黄河晋陕峡谷1.1 Ma阶地的形成及其构造背景*

对黄河晋陕峡谷河曲、黑峪口、延水关和壶口等4个地区进行了详细的野外考察。河曲地区共发现3级河流阶地,更高的则为唐县期宽谷;唐县期宽谷的海拔高度约1000m(拔河高度150m),而3级河流阶地的拔河高度分别约为110m、80m和12m。黑峪口地区也存在唐县期宽谷,宽谷之下发育5级河流阶地,唐县期宽谷西高东低,海拔高度位于970m和940m之间,5级河流阶地的拔河高度分别约为130m,80m、50m、12m和4m。延水关地区共发现6级河流阶地,全部为第四纪期间形成,6级河流阶地的拔河高度分别为180m、130m、95m、50m、20m和4m。壶口地区共存在8级阶地,也全部为第四纪期间的阶地,阶地的拔河高度分别约为260m、210m、180m、120m、80m、60m、35m和15m。对壶口最高阶地进行了地层学研究,发现这一阶地上覆厚度约110m的黄土地层,黄土层的最底部为L13,古地磁研究结果和古土壤断代都指示了这一阶地的形成时间在距今1.1Ma左右。综合晋陕峡谷地区现有的研究结果认为,3.3Ma之前,鄂尔多斯地块内部构造极为稳定,发育了唐县期夷平面,古黄河在此夷平面上主要以侧蚀拓宽为主,下蚀极其微弱;3.3-1.1Ma,鄂尔多斯地块的构造稳定可能被打破,黄河小幅度下切;而1.1Ma以来,受鄂尔多斯地块快速抬升的影响,黄河发生剧烈下切,1.1 Ma阶地和晋陕峡谷的主体在这一时期形成。     

Pleistocene tectonics inferred from fluvial terraces of the northern Upper Rhine Graben, Germany

This study of fluvial terraces of the River Rhine and tributaries aims to search for indications of Pleistocene tectonic activity. The study area includes the northern Upper Rhine Graben (URG), the Mainz Basin and the adjacent Rhenish Massif with the Middle Rhine Valley. High rates of Quaternary surface processes, large amount of human modifications, relatively slow tectonic deformation and presently low intra-plate seismic activity characterize this area. Therefore, the records of relatively slow tectonic deformation are less well preserved and thus difficult to detect. This study uses the relative position of fluvial terraces to determine the more local effects of fault movements on the terraces and to evaluate their displacement rates and patterns. The research is based on a review of previous terrace studies and new terrace mapping from the eastern Mainz Basin and the bordering URG using topographic map interpretations and field observations. This newly mapped sequence of terrace surfaces can be correlated to other terraces in the vicinity on the basis of relative height levels. Terrace correlation between the western Mainz Basin and Middle Rhine Valley relies on a single chronostratigraphic unit (Mosbach sands) and additional relative height correlations. This is the first study to present a continuous correlation of terraces from the western margin of the URG to the Rhenish Massif and enables the study of the transition from the subsiding graben to the uplifted Rhenish Massif. By means of a longitudinal profile, which ranges from the URG to the Rhenish Massif, the influence of individual fault movements on the terrace levels and the large-scale regional uplift is demonstrated. It is evident from the profile that the uplift of Early to Middle Pleistocene terraces increases northwards, towards the Rhenish Massif. The uplift was diachronic, with a significant pulse occurring first in the northern URG (Lower Pleistocene) and later in the Rhenish Massif (Middle Pleistocene). The largest vertical displacements are recorded for the boundary fault separating the Mainz Basin and the Rhenish Massif (Hunsrück–Taunus Boundary Fault) and for faults bounding the northeastern Mainz Basin. The motions and displacement rates calculated for individual faults indicate deformation rates in the order of 0.01–0.08 mm/year. At this stage, the calculation of displacement rates depends mostly on a single dated stratigraphic unit. Additional dating of terrace deposits is urgently needed to better constrain the temporal development of the terrace sequence and the impact of tectonic movements.     

Dating of coal fires in Xinjiang, north-west China

Coal fires in China consume vast amounts of fuel and cause serious environmental problems. Most of these coal fires are related to mining activity. However, naturally produced palaeo coal fires in Xinjiang, north‐west China, have been recognized via burnt rocks. The burnt rocks in the study area are found at different river terraces underlying unburnt alluvial and river terrace deposits. Several age groups of coal fires have been identified based on the positions of burnt rocks at river terraces and the relationship between the burnt rocks and the terrace deposits. These palaeo coal fires are: (1) Pliocene – Early Quaternary in age at 200 m above present river terrace deposits; (2) Middle Pleistocene in age, at > 90 m; (3) Late Pleistocene, at 90–70 m; (4) Holocene; (5) burnt rocks relating to active coal fires. Palaeomagnetic data of the burnt rocks from different terraces give normal remanent magnetization and help further to constrain the ages of the coal fires.     

川西高原岷江上游河流阶地初步研究

基于岷江上游干流阶地地貌的野外观察和阶地沉积物的ESR年代测定,结合前人阶地测年数据,阐述了岷江上游干流晚第四纪阶地的形成过程和河谷下切历史,探讨了阶地演化对岷山和龙门山构造带隆升的响应过程。      

Stratigraphy and magnetic polarity of the high terrace remnants in the upper Ohio and Monongahela Rivers in West Virginia, Pennsylvania, and Ohio

A synthesis of previous work and new data on the stratigraphy of high terraces of the Ohio and Monongahela Rivers upstream from Parkersburg, West Virginia, indicates a correspondence between terrace histories in the ancient Teays and Pittsburgh drainage basins. Four terraces are identified in each. Sediments of the lower three alluvial and slackwater terraces, correlated with Illinoian, early Wisconsin, and late Wisconsin glacial deposits, have been traced along the modern Ohio River through the former divide between the Teays and Pittsburgh basins. Sediments in the fourth terrace, the highest well-defined terrace in each basin, were deposited in two ice-dammed lakes, separated by a divide near New Martinsville, West Virginia. Some deposits of the highest slackwater terrace in both the Teays and Pittsburgh basins have reversed remanent magnetic polarity. This, and the stratigraphic succession in the two basins, suggests that both were ponded during the same glaciation. Reversed polarity in these terrace sediments restricts the age of the first ice-damming event for which stratigraphic evidence is well-preserved to a pre-Illinoian, early Pleistocene glaciation prior to 788,000 yr ago. In contrast, slackwater sediments in the Monongahela River valley, upstream from an outwash gravel dam at the Allegheny-Monongahela confluence, have normal remanent magnetic polarity, corroborating correlation with an Illinoian ponding event.     

The tunica hills,Louisiana-Mississippi: Late glacial locality for spruce and deciduous forest species

Reinvestigation of Quaternary sediments in West Feliciana Parish, southeastern Louisiana, and adjacent Wilkinson County, southwestern Mississippi, has resulted in revision of previous terrace stratigraphy of this portion of the Gulf Coastal Plain. Plant-macrofossil and pollen assemblages incorporated in fluviatile terrace deposits in the study area are reexamined in light of the current stratigraphic understanding. Macrofossils identified as white spruce (Picea glauca), tamarack (Larix laricina), and northern white cedar (Thuja occidentalis), recovered from these terrace deposits along with fossil remains of distinctly southern plant species, were initially interpreted as the result of dynamic intermixing of aggressive boreal species within a southern forest during the early Wisconsin (Brown, 1938). Failure to distinguish chronologically separate fossiliferous deposits resulted in the conceptual “mixing” of northern and southern plant species which came from two distinct fluviatile terrace sequences. Terrace 2 is now believed to be a fluviatile and coastwise depositional terrace of Sangamon Interglacial age; deposits of terrace 2 contain a distinctly warm-temperate plant assemblage. Fluviatile terrace 1 dates from 12,740 ± 300 to 3457 ± 366 BP and is now considered to be related to late glacial and Holocene aggradation and lateral migration of the Mississippi River (the local base level for streams in the study area); basal portions of terrace 1 contain fossils of white spruce, tamarack, and many plant species today characteristic of the cool-temperate Mixed Mesophytic Forest Association. Terrace 1 fossil deposits occur in fluviatile terraces along tributary streams of the Mississippi River at elevations 15 to 30 m above the maximum recorded historic flood stage of the Mississippi River. The plant macrofossils represent remains of species that grew at or very near the site of deposition; they were not “rafted in” by floodwaters of the Mississippi River. We present quantitative data for plant macrofossils and pollen that support our hypothesis that at least local cooling along the Blufflands of Mississippi and Louisiana promoted southward migrations of mixed mesophytic forest species and certain boreal species along this major pathway during late Wisconsin continental glaciation.     

Sequence stratigraphy in the context of rapid regional uplift and high‐amplitude glacio‐eustatic changes: the Pleistocene Cutro Terrace (Calabria,southern Italy)

The Cutro Terrace is a mixed marine to continental terrace, where deposits up to 15 m thick discontinuously crop out in an area extending for ca 360 km² near Crotone (southern Italy). The terrace represents the oldest and highest terrace of the Crotone area, and it has been ascribed to marine isotope stage 7 (ca 200 kyr bp ). Detailed facies and sequence‐stratigraphic analyses of the terrace deposits allow the recognition of a suite of depositional environments ranging from middle shelf to fluvial, and of two stacked transgressive–regressive cycles (Cutro 1 and Cutro 2) bounded by ravinement surfaces and by surfaces of sub‐aerial exposure. In particular, carbonate sedimentation, consisting of algal build‐ups and biocalcarenites, characterizes the Cutro 1 cycle in the southern sector of the terrace, and passes into shoreface and foreshore sandstones and calcarenites towards the north‐west. The Cutro 2 cycle is mostly siliciclastic and consists of shoreface, lagoon‐estuarine, fluvial channel fill, floodplain and lacustrine deposits. The Cutro 1 cycle is characterized by very thin transgressive marine strata, represented by lags and shell beds upon a ravinement surface, and thicker regressive deposits. Moreover, the cycle appears foreshortened basinwards, which suggests that the accumulation of its distal and upper part occurred during forced regressive conditions. The Cutro 2 cycle displays a marked aggradational component of transgressive to highstand paralic and continental deposits, in places strongly influenced by local physiography, whereas forced regressive sediments are absent and probably accumulated further basinwards. The maximum flooding shoreline of the second cycle is translated ca 15 km basinward with respect to that of the first cycle, and this reflects a long‐term regressive trend mostly driven by regional uplift. The stratigraphic architecture of the Cutro Terrace deposits is the result of the interplay between regional uplift and high amplitude, Late Quaternary glacio‐eustatic changes. In particular, rapid transgressions, linked to glacio‐eustatic rises that outpaced regional uplift, favoured the accumulation of thin transgressive marine strata at the base of the two cycles. In contrast, the combined effect of glacio‐eustatic falls and regional uplift led to high‐magnitude forced regressions. The superposition of the two cycles was favoured by a relatively flat topography, which allowed relatively complete preservation of stratal geometries that record large shoreline displacements during transgression and regression. The absence of a palaeo‐coastal cliff at the inner margin of the terrace supports this interpretation. The Cutro Terrace provides a case study of sequence architecture developed in uplifting settings and controlled by high‐amplitude glacio‐eustatic changes. This case study also demonstrates how the interplay of relative sea‐level change, sediment supply and physiography may determine either the superposition of cycles forming a single terrace or the formation of a staircase of terraces each recording an individual eustatic pulse.     

末次间冰期以来西宁市河谷沉积与环境

在西宁市区开展的钻探工作,获得了河谷平原区第四系的分布及沉积特征。通过对沉积厚度最大部位的2个钻孔岩芯的地层岩性、年代测试、孢粉组合及粒度分析等,探讨了西宁河谷平原区晚第四纪沉积与环境的关系。认为现今西宁市河谷平原内的主体沉积——低阶地沉积及上覆黄土堆积主要是末次间冰期旋回形成,在暖湿气候条件下沉积河流相砂砾石层,在干冷气候期接受风成黄土堆积,推测T3阶地形成于距今7.4万年前后气候由暖湿向干冷的过渡时期。     

Quaternary crustal deformation along a major branch of the San Andreas fault in central California

Deformed marine terraces and alluvial deposits record Quaternary crustal deformation along segments of a major, seismically active branch of the San Andreas fault which extends 190 km SSE roughly parallel to the California coastline from Bolinas Lagoon to the Point Sur area. Most of this complex fault zone lies offshore (mapped by others using acoustical techniques), but a 4-km segment (Seal Cove fault) near Half Moon Bay and a 26-km segment (San Gregorio fault) between San Gregorio and Point Ano Nuevo lie onshore.At Half Moon Bay, right-lateral slip and N—S horizontal compression are expressed by a broad, synclinal warp in the first (lowest: 125 ka?) and second marine terraces on the NE side of the Seal Cove fault. This structure plunges to the west at an oblique angle into the fault plane. Linear, joint0controlled stream courses draining the coastal uplands are deflected toward the topographic depression along the synclinal axis where they emerge from the hills to cross the lowest terrace. Streams crossing the downwarped part of this terrace adjacent to Half Moon Bay are depositing alluvial fans, whereas streams crossing the uplifted southern limb of the syncline southwest of the bay are deeply incised. Minimum crustal shortening across this syncline parallel to the fault is 0.7% over the past 125 ka, based on deformation of the shoreline angle of the first terrace.Between San Gregorio and Point Ano Nuevo the entire fault zone is 2.5–3.0 km wide and has three primary traces or zones of faulting consisting of numerous en-echelon and anastomozing secondary fault traces. Lateral discontinuities and variable deformation of well-preserved marine terrace sequences help define major structural blocks and document differential motions in this area and south to Santa Cruz. Vertical displacement occurs on all of the fault traces, but is small compared to horizontal displacement. Some blocks within the fault zone are intensely faulted and steeply tilted. One major block 0.8 km wide east of Point Ano Nuevo is downdropped as much as 20 m between two primary traces to form a graben presently filling with Holocene deposits. Where exposed in the sea cliff, these deposits are folded into a vertical attitude adjacent to the fault plane forming the south-west margin of the graben. Near Point Ano Nuevo sedimentary deposits and fault rubble beneath a secondary high-angle reverse fault record three and possibly six distinct offset events in the past 125 ka.The three primary fault traces offset in a right-lateral sense the shoreline angles of the two lowest terraces east of Point Ano Nuevo. The rates of displacement on the three traces are similar. The average rate of horizontal offset across the entire zone is between 0.63 and 1.30 cm/yr, based on an amino-acid age estimate of 125 ka for the first terrace, and a reasonable guess of 200–400 ka for the second terrace. Rates of this magnitude make up a significant part of the deficit between long-term relative plate motions (estimated by others to be about 6 cm/yr) and present displacement rates along other parts of the San Andreas fault system (about 3.2 cm/yr).Northwestward tilt and convergence of six marine terraces northeast of Ano Nuevo (southwest side of the fault zone) indicate continuous gentle warping associated with right-lateral displacement since early or middle Pleistocene time. Minimum local crustal shortening of this block parallel to the fault is 0.2% based on tilt of the highest terrace. Five major, evenly spaced terraces southeast of Ano Nuevo on the southwest flank of Mt. Ben Lomond (northeast side of the fault zone) rise to an elevation of 240 m, indicating relatively constant uplift (about 0.19 m/ka and southwestward tilt since Early or Middle Pleistocene time (Bradley and Griggs, 1976).     

祁连山及邻区第四纪地层区划与沉积序列

在前人资料和野外勘查的基础上对祁连山及邻区贵德盆地、循化—化隆盆地、同仁盆地、西宁盆地、门源盆地、临夏盆地、兰州盆地、定西盆地、天水盆地、肃北盆地、酒泉盆地、玉门盆地、张掖盆地、武威盆地、哈拉湖盆地、苏里盆地、木里盆地、民和盆地、共和盆地、青海湖盆地及柴达木等20余个盆地的第四纪地层进行了研究。以祁连山第四纪构造地貌演化、盆地沉积序列、古生物及古气候特征为地层分区依据,对祁连山及邻区第四纪地层进行了地层分区,并对部分地层名称做了厘定或统一。祁连山及邻区第四纪沉积特征总体为东部(主要为陇中地区)黄土分布广泛,堆积了世界上最厚的黄土地层;北部(河西走廊地区)冲洪积扇堆积及风沙发育;南部(柴北盆地)以冲洪积-湖积为主,晚更新世以来发育风成沙及黄土;共和盆地由湖泊转向冲积扇和风沙沉积;青海湖盆延续至今;中西部高山及山间盆地冰碛、冰水堆积以及河流阶地堆积发育。根据上述特征及划分原则,将祁连山及邻区第四纪地层区划分为:兰州—西宁地层区,贵德地层区,酒泉—张掖地层区,柴北地层区,共和地层区,青海湖地层区及肃北—门源地层区。     

我国南部西沙群岛地区第四纪地质初步探讨

美丽富饶的西沙群岛,像一颗颗闪闪发光的宝石,镶嵌在烟波浩淼的祖国南海西北部。主要由30多个沙岛、沙洲和礁滩所组成。按其地理分布特点,又将这些岛屿分成永乐群岛、宣德群岛和其他诸岛(图1)。西沙群岛和南海诸岛自古以来就是我国神圣领土,勤劳勇敢的中国人民世世代代就在这里从事生产劳动。     

The Mazafran river (western Sahel of Algiers): superimposition or antecedence?

At the western Sahel of Algiers, the watercourse of the Mazafran river is perpendicular to the Sahel fold, forming a gorge that has developed in a tectono-eustatic context characteristic of the Sahel region. This gorge has formed in a regime of superimposition which involves the evolution of antecedence in relation to the Sahel uplift. This deduction is the result of multiple analyses that are based on a stratigraphic study which characterizes the succession of continental and marine deposits and the analyses of lineament map of tectonic evolution during the Quaternary which is marked by the Sahel folding. In order to correlate the chronology between the fluvial and marine sedimentary dynamics, a geomorphological study of the Mazafran alluvial terraces associated with the paleoshorelines was realized. The obtained results reveal that the development of the Mazafran river gorge is complex.     

Late Quaternary fluvial terraces of the Romagna and Marche Apennines,Italy: Climatic,lithologic, and tectonic controls on terrace genesis in an active orogen

We synthesize a new fluvial terrace chronostratigraphy of the Bidente and Musone Rivers cast within a broader European framework, which forms the basis of a terrace genesis and river incision model for the northern Apennines, Italy. Our model, supported by terrace long profiles, correlation to Po foreland sediments, 15 new radiocarbon dates, and published numeric and relative stratigraphic ages, highlights how drainage basin substrate drives concurrent formation of strath terraces in the Bidente basin and fill terraces in the Musone basin. Quaternary climate change paces the formative geomorphic processes through unsteady discharges of water and sediment. In the weathering-limited setting represented by the Bidente basin, siliciclastic detritus carves broad strath surfaces during glacial climates that are preserved as terraces as the river incises during the transition to an interglacial climate. In contrast, the transport-limited and carbonate detritus dominated Musone basin sees valleys deeply buried by aggradation during glacial climates followed by river incision during the transition to an interglacial climate. Incision of these rivers over the past ～1 million years has been both unsteady and non-uniform. These and all Po-Adriatic draining rivers are proximal to a base level defined by mean sea level and have little room for increasing their longitudinal profile concavities through incision, particularly in their lower reaches despite periodic glacio-eustatic drawdowns. As a result, the observed incision is best explained by rock uplift associated with active local fault or fold growth embedded in the actively thickening and uplifting Apennine foreland.     

Ipswichian (Eemian) floodplain deposits and terrace stratigraphy in the lower Great Ouse and Cam valleys,southern England,UK

Gao, C. & Boreham, S. 2010: Ipswichian (Eemian) floodplain deposits and terrace stratigraphy in the lower Great Ouse and Cam valleys, southern England, UK. Boreas, 10.1111/j.1502‐3885.2010.00191.x. ISSN 0300‐9483. Thick argillaceous deposits named the Mannings Farm Beds recently uncovered in the third terrace at Mannings Farm near Willingham, Cambridgeshire contain a pollen sequence covering the transitions from Ipswichian/Eemian substages I to II and II to III, when oak and hornbeam expanded, respectively. This is the longest record hitherto obtained in Britain, providing important insight into the major forest successions in this temperate stage. The frequent occurrence of Ipswichian deposits in the third terrace suggests the development of an extensive floodplain on the valley bottom, similar to the case for the present‐day lower Great Ouse and Cam. The Mannings Farm Beds testify to a complete interglacial sequence emplaced between cold‐climate gravels that was directly associated with the terrace development. The third terrace developed during the Ipswichian and the preceding and succeeding cold stages. Major river downcutting, which shaped the third terrace, occurred during the Early Devensian/Weichselian. Previously reported interglacial fossils from this terrace that are inconsistent with an Ipswichian affinity are probably reworked material derived from pre‐Ipswichian interglacial deposits, or their significance as biostratigraphical indicators needs to be confirmed. The second and first terraces developed from the late Early Devensian onwards. Ipswichian deposits filling flood‐scoured deep channels in bedrock are preserved locally below these low terraces.     

Quantification of Quaternary vertical movements in the central Pannonian Basin: A review of chronologic data along the Danube River, Hungary

This study aims at a new quantification of neotectonic deformation of the central part of the Pannonian Basin. We use terrace levels and associated travertine as well as speleothem data along the Danube River to quantify its incision rate and thus, estimate the amount and rate of uplift at the axis of the Hungarian Mountain Range (HMR).

Several terrace levels and other geomorphic features along the Danube river are indicative for Quaternary uplift of the axial part of the emerging Hungarian Mountain Range. While the correlative terraces are at considerable height at the axis of the HMR, the terraces are gradually dipping below the basin fill of the adjacent lowlands. The correlation of the terrace segments is difficult because of their poor preservation, small size and variable height. The geomorphologic horizons indicate gradual incision of the river throughout the Quaternary during simultaneous deformation. However, no reliable chronological data have been available so far to quantify landscape-forming processes such as uplift, incision or erosion rates.

A reconsideration of existing published data for three consecutive segments of the Danube valley yields incision rates between 0.14 and 0.41 mm/year for the last 360 ky, with the highest value for the area of the Danube Bend. Accordingly, the middle to late Quaternary uplift rate of the axial zone of the HMR exceeded significantly that of the marginal areas. These rates represent an approximation as some quantitative data are still controversial. Our results suggest that formation of the Danube terraces is result of river incision triggered by the uplift of the HMR and modified by periodic climate changes.     

Quaternary sea-level events on northern San Clemente Island, California

Global sea-level changes are expressed in the coastal landforms and deposits of northern San Clemente Island. Stratigraphic, radiometric, amino acid, and pedologic dating techniques have allowed the development of a chronology of sea-level changes for about the last 500,000 yr. A uranium-series date on coral of about 127,000 yr for the 2nd terrace serves as a calibration point for amino acid age estimates of four other mapped terraces. Two of these terraces have age estimates of about 80,000–105,000 yr, another has an age estimate of about 127,000 yr, and the 5th terrace on the west side of the island is estimated to be about 415,000–575,000 yr old. These dates correlate reasonably well with marine terraces dated elsewhere and with stages of the oxygen-isotope record that are thought to represent high stands of the sea. Weakly cemented calcareous dune sands (eolianites) are moderately extensive on northern San Clemente Island and appear to represent low stands of the sea, since calcareous shelf sands were the most likely source. A radiocarbon date of about 22,000 yr suggests that the youngest eolianite was deposited during the last glacial maximum. An older eolianite is estimated to be about 140,000–195,000 yr old based on stratigraphic relations and degree of soil development. The suggested ages for the eolianites also correlate well with oxygen-isotope estimates of low sea levels.     

Quaternary marine terraces on Sal Island (Cape Verde archipelago)

The Quaternary sedimentary record of Sal Island includes marine and related aeolian and alluvial fan deposits. The substratum of the island is volcanic, with ages between 25 and 0.6 Ma. Quaternary marine units generally occur as raised marine terraces forming a broad staircase between elevations of 55–60 m and present sea level. Terraces include a basal conglomerate overlaid by calcarenite; both host corals, algae and molluscs.A chronostratigraphic framework for the Middle Pleistocene to Holocene units has been generated based on a geomorphologic map of the Quaternary landforms and associated deposits and morphosedimentary analysis, with support of laboratory dating: U-series by TIMS in corals, ¹⁴C analyses, palaeomagnetic measurements, and K/Ar ages from other literature. U-series dating of corals from marine terraces provides benchmarks for the Last Interglacial (Oxygen Isotope Substage 5e) and Holocene deposits. The present elevation of the marine terraces and their staircase arrangement suggest a change in vertical movement trend around 330 ka from an uplift to either subsidence or stabilization.     

Lower-middle Eocene formations of the Crimea: Facial peculiarities and forming conditions

This work considers the structure and conditions of the formation of deposits of the Simferopolskoe regional stage of the Crimea. The deposits of this stage include planktonic foraminifera zones Morozovella aragonensis and Acarinina bullbrooki and nanoplaktonic zones Marthasterites tribrachiatus (the upper part), Discoaster lodoensis, Discoaster sublodoensis (lower part). The deposits of this interval throughout most of the Crimea represent a nummulitic bank, which formed in shallow warm-water basin and was isolated carbonate platform. The distribution of rocks of this regional stage, the facial change, and a number of interruptions are shown in the chronostratigraphic profile. The facial transitions within the carbonate platform point to variations in the basin’s depth, as well as periodical changes in the relative sea level, which were not only of a eustatic nature, but were determined by the periodic rise of the Simferopol Uplift.     

Depositional and soil history along the Lower Macleay River,New South Wales

Extensive terrace and flood plain deposits occur along the Lower Macleay River. A sequence of terraces from oldest to youngest was named: Madron, Corangula, Mungay, Mooneba, Belgrave and Macleay deposits (contemporary). Basal sediments in the Mooneba terrace were dated by radiocarbon analysis at 3,280 ± 55 years; basal sediments of the Mungay terrace were dated at 6,425 ± 105 years. The Madron and Corangula terraces are considered very much older than the Mungay. The flood plain consists of two early cycles of aggradation buried under 23m of estuarine sediment, which in turn is overlain by up to 6m of alluvium. The estuarine sediments were dated at 8,530 ± 200 years at elevation —4m relative to mean sea level. The base of the overlying Smithtown alluvium was dated at 3,295 ± 95 years. A general chronology is presented for the Lower Macleay valley, and a sequence of terrace soils is discussed.     

New Data About Cosmic Spherules and Microdiamonds from Middle Pleistocene Selenge River Basin in North Mongolia

This paper deals with new discovery of cosmic spherules and microdiamonds from Middle Pleistocene Selenge river basin on the Teel aggradation terrace. The Teel aggradation terrace is located at the left edge of the Selenge River, at the pedestal of mountain Namnan uul (Dorjnamjaa et al., 2008). The Teel ter-race is those whose cusp and bench entirely composed of alluvial deposits. This indicates that the Selenge River has a long history of development, and had time to develop a flood plain and to deposit alluvium, through which it cut subsequently and left behind a Teel terrace. Alluvium studies may be of great practi-cal interest because in some areas, river terraces are veritable treasure-troves of economic minerals. With river terraces are associated most placer deposits of such important economic minerals as gold, platinum, diamond, etc. Numerous engineering projects, such as bridges(Kherlen, Tuul, Selenge, Orkhon, Baidrag, Zavkhan, etc.), dams (Ulaan Boom), hydropower plants(Durgun Nuur, Ulaan Boom) are built on alluvial deposits. Hence we need to know all the essential fea-tures of the geostructure of river terraces. Our investi-gation of the Selenge river terraces in 2006-2008 gave a possibility to discover the placer diamonds within the Teel aggradation terrace for the first time in Mongolia.