worldwide biostratigraphic correlation of Saharan boreholes and surface sections. The present faunal association indicates a middle Telychian age (upper crispus, griestoniensis and lowermost crenulata/tullbergi biozones) for the strata and suggests palaeobiogeographical links between North African pericratonic basins and Ibero-Armorican shelves. M. flamandi has not been found outside this NW-Gondwanan realm.     

Constraints and Opportunities for Sustainable Livelihoods and Cash Income Generation from NTFPs in the Mountains of Northern Parts of Pakistan

Pakistan′s forest resource base is mostly found in the mountains of the North-West Frontier Province (NWFP) supporting the livelihood of the rural poor and providing different ecological services. The present study was, therefore, initiated with the aim to evaluate different constraints and opportunities for sustainable livelihoods and cash income generation from NTFPs in the mountainous area of NWFP, Pakistan during 2008. Information was collected through questionnaire and interviews during field trips. A total of 117 NTFPs species have been recorded which are being used locally for various purposes such as fuel wood, fodder, medicinal plants, vegetables, mushroom, agricultural tools making, furniture, thatching, shade, fencing/ poles, ornamental purpose and animal products. The majority of plants are multi-functional like Pinus wallichiana provides timber, firewood, torch wood, the leaves/small branches are used as thatch for roofing, split logs are used for fencing and the decomposed needles are collected as humus for agricultural fields. These products were widely used by the indigenous community supporting their livelihood. The study proposes protection and sustainable management of these valuable resources for rural livelihoods, which might be useful for developing regional strategies of sustainable management of forest resources.     

A revised ammonite zonation of the Boreal Oxfordian and its application in northeast Greenland

A revised ammonite zonation for use in the Middle–Upper Oxfordian of the Boreal province is put forward. The zonation is used to date late Jurassic sediments in the Wollaston Forland area of northeast Greenland. The sediments broadly comprise basinal mudstones and shallow marine and shoreline sandstones, which were deposited in westerly tilted fault blocks during three transgressive pulses. On the peneplaned surfaces of wide tilted fault blocks a thick sequence of tidally and fluvially influenced marine sandstones of Middle Jurassic age was deposited. In the Upper Jurassic deposition initially took place in the centre of the basin where 80 m of shoreface sandstones accumulated (Jakobsstigen Member). In the second pulse the upthrown margin of the next fault block to the west was transgressed and deposition of basinal mudstones (Bernbjerg Formation) commenced in the basin centre on the main part of the dip-slope of the eastern block. Finally the crestal areas of the block on Kuhn Ø were inundated in Kimmeridgian times, and then subsided rapidly.     

A comparative analysis of the upper thermal tolerance limits of eastern Pacific porcelain crabs, genus Petrolisthes: influences of latitude, vertical zonation, acclimation, and phylogeny

Marine intertidal organisms are subjected to a variety of abiotic stresses, including aerial exposure and wide ranges of temperature. Intertidal species generally have higher thermal tolerance limits than do subtidal species, and tropical species have higher thermal tolerance limits than do temperate species. The adaptive significance of upper thermal tolerance limits of intertidal organisms, however, has not been examined within a comparative context. Here, we present a comparative analysis of the adaptive significance of upper thermal tolerance limits in 20 congeneric species of porcelain crabs, genus Petrolisthes, from intertidal and subtidal habitats throughout the eastern Pacific. Upper thermal tolerance limits are positively correlated with surface water temperatures and with maximal microhabitat temperatures. Analysis of phylogenetically independent contrasts (from a phylogenetic tree on the basis of the 16s rDNA gene sequence) suggests that upper thermal tolerance limits have evolved in response to maximal microhabitat temperatures. Upper thermal tolerance limits increased during thermal acclimation at elevated temperatures, the amount of increase being greater for subtidal than for intertidal species. This result suggests that the upper thermal tolerance limits of some intertidal species may be near current habitat temperature maxima, and global warming thus may affect the distribution limits of intertidal species to a greater extent than for subtidal species.