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Item Geology of selected sites along the northern margin of the Barberton Greenstone Belt(2022) Mashele, Nonkululeko PhumeleleAn increasing number of UNESCO World Heritage Sites are recognised for their geological significance. One such site forms part of the Barberton Greenstone Belt (BGB), which has been widely acknowledged as an outstanding site for Archean geology research. Though members of the geoscience community are familiar with the outstanding universal value of the Barberton Greenstone Belt, the people who live on it often do not. With the World Heritage Status (2018) comes an obligation to unpack the geological heritage of the Barberton region to local people and visitors, and to promote further research so the true value of the geological importance of the region may be better understood. For this reason, this project set out to interpret and contribute to concepts formulated from studies of BGB rocks to produce a thesis usable for generating various science communication media and topics for further research. Themes discussed in this thesis include granite-greenstone relationships, alteration of ultramafic rocks and the associated economic products, as well as deformation of various lithologies. Ease of access guided the selection of eight mostly roadside outcrops along the R38 secondary road linking Barberton to the southern gate of the Kruger National Park. These sites link up to form a geological trail along the northern margin of the Barberton Greenstone Belt, allowing visitors to easily interact with outcrops on their way to other popular attractions. By driving along the R38 with science communication media produced from this project, locals and visitors will learn how geology shaped their world. They will gain insight on how mineable concentrations of verdite, talc and magnesite occur in certain ultramafic bodies. They will also learn of different ways in which rocksrespond to stress as a common perception of rocks among laypersons is that they are solid, stable and unchanging.Item Geophysical investigation of the mineral prospect on the Wortel Farm, Namaqua Belt, Northern Cape, South Africa(2020) Buthelezi, MinenhleThe Wortel Farm no. 42 is one of many areas in the Namaqua metamorphic terrain with mineral occurrences whose source, potential and extent have not been investigated. Mapped copper and tungsten mineral occurrences are identified on the farm, sitting on the Koeipoort granite of the Kheisian Period (~2.0 Ga); gneisses, schist, shale, amphibolite and quartzites of the Bushmanland Group and intruding dykes and sheets of the Gareskop Suite. The farm is located 20 km north of the well-known Aggeneys base metal sulphide deposits and 120 km north-east of the O’kiep copper district, all consisting similar lithologies with minor variations. This research was aimed at investigating (and delineating) the potential of the copper occurrence on the farm using multiple geophysical techniques. Gravity, aeromagnetic, DC resistivity and magnetotelluric methods were chosen to map the geology framework, both spatially and in depth, and induced polarization (IP) technique was used for the direct targeting of the mineralisation. The Namaqua Sector of the Namaqua-Natal Mobile Belt, which is composed of low-to-high metamorphic grade rocks, experienced orogenic deformations that occurred between 2.0 – 0.95 Ga, resulting in strongly metamorphosed, overturned and deformed sequences, with a wide a range of mineral occurrences across the sector (only partially investigated). Based on outcrop mapping and geophysical data interpretation, five previously unidentified faults at least 200 m long, and striking E-W, NW and NE, were identified in the various lithologies. Multiple folds were also mapped on surface through dip measurements and inferred from interpretations of the geophysical data and they ranged in strike length between centimetres and kilometres. The geochemical analyses showed that the study area has elevated concentrations of Cr, Co, Cu, Fe, Li, Mg and Ni elements. Aeromagnetic data collected at 80 m flight height and 200 m line spacing were interpreted and modelled with the PyGMI software written in Python. The IP data were acquired over the high magnetic amplitude anomaly. A 2 km x 600 m zone of high magnetism (26380 nT or -265 nT with IGRF removed) is spatially coincident with parts of a 8 – 11 mV/V chargeability anomaly which is also correlated with the mapped Gareskop Suite dykes and Koeipoort granite. The high chargeabilities were interpreted as a possible source of the geochemical elements. A resistivity anomaly (4 km x 500 m) coincides with most of the elevated chargeability anomaly, with a similar N-S strike and distribution. This is interpreted as an indicator that the possible mineral occurrence is structurally bound across granites, dykes and sand cover unlike the Aggeneys sulphide deposits that are strata-bound in the Gams Formation. Although Aggeneys and Wortel Farm are 20 km apart with minor differences in lithology their mineral occurences are different in nature: Aggeneys stratabound in Gams Formation and Wortel structurally bound. The mapped geochemical anomalies and occurrences are hosted within the high chargeability zones. The structural confinement of these anomalous features indicate the source(s) of these mineral occurrences are of a pervasive nature as seen in the Springbok vicinity that the Namaqua region was subjected to mineralising fluids of post Namaqua age and yet unknown source. The porphyry system is inferred to be most probable mineralising system, occurring in and around the Gareskop Suite rocks. Interpretation of magnetotelluric data revealed dome-like resistive crustal segments, shearing, folding, thrusting and faulting that may have been pathways for the mineralising hydrothermal fluids and attributed to the final deposition and preservation of the mineralisation. Geology structures are well defined by the gravity data. From a palaeomagnetic study of the rocks surrounding the interpreted mineral occurrence both positive and negative inclination directions were obtained and discounting the effects of induced thermal remanence due to lightning strikes, is interpreted as that the rocks were magnetised at different times. As such a positive magnetic declination of the rocks indicates that the sampled rocks were magnetised when the magnetic north was to the east of the geographic north. This research indicate that the Namaqua sulphide mineral deposits can occur in various forms even in areas with similar lithologies and close proximity, like the Wortel Farm and Aggeneys area. The nature of the Wortel Farm deposit resembles a magmatic segregation of disseminated sulphides while the Aggeneys deposit is of a SEDEX nature, based off the chargeability anomalies of similar amplitudes mapped as separate bodies coinciding with the amphibolite dykes. The geophysical methods chosen for the investigation successfully mapped the subsurface structure with great detail, and delineated the lateral extent of the possible mineralisation. The integration of different geophysical datasets proved crucial and a necessity and complemented other datasets (geology and geochemistry) to highlight various geological details that are required to delineate a base metal deposit in a complex metamorphic terrainItem The geodynamic evolution of the ferké shear zone (fsz): relative timing of the associated tectonic and magmatic events, North-Central Ivory Coast, West Africa(2019) Mkentane, Andile ProtasThe Palaeoproterozoic Baoulé-Mossi domain of the West African Craton in north-central Ivory Coast is crosscut by a north-northeast trending Ferké Batholith, confined by first-order crustal-scale Ferké Shear Zone (FSZ). To present a geodynamic evolution of the FSZ, incorporation of strato-tectonic, geophysical, geochemical, geochronological revisions is pivotal. In the study region, crosscutting relationship resolved that the oldest unit is formed by gneiss that is uncomfortably overlain by volcano-sedimentary sequences which are intruded by post-basin granitoids, i.e. Ferké Batholith. Volcano-sedimentary sequences consist of conglomeratesandstone-siltstone-mudstone succession and meta-volcaniclastic greywacke unit. Intrusive units making up Ferké Batholith include granodioritic gneiss, granodiorite, granite, tonalite, diorite and pegmatite. U-Pb zircon analysis of samples from the orthogneiss gave a crystallization age of the orthogneiss at 2282 ± 4 Ma, and these were affected by Dext extensional phase around 2132 ± 12 Ma that resulted in basin formation. Fining-upwards volcano-sedimentary sequences were deposited in the extensional-subsiding setting between 2109–2079 Ma. At 2097 Ma, Ferké Batholith emplacement was coeval with the formation of the FSZ. Four main deformational events were recognised crosscutting these rock units. D1 is a progressive deformation event that is dominated by ductile-brittle structures that formed at ~2097 Ma, and is responsible for development of north-northeast trending sinistral shear zones, steeply dipping foliation (S1 and S1-C), sub-horizontal L1 lineation and tight F1 folds. Ferké Batholith emplacement is constrained between 2097 and 1842 Ma U-Pb ages supported by crosscutting relationships. U-Pb age of 2097 Ma constrains D1 and minimum age for deposition of metasedimentary units. Late D1 structures are defined by northwest trending sub-vertical displaced fractures. Northwest trending dilational jogs and sigmoidal en-echelon fractures were formed during late D1. D1 event is related to north-northwest and south-southeast directed principal compressive strain axis. The D2 structures comprise northwest trending F2 folds and foliation (S2) from refolding of D1 structures S1 and F1. Dextral sense of displacement from north-northeast trending shear zones and L2 lineation along the Ferké-Bandama branch developed during D2. West, northwest and west-northwest trending veins (V2) are associated with D2 deformation. Kinematic analysis indicated that the principal compressive strain axis was northnortheast or northeast directed during D2 deformation. iii Brittle fractures, including the northwest to west trending fractures and faults formed the third generation of structure (D3). The traces of D3 structures crosscut those of D1 and D2 features throughout the study area. Northwest sinistral en echelon structures and northeast trending displaced fractures correlate with D3 characteristics i.e. overall north-northeast to northeast maximum shortening direction. Geochemical data show that various granitoids making up the Ferké Batholith are true granites. These intrusive units geochemical character shows calc-alkaline affinities with a very high-K character, mostly I-type and peraluminous composition. Tectonic discrimination diagrams confine the batholith within syn-collision fields. Gold mineralisation associated with FSZ occurs in the metasedimentary units to the southwest (Tortiya region) and northeast (north of Kouloukorosso) of the Ferké Batholith. These regions are structurally controlled and spatially associated with FSZ and hydrothermal veins that formed in response to the regional extensional stress field. The shape of the batholith and/or shear zone sense of displacement permits releasing bends (normal faults) to develop in the regions of Tortiya and Kouloukorosso.Item Climate related societal consequences and responses during the 19th century, South Africa and Lesotho, 1830-1900(2019) (Rampath) Beharie, ShantalDocumentary evidence and established chronologies for southern Africa contain rich sources of information on social and environmental impacts and consequences on past societies in southern Africa. The primary aim of this research is to use such established chronologies to determine the environmental and social consequences and relevant responses that followed such droughts and floods including ENSO years where possible. All relevant information was extracted from existing research as well as original data that had already been collected for such regions. The data used for this study involved collecting historical records from the various regions that reflected social and environmental consequences and responses from published historical projects. Such published projects contained 19th century climatic chronologies that were already established from raw primary data such as newspapers, journals, diaries, newsletters and government annual reports in order to make relevant associations between climatic events, societal impacts, consequences and responses. All qualitative data for impacts and consequences were also converted into quantitative data. The outcomes of the study revealed that the impact of droughts had a major impact towards livelihoods and resource availability for southern Africa. In comparing adaptive capacity across the regions, the data revealed that KwaZulu-Natal may have taken longer to recover from most of the impacts, while regions such as Namaqualand and Lesotho were shown to have shorter impact periods and quicker recovery times for certain impacts such as poverty and famines. Qualitative data also showed that various responses were undertaken to cope with such impacts. Coping mechanisms which included religious responses, such as rainmaking and prayer for rains were common throughout Lesotho and KwaZulu-Natal, while migration and transhumance practices were common the coping mechanisms in Namaqualand during droughts and resource shortages in the 19th century.Item The geology, geochemistry and petrology of the metagabbro units of the tati N1-CU sulphide mines and deposits and associated PGEs mineralisation(2019) Thari, Kabelo ThabisoVarious metagabbro bodies host sulphide mineralisation in the Tati Sulphide Mines and Deposits Complex located in the Tati greenstone belt, southwestern margin of the Zimbabwe craton. The Tati Sulphide Mines and Deposits Complex, referred to here as the TSMDC, is a major metallogenic zone in east Botswana. This study focuses on gaining insight into the geology, whole-rock geochemistry and petrology of the Ni-Cu-PGE- mineralised gabbro units and contact lithologies in order to develop effective exploration targets for the TSMDC. The TSMDC mainly comprises three types of gabbroic units-melanogabbro, mesogabbro and leucogabbro-in contact with a wide range of magmatic rocks that include, granodiorite, porphyritic granodiorite, quartz diorite, tonalite, amphibolite, basalt, dolerite and pegmatites. The gabbro units occur near metasedimentary units that include dolomite, Banded Iron Formation (BIF) and quartzite. Some of the gabbro units host sulphide mineralisation comprising mainly pyrrhotite, pentlandite, chalcopyrite and pyrite, whereas some gabbro units are barren. The gabbro units are generally medium grained and composed mainly of variable propositions of the primary minerals pyroxene (20-30%), plagioclase (30-35%) and quartz (2-7%) and minor secondary minerals that include, chlorite (~2%) and epidote (~1%). The major and trace elements data indicate a suite of variably magmatically evolved gabbro units, which show a wide compositional range in MgO (4-17 wt. %), FeOt (5-20 wt. %), SiO₂ (45-52 wt. %), Al₂O₃ (10-17 wt. %) and CaO (5-15 wt. %). Based on the positive correlations between MgO and FeOtotal, CaO and MgO and Y and Zr, the gabbro units are interpreted as having been generated through a fractional crystallisation process, where pyroxene and plagioclase were the dominant rock-forming minerals. Fractional crystallisation is also evidenced by positive correlation between SiO₂ and Na₂O, + K₂O, and resulted in the formation of an enriched quartz mineralogy in granitoid units of the TSMDC. Generally, gabbro units show chondrite-normalised plots with slight enrichment of LREE relative to depletion of HREE. There is a weak positive Eu anomaly, which suggests plagioclase in combination with pyroxene and sphene controlled the fractionation of the partial melts in the upper crust. The gabbro units and contact lithologies were emplaced in a continental margin environment prior to and following several deformation events. Three deformation events, D1, D2 and D3 were identified in TSMDC. D1 is ductile-brittle in nature and is characterised by folding (fo1), foliation S1, and NE-SW and NNE-SSW trending faults (F1). D2 resulted in the formation of the Phoenix, Selkirk and Rooikoppie shear zones associated with a regional foliation (S2), lineation (L₂) and en echelon quartz veins (V₂). The third deformation event, D₃, is associated with formation of fracture cleavage and joints that dominate most of the study area. On a regional scale, the N-S and NE-SW trends of crustal lineaments controlled the geometry of the Phoenix, Selkirk mines, Tekwane and Rooikoppie deposits. On a local scale, the structural factors controlling the current position of the Phoenix, Selkirk mines, Tekwane and Rooikoppie deposits are a network of proximal fractures to the crustal lineaments, which provided transport and settling of differentiated magma during interaction with sulphide minerals in the formation of the Ni-Cu-PGEs mineralisation. The integration of the geology, whole rock geochemistry and petrology suggests that various gabbro units host Ni-Cu-PGEs mineralisation and are affected by structural lineaments, which include shear zones in TSMDC. The shear zones acted as conduits for the propagation of Ni-Cu-PGEs mineralisation and hydrothermal fluids. The geometry of the Phoenix, Selkirk mines, Tekwane and Tekwane deposits is coincident with NE and NW trends of the shear zones.Item The transition from hypogene to supergene mineralisation at the Mashtu South Cu-co deposit, Katanga, Democratic Republic of Congo(2018) Gigler, Gruffudd MorganMashitu South is a Cu-Co deposit situated in the Katanga Province of the Democratic Republic of the Congo (DRC), about 25km to the east of the city of Kolwezi. It lies within the northwestern portion of the Central African Copperbelt (CAC), an arcuate region with a world class abundance of copper deposits that straddles the external-fold-and-thrust-belt and the Domes region of the Lufilian arc, an orogenic belt that formed during the ∼600-500Ma Pan African orogeny. Cu-Co mineralisation at Mashitu South is hosted in the rocks of the Mines Series and Roches Argillo-Talceuses (RAT) subgroups of the Roan Group, deposited during the early stages of the opening of the Katangan basin, which is constrained to a maximum age of ∼880Ma. This study characterises the mineralisation stages and geochemistry of Mashitu South through a combination of core logging, geostatistical and petrographic techniques. The mineralogical and geochemical changes which occurred to the deposit throughout its paragenetic history are also explored. This is done with the purpose of linking the mineralisation at the deposit to regional metallogenic and geodynamic events, as well as developing vectors to Cu-Co mineralisation. Mineralisation at Mashitu South occurred in four stages. The first stage is characterised by the development of stratiform-disseminated, zoned Cu-Co sulphides restricted to the rocks of the Mines Series, in a manner comparable to the sedimentary hosted stratiform copper (SSC) deposit model. A protracted, syn-diagenetic timing is inferred for this stage, which caused the formation of hypogene, stratiform orebodies, primarily in the Kamoto Formation. Metals emplaced during the first stage were remobilised during the second mineralisation stage, which resulted in the development of vein-hosted hypogene Cu Co sulphides, but does not appear to have concentrated metals into significant orebodies at Mashitu South. The second period of mineralisation is inferred to be early/syn-orogenic in age. Hypogene mineralisation at Mashitu South is found to have an element association of Cu + Co + Bi + Ni + V + S ± Mo ± As ± Fe ± Zn. The deposit was subsequently affected by two discrete stages of supergene alteration and mineralisation. Supergene alteration has resulted in the in-situ oxidation of hypogene Cu-Co sulphides, and also the leaching and remobilisation of metals from hypogene mineralisation. The leaching and remobilisation process formed supergene, malachite-dominated orebodies which have an element association of Cu + Be + P ± Zn, the location of which is primarily controlled by metal availability and permeability of the host rocks. The RAT Subgroup is frequently host to such orebodies, underneath leached and eroded away Mines Series strata. These orebodies are usually found at a depth of ∼30 50m. An occurrence of bacillus-shaped features composed of Cu-Co sulphides was discovered in the lower Shales Dolomitique du Base (SDB) unit of the Mines Subgroup, and investigated with respect to the potential biogenicity and antiquity of the features as candidate microfossils. Further study found these features to be pseudofossils formed primarily by the replacement of diagenetic rutile crystals by sulphides, during the primary, stratiform mineralisation stage. The various elements of the hypogene geochemical association are shown to have different mobilities in the supergene leaching environment, with Cu being relatively mobile and Co + Bi + Ni + V ± Mo being relatively refractory. This variation in mobility between elements, which are associated with Cu in the hypogene environment, suggests a zonation of these elements around Cu in the supergene environment, controlled by the hydrological gradient. At Mashitu South, this has resulted in the relative enrichment of Bi, Mo, V and Co in the upper 10m of the rock profile. Nickel is not as depleted in this interval as Cu, which is strongly depleted in the near-surface environment. It is therefore hypothesised that Bi, Mo, V, Co and Ni would make better surface vectors towards buried Cu-Co mineralisation than Cu, in regions where the supergene leaching process is particularly effective. ‘Cobalt caps’ above Cu-Co deposits in Katanga are well known, but this study suggests that Bi, Mo and V may make even better surface vectors to mineralisation than Co.Item S-wave receiver function studies in African sedimentary basins(2017) Inguane, Helio FilemoneSedimentary basins are the result of prolonged subsidence of the Earth’s surface. They occupy 45% of the African surface. Knowledge of their area and depth is important because they often contain mineral, energy and groundwater resources. The transition between crust and mantle (the Moho) is believed to hold important clues to the Earth’s evolution and has been the subject of many studies, including P-wave Receiver Function (PRF) studies, to determine the structure and composition of the crust and uppermost mantle in Southern and Eastern Africa. The PRF method relies on the partial conversion of P-waves produced by teleseismic earthquakes to S-wave waves at the Moho. The travel-time delay between the direct P-wave and the Ps phase is used to deduce the thickness and average velocity of the crust. However, the PRF technique fails in regions where there is strong intracrustal layering (such as sedimentary basins), because the reverberations produced by the layers arrive at the seismometer simultaneously with the Ps phase. Here the S-wave Receiver Function (SRF) method works better, as the Sp phase arrives before any reverberations produced by intracrustal layering. In this study I have used the SRF method to investigate crustal structure beneath sedimentary basins in Southern and Eastern Africa. The aim of this research was to constrain the crustal thickness and shear wave velocity in seven sedimentary basins in Eastern and Southern Africa using S-wave Receiver Functions (SRFs). Teleseismic earthquakes with magnitude ≥5.5 and 60 to 82 degree epicentral distance were used to generate the SRFs using data acquired by seismic stations that were deployed between 2007 and 2013 in three rift basins (Lake Albert, Lake Edward and Rukwa) and four pull–apart basins (Mandawa, Mozambique, Rovuma and Ruvu). A moveout correction was made to align the SRFs obtained from different earthquakes, enabling them to be stacked to reduce random noise and enhance the signal-to-noise ratio of the SP phase and the accuracy of the pick of the SP arrival time. The SP arrival time uncertainties, typically 0.05 s of time error, were estimated for each station using the bootstrapping method. The surface wave group velocity models for each station (at 10, 15, 20, 25 and 30s periods) were used to constrain the depth–velocity models. The grid search modeling was performed using the DISPER80 package. The following crustal thicknesses (H) and average crustal shear velocities (Vs) were obtained: Lake Albert and Lake Edward rift basins situated within the Mesoproterozoic Ruwenzori orogenic belt: H of 38.8 ± 2.4 km and 33.83 ± 0.9 km, respectively; Vs of 3.72 km/s and 3.73 km/s, respectively; Rovuma, Mandawa and Ruvu pull–apart basins within the Neoproterozoic Mozambique mobile belt: H of 32.73 ± 1.8 km, 37.79 ± 2.2 km and 39.63 ± 2.2 km, respectively; Vs of 3.68 km/s, 3.76 km/s and 3.79 km/s, respectively; and Phanerozoic Mozambique pull-apart basin: H of 36.9 ± 2.1 km and Vs of 3.7 km/s. These results were compared with previous studies. The crustal thickness reported in a global review of Proterozoic terrains (Durrheim and Mooney, 1994) ranged between 40-55 km, while Rudnick and Fountain (1995) reported an average thickness of 43 km. For stations located in basins in the Mesoproterozoic Ruwenzori orogenic belt, this study produced estimates of H and Vs of 36.3 ± 2.4 km and 3.7 km/s, respectively. Vs is similar to estimates by Julià et al. (2005) and Tugume et al. (2013) for stations in the same region, while H is a few kilometers thinner. This study obtained H of 32-40 km beneath Neoproterozoic pull-apart Tanzanian coastal basins located within the Mozambique mobile belt (Chatellier and Slevin, 1988), while Tugume et al. (2013) estimated the crust of the adjacent Tanzanian craton to be 39 km thick. In the Phanerozoic Mozambique basin, this study found H and Vs of 36.9 ± 2.1 km and 3.7 km/s, respectively. Kgaswane et al. (2009), using joint inversion of receiver functions and Rayleigh wave dispersion, estimated the H and Vs for the northeast Limpopo belt (west of the Mozambique basin) to be 40 ± 3 km and 3.7 km/s, respectively. In general, this study found thinner crust and slower Vs than previous studies. However, it is important to note that the station locations were different. Previous studies analysed P-wave Receiver Functions (PRFs) recorded by stations located in the interior of the continent and near to the Tanzania craton, while this study analysed S-wave Receiver Functions (SRFs) recorded by stations located in rift and coastal sedimentary basins. It is likely that the crust thinned during extension and continental break-up.Item The felsic intrusives In E.R.P.M., Boksburg(2015-03-16) Fumerton, Stewart Lloyd; ;Item Spatio-temporal trends for long-lasting contemporary snow in Lesotho : implications for human and livestock vulnerability(2012-03-15) Linde, Jonathan HarrisProlonged snow cover in Lesotho frequently results in human and livestock deaths, due to isolation and exposure. MODIS Rapid Response imagery is emerging as an important source of near real-time data for global hazard mapping and emergency response. A dataset of daily MODIS snow cover images for the period 2003 – 2010 was acquired for Lesotho. Combined with high-resolution SPOT satellite images for two study areas, MODIS snow cover images were used to establish the frequency, extent and timing of snowfalls. A digital elevation model was used in conjunction with mean air temperature data to investigate the effects of altitude, aspect and temperature on the mean rate of daily snowmelt. A strong correlation exists between mean day-time temperatures and the mean rate of daily snowmelt throughout the winter season. The mean rate of snow dissipation is most rapid after late season (September – November) snowfalls and least rapid after mid season (July – August) snowfalls. Snow cover persisting for 1 – 5 days dissipates at a higher mean rate than snow cover that has persisted for 6 – 10 days. Snow lasts longest on south-facing slopes above 2500m a.s.l, with evidence of increased ablation due to wind deflation and higher insolation levels in the highlands above 3400m a.s.l. The southern Drakensberg highlands in the district of Quthing have the highest mean duration of snow cover (21 – 25 days per annum). The seasonal extent and duration of snow cover was related to the spatial location of villages and roads in Lesotho, in order to determine individual vulnerability to negative impacts associated with prolonged snow cover. A ranking system was applied to each village according to the seasonal duration of snow cover, and the accessibility and proximity to the nearest road. Snowfalls occur between 1 and 8 times per annum on average. Therefore, village vulnerability is generally low, as most settlements are situated on predominantly north-facing slopes in the western lowlands and Senqu River Valley, which remain largely snow-free throughout the winter season. Few villages experience prolonged snow cover, which is limited to predominantly south-facing slopes above 2500m a.s.l along the escarpment and interior mountain ranges. Village vulnerability increases during the mid season period as a result of the increased frequency and duration of snow cover in July and August. The villages of Thoteng (Butha-Buthe), Letseng-la-Terae (Mokhotlong) and Mabalane (Butha-Buthe) have the highest vulnerability for the 2003 – 2010 period.