Late quaternary environmental history of the southern Levant

The Late Quaternary history of northern Sinai and the western Negev is inferred from a number of stratigraphic sequences rich in prehistoric and archaeologic remains. Exposures are abundant along the wadi courses which drain the highlands westward to the Mediterranean. Earliest deposition is represented by coarse, well rounded gravels containing Middle Paleolithic artifacts and is dated to ca. 90,000 to 70,000 B.P. These are overlain by finer grained sands, silts, and clays, ultimately of eolian origin, but re-deposited by low energy stream flows under marshy conditions. These contain in situ Upper Paleolithic (ca. 40,000 to 22,000 B.P.) and Epi-Paleolithic (ca. 15,000 to 12,000 B.P.) sites; commonly an erosional phase (ca. 22,000 to 15,000 years ago) separates the two groups of industries. In areas closer to the coast, temporally equivalent deposits are predominantly sandy, reflecting their proximity to the source in western and northern Sinai. The Holocene is generally characterized by downcutting but deposition of fluviatile and eolian silts is well documented during the Chalcolithic (ca. 6,000 B.P.). The last depositional event is the accumulation of 3–4 m of fluviatile silts containing Byzantine artifacts and radiocarbon dated between ca. 1750–600 B.P.). Whereas most of the sequences can be explained in climatic terms, the Byzantine or “Historical Fill” may have an anthropogenic origin.     

The Triassic of the southern margin of the Tethys in the Levant and its correlation across the Jordan Rift Valley

The Triassic of the Levantine region consists of four sedimentary cycles: I. Scythian — Lower Anisian; II. Early Upper Anisian; III. Late Upper Anisian — Carnian; IV. Late Carnian — Norian.Regional biofacial affinities point to the existance of a western Tethyan Werfen facies (cycle I), a sephardic biofacies (cycles II and III) and a rather alpinotype platform facies (cycle IV). A correlation across the Jordan Rift Valley is suggested, primarily based on bio- and lithostratigraphic evidence of the Permo-Triassic rocks. The stratigraphic implications of this correlation support the existance of a left lateral strike slip along the Jordan Rift Valley.

---

Zusammenfassung Die Trias im Levant ist in vier Sedimentationszyklen gegliedert: I. Skythian — Unteres Anisian; II. Oberes Anisian; III. Oberes Anisian — Karnian; IV. Oberes Karman — Norian.Die regionalen Faziesbeziehungen deuten auf das Vorhandensein einer Westtethyalen Werfener Fazies (Zyklus I), einer West- und Südtethyalen Sephardischen Fazies (Zyklen II und III) und einer eher alpinotypischen Plattformfazies (Zyklus IV).Eine Korrelation der permisehen und untertriadischen Gesteine auf beiden Seiten des Jordantales wird vorgeschlagen. Die stratigraphischen Folgerungen dieser Korrelation unterstützen die Existenz einer linken Transversalverschiebung entlang des Jordantal Rifts.

---

Résumé Le Trias du Levant comprend quatre cycles sédimentaires: I. Scythien-Anisien inférieur; II. Anisien supérieur; III. Anisien supérieur — Carnien; IV. Carnien supérieur — Norien.La succession des biofaciès débute par le faciès Werfénien, qui englobait pratiquement la Téthys occidentale éotriasique toute entière (cycle I). Dans le courant du Mésotrias, le faciès Sépharade s'étend aux marges méridionales et occidentales de la Téthys (cycles II et III), tandis qu'un faciès de plateforme d'affinité plutôt alpine représente le Trias terminal (cycle IV).Une corrélation des séries Permo-Eotriasiques du Néguev et de Transjordanie est proposée. Les implications stratigraphiques de cette corrélation appuient l'existence d'un coulissage sénestre tout au long du Rift de la vallée du Jourdain.

---

4 : 1. — ; 2. ; 3. — ; 4. — . — 1, — 2 3 — 4. - , .

     

Transition from arid to hyper-arid environment in the southern Levant deserts as recorded by early Pleistocene cummulic Aridisols

The time at which deserts established their current arid or hyper-arid conditions remains a fundamental question regarding the history of Earth. Cosmogenic isotope exposure ages of desert pavement and welded, calcic–gypsic–salic Reg soils that developed on relatively flat alluvial surfaces ～2 Ma ago in the Negev Desert indicate long geomorphic stability under extremely dry conditions. Over a short interval during their initial stage of development between 1–2 Ma, these cumulative soils are characterized by calcic soils reaching maximum stage III of carbonate morphology. This interval is the only period when calcic soil horizons formed on stable abandoned alluvial surfaces in the southern Negev Desert. Since ～1 Ma pedogenesis changed toward more arid soil environment and the formation of gypsic–salic soil horizons that were later followed by dust accumulation. The dichotomy of only moderately-developed calcic soil (stages II–III) during a relatively long time interval (10⁵–10⁶ years) indicates an arid environment that does not support continuous development but only occasional calcic soil formation. The very low δ¹⁸O and relatively high δ¹³C values of these early pedogenic carbonates support soil formation under arid climatic conditions. Such an environment was probably characterized by rare and relatively longer duration rainstorms which occasionally allowed deeper infiltration of rainwater and longer retention of soil moisture. This, in turn enabled the growth of sparse vegetation that enhanced deposition of pedogenic carbonate. At ～1 Ma these rare events of slightly wetter conditions ceased and less atmospheric moisture reached the southern Negev Desert leading to deposition of soluble salts and dust deposited in the soils. The combination of long-term hyperaridity, scarcity of vegetation and lack of bioturbation, salts cementation, dust accumulation and tight desert pavement cover, has protected the surfaces from erosion forming one of the most remarkably stable landscapes on Earth, a landscape that essentially has not eroded, but accumulated salt and dust for more than 10⁶ yr.     

藏南冲木达铜矿地质特征

藏南冲木达铜矿床属矽卡岩型铜矿床。矿区出露地层为上侏罗统—下白垩统桑日群比马组,遭受不同程度的矽卡岩化蚀变或区域浅变质作用。矿区铜矿(化)体主要赋存于比马组3~4段透辉石榴矽卡岩、矽卡岩化大理岩中,并主要产出于断裂构造带及其断裂两侧附近。铜矿(化)的形成经历了矽卡岩化阶段和热液硫化物阶段。     

西藏玉龙铜矿带南段马牧普铜多金属矿床矿物学特征

西藏马牧普铜多金属矿床是玉龙铜矿带南段的重要组成部分，最新勘查进展揭示其铜、金资源量均已达到中型规模，但理论研究工作仍十分薄弱。本文基于系统的镜下鉴定和电子探针分析，对马牧普铜多金属矿床矿物学进行详细研究，进而探究矿床成因。马牧普矿床主矿体为中—厚层板状的角砾岩型矿体，矿石类型以角砾状为主，局部矿体呈透镜状产于角岩中。矿区发育广泛的绿泥石化、角岩化、金云母化和弱绢云母化蚀变。电子探针分析结果表明，矿区内矽卡岩矿物中辉石主要为透辉石，云母主要为金云母，角闪石则以透闪石为主。马牧普矿床成矿阶段和矿物组合为：Ⅰ进变质阶段，矿物组合为透辉石- 石榴子石- 磁铁矿±白钨矿；Ⅱ退变质阶段，矿物组合为透闪石- 金云母±磁铁矿±绿泥石±绿帘石±白钨矿；Ⅲ硫化物阶段，矿物组合为黄铁矿- 黄铜矿±辉钼矿±磁黄铁矿±辉铋矿±方铅矿±闪锌矿±萤石±石英，为主成矿阶段；Ⅳ碳酸盐阶段，矿物组合为赤铁矿±萤石±方解石±石英±玉髓。矿物学特征表明，矽卡岩演化经历了岩浆期后高温—中低温演化的过程，随着温度的降低，镁质矽卡岩矿物从进变质阶段的透辉石转变为退变质阶段的金云母；矽卡岩形成过程中经历了早期相对较为氧化的环境到晚期相对较为还原环境的转变。矿区角砾岩层为原沉积地层中存在的白云质、钙质碳酸盐夹层，广泛的热液交代作用使得大部分碳酸盐呈角砾状。含矿岩浆热液流体沿着碳酸盐岩产状侵位并发生交代作用，使得金属矿物在角砾岩层中沉淀并富集成矿。     

阿尔泰铜矿带南缘希勒克特哈腊苏斑岩铜矿的发现及其意义

希勒克特哈腊苏铜矿位于阿尔泰铜矿带南缘,即原卡拉先格尔斑岩铜矿带内。初步的研究和钻孔资料表明,铜矿体完全受斑岩体(石英闪长斑岩和花岗闪长斑岩)控制,矿石具细脉浸染状构造,金属矿物主要为黄铜矿和黄铁矿以及少量的磁铁矿、斑铜矿和镜铁矿。其中磁铁矿形成早于黄铜矿,指示了岩浆具有较高的氧化状态。矿化蚀变分带与斑岩铜矿基本相似,岩体内见钾长石化、黑云母化、硅化和黄铁矿化,接触带见石英绢云母化,围岩见青磐岩化。含矿斑岩的地球化学特征表明其属于埃达克岩(adakite):高SiO2(63%～66%)、高Al2O3(15%～17%)、富集Sr(378×10-6～447×10-6)、无负Eu异常、亏损Y(10×10-6～14×10-6)和Yb(1.3×10-6～1.5×10-6)以及低的Sr同位素初始值(0.70439)、高的(εNd)t(+6.9～+8.2)和低的δ18OV-SMOW(<10‰)。其Rb-Sr等时线年龄为(332.8±8.5)Ma,为早石炭世侵位的产物,其形成与蒙古洋板块向南俯冲造成的洋壳部分熔融有关,因此其成矿地质背景与世界巨型斑岩铜矿十分相似。另外,在希勒克特哈腊苏铜矿外围还有数个与其十分相似的铜矿点,因此该地区展示了良好的找矿前景,同时也是中国又一个潜在的斑岩铜矿带。     

The internal grabens of the Levant Rifts and their geodynamic significance

The Levant Rift system is a linear assemblage of rifts and their mountainous flanks that comprise three structural distinct sections. The southern Jordan Rift is built of series of secondary axial grabens that diminish in length northwards and are separated from each other by poorly rifted threshold zones. The central section of the rift system is the Lebanese Baqa’a embedded between mountainous flanks, and a splay of faults that scatter to the north-northeast; the northern section comprises the SW-trending Karasu–Hatay Rifts from which the Ghab graben branches southwards. It is suggested that the rifting of the Jordan Rift is the northern extension of the Red Sea continental break-up, while the Karasu–Tatay section correlates geodynamically with the migration of Anatolia westwards. The Baqa’a, its mountainous flanks and the fault splay mark the termination of the crustal break-up from the south, but rejuvenation of some faults indicate the effects of the Anatolian migration.     

Lithofacies and cyclicity of Mohilla evaporite basins on the rifted margin of the Levant in the Late Triassic,Makhtesh Ramon,southern Israel

Marine‐connected basins with evaporites occur beneath most extensional continental margins that originated at low‐latitudes and often are of major economic significance. Cyclicity in the evaporite lithofacies reflects the degree of restriction of the basin, overprinted by sea‐level changes, and caused by structural movements in the barrier region, whether by fault‐block rotation, footwall uplift or hanging wall subsidence, in both extensional and compressional basins. The Upper Triassic evaporites of the Ramon section in southern Israel model cyclic sedimentation in such environments. The Mohilla Formation is a carbonate–evaporate–siliciclastic succession of Carnian age that fills a chain of basins extending along the Levant margin from southern Israel to Jordan and Syria. The basins developed in half‐grabens adjacent to normal faults that formed during a period of regional extension. Evaporites of this formation are well‐exposed in outcrops at Makhtesh Ramon, the southernmost of these basins. The M2 Member of the Mohilla Formation is composed of 42 sub‐metre cycles of alternating dolostone, gypsum and calcareous shales. Field and microfacies analysis showed these cycles to conform mostly to restricted shallow and marginal marine environments, spatially limited by the uplifted shoulders of the half‐graben systems. A total of 10 facies types belonging to six depositional environments have been identified. From stacking patterns and analysis of bed to bed change, cycles can be categorized into three groupings: (i) low frequency exposure to exposure cycles that developed under eustatic or climate control; (ii) high frequency deepening/shallowing‐upward cycles, characterized by gradual transitions due to short‐term sea‐level or runoff‐event oscillations possibly referable to orbital forcing; and (iii) high frequency shallowing‐upward cycles, characterized by abrupt transitions, attributable to sporadic tectonic events affecting accommodation space or barrier effectiveness. The way facies and cycling of the sedimentary environments was deciphered in the Mohilla evaporite basin can be used to unravel the genesis of many other evaporite basins with barriers of tectonic origin.     

GPS定位技术在福建地壳形变监测中的应用

随着GPS观测及数据处理技术的发展,GPS定位技术在地球动力学方面的应用越来广泛,本文介绍国内外利用GPS定位技术在地球动力学方面的应用现状,着重介绍了GPS精密定位技术在福建地壳形变监测方面的应用现状和取得的初步成果。     

西藏冈底斯成矿带与俯冲-碰撞作用相关的斑岩铜矿的找矿方向

本文从构造-岩浆演化、典型矿床特征、构造-岩浆产物空间分布特征等方面,对冈底斯成矿带形成于195~80Ma的与俯冲-碰撞作用相关的斑岩(-矽卡岩)型铜矿的找矿方向进行了探讨。认为研究区与俯冲-碰撞作用相关的斑岩型铜矿大致可分为早-中侏罗世、晚侏罗-早白垩世、晚白垩世3个成矿时期,分别对应于雅鲁藏布江洋向北、班公湖怒江洋向南相向俯冲、班公湖怒江洋碰撞关闭、雅鲁藏布江洋向北持续俯冲、雅鲁藏布江洋向北晚期俯冲等构造-岩浆事件。与早期相向俯冲相关的雄村式矿床,在拉萨东部达孜-工布江达一带具有良好找矿前景;与中期俯冲-碰撞相关的多龙式矿床,在昂龙岗日、东恰错、桑日等火山岩浆弧区成矿条件较佳;与晚期俯冲相关的尕尔穷式矿床,在冈底斯东段和西段具有较大的找矿潜力。     

The lost world of the olenid trilobites

Trilobites of the Family Olenidae (Upper Cambrian to Upper Ordovidan) were closely tied to an oxygen-poor environment. They show a remarkable range of adaptations, testifying to a singular evolutionary plasticity.     

玉龙斑岩铜矿带南段含矿斑岩体锆石U-Pb年龄、地球化学特征及南北段成矿规模差异分析

藏东缘玉龙斑岩铜矿带是中国重要的产于碰撞造山环境下的斑岩铜矿带,其全长约300千米,主要由1个超大型、2个大型、2个中型斑岩铜矿床及一系列斑岩型矿床(点)组成。玉龙斑岩铜矿带大规模矿化主要位于矿带北段,南段矿化规模相对较小,目前发现的多为小型矿床(点)。为了深入了解玉龙斑岩铜矿带时空演化及南北段矿化规模差异的控制因素,本文分析了玉龙斑岩铜矿带南段色礼、马牧普和总郭这3个矿化点矿化斑岩体锆石LA-ICP-MS U-Pb年龄、地球化学组成及色礼矿化斑岩体锆石Hf同位素。色礼、马牧普和总郭含矿斑岩分别为二长花岗斑岩、正长斑岩及石英二长斑岩,三者锆石LAICP-MS U-Pb年龄分别为39.4±0.2Ma(MSWD=1.10)、38.5±0.3Ma(MSWD=1.79)和39.4±0.2Ma(MSWD=1.05)。矿化斑岩体为偏铝质,具有富碱、高钾(K_2O/Na_2O=1.2~2.4)、富集大离子亲石元素和轻稀土元素,亏损高场强元素,弱Eu负异常特征。3个矿化斑岩具有较高的Sr/Y比值,且都发育角闪石斑晶,呈现富水岩浆特征。色礼二长花岗斑岩的锆石εHf(t)为-2.7~2.8,平均值为-0.4,显示壳幔混合源区特征,并且其明显小于玉龙斑岩铜矿带北段玉龙超大型斑岩铜矿床含矿斑岩体锆石εHf(t)值(4.2)。玉龙斑岩铜矿带南北段含矿斑岩体形成时代相近,都形成于碰撞造山走滑构造背景。玉龙超大型矿床矿化斑岩锆石εHf(t)值明显大于色礼矿化点斑岩体锆石εHf(t)的值,表明矿床规模和岩浆源区物质含幔源物质多少有关,更多亏损地幔物质或新生地壳物质的加入更有利于形成大型斑岩矿床。玉龙斑岩铜矿带南北段成矿规模差异可能为北段斑岩体含更多地幔或新生地壳物质所致。     

铜钴矿样品X荧光快速测定技术的初步研究

使用基于Si-PIN探测器和嵌入式计算机的便携式高能量分辨率X荧光(XRF)分析仪,对采自刚果(金)的铜钴矿样品进行测量。通过对实测数据的处理与分析,分含量段建立目标元素的工作曲线,同时求出相应的基体效应校正模型,并编制到仪器内置X荧光分析应用软件中。实现仪器根据实测多道微分谱线中相关元素的特征X射线计数率,自动切换工作曲线与基体效应修正模型,快速输出Cu和Co的含量的测定结果。通过与化学分析结果比较,快速测定结果精确度较高。     

结合波形互相关的双差定位和线性定位在北京西北地区地震活动性研究中的应用

采用2002年-2012年首都圈台网事件目录和2008年12月-2011年11月中国地质科学院地质力学研究所布设的微震台网记录的地震事件目录,分别运用结合波形互相关的双差定位和Geiger定位方法进行精确定位,对北京西北地区的活动地震构造进行了研究.结果表明北京西北地区分布两条NW向地震断裂带和两条NE向地震断裂带及两个地震密集分布区,地震活动密集分布区均位于NE向地震断裂带与NW向地震断裂带相交处及地处山区-平原过渡区,可能是东北旺断裂与南口 — 山前断裂活动的反映.该地区地震震源深度分布范围主要为5～30 km,主要分布在上地壳和中地壳.     

The structure, isostasy and gravity field of the Levant continental margin and the southeast Mediterranean area

A 3-D layered structure of the Levant and the southeastern Mediterranean lithospheric plates was constructed using interpretations of seismic measurements and borehole data. Structural maps of three principal interfaces, elevation, top basement and the Moho, were constructed for the area studied. This area includes the African, Sinai and Arabian plates, the Herodotus and the Levant marine basins and the Nile sedimentary cone. In addition, an isopach map of the Pliocene sediments, as well as the contemporaneous amount of denuded rock units, was prepared to enable setting up the structural map of the base Pliocene sediment. Variable density distributions are suggested for the sedimentary succession in accord with its composition and compaction. The spatial density distribution in the crystalline crust was calculated by weighting the thicknesses of the lower mafic and the upper felsic crustal layers, with densities of 2.9 g/cm³ and 2.77 g/cm³, respectively. Results of the local (Airy) isostatic modeling with compensation on the Moho interface show significant deviations from the local isostasy and require variable density distribution in the upper mantle. Moving the compensation level to the base of the lithosphere ( 100 km depth) and adopting density variations in the mantle lithosphere yielded isostatic compensation (± 200 m) over most of the area studied. The spatial pattern obtained of a density distribution with a range of ± 0.05 g/cm³ is supported by a regional heat flux. Simulations of the flexure (Vening Meinesz) isostasy related to the Pliocene to Recent sedimentary loading and unloading revealed concentric oscillatory negative and positive anomalies mostly related to the Nile sedimentary cone. Such anomalies may explain the rapid subsidence in the Levant Basin and the arching in central Israel, northern Sinai and Egypt during Pliocene–Recent times. Comparison between the observed (Bouguer) gravity and the calculated gravity for the constructed 3-D lithospheric structure, which has variable density distributions, provided a good match and an independent constraint for the large-scale structure suggested and confirmed an oceanic nature for the Levant Basin lithosphere.     

庐枞火山岩盆地南部拔茅山铜矿深部找矿潜力分析

位于庐枞火山岩盆地南部的拔茅山铜矿,是细脉带蚀变岩型脉状铜矿的代表。研究表明,其深部具有斑岩型铜矿的勘探潜力。为了进一步明确其深部找矿潜力,针对研究区斑岩型、热液型铜多金属矿的岩体、断裂、接触带等主要控矿因素,利用高精度磁法和可控源音频大地电磁测深(CSAMT)成果,分别对拔茅山岩体的分布、产状和深部形态及其与围岩的接触带特征进行了剖析。在此基础上,通过与沙溪斑岩铜矿地质、物探异常特征的类比,指明了研究区的找矿方向和有利找矿部位,为进一步找矿提供了思路和依据。     

The Faunal Remains from Evron Quarry in Relation to Other Lower Paleolithic Hominid Sites in the Southern Levant

The mammalian assemblage and archaeological finds from the Lower Palaeolithic hominid site of Evron Quarry, situated on the northern coastal plain of Israel, are described and discussed. In their lithic and faunal composition, the sites of Latamne (QfIII) (Latamne Formation, Orontes, Syria) and Sitt Markho (Nahr elKebir, Syria) resemble Evron and are probably contemporaneous. It is suggested here, based on their lithic and faunal composition, that these sites may be chronologically closer to the site of Ubeidiya ('Ubeidiya Formation, Jordan Valley, Israel; 1.4 myr) than to the sites of Gesher Benot Ya'akov (dated as <800,000 yr B.P.), which differs in both aspects from Evron. The mammalian faunule from Evron comprises a biogeographical mixture, a result of biotic exchanges with Africa, the Oriental region, and the Palaearctic. This exchange may have been associated with a post-'Ubeidiya hominid dispersal, either from Africa or south Asia via the Levantine "corridor."