Groundwater resources assessment for irrigable agricultural lands in the Wadi Araba area, southern Jordan

The main target of this research paper was to the hydrogeological assessment of the groundwater resources to irrigate 600 ha of irrigable agricultural lands, distributed along the Dead Sea–Aqaba Highway in Umm, Methla, Wadi Musa, Qa’ Saideen and Rahma, southern Jordan. Therefore, a comprehensive groundwater study was commenced by drilling eight new wells which can be used to supply irrigable areas with the existing groundwater that would be enriched by the yield of three proposed recharge dams on Wadi Musa, Wadi Abu-Burqa, and Wadi Rahma. The evaluation of the pumping test data of the drilled was carried out using the standard methods of pumping test interpretation. This was based on the available water table measurements at well locations and knowledge of water flow in the general. The sustainable yield of each well was calculated based on the pumping test parameters. The obtained results indicate that pumping out of Beer Mathkor wells should not exceed 1,100 m³/day in the case of continuous pumping and 8,700 m³/day in the case of intermittent pumping. Since the water table did not significantly change with small changes in pumping (it took eightfolds of magnitude increase in pumping from approximately 1,100 to 8,700 m³/day to show a significant drop in the water table equivalent to about 5.5 MCM per year from the aquifer.     

Chemical composition of pargasite and hornblende in low to High grade metamorphic rocks of the Rhodope zone,Xanthi, Greece

Summary The chemistry of amphiboles from schists, quartzofeldspathic gneisses and migmatites ranging in metamorphic grade from greenschist to amphibolite facies has been determined by electron microprobe. Intercalated amphibolites suggest that some of the rocks retrograded from the eclogite stability field; others were never metamorphosed above greenschist facies. Rocks which contain other mineralogical evidence for an original high pressure assemblage have amphiboles with high Na/K, low Fe and relatively low Ti. Other high-grade rocks contain amphibole of broadly pargasitic composition. The pargasites from more Ca-rich bulk compositions have less substitution of Na for Ca in the M4 site than do those from Ca-poor bulk compositions. A lower grade assemblage of amphiboles ranges from hornblende through actinolitic hornblende to actinolite; this is retrograde in the gneisses and migmatites, but may be prograde in the schists. In contrast, the high-grade assemblage shows almost constant high K with variable Na and quite different trends for edenite-type substitution (^IVAl variation with A site occupancy) and variation of^IVAl with Fe/(Fe + Mg) and with Ti.

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Chemische Zusammensetzung von Pargasit und Hornblende in niedrig- bis hoch-gradig metamorphen Gesteinen der Rhodope-Zone, Xanthi, Griechenland

Zusammenfassung Die Chemische Zusammensetzung von Amphibolen aus Schiefern, Quarz-Feldspat-Gneisen, und Migmatiten, deren metamorpher Grad von Grünschiefer- bis zur Amphibolitfazies reicht, wurde mit der Elektronenstrahl-Mikrosonde bestimmt. Zwischengeschaltete Amphibolite legen die Vermutung nahe, daß einige der Gesteine durch retrograde Metamorphose aus dem Eklogit-Stabilitatsfeld hervorgegangen sind; andere jedoch hatten niemals in ihrer Entwicklung einen höheren Grad als den der Grünschie-ferfazies erreicht. Gesteine, die andere mineralogische Hinweise für eine ursprungliche Hochdruck-Paragenese führen, enthalten Amphibole mit hohem Na/K, niedrigen Eisen und relativ niedrigen Ti. Andere high-grade Gesteine enthalten Amphibol von pargasitischer Zusammensetzung. Die Pargasite aus mehr Kalzium-reichen Gesteinen zeigen geringere Substitution von Natrium für Kalzium an den M4 Plätzen als jene aus Kalzium-armen Gesteinen. Eine niedriger-gradige Paragenese von Amphibolen umfaßt Zusammensetzungen von Hornblende über aktinolitische Hornblende bis zu Aktinolit; diese ist in den Gneisen und Migmatiten retrograd, durfte in den Schiefern jedoch prograd sein. Im Gegensatz dazu zeigt die hochgradige Paragenese fast durchwegs konstant hohe Kalium-Gehalte mit variablem Natrium und einen anderen Trend für Edenit-artige Substitution (^IVAl Variation mit Besetzung der A Plätze) und eine Variation von^IVAl mit Fe/(Fe + Mg) und mit Ti.

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With 4 Figures     

Hillslope processes and archaeology in Wadi Ziqlab,Jordan

Record levels of precipitation during February 1992 generated 290 earth flows and earth slumps in Wadi Ziqlab, Jordan. Geomorphologic and sedimentological characteristics of these landslides and older colluvial deposits were used to identify the dominant mass-wasting processes active in the wadi. Earth flows in 1992 left long linear scars on the steep hillsides and deposited thin, fine and coarse-grained, sheets on the well-developed colluvial slopes below. Older colluvial deposits exposed along the wadi bottom are crudely stratified, heavily bioturbated, and contain paleosols, suggesting colluviation was episodic and occurred through a slow accumulation of successive earth flows. Earth slumps in 1992 produced crescentic scarps, flat benches, and thick colluvial masses; similar features preserved on the wadi slopes were formed by the same process at an earlier time. Annual slope wash does not appear important on the steep, heavily landslide-scarred, slopes. The uneven distribution and episodic occurrence of earth flows and earth slumps in Wadi Ziqlab have resulted in highly variable burial depths of archaeological material, as illustrated in one locality where Roman artifacts are buried over 1 m deeper than a Neolithic site only 200 m away. The ability of earth flows to transport artifacts great distances has given rise to inverted stratigraphy on colluvial slopes and has produced large artifact scatters located beyond the margins of the colluvial slopes. These complex postoccupation disturbances and prehistoric land-use practices would have been difficult to interpret without a full understanding of the hillslope processes active in Wadi Ziqlab and the landscape features they have produced. © 1998 John Wiley & Sons, Inc.     

Evolution of the Pan-African Wadi Haimur metamorphic sole, Eastern Desert, Egypt

By comparison with the general features of metamorphic soles (e.g. vertical and lateral extension, metamorphic grade and diagnostic mineral parageneses, deformation and dominant rock types), it is inferred that the amphibolites, metagabbros and hornblendites of the Wadi Um Ghalaga–Wadi Haimur area in the southern part of the Eastern Desert of Egypt represent the metamorphic sole of the Wadi Haimur ophiolite belt. The overlying ultramafic rocks represent overthrusted mantle peridotite. Mineral compositions and thermobarometric studies indicate that the rocks of the metamorphic sole record metamorphic conditions typical of such an environment. The highest P – T conditions ( c . 700 °C and 6.5–8.5 kbar) are preserved in clinopyroxene amphibolites and garnet amphibolites from the top of the metamorphic sole, which is exposed in the southern part of the study area. The massive amphibolites and metagabbros further north (Wadi Haimur) represent the basal parts of the sole and show the lowest P – T  conditions (450–620 °C and 4.7–7.8 kbar). The sole is the product of dynamothermal metamorphism associated with the tectonic displacement of ultramafic rocks. Heat was derived mainly from the hot overlying mantle peridotites, and an inverted P – T  gradient was caused by dynamic shearing during ophiolite emplacement. Sm/Nd dating of whole-rock–metamorphic mineral pairs yields similar ages of c . 630 Ma for clinopyroxene and hornblende, which is interpreted as a lower age limit for ophiolite formation and an upper age limit for metamorphism. A younger Sm/Nd age for a garnet-bearing rock ( c . 590 Ma) is interpreted as reflecting a meaningful cooling age close to the metamorphic peak. Hornblende K/Ar ages in the range 570–550 Ma may reflect thermal events during late orogenic granite magmatism.     

Petrology of pelitic schists in the oligoclase-biotite zone of the Sanbagawa metamorphic terrain, Japan: phase equilibria in the highest grade zone of a high-pressure intermediate type of metamorphic belt

The oligoclase-biotite zone of the Bessi area, central Shikoku is characterized by sodic plagioclase (X_Ca= 0.10–0.28)-bearing assemblages in pelitic schists, and represents the highest-grade zone of the Sanbagawa metamorphic terrain. Mineral assemblages in pelitic schists of this zone, all with quartz, sodic plagioclase, muscovite and clinozoisite (or zoisite), are garnet + biotite + chlorite + paragonite, garnet + biotite + hornblende + chlorite, and partial assemblages of these two types. Correlations between mineral compositions, mineral assemblages and mineral stability data assuming PH₂O = P_solid suggests that metamorphic conditions of this zone are about 610 ± 25°C and 10 ± 1 kbar.
Based upon a comparative study of mineralogy and chemistry of pelitic schists in the oligoclase-biotite zone of the Sanbagawa terrain with those in the New Caledonia omphacite zone as an example of a typical high-pressure type of metamorphic belt and with those in a generalized'upper staurolite zone'as an example of a medium-pressure type of metamorphic belt, progressive assemblages within these three zones can be related by reactions such as:     

约旦南部瓦迪巴希亚地区铀矿化地球物理特征

通过对瓦迪巴希亚（Wadi Bahiya）地区开展地质调查、岩石取样分析以及地面γ能谱测量等综合研究,认为研究区铀矿化主要产于上白垩统—古新统MCM组近地表风化破碎的灰褐色砂土状泥灰岩之中,矿化类型为现代氧化作用成因的钙结岩型,研究区γ能谱测量铀质量分数平面特征表现为异常规模小,晕圈梯度变化大,深部揭露表明,自近地表向深部铀质量分数逐渐降低,岩石取样分析结果与γ能谱测量具有对应性,铀矿化主要位于地表以下0.5～1.5m的范围内。     

The higher grade metamorphic zonation of the Sambagawa metamorphic belt in central Shikoku, Japan

The higher grade metamorphic zonation of the Sambagawa (= Sanbagawa) belt is established for the first time for the whole area of central Shikoku. As discontinuous reactions to define the isograd are absent, the metamorphic grade is primarily determined by the Mg-Fe partitioning between garnet and chlorite along representative traverses. However, for regional mapping, mineralogical features of the pelitic schists, such as using mineral assemblages of more than divariant equilibrium, the modal garnet to chlorite ratio, and the optical properties of chlorite, are employed as auxiliary criteria.
The presence of the highest grade mineral zone in the middle of the structural level is confirmed, but its spatial distribution is far more complex than hitherto accepted. Thermal axes are now confirmed at three different structural levels. A model is presented in which the stacking of thrust sheets of different grade took place while metamorphic reactions were in progress. Thermal readjustment brought a continuous metamorphic temperature gradient across and within the thrust sheets. Tectonic blocks of metagabbro and ultramafic rock were emplaced synchronously with thinning and subsequently also re-equilibrated. Local anomalies of metamorphic grade, represented by mixing of schists of different metamorphic grade, exist, but they are due to a later stage event.     

Hydrological and hydrogeological characteristics of Wadi el Mujib catchment area,Jordan

Hydrological and hydrogeological data in the area have been verified to evaluate the availability and the potentiality of the water resources for the proposed damsites in the Wadi el Mujib catchment area, which is considered a semiarid to arid region. The quantity of the surface waters is very small compared with the surface area of the basin, however, due to the shortage of precipitation in the country and the necessity to attain socioeconomic objectives, the investigation of these waters has become more vital. The most reliable exploitation can be essentially achieved by constructing small storage dams on the suitable sites in order to benefit from the flood waters coming from the main wadis. For the above purpose, the hydrogeological and hydrological study of Wadi el Mujib catchment area was carried out, where the Wadi Mujib dam site will be constructed. The hydrogeological investigation of the groundwater was performed by constructing a groundwater contour map of the Amman-Wadi Es Sir aquifer (B2/A7) so as to verify the groundwater flow system and to determine the potentiality of the aquifer from the hydraulic parameters obtained from the pumping test analysis. The hydrological feasibility study of the dam was carried out by evaluating the water balance for a long-term period (1970 to 1990) in order to obtain reliable data that can be used to estimate the recharge to B2/A7 aquifer. In addition, a frequency analysis was performed to estimate the flood design of the reservoir area as well as the spillway at the proposed dam site.     

Artificial recharge with surface water; a pilot project in Wadi Madoneh, Jordan

Artificial recharge with surface water in Jordan has been discussed at length in several reports and papers, but so far this technique has hardly been applied in the country. This article describes the site selection, design, construction and operation of four small retention structures in Wadi Madoneh during the period 2003–2009. The catchment (37 km²) is located some 20 km east of Amman in a desert region (average annual precipitation is 160 mm). The project is based on a feasibility study conducted in the 1990s. It is shown that in the previous study the retention structures have been largely overdesigned, because of absence of discharge measurements and the negligence of climate change. For this pilot an extensive hydrological study was carried out, based on historical data and contemporary measurements, to derive design parameters for small in-channel dams with a height of 3–6 m. The retention structures are designed to retain the floods in order to slowly release this water for infiltration in the Wadi bed downstream. Four retention structures were installed by a local contractor in 2007. This study shows that virtually all surface runoff from the catchment has ceased which makes the method very effective while the costs are low. Artificial recharge with small retention structures is recommended for application on a larger scale and considered a cheap alternative for other non-conventional water resources supply methods. From experience with vandalism and interaction with the local community, improvements to the design of the dams are recommended.     

Mopping up leaking carbon: A natural analog at Wadi Namaleh,Jordan

Carbon capture and sequestration (CCS) is one of the important options available for partially stemming greenhouse gas emissions from large point sources. The possibility of leaking from deep storage needs to be addressed. The Wadi Namaleh area in southern Jordan provides an interesting case study of how excess CO₂ can be trapped in the form of carbonates in the near surface, even when the local geology is not obviously conducive for such a process.Carbonate veins are formed in surface alteration zones of rhyolite host rock in this arid region. The alteration zones are limited to areas where surface soil or colluvium are present. Oxygen, deuterium and carbon isotopes of the carbonates and near-surface ground water in the area suggest that the source of carbon is deep seated CO₂, and that the carbonate precipitated in local meteoric water under ambient temperature conditions. Analysis of strontium in the carbonate, fresh rhyolite and altered host shows that the source for calcium is aeolian. Trace elements show that metal and REE mobility are constrained to the alteration zone.Thus, interaction of H₂O, CO₂ and atmospheric wet and dry deposition lead to the formation of the clayey (montmorillonite) alteration zone. This zone acts to trap seeping CO₂ and water, and thus produces conditions of progressively more efficient trapping of carbon dioxide by means of a positive feedback mechanism. Replication of these conditions in other areas will minimize CO₂ leakage from man-made CCS sites.     

藏东巴青县以北基底变质岩系的发现

在125万仓来拉幅区域地质调查中首次发现上三叠统结扎群底部出露的一套变质岩系,通过与区域上变质基底岩系对比,将其归并为吉塘群酉西岩组,主要岩性为云母石英构造片岩、石英钠长构造片岩等.根据野外露头接触关系及"构造角砾岩"特征,确定该套岩系与上覆上三叠统为滑脱构造接触关系,滑脱面迁就了早期的角度不整合面,并认为研究区为"浅基底".     

On folding-movements in the zone of the basement

The tectonic style of basement gneiss terrains is discussed and exemplified. The origin of migmatic domes and migmatite naps is explained as the result of secondary forces caused by horizontal flow in the infrastructure. The relationship between structural patterns in different dimensions is discussed.

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Zusammenfassung Der tektonische Stil der Gneisbildungen innerhalb der Sockel wird an Hand von Beispielen dargelegt. Die Entstehung der Migmatit-Kuppeln und -Decken wird als Ergebnis von Sekundärkräften durch horizontales Fließen im Unterbau erklärt. Das Verhältnis zwischen Bautypen verschiedener Größenordnungen wird besprochen.

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Résumé Plusieurs exemples de style des terrains gneissiques des socles sont présentés et discutés. L'origine des dômes et des nappes de migmatites est considérée comme le résultat de forces secondaires ayant comme conséquence des phénomènes d'écoulement dans l'infrastructure. Les rapports entre des types de structure d'ordre de grandeur différente sont discutés.

     

Geologic and metamorphic evolution of the basement complexes in the Kontum Massif,central Vietnam

This paper presents a regional scale observation of metamorphic geology and mineral assemblage variations of Kontum Massif, central Vietnam, supplemented by pressure–temperature estimates and reconnaissance geochronological results. The mineral assemblage variations and thermobarometric results classify the massif into a low- to medium-temperature and relatively high-pressure northern part characterised by kyanite-bearing rocks (570–700 °C at 0.79–0.86 GPa) and a more complex southern part. The southern part can be subdivided into western and eastern regions. The western region shows very high-temperature (> 900 °C) and -pressure conditions characterised by the presence of garnet and orthopyroxene in both mafic and pelitic granulites (900–980 °C at 1.0–1.5 GPa). The eastern region contains widespread medium- to high-temperature and low-pressure rocks, with metamorphic grade increasing from north to south; epidote- or muscovite-bearing gneisses in the north (< 700–740 °C at < 0.50 GPa) to garnet-free mafic and orthopyroxene-free pelitic granulites in the south (790–920 °C at 0.63–0.84 GPa). The Permo-Triassic Sm–Nd ages (247–240 Ma) from high-temperature and -pressure granulites and recent geochronological studies suggest that the south-eastern part of Kontum Massif is composed of a Siluro-Ordovician continental fragment probably showing a low-pressure/temperature continental geothermal gradient derived from the Gondwana era with subsequent Permo-Triassic collision-related high-pressure reactivation zones.     

Geologic and metamorphic evolution of the basement complexes in the Kontum Massif, central Vietnam

This paper presents a regional scale observation of metamorphic geology and mineral assemblage variations of Kontum Massif, central Vietnam, supplemented by pressure–temperature estimates and reconnaissance geochronological results. The mineral assemblage variations and thermobarometric results classify the massif into a low- to medium-temperature and relatively high-pressure northern part characterised by kyanite-bearing rocks (570–700 °C at 0.79–0.86 GPa) and a more complex southern part. The southern part can be subdivided into western and eastern regions. The western region shows very high-temperature (> 900 °C) and -pressure conditions characterised by the presence of garnet and orthopyroxene in both mafic and pelitic granulites (900–980 °C at 1.0–1.5 GPa). The eastern region contains widespread medium- to high-temperature and low-pressure rocks, with metamorphic grade increasing from north to south; epidote- or muscovite-bearing gneisses in the north (< 700–740 °C at < 0.50 GPa) to garnet-free mafic and orthopyroxene-free pelitic granulites in the south (790–920 °C at 0.63–0.84 GPa). The Permo-Triassic Sm–Nd ages (247–240 Ma) from high-temperature and -pressure granulites and recent geochronological studies suggest that the south-eastern part of Kontum Massif is composed of a Siluro-Ordovician continental fragment probably showing a low-pressure/temperature continental geothermal gradient derived from the Gondwana era with subsequent Permo-Triassic collision-related high-pressure reactivation zones.     

河南焦作云台山早前寒武纪变质基底锆石SHRIMP U-Pb年龄

应用离子探针技术,对华北太行山南缘钾长石化长英质副片麻岩和钾长石化片麻状奥长花岗岩进行了锆石年龄测定。钾长石化长英质副片麻岩的变质原岩为泥砂质碎屑沉积岩,其形成时代很可能为新太古代。碎屑锆石普遍存在强烈铅丢失,靠近上交点的5个数据点207Pb/206Pb加权平均年龄为3399Ma±8Ma,代表了物源区组成的时代。钾长石化片麻状奥长花岗岩2组锆石207Pb/206Pb加权平均年龄分别为2511Ma±13Ma(岩体形成时代)和2735Ma±16Ma(残余锆石年龄),分别代表该岩体形成时代和残余锆石年龄。新的资料支持了华北克拉通中部造山带太古宙地质体与其东部陆块存在亲缘关系的认识。     

Mineralogy, geochemistry, and origin of felsic dike swarms in Aqaba complex (Wadi Al-Yutum), South Jordan

The present work deals with the geologic setting and mineralogical and geochemical study of Late Precambrian magmatic rocks especially the felsic dike swarms of northeast Aqaba complex in South Jordan. The northeast Aqaba complex represents one of the most significant regions in the South Jordan basement. The basement rocks in the studied region are composed of schists, gneisses, migmatites, met gabbros, diorite, and granite. It is invaded by post-orogenic dike swarms. The post-orogenic dike swarms have been recognized as felsic dikes of dacite, rhyodacite, and rhyolite composition. They are composed of plagioclase, K-feldspar, quartz, biotite, and hornblenble with a porphyritic texture. Chemically, they are enriched in compatible elements especially in the large ion lithophile elements such as K, Rb, and Ba. The values of A/NK are more than A/CNK, indicating that dacitic dike swarms have metaluminous nature. Meanwhile, the values of A/NK are less than A/CNK in rhyodacitic and rhyolitic dike swarms of prealuminous nature. This felsic dike can be related to an intercontinental setting that was accompanied by a chemical evolution of the extensional movements and is formed by partial melting of crustal rocks, which are already known from other areas in the northeast portion of the Arabian-Nubian Shield.     

Hydrochemistry and environmental isotopes of spring water and their relation to structure and lithology identified with remote sensing methods in Wadi Araba,Egypt

Springs located at the historical sites of Wadi Araba (Eastern Desert of Egypt) and emerging from the escarpments of the Northern and Southern Galala Plateaus were investigated. A combination of methods, including hydrochemistry, stable and radioisotope composition, and structural analyses based on satellite data, provided information about the structure of the subsurface and the derived groundwater flow paths. Satellite images reveal karst features within the northern plateau, e.g. conical landforms. Karstic caves were documented along both escarpments. Chemical analysis of floodwater from Wadi Araba indicates higher concentrations of terrestrial salts compared to floodwaters from central and southern parts of the desert. δ¹⁸O and δ²H signatures in spring waters resemble those of floodwater and fall on the global meteoric water line, confirming their fast infiltration with minor influence of evaporation. The aquifer feeding the springs of the Northern Galala Plateau has low retention and the springs dry out quickly, even after heavy rainfall. Contrastingly, ³H activities in springs emerging from the Southern Galala Plateau refer to much slower subsurface passage. With respect to ³H content (3.8 TU) in recent flood waters, the spring water at Southern Galala Plateau contains about 40% recently recharged groundwater. However, its largest spring—the St. Antony spring—discharges water with a radiocarbon age of about 15,000 years. In combination with this spring’s constant and high discharge over a period of several months, that age estimate suggests a large reservoir with moderate to high retention.

     

The stability of osumilite in high grade metamorphic rocks

Osumilite, approximate composition K(Mg,Fe)₂ Al₅Si₁₀O₃₀, has been reported recently from two granulite localities. The mineral has been synthesised in a model pelitic composition at 1000 and 1100 ° C and 3.6–6.3 kb under conditions of low water and oxygen fugacity. Osumilite coexists, apparently stably, with hypersthene, cordierite and quartz (?) thus duplicating the mineral assemblage of one of the natural occurrences. Osumilite is in a divariant reaction relationship with cordierite and hypersthene i.e. osumilite ? cordierite + hypersthene + orthoclase+quartz. This reaction runs to the right with increasing pressure. Experimental data and field observations suggest that the joins osumilite-garnet and osumilite-sillimanite are not stable. It is suggested osumilite is involved in an invariant point in the system K₂O-MgO-FeO-A1₂O₃-SiO₂ with the phases cordierite, hypersthene, sapphirine, spinel, orthoclase and quartz. The invariant point should occur at 1000 ± 100 °C and 7± 2kb.     

Tourmaline breakdown in the migmatite zone of the Ryoke metamorphic belt,SW Japan

A sharp line delimitating the distribution of tourmaline (termed as a ‘tourmaline‐out isograd’) is defined in the migmatite zone of the Ryoke metamorphic belt, Japan. The trend of the tourmaline‐out isograd closely matches that of the isograds formed through the regional metamorphism, suggesting that it represents the breakdown front of tourmaline during regional metamorphism. This is confirmed by the presence of the reaction textures of tourmaline to sillimanite and cordierite near the tourmaline‐out isograd. The breakdown of tourmaline would release boron into associated melts or fluids and be an important factor in controlling the behaviour of boron in tourmaline‐bearing high‐temperature metamorphic rocks. Near the tourmaline‐out isograd, large tourmaline crystals occur in the centre of interboudin partitions containing leucosome. In the melanosome of the intervening matrix, reaction textures involving tourmaline are locally observed. These observations imply that tourmaline breakdown is related to a melting reaction and that the boron in the leucosome is derived from the breakdown of tourmaline in the melanosome during prograde metamorphism. Boron released by tourmaline breakdown lowers both the solidus temperature of the rock and the viscosity of any associated melt. Considering that the tourmaline‐out isograd lies close to the schist–migmatite boundary, these effects might have enhanced melt generation and segregation in the migmatite zone of the Ryoke belt. The evidence for the breakdown of tourmaline and the almost complete absence of any borosilicates throughout the migmatite zone suggest that boron was effectively removed from this region by the movement of melt and/or fluid. This implies that the tourmaline‐out isograd can reflect a significant amount of mass transfer in the anatectic zones.