The prehistoric and preindustrial deforestation of Europe

Humans have transformed Europe's landscapes since the establishment of the first agricultural societies in the mid-Holocene. The most important anthropogenic alteration of the natural environment was the clearing of forests to establish cropland and pasture, and the exploitation of forests for fuel wood and construction materials. While the archaeological and paleoecological record documents the time history of anthropogenic deforestation at numerous individual sites, to study the effect that prehistoric and preindustrial deforestation had on continental-scale carbon and water cycles we require spatially explicit maps of changing forest cover through time. Previous attempts to map preindustrial anthropogenic land use and land cover change addressed only the recent past, or relied on simplistic extrapolations of present day land use patterns to past conditions. In this study we created a very high resolution, annually resolved time series of anthropogenic deforestation in Europe over the past three millennia by 1) digitizing and synthesizing a database of population history for Europe and surrounding areas, 2) developing a model to simulate anthropogenic deforestation based on population density that handles technological progress, and 3) applying the database and model to a gridded dataset of land suitability for agriculture and pasture to simulate spatial and temporal trends in anthropogenic deforestation. Our model results provide reasonable estimations of deforestation in Europe when compared to historical accounts. We simulate extensive European deforestation at 1000 BC, implying that past attempts to quantify anthropogenic perturbation of the Holocene carbon cycle may have greatly underestimated early human impact on the climate system.     

Groundwater development in Lemoa, Guatemala

In the rural Guatemalan Central Highlands, drinking water wells are a rare commodity due to lack of data regarding depth and sustainability of groundwater. At a study well in Lemoa, aquifer sustainability and other characteristics were estimated using hydrograph data and Theiss recovery method for pumping tests. These tests showed that while specific capacity remained fairly constant, transmissivity increased, indicating development of the well subsequent to installation of the study well. The time domain electromagnetic (TDEM) method was evaluated at the site as a prospective groundwater prospecting technique. Characterization of subsurface conditions using TDEM is feasible with local subsurface data for correlation; however, it is limited to delineating low electrical resistive zones without geologic data for correlation. Data showed that groundwater produced from volcanic alluvium at approximately 79 m in depth is sustainable at the study area at current use rates.     

Forecasting areas vulnerable to forest conversion using artificial neural network and GIS (case study: northern Ilam forests,Ilam province,Iran)

Forest conversion due to illegal logging and agricultural expansion is a major problem that is hampering biodiversity conservation efforts in the Zagros region. Yet, areas vulnerable to forest conversion are unknown. This study aims to predict the spatial distribution of deforestation in western Iran. Landsat images dated 1988, 2001, and 2007 are classified in order to generate digital deforestation maps which locate deforestation and forest persistence areas. Meanwhile, in order to examine deforestation factors’ investigation, deforestation maps with physiographic and human spatial variables are entered into the model. Areas vulnerable to forest changes in the Zagros forest region are predicted by a multilayer perceptron neural network (MLPNN) with a Markov chain model. The results show that about 19,294 ha forest areas are deforested in the last 19 years. The predictive performance of the model appears successful, which is validated using the actual land cover map of the same year from Landsat data. The validated map is found to be 94 % accurate. The validation is also tested using the relative operating characteristic approach which yielded a value of 0.96. The model is then further extended to predict forest cover losses for 2020. The MLPNN approach was found to have a great potential to predict land use/land cover changes because it permits developing complex, nonlinear models.     

IGU Commission on Changing Rural Systems Subcominission on Highlands and High-Latitude Zones

The International Geographical Union Reports

IGU Commission on Changing Rural Systems Subcominission on Highlands and High-Latitude Zones     

Experimental study of the effect of material and arrangement of electrodes and voltage on the electro-remediation of saturated clays containing chloride and sulfate ions

Electro-remediation process (ERP) is used for dewatering and decontaminating of the soil and improving its mechanical properties. In this study, the effect of voltage, electrode materials, and their arrangement on ERP were studied. The saturated clayey soil was remolded in four boxes at a dry density of 16.2 kN/m³. The process was performed in three stages. The chemical tests at the end of ERP indicated that the absorption of chloride ions in the anode may differ from 89 to 642% due to electro-migration phenomenon. The pH of the soil decreases in anode zone and increases towards the cathode zone. Up to 92% of the sulfate ions were transported and accumulated in the anode. However, in highly contaminated soil, the absorption ratio is 5% in the cathode due to the domination of electro-osmosis process. It was indicated that the electro-osmosis permeability coefficient (K_e) depends on the applied voltage, the soil type, and temperature and its reduction versus time is inversely related to applied voltage. Also, sulfate ions reduced by 74% in the anode due to a change in absorption direction. The results showed that the optimum configuration is linear along with a voltage of 18 V.     

Predictive modelling of the spatial pattern of past and future forest cover changes in India

This study was carried out to simulate the forest cover changes in India using Land Change Modeler. Classified multi-temporal long-term forest cover data was used to generate the forest covers of 1880 and 2025. The spatial data were overlaid with variables such as the proximity to roads, settlements, water bodies, elevation and slope to determine the relationship between forest cover change and explanatory variables. The predicted forest cover in 1880 indicates an area of 10,42,008 km², which represents 31.7% of the geographical area of India. About 40% of the forest cover in India was lost during the time interval of 1880–2013. Ownership of majority of forest lands by non-governmental agencies and large scale shifting cultivation are responsible for higher deforestation rates in the Northeastern states. The six states of the Northeast (Assam, Manipur, Meghalaya, Mizoram, Nagaland, Tripura) and one union territory (Andaman & Nicobar Islands) had shown an annual gross rate of deforestation of >0.3 from 2005 to 2013 and has been considered in the present study for the prediction of future forest cover in 2025. The modelling results predicted widespread deforestation in Northeast India and in Andaman & Nicobar Islands and hence is likely to affect the remaining forests significantly before 2025. The multi-layer perceptron neural network has predicted the forest cover for the period of 1880 and 2025 with a Kappa statistic of >0.70. The model predicted a further decrease of 2305 km² of forest area in the Northeast and Andaman & Nicobar Islands by 2025. The majority of the protected areas are successful in the protection of the forest cover in the Northeast due to management practices, with the exception of Manas, Sonai-Rupai, Nameri and Marat Longri. The predicted forest cover scenario for the year 2025 would provide useful inputs for effective resource management and help in biodiversity conservation and for mitigating climate change.     

Long term changes in forest cover and land use of Similipal Biosphere Reserve of India using satellite remote sensing data

The spatial changes in forest cover of Similipal biosphere reserve, Odisha, India over eight decades (1930–2012) has been quantified by using multi-temporal data from different sources. Over the period, the forest cover reduced by 970.8 km² (23.6% of the total forest), and most significantly during the period, 1930–1975. Human-induced activities like conversion of forest land for agriculture, construction of dams and mining activities have been identified as major drivers of deforestation. Spatial analysis indicates that 399 grids (1 grid = 1 × 1 km) have undergone large-scale changes in forest cover (>75 ha) during 1930–1975, while only 3 grids have shown >75 ha loss during 1975–1990. Annual net rate of deforestation was 0.58 during 1930–1975, which has been reduced substantially during 1975–1990 (0.04). Annual gross rate of deforestation in 2006–2012 is indeed low (0.01) as compared to the national and global average. This study highlights the impact and effectiveness of conservation practices in minimizing the rate of deforestation and protecting the Similipal Biosphere Reserve.     

Participatory forestry as a strategy for reforestation in Bangladesh

Deforestation has been a serious ecological problem in Bangladesh for the past four decades. Illegal logging, demand for fuelwood and farmland encroachment are the principal causes of dwindling biomass resource. About 17.8% of the total area of the country are under forest cover (BBS 1993), but less than half of that area are under real tree formations. It is estimated that Bangladesh loses its forest lands by about 3.3% every year (World Bank 1994). This paper attempts to present a review of a newer strategy to meet this challenge; a strategy, not merely of halting deforestation, but of reforestation on a national scale and through people's participation in the process.In response to the crisis in the forestry sector, traditional government forest management programs have been replaced by participatory forestry in recent years as the principal strategy for reforestation. This change in strategy has two goals (1) encourage new plantations, and (2) generate income and create jobs for the rural poor. Participatory forestry is a benefit sharing scheme in which the landless and the marginal farmers are employed in tree plantation work.     

Deforestation in the Buea-Limbe and Bertoua regions in southern Cameroon (1984–2000): modernization,world-systems,and neo-Malthusian outlook

This paper characterizes changes in land use and forest cover in southern Cameroon. In doing so, we use remotely sensed data to define the rates and area of forest loss and cover change in two reference areas over a period of 16 years (from 1984 to 2000)—the Buea-Limbe area in the southwest province and the Bertoua area in the east province. We relate socio-economic data of these study areas with results from the empirical spatial analysis to explain causes of deforestation. A second set of explanations, which we call the theoretical perspective, attributes deforestation in southern Cameroon to the intricacies of modernization, world-systems, and neo-Malthusian theories.     

Shoshonitic and calc-alkaline lavas from the Highlands of Papua New Guinea

Pleistocene to Recent stratovolcanoes in the Highlands of Papua New Guinea are made up of calc-alkaline to shoshonitic lava, tuff, agglomerate, ash, and lahar deposits. The volcanic rocks are characterized by high and variable Al, high K and total alkalis, and low Fe, Mg, and Ca. There is a continuous variation between high-K calc-alkaline, low-Si high-K calc-alkaline, and shoshonitic rocks. The elements V, Rb, Sr, Zn, Nb, and Ba are high relative to general andesitic abundances, particularly in the shoshonites. The Highlands volcanic rocks originated either in the base of thick sialic crust which is undergoing stabilization after major orogeny and uplift, or more probably, in eclogite sinking through the underlying mantle. Variation in content of K and other incompatible elements was either inherited from the source rocks in the base of the crust, or was produced by zone refining in a thick upper mantle zone containing interstitial fluid rich in these elements. Further variation, mainly in Fe/Mg, Si, and total alkalis, was caused by minor low-pressure crystal fractionation involving olivine, clinopyroxene, and, to a lesser extent, calcic plagioclase.     

Population and poverty in Jamaican deforestation: Integrating satellite and household census data

This study uses MSS data to derive sub-national level deforestation rates at the constituency administrative level for Jamaica for 1987 and 1992. It then investigates the role of poverty and population in driving forest loss during this period by linking these estimates in a GIS with constituency level demographic and socioeconomic census data for the island. OLS regression results support the importance of population pressures and poverty in driving the destruction of Jamaica's forests and the relative contribution to deforestation of their various measures are noted and discussed. In addition to providing information on Jamaica's deforestation attributes, the study demonstrates how remotely sensed data can be used in conjunction with household census data to derive information on human-forest interactions at the sub-national level. A small simulation experiment based on regression results using key variables suggests that under any scenario, the impacts of key social and demographic changes on Jamaica's remaining forest cover may be substantial by the year 2010. This revised version was published online in July 2006 with corrections to the Cover Date.     

Electron-probe studies of the earlier pyroxenes and olivines from the Skaergaard intrusion,East Greenland

Pyroxenes and olivines from the earlier stages of fractionation of the Skaergaard intrusion (Wager and Brown, 1968; Brown, 1957) have been studied using the electron microprobe. The subsolidus trend for both Ca-rich and Ca-poor pyroxenes has been established, from the Mg-rich portion of the quadrilateral to the Hed-Fs join, together with the orientations of the tie-lines joining coexisting pyroxenes. For the Mg-rich Ca-poor pyroxenes, Brown's (1957) solidus trend has been modified slightly. From a study of a previously undescribed drill core, reversals in the cryptic layering have been found in the Lower Zone. The reversals are attributed to existence within the convecting magma chamber of local temperature differences. The Skaergaard magma temperatures are postulated to have passed out of the orthopyroxene stability field into the pigeonite stability field at EnFs ratios of 7228, for Ca-free calculated compositions, and specimen 1849, a perpendicular-feldspar rock, is interpreted as straddling the orthopyroxene-pigeonite transition interval. The cessation of crystallisation of Ca-poor pyroxene and the increase in Wo content of the Ca-rich pyroxene trend have been reexamined, and Muir's (1954) peritectic reaction (pigeonite+liquid=augite) has been confirmed. The composition at which Ca-poor pyroxene starts reacting with the liquid is postulated as Wo₁₀ En_36.7Fs_{53 3}. It is suggested that the cessation of crystallisation of Ca-poor pyroxene is sensitive to the amount of plagioclase crystallising from the liquid.A complete series of accurate olivine compositions for the whole Skaergaard sequence is presented for the first time, including the compositions of the Middle Zone olivine reaction rims.     

The geochemistry of Dinantian volcanism in south Kintyre and the evidence for provincialism in the southern Scottish mantle

Scottish Dinantian transitional to mildly alkaline volcanism is represented by abundant outcrops in the Midland Valley, Southern Uplands and Highlands provinces. Dinantian volcanic rocks from Kintyre in the Scottish Highlands range in composition from basalt through basaltic hawaiite, hawaiite, mugearite and benmoreite to trachyte, the compositions of the evolved types being largely due to differentiation from the basaltic parents.Recent geochemical investigations of Scottish Caledonian granitoids, Siluro-Devonian Old Red Sandstone (ORS) lavas and xenolith suites from numerous vents and dykes of Permo-Carboniferous to Tertiary age have revealed that the Scottish crust and upper mantle both increase in age and are increasingly enriched in incompatible elements towards the north and northwest. The upper mantle and lower crust below the Highlands province are therefore largely considered to be more enriched and in parts older than those below the Midland Valley and Southern Uplands. Dinantian alkali basalts from these latter two provinces have Nd values predominantly in the range +3 to +6, initial ⁸⁷Sr/⁸⁶Sr values of 0.7029–0.7041 and ²⁰⁷Pb/ ²⁰⁴Pb values of 15.48–15.60. However, similar basalts from Kintyre and Arran in the Highlands have lower Nd (+0.1 to +3.4) and ²⁰⁷Pb/²⁰⁴Pb (for given ²⁰⁶Pb/²⁰⁴Pb ratios; 15.49–15.51) and slightly higher ⁸⁷Sr/⁸⁶Sr (0.7033–0.7046). This regional variation correlates well with the differences seen between Midland Valley and Highland magmas in the ORS calc-alkaline suite (Thirlwall 1986) and it is suggested that both the ORS and Dinantian basic rocks are derived from similar types of mantle, although no lithospheric slab component is present in the later Dinantian suites. Isotopically-distinct portions of mantle therefore appear to have been present below the Highland and Midland Valley-Southern Upland provinces from at least Caledonian to Carboniferous times. The combined incompatible element and Sr-Nd-Pd isotopic evidence from Kintyre and Arran basaltic rocks does not allow unequivocal distinction between a lithospheric mantle and a sublithospheric mantle source. The observed correlation between isotopic composition of Dinantian basalts and the chemical composition of the lithosphere, together with the apparent involvement of long-term separated source reservoirs suggests that Kintyre and Arran lavas were derived largely from a lithospheric mantle source. On the other hand, the isotopic enrichment of Kintyre basaltic rocks is not extreme; trace element and isotopic compositions are still comparable to modem OIB. Sublithospheric mantle could therefore also be a viable source for Kintyre and Arran Dinantian volcanism.     

The origin of fumarolitic andradite at Menoyre,France and Fant'Ale,Ethiopia

Recent discoveries of fumarolitic andradite in alkaline or peralkaline trachytes (Menoyre, Cantal, France, and Fant'Ale, Ethiopia) are interpreted genetically.The andradites were formed from the constituents of pyroxene, always calcic and iron-rich in these rocks. The elements Ca and Fe were fixed on the surface of fractures by late fumaroles of high oxidizing capacity.The following reaction can be established at Menoyre: hedenbergite+O₂andradite+hematite+cristobalite.In a hyperalkaline medium, which is the case for the trachyte of Fant'Ale, the reaction is: Hedenbergite+sodium metasilicate+O₂andradite+aegirinic pyroxene+cristobalite.     

On Afro-Arabian graben tectonics

This study of the Afro-Arabian gräben, which concentrates on the region between Kenya and the Levant reviews their evolution that begun not earlier than in the latest Oligocene or in the lower Miocene. The gräben continue to sink in several major downfaulting phases, especially during the transitional times of Miocene to Pliocene, of Pliocene to Pleistocene and in the Mid-Pleistocene. We have no proof of erstwhile major graben structures in the crystalline Precambrian basement or in the pre-Oligocene sedimentary cover revived during the young Cenozoics that could have redeemed the formation of the Afro-Arabian megagräben. Significant faults in the pre-Oligocene sedimentary cover are seldom observed. Where they occur, their tectonic direction scarcely runs parallel to the principal trend of the Cenozoic graben. At best these ancient faults may have had an impact on the development of cross — and diagonal faulting which played also a role in the disposition of the subgräben, grabensplays and other offshoots of the main gräben. Equally rarely has parallelism of trend between the basement metamorphics as well as their intrusive dykes and that of the main graben lineations been established. The Afro-Arabian gräben originated in a lower Tertiary peneplain of regional dimension which had expanded over large part of Gondwana. The graben dissection thus took place regardless of former tectonic highs and lows such as swells and basins — a phenomenon that negates the theory of key-stone dropping as a result of preceding upwarping. The occasional impression of vaulting with the graben as its axis is purely of morphological significance; it is due to “isostatic” uplifting and tilting of the main horsts attached to the main graben. Besides, most megahorsts are not “halfhorsts” but huge blocks mountains (Levant, Etbai, Ethiopia, Danakil, Yemen) bordered on both flanks by major tensional faults with throws of thousands of meters. These major uplifts, which are especially noticed in the Plio-Pleistocene, caused, moreover, the removal of the sedimentary cover by erosion and denudation in the elevated parts of the graben shoulders and its hinterland. The few known outcrops of Cretaceous-Eocene in the coastal area of the Red Sea, believed to be indications of ancient marine gulfs and thus forerunners of the Rift valley are in all likelihood the relics of such coverbeds that were saved from erosion in the down dropped blocks of the graben. The surveyed marginal faults are normal dip-slips of average 70° dip. These remained in the ensuing taphrogenic episodes the “localized” fixed graben frames. In the interior of the graben they are followed by a Vorberge zone consisting of tilted blocks that implicate also subsidiary horsts and gräben. In the superdimensional rifts of Afar and Red Sea, the subsidiary gräben and horsts of the Vorberge zone may approach a width comparable to that of the East Levant rift valleys. In the axial part of the Afar, Red Sea and Gregory Rift valley appears as youngest, that is, Pleistocene structural element a distinct graben-in-graben or rift-in-rift. This young structure is much less developed in the graben of the Gulf of Aden. The Aden graben differs also in other aspects from the pattern of the Red Sea, particularly in its submarine axial topography and in the peculiar transversal fault offsets, both morphotectonic features reminiscent of the Indian mid-oceanic ridges. A comparison of geophysical, especially of gravity measurements, carried out in the various main gräben reveals very conflicting results. While higher positive Bouguer values led to the conjecture of heavy magmatic material in the bottom of the rift-in-rift of the Red Sea, in most of the Afar fault-funnel and in the entire Gregory Rift valley there prevails an unusual large gravity deficiency that would point to an extremely thick crust. This is all the more remarkable as both rift valleys and horsts of Ethiopia and of Kenya are dominated by huge basaltic trap lavas and by other basic volcanic material. The hypothesis of anticlockwise rotation and drifting of the Arabian peninsula (including its supposed impact on the orogenic origin of the Zagros fold belt) has many pitfalls.

1. As the taphrogenic destruction is not restricted to the intercontinental Afro-Arabian gräben, but extended far into the Mediterranen and into the Indian Ocean, any anticlockwise rotation of Arabia must exceed the 7° postulated movement.
2. Yemen and Ethiopia, that is Arabia and Africa, were in the Miocene still a continuous continent. When they became separated in the Pliocene by the Bab el Mandeb splay, northern Sinai and northernmost Egypt had been transformed into a landlocked isthmus that has remained a continental bridge to this day. In fact at the end of the Miocene the Red Sea graben had already been turned — though for a short period — into an enclosed evaporitic basin.
3. As regards the axial graben-in-graben of the Red Sea that especially prompted the assumption of a drift between Africa and Arabia, its Pleistocene age would demand a drifting rate of half a meter per year. There are, however, at the coastal area of the Red Sea no prehistoric, historic or recent witnesses of lateral stretching at the Red Sea and certainly not of such excess. The deduced annual drift of half a meter there, exceed even the most optimistic calculations and images hitherto made by the adherents of such large drifting as has been postulated to have taken place between Africa and South America.
4. Finally, in the studies on drifts — and this also applies to the question of horizontal fault displacement — there is wanting a proper discussion on the mechanical deformations to which the rigid crustal parts must have been subjected in the course of such intensive tearing apart motions.

     

Impact assessment of land cover changes on the runoff changes on the extreme flood events in the Kelantan River basin

In the current years, changing the land cover/land use had serious hydrological impacts affecting the flood events in the Kelantan River basin. The flood events at the east coast of the peninsular Malaysia got highly affected in the recent decades due to several factors like urbanisation, rapid changes in the utilisation of land and lack of meteorological (i.e. change in climate) and developmental monitoring and planning. The Kelantan River basin has been highly influenced due to a rapid change in land use during 1984 to 2013, which occurred in the form of transformation of agricultural area and deforestation (logging activities). In order to evaluate the influence of the modifications in land cover on the flood events, two hydrological regional models of rainfall-induced runoff event, the Hydrologic Engineering Center (HEC)-Hydrologic Modeling System (HMS) model and improved transient rainfall infiltration and grid-based regional model (Improved TRIGRS), were employed in this study. The responses of land cover changes on the peak flow and runoff volume were investigated using 10 days of hourly rainfall events from 20 December to the end of December 2014 at the study area. The usage of two hydrological models defined that the changes in land use/land cover caused momentous changes in hydrological response towards water flow. The outcomes also revealed that the increase of severe water flow at the study area is a function of urbanisation and deforestation, particularly in the conversion of the forest area to the less canopy coverage, for example, oil palm, mixed agriculture and rubber. The monsoon season floods and runoff escalate in the cleared land or low-density vegetation area, while the normal flow gets the contribution from interflow generated from secondary jungle and forested areas.     

Understanding salt-marsh accretion,Scolt Head Island,Norfolk, England

Measurements of surface sediment accretion have been obtained for Hut Marsh, Scolt Head Island, Norfolk, England, using sand marker horizons. More than eighty 1-m² marker sites were deployed in October 1983, and vertical accretion measured at them in April and October 1986 and April 1987. Elevations relative to Ordnance Datum were established by levelling each site at the time of deployment. Data collected by Steers between 1935 and 1957 on the same marsh show a clear relationship between marsh elevation and sedimentation. The results of the current more detailed study, presented as mean annual accretion rates, indicate a complex pattern of sediment distribution at this macrotidal location. These data, together with the results of tidal flow monitoring in the creeks on Hut Marsh, show the importance of spatial and temporal patterns of sediment delivery and variations in depositional processes in determining the distribution of sedimentation across the marsh surface.     

Distribution and Stratigraphic Potential of the Mesozoic Radiolarian Family Prunobrachidae

The distribution and stratigraphic potential of the family Prunobrachidae Pessagno are studied. The recent discovery of new locations of the Prunobrachidae representatives in the Northeast of Russia increases the correlation potential of this family. In the Pacific Province in the Northern Hemisphere, the northernmost location of the prunoid radiolarians, is in the Chaun Bay region at 69° N (in modern coordinates) and the southernmost location is the Shikotan Island (Lesser Kuril Ridge) at 43° N. The biostratigraphic subdivision as the layer with Prunobrachium articulatum was first traced in the sections of the Koryak Highlands, Kamchatka Peninsula, and Shikotan Island. The level with Prunobrachium articulatum can be traced from the Russian Platform through the Urals and Western Siberia to the Pacific Margin.     

高亚洲积雪分布

高亚洲是全球山地积雪重要分布区，对探测全球气候环境变化，诊断积雪与气候相互作用，以及预测海面上升具有重要意义，本使用１９７８－１９８７年ＳＭＭＲ微波候积雪深度资料，１９７３－１９８９年ＮＯＡＡ周积雪面积图，以及青藏高原６０个基本气象台站１９５７－１９９２年逐日积雪深度，密度和月积雪日数记录，提示出亚洲积雪时空分布特征。     

Petrology,geochronology and Sr–Nd isotopic geochemistry of the Konso pluton,south-western Ethiopia: implications for transition from convergence to extension in the Mozambique Belt

Granites were shown to be excellent geochronological, structural and geodynamic markers. Among several generations of granites described in the Neoproterozoic of Ethiopia, we studied the post-tectonic Konso pluton to characterise the post-Pan-African evolution of the Mozambique Belt (MB) of southern Ethiopia. The Konso pluton is a composite intrusion of slightly peraluminous and ferro-potassic, bt (biotite)–leucogranites, bt–hbl (hornblende)–granites and subordinate coeval metaluminous monzodiorites, intruded into high-grade gneiss–migmatite associations of the MB. The whole suite displays chemical features of A-type granites. It is LIL- and HFS-elements enriched with Y/Nb and Yb/Ta1.2. The granites and leucogranites show non-fractionated to fractionated REE patterns [(La/Yb)_N=0.3–9.4] with strong negative Eu anomalies. The monzodiorites show fractionated REE patterns [(La/Yb)_N=5.5–7.4] with negligible negative Eu anomaly. The low initial (⁸⁷Sr/⁸⁶Sr)₄₅₀ ratios (0.70113–0.70441) and positive Nd₍₄₅₀₎ values (+1.8 to +3.3) suggest an isotopically primitive source. The Konso granites are likely to be derived from a basaltic parent, with minor contamination by crustal material with high Y/Nb and low Sr initial isotopic ratios. Age of pluton emplacement is constrained by a Rb–Sr isochron and zircon U–Pb data at 449±2 Ma. The Konso pluton is, therefore, the witness of an Ordovician A-type magmatic event, which marks a change from convergence, related to the Pan-African collision, to extension in the Mozambique Belt of southern Ethiopia.