Extreme Northeast Research Articles

Industrial Development in Eritrea in Post-Liberation Era: A Study

Eritrea, a young nation (1991 independence), is located in the extreme North East of Africa. Its north east side is surrounded by beautiful Red Sea (1000 Km coastal line). In the absence of population census, actual data on population are not available. Different estimations have been made by different organizations like Government of Eritrea and World Bank etc. According to World Bank’s publication of “World Development Indicators” 2005, the population of Eritrea was 4 million in 2003 with a surface area of 118,000 square kilometers. Density of population is comparatively low as it is only 43 persons per square kilometers. Per capita income is also low 190 US D in 2003. Eritrea got its’ independence in 1991. In fact it was a colony of Italy from 1887 to 1941, subsequently ruled by British and Ethiopia. The country consists of six regions (provinces), locally known as Zoba. Capital of Eritrea is Asmara. Its currency is known as Nakfa, which in US Dollar value is equal to 15 Nakfa. (1 US $ = 15 Nakfa approx.).Modern manufacturing establishments in Eritrea began with the advent of Italian colonialism. Before the Italian rule (1887) the traditional mode of production was the mainstay of the Economy in Eritrea. The majority of the people were dependent on pastoralism and caravan and other forms of petty trade. They (Italians) established a number of manufacturing units in between 1887 and 1930. During Second World War British occupied Eritrea in April 1941.Industrial firms started operation within five months. The end of British rule in Eritrea was followed by ten years of federal rule under Ethiopia (1952-1962). During this period manufacturing units established by the British and Italian continued to function. Ethiopia annexed Eritrea in 1962. They “followed policies that were hostile to Eritrea’s economic growth”. According to Business Licensing Office (BPO) of Eritrea, total number of licensed industrial manufacturing establishments was 2241 in 2004. Out of these, 276 were medium and large scale establishments.The medium and large scale establishments are not only helping Eritrea to increase gross domestic product (GDP) but also providing employment. To get an idea about the conditions of workers a study was conducted in only tea packaging industry in Eritrea. The findings of the study are presented in this article.

A genetic perspective of prehistoric hunter-gatherers in the Siberian Arctic: Mitochondrial DNA analysis of human remains from 8000 years ago

Archaeological evidence of human occupation in Arctic Siberia dates to at least 27,000years before present (YBP) but the population history of these early inhabitants is not fully understood. Genetic research on contemporary indigenous Siberian populations has suggested a distinct pattern between populations from south/central Siberia and the extreme northeast Siberia. However, the picture is complicated by the fluctuations of movement by various cultural groups in the last millennium that has resulted in admixture as well as genetic drift. In order to better understand the genetic history of early humans in northern Siberia, we obtained ten human skeletal remains from four areas of the eastern Siberian Arctic, stretching from the low Yana River in the west to midstream of Bol'shaya Chukoch'ya River and Kolyma River in the east, and the Zhokhov site in the New Siberian Islands. We extracted DNA from the skeletal remains ranging from around 27,000YBP to as recent as the 18th century AD and analyzed the mitochondrial DNA (mtDNA) control region. We successfully identified five haplotypes that include haplogroups A2 and C4. The presence of haplogroup C4 in Arctic Siberia by 8000years ago illustrates the antiquity and widespread distribution of the maternal lineage in the region. On the other hand, haplogroup A2 is frequent among contemporary northeastern Siberian populations. Overall, the results from our ancient DNA analysis suggest maternal lineages among contemporary Siberians were present as far back as 8000years ago in the Siberian Arctic.

Distribution of Amblydromalus limonicus in northeastern Spain and diversity of phytoseiid mites (Acari: Phytoseiidae) in tomato and other vegetable crops after its introduction

Amblydromalus limonicus (Garman and McGregor) was detected for the first time in 2011 on tomatoes of several locations of the northeastern Spain. During 2012 and 2013 samplings on tomato crop cultivars in the two provinces of Catalonia where the species was found were carried out. The goals of the study were to know the range of spread of the species in these two provinces, its abundance in tomato cultivars, non-crop vegetation among them, in the different parts of the tomato plant and in some other vegetable crops. Results showed that A. limonicus was present at both regions sampled, although there were significant differences in the abundance of the species between sampling points. It is the second in abundance in tomato and the cultivars that most frequently host A. limonicus were Anaidis, Hybrid and Marmande. No significant differences were found in the abundance of A. limonicus among tomato plant canopy strata. On average, it accounted for 31.6% of all sampled phytoseiids. It was present in four crops (tomato, bean, cucumber and strawberry) and in Amaranthus cruentus, Chenopodium polyspermum, Cynodon dactylon, Mentha sp., Parietaria officinalis and Phleum pratense. Amblydromalus limonicus is well established in the extreme northeast of Spain all year round in crops and non-crops.

The northern Caribbean plate boundary in the Jamaica Passage: Structure and seismic stratigraphy

Multibeam bathymetry data and multichannel seismic reflection profiles have been collected at the end of 2012 along the Enriquillo-Plantain-Garden Fault Zone (EPGFZ) in the Jamaica Passage, between Jamaica and Hispaniola. Analysis of the data set reveals the tectonic evolution and the stratigraphic complexity of the northern Caribbean boundary. Stratigraphic correlations with previous marine and on land studies are proposed to place the identified seismic sequences in their regional tectonic history. Two distinct crustal domains are interpreted. Typical stratigraphic sequences for the rifted blocks of the Eastern Cayman Trough margin are identified in five basins of the Jamaica Passage, highlighting the eastward limit of the Cayman Trough margin. These inherited basins are deformed and folded during a first phase of compression that could correspond to the regional tectonic rearrangement recorded in the early Miocene (about 20Ma). A distinct crustal domain that we propose to relate to the Carib Beds (Caribbean typical reflectors A″, B″ and V) is identified in the southern part of the Jamaica Passage, indicating that the Caribbean Large Igneous Province could extend up to the extreme northeast part of the Lower Nicaragua Rise. The left-lateral EPGFZ currently cuts across two pre-existing basins, the Morant and Matley basins. During the activity of the EPGFZ, these basins are deformed and folded indicating a second phase of compression. In contrast, the Navassa basin, located in the middle of the Jamaica Passage, results from the strike-slip motion of the EPGFZ and is interpreted as an asymmetrical basin bordered by the EPGFZ only on its northern side.

Ethnobotanical study close to the population of the extreme north east of Algeria: The municipalities of El Kala National Park (EKNP)

As part of the medicinal plants value, an ethnobotanical study was conducted among 600 of EKNP herbalists in the forest area of El Tarf department (Algeria), which frequently use plants in traditional medicine.The survey was conducted during the period of 2011–2014 and permitted to identify 40 plants used in the treatment of various diseases by the local population of EKNP, which were mainly collected in spring.Our study showed that the leaves are the most part used of the plant, where the majority of therapeutic recipes were prepared in the infusion form.

Geomorphological control on boulder transport and coastal erosion before, during and after an extreme extra‐tropical cyclone

AbstractExtreme wave events in coastal zones are principal drivers of geomorphic change. Evidence of boulder entrainment and erosional impact during storms is increasing. However, there is currently poor time coupling between pre‐ and post‐storm measurements of coastal boulder deposits. Importantly there are no data reporting shore platform erosion, boulder entrainment and/or boulder transport during storm events – rock coast dynamics during storm events are currently unexplored. Here, we use high‐resolution (daily) field data to measure and characterize coastal boulder transport before, during and after the extreme Northeast Atlantic extra‐tropical cyclone Johanna in March 2008. Forty‐eight limestone fine‐medium boulders (n = 46) and coarse cobbles (n = 2) were tracked daily over a 0.1 km2 intertidal area during this multi‐day storm. Boulders were repeatedly entrained, transported and deposited, and in some cases broken down (n = 1) or quarried (n = 3), during the most intense days of the storm. Eighty‐one percent (n = 39) of boulders were located at both the start and end of the storm. Of these, 92% were entrained where entrainment patterns were closely aligned to wave parameters. These data firmly demonstrate rock coasts are dynamic and vulnerable under storm conditions. No statistically significant relationship was found between boulder size (mass) and net transport distance. Graphical analyses suggest that boulder size limits the maximum longshore transport distance but that for the majority of boulders lying under this threshold, other factors influence transport distance. Paired analysis of 20 similar sized and shaped boulders in different morphogenic zones demonstrates that geomorphological control affects entrainment and transport distance – where net transport distances were up to 39 times less where geomorphological control was greatest. These results have important implications for understanding and for accurately measuring and modelling boulder entrainment and transport. Coastal managers require these data for assessing erosion risk. © 2016 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.

Nonstationarity of low flows and their timing in the eastern United States

Abstract. The analysis of the spatial and temporal patterns of low flows as well as their generation mechanisms over large geographic regions can provide valuable insights and understanding for climate change impacts, regional frequency analysis, risk assessment of extreme events, and decision-making regarding allowable withdrawals. The goal of this paper is to examine nonstationarity in low flow generation across the eastern US and explore the potential anthropogenic influences or climate drivers. We use nonparametric tests to identify abrupt and gradual changes in time series of low flows and their timing for 508 USGS streamflow gauging sites in the eastern US with more than 50 years of daily data, to systematically distinguish the effects of human intervention from those of climate variability. A time series decomposition algorithm was applied to 1-day, 7-day, 30-day, and 90-day annual low flow time series that combines the Box–Ljung test for detection of autocorrelation, the Pettitt test for abrupt step changes and the Mann–Kendall test for monotonic trends. Examination of the USGS notes for each site showed that many of the sites with step changes and around half of the sites with an increasing trend have been documented as having some kind of regulation. Sites with decreasing or no trend are less likely to have documented influences on flows. Overall, a general pattern of increasing low flows in the northeast and decreasing low flows in the southeast is evident over a common time period (1951–2005), even when discarding sites with significant autocorrelation, documented regulation or other human impacts. The north–south pattern of trends is consistent with changes in antecedent precipitation. The main exception is along the mid-Atlantic coastal aquifer system from eastern Virginia northwards, where low flows have decreased despite increasing precipitation, and suggests that declining groundwater levels due to pumping may have contributed to decreased low flows. For most sites, the majority of low flows occur in one season in the late summer to fall, as driven by the lower precipitation and higher evaporative demand in this season, but this is complicated in many regions because of the presence of a secondary low flow season in the winter for sites in the extreme northeast and in the spring for sites in Florida. Trends in low flow timing are generally undetectable, although abrupt step changes appear to be associated with regulation.

Long-Term Variability of Extreme Significant Wave Height in the South China Sea

This paper describes long-term spatiotemporal trends in extreme significant wave height (SWH) in the South China Sea (SCS) based on 30-year wave hindcast. High-resolution reanalysis wind field data sets are employed to drive a spectral wave model WAVEWATCH III™ (WW3). The wave hindcast information is validated using altimeter wave information (Topex/Poseidon). The model performance is satisfactory. Subsequently, the trends in yearly/seasonal/monthly mean extreme SWH are analyzed. Results showed that trends greater than 0.05 m yr−1are distributed over a large part of the central SCS. During winter, strong positive trends (0.07–0.08 m yr−1) are found in the extreme northeast SCS. Significant trends greater than 0.01 m yr−1are distributed over most parts of the central SCS in spring. In summer, significant increasing trends (0.01–0.05 m yr−1) are distributed over most regions below latitude 16°N. During autumn, strong positive trends between 0.02 and 0.08 m yr−1are found in small regions above latitude 12°N. Increasing positive trends are found to be generally significant in the central SCS in December, February, March, and July. Furthermore, temporal trend analysis showed that the extreme SWH exhibits a significant increasing trend of 0.011 m yr−1. The extreme SWH exhibits the strongest increasing trend of 0.03 m yr−1in winter and showed a decreasing trend of −0.0098 m yr−1in autumn.

Quaternary Vegetation History of the Lower Bengal Basin (India) Inferred from Palaeo-palynological Analysis

Black peat samples deposited in between sandy clay layers were collected from an uncovered profile at Rajarhat,24 Paraganas (N), 20 km extreme North East of the city of Kolkata, (22°34’N, 88°30′ E) West Bengal. The profile resulted from an excavation made during the construction of a multi story building. Palynological investigations of the peat samples revealed a large deposits of pollen grains of mangrove species such as Heritiera, Excoecaria, Rhizophora, Sonneratia, Avicennia, Bruguiera, Nypa Barringtonia, Phoenix paludosa, Aegicerasetc. Pollen grains of grasses, some freshwater plants, as well as fern spores (such as Acrostichum, Pteris, Pteridium and Polypodium) were also recovered in large quantities. All were found from a peat layer formed at a depth of about 5.35m to 6.14m from the surface. The fossil pollen assemblage found indicates the prevalence of a past typical mangrove vegetation, which is presently observed in the Sundarbans region (a mangrove swamps, about 85km south of greater Kolkata). The present study reflects a low lying landscape frequently transgressed by sea water and getting supply of fresh water from rivers. Ecological and edaphic factors such as increase of salinity, submergence, reclamation, flood etc. could have been responsible for any vegetation fluctuations.

A Field Guide to the Ants of New England, by Aaron M. Ellison, Nicholas J. Gotelli, Elizabeth J. Farnsworth and Gary D. Alpert. New Haven: Yale University Press, 2012. 398 pp. $29.95.

The ants are ‘the largest proportion of animal biomass in many places’. They may turn over more soil than the earthworms and are clearly important enough to justify research and study in many terrestrial sites. This book deals with the ants of New England in the extreme North-east of the United States, including Maine, New Hampshire, Vermont, Massachusetts and Rhode Island, which have extensive natural habitats and also many areas of exploited conifer woodland and large areas of human occupation. Figure 1.2 shows the five ecoregions of New England. At the beginning of the book, the authors give an excellent account of the basics of ant evolution, behaviour and ecology. Pages 11–27 are essential reading for anyone not very familiar with ants. The subjects covered include the effects of nest shading and drainage, the activities of competitors and human alteration of habitats which is far less dominant a factor than in Britain. Chapter 3 gives advice and instructions on practical matters, ranging from pootering and making a collection of ants to photography. The bulk of this book (132 pp.) is devoted to identification of the species. At the time of writing, the ants constitute 131 species in 31 genera. Not being familiar with the species of New England ants, I tried the key on the European ant Lasius niger, and found it easy to reach a satisfactory result. The excellent keys are profusely and beautifully illustrated with both photographs and very fine drawings by Elizabeth Farnsworth. The book is indeed, as the authors hoped, ‘as much a joy to look at as to read’. An extensive bibliography of books and technical papers and of internet resources, as well as a full index, is included.

Composite Geophysical Study Comprising Gravity, Magnetic, and Resistivity Surveys to Delineate Basement Salt Deposits Near Jabbar Nala East of Kherwa Gorge, Pakistan

A composite geophysical survey has been carried out comprising gravity, magnetic, and resistivity surveys for delineation of salt deposits, thickness of overburden and basement depth over an area of 631 acres near Jabbar Nala east of Khewra Gorge, Sodi, Pakistan. The survey is carried out on the girded pattern of 100 x 100 meters; however, some variability in coverage tends to exist due to the existence of high hills topography. Present research revealed that salt deposits exist within the depth of 75~100 meters at specific locations in the extreme northeast and northwest. Most of the anomalous zones fall in this area is analogous when these three surveys are explored and comprehensive analysis performed. Existing excavated area of salt mine also exists in the northeast where the strong Bouguer gravity, magnetic, and resistivity anomalies have been superimposed, however, anomalous zone extents further in the northeast. Gravity, magnetic, modeling has been carried out along the anomalous zones comprising cross-sections of AA’, BB’ and CC’. However, for further confirmation of the results, a test bore of 90~120 meters depth needs to be drilled at the recommended anomalous zones (Zone B and Zone C).

Carbonate reservoir characteristics and porosity distribution in Souedih Oilfield, northeast Syria

ABSTRACT The Souedih (also spelled Suwaidiyah) Oilfield is located in the extreme northeast of Syria in part of the Mesopotamian Basin. The principal reservoir of most fields in this region is the Upper Cretaceous, carbonate-rich Massive Formation. Using data from 25 wells and 36 samples/thin sections, this study focuses on the nature and distribution of porosity in the main Souedih reservoir. The Massive A reservoir is 100Ð120 m thick and represented by uniform, bioturbated bioclastic packstone and bioclastic packstone-grainstone, deposited in a well-oxygenated, moderate to high-energy, shallow-marine environment. It is generally well cemented by microsparite and micrite, and more rarely by sparite. Porosity is highly variable, ranging from < 1% to 20%. Mouldic porosity is the most common type, with rare channel and fracture porosity. Average porosity values tend to decrease eastward across the reservoir, which can also be divided vertically into five zones. The uppermost of these shows the highest average porosity > 15%. The dominance of mouldic porosity throughout the study area indicates that secondary dissolution was the primary cause and that pre-existing bioclasts were the principal targets for this dissolution. The source of these diagenetic fluids is still unclear, although our data do lend some support to the karstification theory. These characteristics are important for understanding and managing reservoir production, not only for Souedih but for the region in general.

Spectral Depths Estimate of Subsurface Structures in Parts of Borno Basin, Northeastern Nigeria, using Aeromagnetic Data

Spectral depth analysis of aeromagnetic data covering latitude 12.00’N to 13.00’N and longitude 10.00’E to 11.00’E which corresponds to part of Borno basin, Northeastern Nigeria, was carried out for the purpose of investigating the sedimentary thickness beneath the surface. The study area was covered by 4 aeromagnetic maps. The aeromagnetic maps were digitized on a 3km grid and later complied to produce a combined aeromagnetic data file for the area. The data file comprises 1369 data points. Polynomial fittings method was applied in the regional residual separation. The residual map was later sub-divided into 16 spectral sectors. The result of the study shows that the first layer depth was estimated to have a range from 0.18km to about 1.9km while the second layer depth was estimated to have ranged from 2.9km to about 4.2km. The highest sedimentary thickness of 4.2km occurred at the extreme northeast part of the study area and corresponds to areas around Gorgoram. These areas may be subjected for further geophysical method like seismic reflection/refraction, so as to ascertain its hydrocarbon potential.

Ecologia da paisagem de remanescentes florestais na bacia hidrográfica do Ribeirão das Pedras - Campinas -SP

A fragmentação dos extratos florestais e o uso de terras, muitas vezes sem os cuidados necessários para mitigação dos impactos decorrentes das atividades antrópicas, geram ecossistemas fragilizados por fenômenos como o efeito de borda, ou seja, alterações localizadas nas áreas de contato entre a matriz antropizada e o remanescente florestal. Nesse contexto, este trabalho teve por objetivo estudar a fragilidade dos fragmentos encontrados na Bacia Hidrográfica do Ribeirão das Pedras, no Município de Campinas, SP, Brasil, utilizando técnicas de geoprocessamento. Com a base cartográfica do município, avaliaram-se o tamanho do fragmento e a tendência de formato alongado ou circular. Com base em dados cartográficos de 1962, 1972 e 2006, observou-se o declínio quantitativo e qualitativo dos fragmentos. Devido ao processo de urbanização não planejada do município, os fragmentos de menor área foram desmatados. Estes, apesar de não terem capacidade ecológica para sustentar níveis tróficos mais elevados, servem como "trampolins ecológicos", contribuindo para o fluxo biológico. De maneira análoga, os remanescentes maiores também foram desmatados e sua área, reduzida. De maneira geral, o formato dos fragmentos passou a tender para o formato alongado, o que sugere maior contato entre os remanescentes e a matriz antrópica, aumentando, assim, a vulnerabilidade dos fragmentos. Destaca-se o caso do remanescente de Cerrado encontrado no extremo nordeste da bacia que possui tendência de formato alongado (IC = 0,62) e área reduzida (0,38 ha), mostrando-se, assim, muito vulnerável às pressões antrópicas. Assim, conclui-se que os fragmentos florestais da bacia hidrográfica estudada estão altamente vulneráveis.

Autosomal and uniparental portraits of the native populations of Sakha (Yakutia): implications for the peopling of Northeast Eurasia.

BackgroundSakha – an area connecting South and Northeast Siberia – is significant for understanding the history of peopling of Northeast Eurasia and the Americas. Previous studies have shown a genetic contiguity between Siberia and East Asia and the key role of South Siberia in the colonization of Siberia.ResultsWe report the results of a high-resolution phylogenetic analysis of 701 mtDNAs and 318 Y chromosomes from five native populations of Sakha (Yakuts, Evenks, Evens, Yukaghirs and Dolgans) and of the analysis of more than 500,000 autosomal SNPs of 758 individuals from 55 populations, including 40 previously unpublished samples from Siberia. Phylogenetically terminal clades of East Asian mtDNA haplogroups C and D and Y-chromosome haplogroups N1c, N1b and C3, constituting the core of the gene pool of the native populations from Sakha, connect Sakha and South Siberia. Analysis of autosomal SNP data confirms the genetic continuity between Sakha and South Siberia. Maternal lineages D5a2a2, C4a1c, C4a2, C5b1b and the Yakut-specific STR sub-clade of Y-chromosome haplogroup N1c can be linked to a migration of Yakut ancestors, while the paternal lineage C3c was most likely carried to Sakha by the expansion of the Tungusic people. MtDNA haplogroups Z1a1b and Z1a3, present in Yukaghirs, Evens and Dolgans, show traces of different and probably more ancient migration(s). Analysis of both haploid loci and autosomal SNP data revealed only minor genetic components shared between Sakha and the extreme Northeast Siberia. Although the major part of West Eurasian maternal and paternal lineages in Sakha could originate from recent admixture with East Europeans, mtDNA haplogroups H8, H20a and HV1a1a, as well as Y-chromosome haplogroup J, more probably reflect an ancient gene flow from West Eurasia through Central Asia and South Siberia.ConclusionsOur high-resolution phylogenetic dissection of mtDNA and Y-chromosome haplogroups as well as analysis of autosomal SNP data suggests that Sakha was colonized by repeated expansions from South Siberia with minor gene flow from the Lower Amur/Southern Okhotsk region and/or Kamchatka. The minor West Eurasian component in Sakha attests to both recent and ongoing admixture with East Europeans and an ancient gene flow from West Eurasia.

Pleistocene glaciations of northern Russia – a modern view

The size, age and dynamics of Pleistocene glaciers, especially ice sheets that periodically covered the northern seaboard of Eurasia, are crucial for understanding the evolution of arctic climates, sea‐level changes, the biota and tectonism. General ideas on the glacial history of the vast areas of northern Russia between 48° and 148°E, beyond the limits of the Fennoscandian glaciation, have considerably changed during the last two decades. The change towards modern views may even be considered as a paradigm shift from the conventional wisdom of the previous half‐century. The transformation of the main landmarks of late Quaternary glacial history started in the 1970s and accelerated after 1993 as a result of international collaboration in the Russian Arctic. A wealth of new sedimentological, geomorphic and stratigraphic data has recently accumulated for the sedimentary record of the last 200 ka. This information, together with data collected from native geological surveys, has been synthesized in the form of digital maps of ice limits based on key stratigraphic sites. The results have been published as contributions to the international programs QUEEN and APEX and also as parts of global compilations. These publications give general overviews of the Eurasian glacial history, but some important modern data are reported only in the Russian literature and therefore are hardly known to the international community. In this paper I will first consider the background material on the non‐Scandinavian glaciations and then follow this with a review of the modern results obtained in the course of international cooperation. The outcome is inevitably influenced (or biased) by my long‐term experience in studying the Pleistocene of northern Russia. I will not discuss here the extreme northeast of Siberia (western Beringia), as this is a distinct topic partly overviewed in recent publications.

From private initiative to public intervention in Spanish water management: the case of the Muga and Fluvià rivers (1850–1930)

During the second half of the nineteenth century and the first third of the twentieth century, Spain, along with some other European countries, underwent a process of transition regarding water resources management. One of the most obvious transformations that occurred during this period was the increasing lead taken by the government in the building of large hydraulic structures and the subsequent decrease in the influence of private initiative in this matter. The government's aim was to exploit the water resources provided by the rivers to their full, and in particular to use the water that was destined for irrigation to maximum effect. The repeated failure of projects promoted by private companies led the government, not without problems, to enact regulations and create hydraulic plans to be put into motion by the public sector. This change in focus is the key to understanding the frenetic pace of hydraulic infrastructure construction that occurred later and which made Spain one of the world's leading nations in terms of indicators such as the number of large reservoirs in use. This article focuses on the transition from private initiative to public intervention and evaluates the main stages of this process in Spain. The cases of the basins of the Muga and Fluvià rivers, located in the extreme north-east of the Iberian Peninsula in Catalonia, are described in light of this process. This research attempts to verify that despite their modest size and their distance from the main decision-making centres, these two cases reflected the situation at the national level. This was just one of the many local effects of the transition process of water resources management in Spain, even though the results of this transformation would be neither immediate nor effective in the short term.

Youwanjela, a new genus of land snail from the Kimberley, Western Australia (Eupulmonata, Camaenidae)

A new genus of camaenid land snail, Youwanjela, is described from the Kimberley Region, Western Australia for the species previously named Hadra wilsoni Solem, 1979. The original description and genus affiliation of this species was based exclusively on shell characters. Here we describe the genital anatomy for the first time based on examination of topotypic material from the valley of the Youwanjela Creek, Prince Regent Nature Reserve, north-western Kimberley. The new genus Youwanjela is characterised by unique combination of key characteristics in shell and genitalia that is not found in any other camaenid genus in Australia, particularly not in Hadra bipartita (Ferussac, 1822) from Queensland, the type species of the genus Hadra, or other camaenids from the Kimberley. This combination of features comprises a comparatively large, thin, broadly subglobose and almost uniform brown shell, an elongated vagina with corrugated longitudinal pilasters on its inner wall, a long and tubular bursa copulatrix, an elongated penis with interlocking, rhomboid pustules in posterior and corrugated longitudinal pilasters in anterior part of the inner penial wall, lack of a penial sheath, a well developed, tubular epiphallus with corrugated pilasters on inner wall with a tiny flagellum. By removing the present species from the genus Hadra, we demonstrate that this genus is endemic to the Wet Tropics of north-eastern Queensland, including Cape York and Torres Strait islands. By contrast, Youwanjela is an endemic camaenid of the Kimberley, Western Australia. This taxonomic treatment is supported by molecular phylogenetic data and reflects general patterns of distribution in the Australian Camaenidae, which are characterised by marked local endemism on the species to genus level and by a phylogeographic divide between eastern and western Australian groups. Our finding underpins the importance of both the extreme north-east and north-west of Tropical Australia as hotspots of endemism and diversity for camaenid land snails. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Geodynamics of rift–plume interaction in Iceland as constrained by new 40Ar/ 39Ar and in situ U–Pb zircon ages

The interaction between a rift zone and a mantle plume leads to exceptional situations in Iceland where the island is 1.5 wider than expected, given the North-Atlantic spreading rate. In order to give a better idea of the timeframe of this evolution, we present 32 new 40Ar/ 39Ar and in-situ U–Pb dating on zircon from 16 volcanic systems located from the west to east coasts of Iceland. The North Iceland Rift Zone (NIRZ) was initiated at least 12 Ma ago. Furthermore, during these last 12 Ma, the NIRZ half spreading rate was between 0.7 and 1.2 cm/yr and it propagated to the south at a rate of 1.0–1.2 cm/yr. The excess width of Iceland can thus not be explained by faster spreading rate in the past. Here we discuss a model that explains the ~ 200 km ‘excess’ of crust, taking into account the eastward relocation of the rift zone and corresponding older crustal capture over the course of Iceland's geological history. The most recent rift relocation is dated at approximately 6 Ma at Snæfellsnes Peninsula in the west, whereas the oldest volcanic systems (15–13 Ma) from the extreme north east of Iceland were most likely generated at the Kolbeinsey ridge north of Iceland rather than in the NIRZ itself. The need for rift relocations and crustal capture to explain the width of Iceland strongly suggests that during rift–plume interaction the mantle plume plays an active role. It forces the active rift zone to be frequently relocated by rift jumps above its center leaving inactive rift zones as older synclines in the geological record. This result in an eastward position of the rift zone in Iceland relative to the North Atlantic ridge, and it can be predicted that in a few tens of millions of years the Mid-Atlantic ridge and the Icelandic plume may become decoupled.

Molecular Phylogenetics and Chronometrics of Tarsiidae Based on 12S mtDNA Haplotypes: Evidence for Miocene Origins of Crown Tarsiers and Numerous Species within the Sulawesian Clade

We report new mitochondrial DNA sequence data from tarsiers sampled from several populations, including the extreme northeast and southwest of the range of the Tarsius tarsier species complex, the most extensive sampling ever reported for this taxon. Our results provide the opportunity to produce the first ever molecular chronometric analysis of Tarsiidae. These results date the age of crown tarsiers, minimally, to the middle Miocene, and each of the 3 tarsier species groups, Tarsius bancanus, T. syrichta, and the T. tarsier complex, to the early or middle Miocene. Thus, each of these 3 species has evolved in isolation for a period of time that is consistent with that which would be expected for multiple speciation events. Our analysis of the Tarsius tarsier complex reveals 5 subclades, each of which is interpreted to represent a haplogroup at, or above, the species level, a result that is consistent with current hypotheses about numerous cryptic species within this species complex. The implications for conservation within the Sulawesi biogeographic region are that Sulawesi is subdivided into numerous subregions of endemism and that, by extrapolating the example of cryptic tarsier species to other taxa, biodiversity may be underestimated by an order of magnitude. The practical realties of conservation in Sulawesi are such that it is most reasonable to assume that anthropogenic extinctions are occurring, and that some species will go extinct before they have even been identified.