Northern Libya Research Articles

Elevational Effect on Aleppo Pine Seed Production and Seed Germination in east north Libya

Al Jabal Al Akhdar mountain south of the Mediterranean in Northern Libya is the only native habitat for Aleppo Pine (Pinus halepensis Mill.) in eastern North Africa. Located between the Mediterranean Sea and the Sahara Desert, climate change and human activities are threatening its existence. We studied three woodlands of P. halepensis at different elevations in this unusual and rare ecosystem. We found that P. halepensis is producing more cones per tree and more seeds per cone than trees in more northern populations, with a net result at higher altitude of more than 7 times the number of seeds per tree compared to the northern Mediterranean. Moreover, seeds from woodland at the highest altitude showed better germination, longer root length, higher root and shoot dry mass and better growth than the other two populations, so are most likely to grow better during intermittent precipitation and be big enough to survive subsequent dry periods. We conclude that P. halepensis is capable of self-maintenance in this southern outpost in the short-term, but is likely to rapidly deteriorate in the face of climate change and a lack of protection. Conservation action to protect and facilitate spread of natural stands is urgently needed.

First record of Pluchea dioscoridis (Asteraceae) in Northern Libya

Pluchea dioscoridis (L.) DC. is a species native to Eastern Africa that has been recorded for the first time in northern Libya. It was discovered growing around the city of Benghazi in populations of more than 100 plants beside roads and inside city gardens, and also on the edge of the salt marshes in a typical wet habitat of halophyte plants about five kilometres east of Benghazi and not far from the shoreline in north-east Libya. Populations of this plant were first noticed in 2018 once the civil war was over in Benghazi and confirmed during an investigative research project that aimed to evaluate the state of vegetation four years after the evacuation of the city.

North Atlantic Oscillation (NAO) and its relationship to rain in northern Libya

The North Atlantic Oscillation (NAO) plays a role an important in climate variability in the Northern Hemisphere, which effects on Europe, Northeast North America and North Africa climate, However, the previous studies have described the effect of the NAO on winter climate conditions in Europe, North Africa and a few regions. It is still unclear to what extent the North Atlantic Oscillation is related to the fluctuations of rain in northern Libya, so the purpose of this study is to examine the relationship between the NAO and rainfall in the north of Libya in the winter using correlation analysis. The results show that the influence of NAO on the amounts of rainfall and the winter rains were positively related to the whole region, and it is more closely related to Al-Asa and Zuwara which located in the west of study area. In addition, winter rains in March were weaker than in the winter in all study stations. Moreover, the results of the statistically significant relationship for the studied stations were PValue less than (0.05) in 9 stations for the winter. While the winter rain with March rain was represented in only three stations in the northwest, this may explain air circulation did not correlate well with the NAO index. Keywords:North Atlantic Oscillation, NAO, Rain, Libya.

Organic geochemical characterization of crude oils and source rocks from Concession 6, central Sirt Basin, Libya

The Sirt Basin contains most of Libya’s producing oil fields and is in northern Libya, south of the Gulf of Sirt in the Mediterranean Sea. The main aims of this study were to characterize the type of organic matter and depositional conditions of the source rocks and thermal maturity of the crude oils in this region using a variety of geochemical techniques including gas chromatography (GC), gas chromatography/mass spectrometry (GCMS), stable carbon and hydrogen isotopes, total organic carbon (TOC), and Rock Eval analysis. Twelve crude oil samples from Cambrian–Ordovician Gargaf, Upper Paleocene Zaltan, and Middle Eocene Gialo reservoirs and seventy-nine source rock samples representing Sirt Shale samples from nine wells were collected from the Zaltan Platform and surrounding troughs in the central Sirt Basin. Organic geochemical parameters indicate that these oils were sourced from marine organic matter deposited under oxic to suboxic conditions. The oils were divided into three groups based on their whole oil carbon and hydrogen isotopic composition and thermal maturity as manifested by several saturate and aromatic hydrocarbon maturity parameters. Based on the geochemical data, it is proposed that there are at least two sources for the crude oils in the Zaltan Platform area of the central Sirt Basin. The study also indicates that the Sirt Shale source rocks from Maradah Trough are dominated by marine organic matter and have reached the main phase of oil generation.

Description of a new Tegenaria Latreille, 1804 from southern Turkey with remarks on the Tegenaria ariadnae species-complex (Arachnida, Araneae).

A new cave-dwelling species of Tegenaria, T. lazarovisp. nov., is described from southern Turkey, based on both sexes. The new species belongs to the T. ariadnae species-complex which is distributed in the Eastern Mediterranean (Crete, northern Libya). The new species is compared to its morphologically closest congeners. New taxonomically relevant pictures are given for two of them. The distribution of the Tegenaria ariadnae species-complex is summarized and discussed.

On the connection between large-scale atmospheric circulation and winter GPCP precipitation over the Mediterranean region for the period 1980-2017

Abstract The influence of the large-scale atmospheric circulation on winter precipitation over the Mediterranean region is studied with the use of monthly 2.5° × 2.5° ERA-Interim 500 and 1000 hPa geopotential heights and GPCP-v2.3 precipitation, for the period 1980–2017. At first, Principal Component Analysis (PCA) is applied both to geopotential heights and precipitation datasets and the main modes of inter-annual variations are found. Then, these modes are investigated through Canonical Correlation Analysis (CCA) to identify the centers of action of the lower and the middle troposphere that control precipitation variability over the Mediterranean region. Three statistically significant canonical pairs are found. The first one, in the North Atlantic, controls precipitation over western Asia Minor, northern Libya and the western Iberian Peninsula. Τhe second mode corresponds to the see-saw between Greenland and central Europe and controls precipitation over the northern Mediterranean region. The third one is located north of Britain and controls precipitation over NW Africa and northern France. For each canonical pair, the mean geopotential heights and precipitation anomaly patterns for the four (10%) years with the highest and the lowest canonical scores are constructed, confirming the results of CCA. Moreover, the correlation between the canonical scores and the indices of the large-scale atmospheric oscillations, namely the North Atlantic Oscillation (NAO), the Arctic Oscillation (AO), the North Sea – Caspian Pattern (NCP) and the East Atlantic/West Russia Pattern (EA/WR), was studied.

Sensory and some chemical characteristics of olive oils produced in Libya

Libya is one of the considerable olive oil producers in North Africa. The consumption of olive oil in this country is part of the cultural heritage and a large number of individual manufacturers produce oil applying the process of cold pressing. The aim of this work was to determine the sensory profile and some main chemical characteristics, as free fatty acids, peroxide value, total phenols content and induction period of virgin olive oils. Oil samples were extracted from a blend of three olive cultivars typical for Libya: Roghiani, Hammudi and Endori, harvested in five different regions of northern Libya in the crop year 2015. Obtained results have shown that investigated olive oil samples were characterized by different sensory profile and chemical characteristics, due to peculiar effect of harvest areas of olive fruit. On the basis of investigated attributes, some oils were of excellent quality, but other were under. The free fatty acid contents varied between 0.73% to 2.78 % of oleic acid, peroxide values ranged from 6.40 mml/kg to 13.65 mmol/kg and induction period from 4.89 h to 18.33 h. The content of total phenols, as especially important compound for health benefit of olive oil, was also significantly various, from 56.0 to 238.3 mg GAE/kg of oil. It can be concluded that the oil from Gharyan production region was quite different from the other Libyans? olive oils. This oil had the best sensory profile, basic chemical quality, oxidative stability and the highest phenolic content.

Phytochemical profile and antioxidant capacity of virgin olive oil obtained from the olive cultivar <em>‘Roghiani’</em> from different regions of northern Libya

The aim of this work was to determine the fatty acids (FA), tocopherols, phenols, and antioxidant capacity (AC) of five virgin olive oils (VOO) obtained from the olive cultivar ‘Roghiani’, from different regions of northern Libya during the crop year 2015. The parameters determined for the oils were investigated for the first time. Seven principal FAs were detected in the VOO samples. Oleic, palmitic, and linoleic acids were the dominant ones. The highest percentage of palmitic acid was found in Tripoli VOO (P ≤ 0.05). Oleic acid was dominant in all the VOO samples. Gharyan VOO possessed the highest value of oleic acid, O/L ratio, monounsaturated fatty acids (MUFA), total phenols content (TPC), total tocopherol and tocotrienol contents (TTC), and ACDPPH % (P ≤ 0.05). A strong positive relationship between TPC and (AC) as (1/EC50DPPH) was observed, (r) was +0.831. On the other hand, (1/EC50DPPH) showed a positive correlation with TTC, (r) was +0.768.

(Anatomical study of the Cerebrum of the laughing dove (Stigmatopelia senegalensis

This species of bird distribution in Northern Libya AL-beda from Jebel Akhdar, scanty documentation exist on the neuroanatomy of this species of wild bird. So Morphological and histological study was conducted to examine the structure of prosencephalon (Cerebrum). five animals in the present study. Measurement of weight, length, width, height and volume of the intact cerebrum. from this study were observed to be The mean brain weight obtained for about 2.97g. The mean Cerebrum weight was 1.13 g. The mean Cerebrum length was 10.93mm, The mean Cerebrum width was observed to be 11.85mm, The mean Cerebrum height was 6.65mm, The mean Cerebrum volume was 0.78ml.The histological results revealed that the cerebral cortex constituted the gray matter which has six layers namely molecular layer, external granular layer, pyramidal or external pyramidal layer, internal granular layer, internal pyramidal layer and multiform layer.

Plant communities and reproductive phenology in mountainous regions of northern Libya

Within the semi-desert landscape of northern Libya, two sub-humid escarpments occur: Al-Akhdar in the east and Nafusa (Jabal Al-Gharbi) in the west. This study compares plant communities in the two regions, which are along an elevation gradient, in terms of species composition and diversity, frequency of different Raunkiaer life forms, and reproductive phenology. The two regions differed in species composition and life-form frequency between regions and between elevation zones within each region. Patterns were associated with the lower rainfall and lower moisture-holding capacity of soils at Nafusa, resulting in more xeric conditions. Only 13% of species were shared between the two regional landscapes. Species diversity, life-form frequency, and duration of the flowering–fruiting phenophase were all affected by elevation above sea level. The duration of flowering and fruiting in spring and fall was associated with environmental conditions, although there were different thresholds in the two regions. There was both a spring and fall episode of flowering at Nafusa, but only spring flowering at Al-Akhdar. It is anticipated that there will be a gradual shift of plant communities to higher elevations and loss of certain sensitive species in response to ongoing climate change.

The exploitation of wild plants in Neolithic North Africa. Use-wear and residue analysis on non-knapped stone tools from the Haua Fteah cave, Cyrenaica, Libya

The North African region offers up essential data for the study of the origins of the earliest forms of plant exploitation. Data available from several Saharan and coastal areas in the region have revealed that the arrival of domestic wheat and barley from the Levant during the Mid Holocene did not replace the exploitation of autochthonous wild plants, especially grasses. The Neolithic layers of the Haua Fteah cave, in Cyrenaica (Northern Libya), have so far produced archaeobotanical assemblages exclusively made up of wild species. This paper investigates production and use of non-knapped stone tools, mainly grinding stones, from the Holocene sequence of the Haua Fteah Cave. The presence of grinding stones may indicate a certain level of behavioural change and the adoption of new economic strategies, relying more strongly on plant exploitation. This assumption has been tested using an integrated approach of use-wear and residue analysis. These methods allowed us to obtain significant new information as to how tools were originally used.Use-wear analysis was carried out adopting a low power approach; such study was complemented by residue analysis, in particular starch granules analysis, only rarely applied in North African contexts. This combined approach was carried out on a selected sample of tools, in order to test survival of plant micro-remains and, where possible, the types of plants processed by the Holocene communities in the cave. Here we confirm the lack of evidence of domesticated crops and the presence of starch granules only belonging to wild plants.The importance of wild plants in the economy of North African prehistoric groups has often been underestimated, on the assumption that they were replaced by the Near Eastern domesticated crops and animals once they were firstly introduced in North Africa. The results of our study show a different picture, confirming the role of the wild species as an important food source during the Holocene.

A Preliminary Documentation of the Coral Reefs from Libya

Corals studies in Libya are very limited, although they play an important role in the oil exploration as they form excellent reservoirs of coral reef buildups at some oil fields of Sirt Basin (e.g. Intisar “Idris” and Sahabi Fields). Both fields are produced from Paleocene coral reefs. Meanwhile, in Cyrenaica, corals are of less importance as they are not reported in subsurface tertiary rocks, which probably in the environmental settings of these sediments out of the core of reef as occurred in the surface. Meanwhile, corals are reported from older (Jurassic) subsurface successions as in Concession NC-152, but the cementation diagenesis leads to blocking and destroying the porosity. This study presents the first surface documentation work of eight scleractinian coral species from the exposed sediments in northern Libya, where sixtaxa is reported from Al Jabal al Akhdar region, these include a) an association of huge colonies of Caulastrea sp. and Stylophora sp., from the Middle Eocene Darnah Formation at West Darnah road cut section. Theco-existence of the fastCaulastrea sp. with the slow Stylophora sp. is due to the competition strategy; b) Antiguastrea sp. which is reported from the Oligocene Algal Limestone of Al Bayda Formation at Daryanah-Abyar Roadcut section; c) Cyphastrea sp. andAleveopora sp. from Oligo-Miocene Al Faidiyah Formation at Al Fatayah cement quarry and d) Tarbellastraea sp. From Middle Miocene Benghazi Formation at Benghazi Cement Quarry. In addition, two species Astraeaopora sp. and Actinacis paroraiare reported from the Upper Miocene sediments of formation “M” in As Sahabi area.

Cenozoic rivers of northeast Africa: Evidence of trans-Saharan drainage

Radar imagery of the Sahara of Egypt and eastern Libya has dramatically changed previous concepts in regard to long term aridity of this region, revealing an extensive network of buried fluvial channels documenting the river systems that developed in the proto-Sahara during the Late Paleogene and Neogene, following the early Eocene regression of the Mediterranean Sea, and prior to Pleistocene aridification. The fall in base level associated with the end-Miocene Messinian desiccation of the Mediterranean led to deep down-cutting and extension of river systems throughout much of North Africa and South Europe. The deep, infilled canyons beneath the modern Rhone and Nile are well known, but the radar imagery identifies other deep canyons under the North African Sahara that are now invisible. In eastern Libya, drainage from Serir Tebisti (Tebisti Massif) into the Mediterranean via the Sirt Basin was channeled by two main rivers, the Sahabi in the west and the Kufra in the east; these were subsequently united in the Early Pliocene when the latter captured the former. The Gilf River was another important channel that drained north from the Uweinat-Gilf highland in southwest Egypt, in a system that may have been connected with the Kufra during the Neogene and enabling fish to move from the presently isolated Chad Basin to northern Libya and Egypt. The interplay of these north-flowing rivers and the constant northward retreat of the Mediterranean shoreline from Oligocene onward resulted in deposits of fluvial and marine sedimentation in every possible combinaton that have been described by many authors in the region between the Tebisti and the present Mediterranean shoreline. Prior to the establishment of the Nile, a southwestward drainage, the Qena River, was initiated by Oligocene uplift and lateral faulting along the Red Sea shoulder of the East African Rift. This river discharged into a distributive network known as the Radar Rivers near latitude 23° 30'N in the Southwestern Desert. It has been suggested that waters from the Qena River continued to flow southwestward to the Atlantic Ocean, in what is known as Trans African Drainage System (TADS).

Earthquake Scenario-Based Tsunami Wave Heights in the Eastern Mediterranean and Connected Seas

We identified a set of tsunami scenario input parameters in a 0.5° × 0.5° uniformly gridded area in the Eastern Mediterranean, Aegean (both for shallow- and intermediate-depth earthquakes) and Black Seas (only shallow earthquakes) and calculated tsunami scenarios using the SWAN-Joint Research Centre (SWAN-JRC) code (Mader 2004; Annunziato 2007) with 2-arcmin resolution bathymetry data for the range of 6.5—Mwmax with an Mw increment of 0.1 at each grid in order to realize a comprehensive analysis of tsunami wave heights from earthquakes originating in the region. We defined characteristic earthquake source parameters from a compiled set of sources such as existing moment tensor catalogues and various reference studies, together with the Mwmax assigned in the literature, where possible. Results from 2,415 scenarios show that in the Eastern Mediterranean and its connected seas (Aegean and Black Sea), shallow earthquakes with Mw ≥ 6.5 may result in coastal wave heights of 0.5 m, whereas the same wave height would be expected only from intermediate-depth earthquakes with Mw ≥ 7.0 . The distribution of maximum wave heights calculated indicate that tsunami wave heights up to 1 m could be expected in the northern Aegean, whereas in the Black Sea, Cyprus, Levantine coasts, northern Libya, eastern Sicily, southern Italy, and western Greece, up to 3-m wave height could be possible. Crete, the southern Aegean, and the area between northeast Libya and Alexandria (Egypt) is prone to maximum tsunami wave heights of >3 m. Considering that calculations are performed at a minimum bathymetry depth of 20 m, these wave heights may, according to Green’s Law, be amplified by a factor of 2 at the coastline. The study can provide a basis for detailed tsunami hazard studies in the region.

Impact of waste water discharge on the plant communities and size structure of Wadi El‐Shees, Al‐Jabal Al‐Akhdar, Libya

AbstractThe present study assesses the impact of waste water discharge on the plant communities and size structure of the common woody species in Wadi El‐Shees, Al‐Jabal Al‐Akhdar, Libya. Thirty stands were selected along two adjacent tributaries (polluted and un‐polluted) in Wadi El‐Shees. Sixty‐five species belonging to 60 genera and 34 families were recorded, predominated with therophytes and mono‐regional taxa and only one endemic species (Arbutus pavarii). The application of TWINSPAN on the data set, led to the recognition of 4 vegetation groups, two represented each of the polluted and un‐polluted regions. Soils of the polluted area have significant higher values of organic matter, salinity, chloride and iron. Ten common woody perennials were selected for estimating the variation in their size structure in the polluted and un‐polluted tributaries. These species include one shrublet, two shrubs and 7 trees. It was found that the density and volume of all species except A. pavarii and Sarcopoterium spinosum were higher in the polluted than the un‐polluted area. Four size distributions were recognized: inverse J‐shaped, bell‐shaped, positive and negative skewed distributions. It was concluded that pollution had significant impact on the plant density and sizes structure of the common woody plants in Wadi El‐Shees. Such study may help in managing and conserving plant diversity in Northern Libya. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Enhancing the chronology of climatic and archaeological sequences in Cyrenaica, Northern Libya, using Optically Stimulated Luminescence (OSL) dating and tephrochronology

Enhancing the chronology of climatic and archaeological sequences in Cyrenaica, Northern Libya, using Optically Stimulated Luminescence (OSL) dating and tephrochronology

Enhancing the chronology of archaeological sequences in Cyrenaica, Northern Libya, using small aliquot and single grain Optically Stimulated Luminescence (OSL) dating of fine sand

Enhancing the chronology of archaeological sequences in Cyrenaica, Northern Libya, using small aliquot and single grain Optically Stimulated Luminescence (OSL) dating of fine sand

Petrogenesis of Cenozoic volcanic rocks in the NW sector of the Gharyan volcanic field, Libya

The north-western sector of the Gharyan volcanic field (northern Libya) consists of trachytic-phonolitic domes emplaced between ~41 and 38Ma, and small-volume mafic alkaline volcanic centres (basanites, tephrites, alkali basalts, hawaiites and rare benmoreites) of Middle Miocene-Pliocene age (~12–2Ma). Two types of trachytes and phonolites have been recognized on the basis of petrography, mineralogy and geochemistry. Type-1 trachytes and phonolites display a smooth spoon-shaped REE pattern without negative Europium anomalies. Type-2 trachytes and phonolites show a remarkable Eu negative anomaly, higher concentration in HFSE (NbTaZrHf), REE and Ti than Type-1 rocks. The origin of Type-1 trachytes and phonolites is compatible with removal of clinopyroxene, plagioclase, alkali feldspar, amphibole, magnetite and titanite starting from benmoreitic magmas, found in the same outcrops. Type-2 trachytes and phonolites could be the result of extensive fractional crystallization starting from mafic alkaline magma, without removal of titanite. In primitive mantle-normalized diagrams, the mafic rocks (Mg#=62–68, Cr up to 514ppm, Ni up to 425ppm) show peaks at Nb and Ta and troughs at K. These characteristics, coupled with low 87Sr/86Sr(i) (0.7033-0.7038) and positive εNd (from +4.2 to +5.3) features typical of the mafic anorogenic magmas of the northern African plate and of HIMU-OIB-like magma in general. The origin of the mafic rocks is compatible from a derivation from low degree partial melting (3–9%) shallow mantle sources in the spinel/garnet facies, placed just below the rigid plate in the uppermost low-velocity zone. The origin of the igneous activity is considered linked to passive lithospheric thinning related to the development of continental rifts like those of Sicily Channel (e.g., Pantelleria and Linosa) and Sardinia (e.g., Campidano Graben) in the Central-Western Mediterranean Sea.

A comparison of single-grain and small aliquot dating of fine sand from Cyrenaica, northern Libya

Over the last decade, single-grain studies have significantly enhanced optically stimulated luminescence dating of quartz from Quaternary and archaeological sediments. However, single-grain dating is time-consuming and requires specialised equipment, leading a number of authors to advocate measurement of small, multi-grain aliquots, as a viable alternative. In this study, we compare single-grain and small aliquot data from four samples from Cyrenaica, northern Libya. Discrepancies are found between the results obtained using these two techniques, which we attribute to: (1) grains with poor luminescence properties, which are present in the small aliquot data but not the single-grain data and (2) averaging effects in multi-grain aliquots. We suggest that small aliquot measurements are not always an appropriate alternative to single-grain analysis, and that small aliquot datasets should be treated with caution.

An integrated remote sensing and GIS analysis of the Kufrah Paleoriver, Eastern Sahara

A combined remote sensing (optical and radar imagery) and GIS (hydrologic network delineation) analysis allows mapping of the Kufrah Paleoriver of Libya and sheds light on its geomorphic evolution during the Neogene. The Kufrah system, which is now largely buried beneath the windblown sands of the Eastern Sahara, drained an area of about 236,000 km 2 in central and southern Libya. The river discharged across a large inland delta to the Al-Jaghbub depression in northern Libya, and ultimately through the Sirt Basin to the Mediterranean Sea. Radar imagery reveals buried features of the landscape including drainage divides, locations of possible stream capture, deeply-incised valleys, and the distal margins of the inland delta. Previous studies have shown that the Kufrah Paleoriver is the successor of the Sahabi River, which drained most of central Libya during the late Tertiary. Satellite imagery supports the concept of large-scale drainage rearrangement in the Quaternary, driven by tectonic subsidence that diverted streamflow and sediment discharge away from the Sahabi basin toward the inland delta of the lower Kufrah basin. Paleochannels crossing the delta suggest that at various times during the Quaternary, the Kufrah Paleoriver either drained externally through the deeply-incised Sahabi Paleochannel to the Mediterranean Sea, or drained internally to paleolakes in the Al-Jaghbub depression. Thick alluvial deposits on the delta and lake margins likely provided a major sediment source to build the Great Sand Sea, which covers the region today. The southwestern branch of the Kufrah drainage is aligned with an elongated trough that connects to the Amatinga River system in Chad. Thus the Kufrah watershed may have served as an outlet from Megalake Chad to the Mediterranean Sea during humid phases of the Neogene. If so, the combined Amatinga/Kufrah system may have served as one of the proposed natural corridors used by human and animal populations to cross the Sahara during the Pleistocene. These findings hold promise for modeling past lake levels and paleoclimates, locating groundwater sources in the region, and exploring for reservoirs of oil and natural gas in the region.