Granite Hills Research Articles

Spatial-temporal patterns of ecological-environmental attributes within different geological-topographical zones: a case from Hailun District, Heilongjiang Province, China

The climate change and extension of human activities are shedding more stresses on ecosystems. Ecological zoning could help manage the ecosystem and deal with environmental problems more effectively. Geology and topography could affect the ecology primarily and are vital perspectives on ecological zoning. It is worth preliminarily understanding the spatial-temporal patterns of ecological-environmental attributes within various geological-topographical ecological zones (GTEZs). The objective of this study was to delineate GTEZs and present a spatial-temporal analysis on soil and land surface parameters within GTEZs. Firstly, Landsat imageries, high resolution satellite imagery products, digital elevation model, regional geological map, black soil thickness, soil bulk density, meteorological data, and ground survey were collected and conducted. Secondly, GTEZs in Hailun District were delineated according to geological and topographical background. Thirdly, soil composition, and monthly land surface temperature (LST), enhanced vegetation index (EVI), net primary productivity (NPP) were derived from ground survey and Landsat imageries. Finally, spatial-temporal patterns of various ecological-environmental attributes within different GTEZs were preliminarily revealed and analyzed. Results show that sand alluvial plain zone and silt-clay undulating plain zone mainly possess thick soil with fine-medium granule and higher bulk density, and are mainly covered by crops and grass, vegetation flourish the most in August with the highest monthly EVI and NPP. While the sand-conglomerate hill zone, sandstone hill zone, and granite hill zone possess relatively thin soil with medium-coarse granule and lower bulk density, and are mainly covered by forest, vegetation flourish the most in June and July, and has the highest yearly total NPP. With thinner soil thickness and higher NPP, hill zones tend to have more vulnerability to disturbance and more contribution to carbon neutrality target.

Сосновые (Pinus sylvestris) леса и редколесья Северо-Западного Приладожья

Сосновые (Pinus sylvestris) леса и редколесья Северо-Западного Приладожья

Estimation of the soil hydraulic properties and parameter characteristics of Benggang erosion in granite in southern China

AbstractBenggang is an erosional landform that forms in granite hills due to coupled hydraulic and gravity erosion, and its unique development makes it difficult to obtain moisture characteristics through direct means. In this study, the soil moisture characteristics were investigated on the collapsing walls with different weathering degrees of two different Benggang types defined as scoop‐shaped Benggang and strip‐shaped Benggang in the typical Benggang erosion areas of southeastern Guangxi. The soil water characteristic curves (SWCCs) of the collapsing wall were measured by the centrifuge method to explore the moisture transport mechanism of Benggang development. The response of moisture characteristics to the Benggang morphology was not significant, but the soil layer changes in the collapsing wall had a significant impact. The Atterberg limits of the surface layer and laterite layer were significantly higher than those of the transition layer and sandy layer, with a liquid limit (LL) value exceeding 55%, indicating high LL clay. The Van Genuchten (VG), Gardner and Fredlund–Xing (FX) models were used to fit the SWCCs, and the results indicated that the VG model had a high fitting accuracy (R2 > 0.984), followed by the FX model (R2 > 0.943); however, the Gardner model had a low fitting accuracy (R2 > 0.891). With the change in matrix suction, the sandy layer had the maximum water release capacity, followed by the transition layer, and finally the surface layer and laterite layer. The variation in equivalent pore size distributions with soil layers showed that the micropores in the laterite layer of the two Benggangs accounted for 44.91% and 44.38% of the total porosity. The macropores of the sandy layer accounted for 35.40% and 36.84% of the total porosity. Both the unsaturated hydraulic conductivity K(θ) and water diffusivity D(θ) exhibited two abrupt changes with increasing soil volumetric water content, and K(θ) and D(θ) of the lower layers were larger than those of the upper layers. The heterogeneity of soil texture and pore conditions among different collapsing wall soil layers can significantly affect the Benggang water conditions. This study provides a database for further investigation of the Benggang development mechanism.

Ethnobotanical knowledge and conservation of Bombax costatum Pellegr. and Vuillet: an overexploited savanna tree species

In regions dominated by savannahs, multipurpose tree species are key resources considering the diversity of services they offer. Such species are proned to overexploitation and improper management that may threaten their survival. Understanding local perception on their uses and conservation is essential to engage local communities in their sustainable management. This study presents the case-study of Bombax costatum in the semi-arid region of Burkina Faso. Specifically, the study (i) assesses the diversity of uses of B. costatum; (ii) analyse the effect of socio-demographic characteristics of local population on its uses and examine their perceptions of the threats and conservation solutions for B. costatum. Individual semi-structured interviews were conducted with 309 local people in Burkina Faso. Data were gathered on informants’ sociodemographic characteristics, use categories, plant parts used and perceived conservation concerns. Descriptive statistics, Principal Components Analysis, and Non-parametric models were used for data analysis. Ten plant parts of the species are used for nine use categories. Food (44.52%), medicine (19.99%), fodder (15.16%) and handicrafts (14 .33%) were the most cited use categories. The most used plant parts were leaves (30.83%), flowers (25.03%), trunk (16.62%) and bark (14.70%). Leaves, flowers, twig bark and petioles were used as food and fodder. Trunk bark, root and resin were used in medicine. Trunk and whole plant were used in handicraft, construction, culture, honey production and spirituality. The harvest of B. costatum plant parts for food uses varied cyclically. Ethnicity, age, education level and main activity were the most influencing sociodemographic factors for the species uses. Furthermore, local population shared the same opinion (Sorensen index > 0.50) on the areas of abundance, threat factors and conservation solutions. They reported the species as abundant in agrosystems (47.08 %), forests (29.57 %) and rocky and granite hills (22.00 %). The main threat factors were tree cutting (32.5 %) and pruning (15.51 %). For its conservation, local people recommended mostly domestication (39.29 %) and strengthening of conservation measures (14.84 ± 2.99 %). This study reveals the importance of B. costatum while also highlighting essential aspects to consider to successfully engage farmers for its sustainable management.

Vegetation analysis on the mountain slopes of Yanaimalai in southern Tamil Nadu

Yanaimalai hill in Southern Tamil Nadu is a rocky granite hill having vegetations in the cracks and crevices. The hill absorbs and irradiates heat waves more in summer making vegetation limited. Despite high temperature and erratic weather conditions, certain vegetations survive. A study on identifying the vegetation can pave way for future breeding programmes. Therefore, this study was undertaken during May 22 to June 5, 2022 to identify the vegetation and classify into weeds, shrubs and trees. Fifty sites identified on the mountain slopes and various phytosociological parameters, viz. weed density, relative density, frequency, relative frequency, abundance, importance value index and summer dominance ratio were estimated. From the study, it was confirmed that vegetation species such as Cleome viscosa, Tephrosia purpurea, Cymbopogon citratus, Canthium spp., Morinda tinctoria and Wrightia tinctoria were predominant. Based on the findings, the identified species can be used for further genetic study on high temperature and drought tolerance for various breeding programmes.

Engineering Geological Assessment at Grandview Heights, Paya Terubong, Pulau Pinang, Malaysia

Grandview Heights, Paya Terubong is an old apartment building situated on a coarse-grained biotite granitic bedrock hillside. Paya Terubong is a landslide prone area where various landslides have been reported since 1998. The granitic hill has been disturbed during construction of the apartment. Due to the possibility of future landslides, an engineering geological study was conducted to assess the stability of this rock hill beneath this apartment. The scopes of study included discontinuity surveys, geomechanical characterization of the rock mass and slope stability analysis. Based on the results of discontinuity surveys, four major joints sets-were identified and labelled as J1 (195°/62°), J2 (248°/65°), J3 (304°/63°) and J4 (230°/39°). One (1) potential planar failure J2 (248°/65°) and one (1) potential wedge failure J1-J2 intersection (213°/60°) were identified based on kinematic analysis. Dry rock density was from 2.56 g/cm3 to 2.61g/cm3. The water content was from 0.14 % to 0.15% with low porosity values from 0.50% to 0.54%. The point load strength index, Is(50) was 6.63 MPa. The Slope Mass Rating (SMR) for was 64 to 79 and classified as class II with the probability of failure of 0.2.

Weathering stage and topographic control on rare earth element (REE) behavior: New constraints from a deeply weathered granite hill

Rare earth elements (REE) are sensitive tracers of rock-water interactions and soil formation processes. In this study, we investigated the REE concentration and distribution patterns for both bulk samples and acid leachable phase for a series of regolith and soil profiles developed on a deeply weathered granite hillslope in a subtropical climate. The exogenous input had little impact on the REE distributions on the studied hillslope. The REE distribution in the profiles was controlled by changes in the physical and chemical environmental parameters and mineral transformation during weathering. However, the specific mechanisms differed among the different weathering stages and profiles located at different positions along the slope. Among the environmental parameters, the profile redox state and acidity were the dominant factors controlling the REE behavior, with organic materials as the main regulators. A strong positive relationship between chemical index of alteration (CIA) and La/Yb was observed for the regolith samples, but the La/Yb ratio decreased upward from a depth of 120 cm (the bottom depth of the soil horizon) as the CIA value increased, suggesting a preference for light REE (LREE) fixation in kaolinite formed during the dissolution of feldspar; however, a conversion occurred during the subsequent pedogenesis period. The hilltop soil profile was characterized by the strongest LREE depletion and the highest positive Ce anomaly (~7.31–14.28), compared with other profiles down the hillslope (~0.84–2.78). The strongest LREE depletion on the hilltop profile JLN-S4 suggested a preference for LREE release resulting from the transformation of kaolinite to gibbsite, and the highest Ce anomaly indicates that Ce was fixed in a more oxidized environment within a well-drained profile. The hill foot profile JLN-S1 had the highest LREE leaching rate, but also the lowest heavy REE (HREE) leaching rate, which was ascribed to its lowest erosion rate, lowest pH value, and reductive conditions in a more hydromorphic zone down the hill. The releasing rates of REE calculated by a mass balance model at different positions along the catena ranged from 1395 to 14,379 μg m−2y−1. All the observed REE fractionation regimes and weathering rate variations along the hillslope illustrated that topography-regulated hydrologic condition played a critical role in the release and migration of REE during granite weathering.

Predicting Granitic Buried-Hill Reservoirs Using Seismic Reflection data—A Case Study From the Bongor Basin, Southwestern Chad

Predicting the distribution of fractured and dissolved reservoirs in granitic buried hills is a prerequisite for finding high-quality hydrocarbon reservoirs and improving the success rate of exploration activities. Granitic buried-hill reservoirs in the Bongor Basin are characterized by strong heterogeneity and poor lateral continuity. Through the analysis of seismic, core, logging and dynamic production data, this study predicts the distribution of fractured reservoirs and fractured-cave reservoirs in the granitic buried hills in the BC Block of the Bongor Basin. In this study, we predict fractured reservoirs using coherence cubes and linearly enhanced attributes and identify fractured-cave reservoirs with single-frequency attribute bodies. Integrated predictions of fractured reservoirs and fractured-cave reservoirs are conducted using attribute fusion techniques. With these methods, good results have been achieved in reservoir prediction in BC buried hills. Furthermore, this study summarizes a set of granitic buried-hill reservoir prediction techniques for densely inverted rift basins in the Central African Rift System.

화강암 분지를 흐르는 미호천의 지형학적 특색

The drainage area of the Miho stream is composed of granitic basins, gneissic and sedimentary mountains. 80 percent of the Miho stream flows through the Jincheon basin and the Cheongju inner-plain within the Daebo granite belt. Because the deep weathering of granitic hills provides a large amount of sands to the streams, there are wide floodplains with thick alluvium developed in the basin and plain. The thickness of the alluvium is 5~10m and the width of the floodplains is 2~2.5km. In the basin outlet area where a stream passes through the mountain canyon, wide floodplains and deep alluvium are developed in other riverside. The Miho stream is a sand-gravel channel flowing through the Cheongju inner-plain with wide floodplains and deep alluvium formed by deep weathering of granite.

"Weathering Characteristics of Granitic Hills Developed in Eastern Jincheon Basin, Korea in Eastern Jincheon Basin, Korea"

"Weathering Characteristics of Granitic Hills Developed in Eastern Jincheon Basin, Korea in Eastern Jincheon Basin, Korea"

ASSESSMENT OF RADON AND THORON EXHALATION FROM SOILS AND DISSOLVED RADON IN GROUND WATER IN THE VICINITY OF ELEVATED GRANITIC HILL, CHIKKABALLAPUR DISTRICT, KARNATAKA, INDIA

In this paper, we intend to evaluate the rate of radon and thoron exhalation from soil with reference to the underlying bedrock and gamma dose rate in the environment of elevated granitic hill-Nandi hills of Karnataka. The measurement of exhalation rates for all the soil samples collected from study area was carried out using a continuous radon-thoron monitor (Smart RnDuo monitor). The surface exhalation rate of thoron from soil samples were found to vary from 4160±326 to 21822±634 mBq m-2s-1. The mass exhalation rate of radon from soil samples were found to vary from 76±6 to 269±19 mBq kg-1h-1. Concentrations of radon activity measurements were carried out for all the groundwater samples from study area. A detailed analysis along with physicochemical parameters of water has been made and discussed in this research paper.

Genesis and classification of soils from granitic hills in southern Brazil

Southern Brazil abounds with granitic hills capped by intricately distributed soils most of which have been classified as Entisols or Inceptisols in medium- and small-scale soil surveys. However, field observations have revealed substantial texture gradients that are consistent with better-developed soils; also, the physical, chemical and mineralogical properties of the soils suggest that they are only slightly to moderately weathered. In this work, we examined the influence of formation-related factors and processes in soils from two granite toposequences. The eight soil profiles studied for this purpose were shallow, their C horizons occurring at depths of less than 100 cm. The low degree of flocculation and the fine/total clay ratio of the soils suggest that lessivage, which contributed to the development of the texture gradient in six of the profiles, was the main pedogenic process responsible for the formation of these soils. The soils at topographically high points were dystrophic or allitic, whereas those at low points were eutrophic. Based on their Ki values, the soils were weathered to a medium extent, which is in conflict with their low clay activity and cation exchange capacity. On the other hand, the Fed/Fes ratios of the soils were consistent with strong weathering, which in turn was consistent with their pH and exchangeable Al values. The iron oxides contents increased with increasing depth in the profiles as a result of lessivage. Feo/Fed ratios were suggestive of a prevalence of crystalline iron oxides. Increased substitution of Al in Fe oxides in the topographically higher soils further confirmed their increased weathering. Based on the foregoing, the soils were classified as Ultisols/Alfisols, Entisols and Inceptisols, the last series being less frequent than suggested by existing soil surveys. The transitional nature of these soil classes reflected in the presence of Ultisols/Alfisols with a thin B horizon, and also of argilluvic Inceptisols.

Estimation of radon potential through measurement of uranium concentrations in granite geology

The geology of an area can be used as a predictor for radon potential. Granite rock typically contains a high concentration of uranium and subsequent elevated emanation of radon gas. The geology of the western part of the Western Cape Province in South Africa is dominated by granite bedrock but very few studies on radon have been conducted in this area. Uranium concentrations were consequently measured on a large granite hill in the Saldanha Bay area of the Western Cape and a relationship between indoor radon and uranium concentrations was used to model radon potential on the outcrop. Results from granite rich environments in India were modelled in order to extract a relationship between indoor radon concentrations, radon exhalation rates and uranium concentrations. Radon exhalation rates greater than 0.35 Bq/m2h were predicted and estimated indoor radon concentrations in excess of 400 Bq/m3 were also predicted for the hill. The modelled results were compared with indoor radon measurements taken in the town of Paarl in the Western Cape, which sits on the same granite bedrock formation. The predicted radon potential correlated well with the physical measurements.
 Significance:
 
 Extensive in-situ uranium measurements were conducted by utilising a self-developed gamma-ray detection instrument (the GISPI) by means of a unique method.

Geochronology and geochemistry of the Thirsty Creek Norite, Westland, New Zealand

ABSTRACTThirsty Creek Norite is a small, undeformed, mafic intrusion intruding gneisses of the Granite Hill Complex in the Buller Terrane. An age of 107.1 ± 4.1 Ma has been obtained using Rb-Sr geochronology. A relatively high MSWD of 4.5 is attributed to sericitization and alteration of plagioclase. This date is consistent with other ages for the timing of high-grade metamorphism in the Granite Hill Complex and may represent a metamorphic age, thus providing a minimum age for metamorphism and emplacement of the norite. However, the relatively undeformed nature of the Thirsty Creek Norite suggests it may postdate metamorphism and we speculate that the date could represent a crystallisation age which is contemporaneous with Rahu Suite granitic magmatism in the adjacent Hohonu Batholith. Several geochemical characteristics, including overlapping initial Sr and Nd isotope compositions, suggest the Thirsty Creek Norite could be a relatively mafic yet contaminated melt that is petrogenetically related to Rahu Suite magmatism. Overlaps in the isotopic compositions of the Thirsty Creek Norite and Rahu Suite granitoids therefore imply that any mafic components involved during granitic magmatism must have had relatively enriched isotopic compositions, and that evolution to more felsic compositions occurred without significant interactions with upper crustal components.

Distribution, life history and conservation assessment of the critically endangered butterfly Pseudolucia parana (Lepidoptera: Lycaenidae)

Pseudolucia parana Bálint, 1993 was described from Castro, Paraná, Brazil, where it was first collected over 120 years ago. It was observed/collected quite sporadically in the second half of the 20th century in a few isolated habitats in the State of Paraná. Excluding a single record since the early 2000s, the species was not observed in all its known sites in Paraná due to urbanization of its habitats or change of land use. Consequently the species in Paraná state is highly endangered, possibly extinct. Efforts to find the species in the state Santa Catarina failed. A new hope to the survival of the species appeared in the southernmost state Rio Grande do Sul, where some relict populations are documented. The results of rescue expeditions to several granitic hills in the region are presented and the current distribution P. parana is assessed. First descriptions of its early stages, ecology, ethology and recommendations for conservation are given. The data provided indicate that the global status of P. parana should be Critically Endangered. Some molecular traits of P. parana are analysed resulting in a preliminary assessment for the age of the populations. With 24 figures.

PL油田花岗岩潜山储层裂缝发育特征厘定

PL油田花岗岩潜山储层裂缝发育特征厘定

Sansevieria rosulata (Asparagaceae), a New Species in Uganda

Summary: Sansevieria rosulata T.G.Forrest, new species, is remarkable for the large number of flexible leaves and dense flowering habit. These features, and others, distinguish it from known large flat-leaved sansevieria in East Africa. Sansevieria rosulata is found at several locations in Eastern Uganda not very far from Mbale town. Because of the rapid loss of habitat, the taxon is largely restricted to rocky granite outcrops and large ant hills. It is considered threatened in the vulnerable category (VU).

Control factors and comprehensive prediction of granite buried hill reservoirs in western segment of Shaleitian bulge,Bohai Sea

Control factors and comprehensive prediction of granite buried hill reservoirs in western segment of Shaleitian bulge,Bohai Sea

长白山地典型农田生态系统土壤跳虫群落结构及其生态分布特征

PDF HTML阅读 XML下载 导出引用 引用提醒 长白山地典型农田生态系统土壤跳虫群落结构及其生态分布特征 DOI: 10.5846/stxb201610242166 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41471211） Community structure and ecological distribution of soil Collembola from typical farmland ecosystems in the Changbai Mountains Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了解长白山地不同地貌类型典型农田生态系统土壤跳虫群落结构及其分布，探讨不同地貌类型对土壤跳虫群落结构和分布及其季节动态的影响，于2015年春季（5月）、夏季（7月）、秋季（9月）分别对长白山地玄武岩台地、花岗岩低山、花岗岩丘陵三种地貌类型玉米田土壤跳虫进行了研究。研究表明，3个生境共获土壤跳虫881头，隶属10科16属22种。其中，玄武岩台地土壤跳虫个体密度是1 760头/m2，17种；花岗岩低山个体密度是2 206.67头/m2，13种；花岗岩丘陵个体密度是1 906.67头/m2，18种。地貌及取样时间的差异对土壤跳虫个体密度、物种数、多样性指数均有一定的影响。花岗岩低山与花岗岩丘陵的个体密度和物种数大小为秋季>春季>夏季，而玄武岩台地的个体密度和物种数表现出随季节变化呈递增的趋势（P < 0.05）。不同地貌土壤跳虫多样性均在秋季达到最大，夏季玄武岩台地多样性指数显著高于花岗岩低山和花岗岩丘陵，秋季，玄武岩台地丰富度指数和均匀度指数显著高于花岗岩低山，玄武岩台地优势度指数显著低于花岗岩低山（P < 0.05）。不同土壤环境因子对跳虫的影响不同，土壤温湿度、有机质、全氮、速效氮和全磷与土壤跳虫的群落结构、生态分布有明显的相关性。综上可知，长白山地农田生态系统土壤跳虫群落结构和生态分布因地貌类型不同而存在差异，季节变化也对其影响明显。 Abstract:Soil Collembola are an important part of terrestrial ecosystems and play important roles in enhancing soil fertility and other soil properties. Furthermore, soil Collembola are good indicator species for the soil environment. At present, most studies have been concerned with community structure and ecological distribution of soil Collembola, but little research has addressed soil Collembola in the Changbai Mountains. To investigate the community structure and ecological distribution of soil Collembola from typical farmland ecosystems in the Changbai Mountains, three typical geomorphic types, including basalt platform, granite low-mountain, and granite hills, were chosen from the Changbai Mountains. The study was conducted in spring (May), summer (July), and autumn (September) of 2015. The results could help to provide a scientific basis for maintaining and managing farmland ecosystems in the Changbai Mountains. The plots (5 m×5 m) were established using permanent signs in each maize field in the three landforms. Within each plot, we randomly selected five subplots, 10 cm×10 cm, where we made collections from the 0-5 cm, 5-10 cm, and 10-15 cm soil layers. Soil Collembola were extracted from each of the soil sample by using a Tullgren funnel extractor. The effects of landforms and seasonal variation on the individual density and species number of soil Collembola were analyzed using a one-way ANOVA. Indexes of diversity were calculated to describe the characteristics of the soil Collembola community. The influence of soil environmental factors on soil Collembola diversity was examined using redundancy analysis (RDA). We obtained 881 collembolan individuals in the three landforms, belonging to 10 families, 16 genera, and 22 species. Significant differences were observed in individual density and species number of soil Collembola for all three landforms. The order for individual density was as follows:granite low-mountain > granite hills > basalt platform. Furthermore, the order for species number was as follows:granite hills > basalt platform > granite low-mountain. In this study, Protaphorura sp.1, Proisotoma sp.1, and Proisotoma sp.2 were the dominant species, accounting for 56.04%. There were 11 common species, accounting for 41.59%. In addition, eight species were rare, accounting for 2.37%. Landforms and sampling time had a significant effect on individual density, species number, and indexes of diversity of soil Collembola. In granite low-mountain and granite hills, the dynamics of individual density and species number of soil Collembola were autumn > spring > summer. In the basalt platform, the dynamics of species number of soil Collembola was autumn > summer > spring. Regardless of landform, soil Collembola had the highest diversity during autumn. The Shannon-Wiener indexes were significantly different in the three landforms during summer (P < 0.05), and the one-way ANOVA showed that a significantly lower abundance and richness of soil Collembola was evident in the basalt platform compared to that of the other landforms in autumn (P < 0.05). In addition, different environmental factors had various influences on soil Collembola. Redundancy analysis (RDA) showed that the community structure and ecological distribution of soil Collembola had obvious correlations with soil moisture, soil temperature, organic matter, total nitrogen, available nitrogen, and total phosphorus. In this study, geomorphic types and seasonal variations had significant effects on community structure and ecological distribution of soil Collembola. 参考文献 相似文献 引证文献

Geology and Petrography of the Nagar Parkar Igneous Complex, Southeastern Sindh, Pakistan: The Kharsar Body

ABSTRACT Kharsar hill is one of many granitic plutons comprising the Nagar Parkar igneous complex. The eastern part of the hill is occupied by grey-pink granite (earlier) and the western part by pink granite (later). They are composed of perthite, quartz, and plagioclase, with minor opaque oxide, biotite, titanite, local amphibole, and secondary chlorite, epidote, leucoxene/titanite. The pink granite is characterized by the presence of mafic clots. Both the granitoids are intruded by microgranite/aplite, and porphyritic mafic and rhyolite dykes, locally in swarms. These are abundant in a NE trending 200 m wide zone cutting the entire granite hill. The dykes may extend over 1 km in length and &amp;gt;10 m in thickness, but most are &amp;lt; 100 m in length. The felsic dykes are of several generations; some are associated with the two varieties of granite, others are contemporaneous with the rhyolite and mafic dykes. The mafic dykes can be grouped into two types one of which contains hornblende and the other augite as the principal mafic mineral. Major element analyses suggest that the granitic rocks are metaluminous. The Kharsar granites, like the others in Nagar Parkar, may be an extension of the Malani igneous suite of Rajasthan. The occurrence of bimodal mafic-felsic dykes and petrographic variation in the mafic dykes are briefly discussed.