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1.
A. V. Panin 《Doklady Earth Sciences》2011,438(1):563-568
Three strong earthquakes that occurred since the end of 8th century have been identified by archeoseismic data in the southwestern
part of the Tere Khol’ Depression. The dates for these events are the 9th, 12th, and first two-thirds of 19th century, and
the average recurrence interval is 500 years. The relative seismic passivity of the Tere Khol’ Depression at present may be
related to the relatively recent discharge of stress in seismogenerating sources. 相似文献
2.
蛇绿岩普遍被发现在碰撞型和增生型两种造山带缝合线上,因此经常被用来确定板块边界。自从欧洲地质学家在19世纪早期提出蛇绿岩的概念以来,蛇绿岩的研究经历了几个发展阶段。早期研究认为蛇绿岩是侵入地槽的一套侵入岩;板块构造理论兴起后,蛇绿岩被认为是产生于大洋中脊的洋壳;在1972年的Penrose会议上,科学家们将蛇绿岩定义为一套从基性岩到超基性岩的,可以区分的复式岩体。此后,蛇绿岩的起源(构造背景),侵位机制,特征等研究都取得了很多进展。进入21世纪,出现了一些较好的蛇绿岩形成模式和划分方法。 相似文献
3.
Pollen analysis and rates of pollen incorporation into a radiocarbon-dated palaeopodzolic soil at Haugabreen, southern Norway 总被引:1,自引:0,他引:1
CHRISTOPHER J. CASELDINE 《Boreas: An International Journal of Quaternary Research》1983,12(4):233-246
Pollen analysis of the organic surface (FH) horizon of a radiocarbon-dated palaeopodzol buried beneath the 'Little Ice Age' outer moraine of Haugabreen west of the Jostedalsbrecn ice-cap, southern Norway, provided evidence for environmental change in the area between ca. 4,000 B. P. and the 13th century A. D. Radiocarbon dating of the profile, apart from providing a chronology for the changes interpreted, also allowed estimation of pollen incorporation rates into the soil which can be compared with pollen influx rates established elsewhere. Two periods of local woodland recession were identified, the first between ca. 3,300 B. P. and ca. 3,600 B. P., after the initiation of the FH horizon, and the second in the 13th century A. D. at the onset of the Little Ice Age. 相似文献
4.
Yu. A. Lavrushin E. A. Spiridonova A. V. Engovatova 《Stratigraphy and Geological Correlation》2016,24(6):637-650
The succession of short-term natural events at the thermal humid maximum in the Middle Ages (10th–12th centuries) within the forest zones of European Russia was established. The archaeological excavation in the most ancient part of the town of Yaroslavl opened a thick cultural horizon, where fragments of lacustrine deposits dating back to the 11th–12th centuries were preserved. The most ancient fragments of the construction, found in lacustrine deposits, date back to the first third of the 13th century. An analysis of the structural and textural peculiarities of these deposits made it possible to reconstruct types of hydrogeological regime in the Timerevo paleolake and a paleostrait between this paleolake and Lake Nero. Thus, the waterway between the central part of the Principality of Rostov and early Yaroslavl (the first Russian settlement at the Great Volga Waterway) was revealed. The probable reasons for a rapid warming event followed by a cooling one in the Middle Ages are discussed. 相似文献
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7.
The Oligo‐Miocene Torquay Group at Bird Rock in south‐eastern Australia comprises a sequence of fine‐grained skeletal carbonates and argillaceous and glauconitic sandstones, deposited in a cool‐water, mid‐shelf environment. The Bird Rock glaucony is autochthonous and consists predominantly of randomly interstratified glauconitic smectite, which constitutes bioclast infills and faecal pellet replacements. The results of Rb–Sr and oxygen isotopic analysis of samples taken from a single glauconitic horizon (the BW horizon) indicate that the glaucony developed through a series of simultaneous dissolution–crystallization reactions, which occurred during very early diagenesis in a closed or isochemical system, isolated from the ambient marine environment. The constituent ions of the glaucony were derived primarily from terrigenous clay minerals, but considerable potassium may have been sourced indirectly from sea water, through potassium enrichment of clay precursors. The pore fluids associated with glauconitization were marine derived, but progressively modified by the dissolution–crystallization of detrital clay minerals and autochthonous glaucony. Rb–Sr data for the BW horizon indicate that dating glauconies may be somewhat problematic, as co‐genetic glauconitic minerals can show a range of initial strontium compositions, which reflect the incorporation of strontium derived from mineralogical precursors and/or contemporaneous sea water. Rb–Sr isochrons indicate that the glaucony of the BW horizon formed at 23 ± 3 Ma. This age is in good agreement with both the established biostratigraphy and a 87Sr/86Sr age for the horizon (23 ± 1 Ma), but could only be determined using the independent age constraint and the estimate of the 87Sr/86Sr ratio of contemporaneous sea water provided by analysis of associated biogenic carbonate. 相似文献
8.
Markus Fiebig Frank Preusser Damian Steffen Edit Tham‐Bozs Michael Grabner Georg J. Lair Martin H. Gerzabek 《Geoarchaeology》2009,24(2):224-241
The validity of optically stimulated luminescence (OSL) has been tested on known‐age (historical) fluvial deposits along the rivers Danube (Austria) and Ebro (Spain). As partial bleaching of the OSL signal prior to deposition can interfere with correct age estimates, different approaches to extracting the dose accumulated during burial are compared. Using the finite mixture model gave OSL ages that are internally as well as stratigraphically consistent and in agreement with independent age control. According to these results, fluvial deposition at the Danube River study site can be attributed to different periods ranging from Bronze Age to the 18th century A.D. Fluvial deposits of Roman age and of the late 17th or early 18th century A.D. were found at the Ebro River study site. This is consistent with the morphological subdivision of the valleys and encourages further investigation of the fluvial and archaeological history of the study areas using OSL. © 2009 Wiley Periodicals, Inc. 相似文献
9.
A. A. Stepashko 《Russian Journal of Pacific Geology》2011,5(1):1-12
The role of the lateral structure of the lithospheric mantle in the seismotectonics and seismicity of the southern part of
the Russian Far East has been investigated. The positions of the epicenters of all the major earthquakes in Sakhalin (M ≥
6.0), as well as in the Amur region and the Primorye zones (M ≥ 5.0), are defined by the boundaries of the Anyui block of
highly ferruginous mantle, which lies at the base of the Sikhote-Alin area. Three cycles of large earthquakes are recognized
in the region: the end of the 19th-beginning of the 20th century, the mid-20th century, and end of the 20th-beginning of the
21st century. In the seismic zone of the Amur region (hereafter, the Amur seismic zone), the epicenters of the large earthquakes
in each cycle migrate from the SW to NE along the Tan-Lu fault megasystem at a rate of 30–60 km/yr. The specific features
of the seismicity of the region are explained by the repeated arrival of strain waves from the west. The waves propagate in
the upper part of the mantle and provoke the activation of the deep structure of the region. The detailed analysis of the
earthquakes in the Sikhote-Alin area (M ≥ 4.0) in 1973–2009 confirmed the clockwise tectonic rotation of the mantle block.
The characteristics of the Primorye zone of deep-focus seismicity at the Russia-China boundary are stated. Since 1973, 13
earthquakes with M ≥ 6.0 have been recorded in the zone at a depth of 300–500 km. This number of earthquakes is at least twice
as many as the number of large deep-focus earthquakes elsewhere in the Sea of Japan-Sea of Okhotsk transition zone. The unique
genesis of the Primorye seismic zone is related to the additional compression in the seismofocal area due to the creeping
of the Anyui mantle block onto the subduction zone during its rotation. The geodynamic implications of the seismotectonic
analysis are examined, and the necessity of division of the Amur plate into three geodynamically independent lithospheric
blocks is substantiated. 相似文献
10.
Hance D. Smith 《GeoJournal》1992,26(4):483-487
The basic patterns of economic and political development of the British Isles region in a European context is outlined for
the half century following Columbus’ discovery of America, noting the separate identities of England, Wales, Scotland and
Ireland. The maritime dimension of these developments was based on trade with Europe, developed mainly in England and Scotland;
and upon considerable development of the fisheries. Exploration and colonial expansion did not begin until after 1550 and
continued into the seventeenth century. The historical role of the British Isles in Europe is considered as a sequence of
approximately half-century phases extending from 1500 until the present, in which British maritime supremacy played a role
in the nineteenth century similar to that played by the Spanish Empire in the sixteenth century. 相似文献
11.
Sudip Jyoti Sahu Bibhash Nath Sharmi Roy Biswapati Mandal Debashis Chatterjee 《Environmental Earth Sciences》2012,65(3):813-821
Groundwater contaminated with arsenic (As), when extensively used for irrigation, causes potentially long-term detrimental
effects to surface soils. Such contamination can also directly affect human health when irrigated crops, such as rice, vegetable
and fruits, are used for human consumption. Therefore, an understanding of the leaching behavior of As in surface soils is
of high importance, because such behavior may increase the bioavailability of As in the soil horizon. In this study, we have
investigated the role of phosphate ions in leaching and bioavailability of As in the soil horizon, where drinking groundwater
contains elevated levels of As (≥50 μg/L). Soil and groundwater samples were characterized in the laboratory and measured
for physical and chemical constituents. The soils are generally neutral to slightly alkaline in character (pH range 7.5–8.1)
with low to moderate levels of free Fe2O3, Al2O3, CaCO3, organic carbon, and clay content. The measured electrical conductivity (mean 599 μS/cm) of the soils demonstrates their
non-saline nature. The Eh values (range −37 to −151 mV) of the groundwater indicate anoxic condition with low to moderate
levels of bicarbonate (range 100–630 mg/L) and phosphate (range 0.002–4.0 mg/L). The arsenic content (range 50–690 μg/L; mean
321 μg/L) in groundwater has exceeded both WHO recommended guideline values (10 μg/L) and the National safe drinking water
limit (50 μg/L). Regression analyses demonstrate that the bioavailability of As in the soil horizon is mainly controlled by
the composition of free Fe2O3 and CaCO3 content of the soils. However, application of P could increase bioavailability of As in the soil horizon and become available
to plants for uptake. 相似文献
12.
Eruptions in the subglacial Katla caldera, South Iceland, release catastrophic jokulhlaups (meltwater floods). The ice surface
topography divides the caldera into three drainage sectors (Ko, So and En sectors) that drain onto Myrdalssandur, Solheimasandur
and Markarfljot plains, respectively. In historical times, floods from the Ko sector have been dominant, with only two recorded
So events. Geological records indicate that floods from the En sector occur every 500–800 years. A probabilistic model for
an eruption is formulated in general terms by a stochastic parameter that simulates a series giving the time interval in years
between two consecutive events. The model also contains a Markovian matrix that controls the location of the event and thereby
what watercourse is hit by the flood. A record of Katla eruptions since the 8th and the 9th century a.d., and geological information of volcanogenic floods towards the west over the last 8,000 years is used to calibrate the model.
The model is then used to find the probabilities for floods from the three sectors: Ko, So and En. The simulations predict
that the most probable eruption interval for the En sector and the So sector is several times smaller than the average time
interval, implying infrequent periods of high activity in these sectors. A correlation is found between the magnitude of eruptions
and the following time intervals. Using the statistical approach and considering this magnitude–time interval correlation,
the probability of an eruption in Katla volcano is considered to be 20% within the next 10 years. This compares to a probability
of 93% if only a simple average is considered. These probabilities do not take account of long-term eruption precursors and
should therefore be regarded as minimum values. 相似文献
13.
Ecological and paleoecological studies from the Patuxent River mouth reveal dynamic variations in benthic ostracode assemblages
over the past 600 years due to climatic and anthropogenic factors. Prior to the late 20th century, centennial-scale changes
in species dominance were influenced by climatic and hydrological factors that primarily affected salinity and at times led
to oxygen depletion. Decadal-scale droughts also occurred resulting in higher salinities and migration of ostracode species
from the deep chanel (Loxoconcha sp.,Cytheromorpha newportensis) into shallower water along the flanks of the bay. During the 19th century the abundance ofLeptocythere nikraveshae andPerissocytheridea brachyforma suggest increased turbidity and decreased salinity. Unprecedented changes in benthic ostracodes at the Patuxent mouth and
in the deep channel of the bay occurred after the 1960s whenCythermorpha curta became the dominant species, reflecting seasonal anoxia. The change in benthic assemblages coicided with the appearance of
deformities in foraminifers. A combination of increased nitrate loading due to greater fertilize use and increased fresh-water
flow explains this shift. A review of the geochemical and paleoecological evidence for dissolved oxygen indicates that seasonal
oxygen depletion in the main channel of Chesapeake Bay varies over centennial and decadal timescales. Prior to 1700 AD, a
relatively wet climate and high freshwater runoff led to oxygen depletion but rarely anoxia. Between 1700 and 1700, progressive
eutrophication occurred related to land clearance and increased sedimentation, but this was superimposed on the oscillatory
pattern of oxygen depleton most likely driven by climatological and hydrological factors. It also seems probable that the
four-to five-fold increase in sedimentation due to agricultural and timber activity could have contributed to an increased
natural nutrient load, likely fueling the early periods (1700–1900) of hypoxia prior to widespread fertilizer use. Twentieth-century
anoxia worsened in the late 1930s–1940s and again around 1970, reaching unprecedented levels in the past few decades. Decadal
and interannual variability in oxygen depletion even in the 20th century is still strongly influenced by climatic processes
influencing precipitation and freshwater runoff. 相似文献
14.
K. Urushibara-Yoshino 《Environmental Geology》1996,28(3):154-160
The properties of soils on previously dated sand dunes from Robe to Naracoorte in South Australia were examined. In these
areas younger sand dunes are composed of fresh sand, but older sand dunes are composed of calcarenited sand. The soils on
the sand dunes developed successionally by the age of sand dunes. The soil properties of these sand dunes differ depending
on the ages of the sand dunes. The properties of sand particles in soils are as follows:
(1) On the sand dunes of 4300 years B.P., A/C profile developed (Rendzina). On the sand dunes older than 125 000 years B.P.
and on the plateau of Tertiary limestone, soil profiles of A1/AB/B/C on the sand dunes of 83 000 years B.P. and A1/A3/B1/B2/C (Terra rossa) are well developed.
(2) Within the sand of A/C horizons of the sand dunes with the age of 4300 year B.P., the calcite grain content is about 64%,
and the quartz content is about 35%. Within the B horizons of soils on the dunes from 83 000 years B.P. to 347 000 years B.P.,
the calcite grain content is only 1–2%; however, the quartz grain content is about 92%. In the B2 horizons of soils on the dune of 690 000 years B.P. and on the Tertiary plateau, there are some calcite grains but the quartz
grain content is about 96%.
(3) The average size of quartz grains in the soils on the sand dunes from 4300 B.P. to 347 000 years B.P. is generally smaller,
but the average size of quartz on the sand dunes of 690 000 year B.P. becomes larger and the grains are well rounded. On the
Tertiary limestone plateau, the average quartz size becomes again smaller, and the grains are more rounded.
(4) Fet in B2 horizon of the soil profiles increases clearly corresponding to the age. Iron activity expressed by Feo/Fed also shows a close relation to the chronological sequence. The B horizon of the soil profiles shows a drastic decrease of
Feo/Fed according to the age. Iron crystalinity, (Fed-Feo)/Fet, has a tendency for a positive relation with increasing age.
Received: 1 June 1995 · Accepted: 4 December 1995 相似文献
15.
J. G. Zötl 《Environmental Geology》1997,29(3-4):176-187
Some years ago the thermal water wells of the spa Deutsch-Altenburg were considered the result of a local water circulation.
Extensive measurements of the water chemistry, trace elements, and environmental isotopes combined with drillings in the river
bed of the Danube resulted in the indication of a key position of the mineral thermal wells of Deutsch-Altenburg for the groundwater
circulation in the entire Vienna basin. The proof of this fact demanded the inclusion of the complicated geological position
of the basin into the argumentation.
The historical background of Bad Deutsch-Altenburg is the Roman municipium Carnuntum. During the reign of the Roman emperor
Marc Aurel (161-180 A.C.) Carnuntum became the largest Roman municipium northeast of Rome with about 50 000 inhabitants covering
the areas of present-day villages Petronell and Deutsch-Altenburg due to its strategic and trade position. The town was totally
destroyed during the era of "migration of nations." The land surface was farmland or meadows. The first document concerning
the thermal water of Deutsch-Altenburg is an expertise of the medical faculty of the University of Vienna (1548). During the
siege of Vienna by the Turkish army under Kara Mustafa (1683–84) Deutsch-Altenburg was again, destroyed. It was only at the
end of the 19th century that the modern installation of the spa began. The healing thermal water with the highest content
of sulfur in Austria made Deutsch-Altenburg one of the most well-known spas in the country. The archaeological excavation
of Carnuntum is the largest in Austria.
Received: 6 October 1995 · Accepted: 13 November 1995 相似文献
16.
Kashperyuk P. I. Pupyrev E. I. Lavrusevich A. A. Krasheninnikov V. S. 《Doklady Earth Sciences》2023,507(1):S137-S143
Doklady Earth Sciences - A sewage sludge storage facility was built in late 20th and early 21st century to free up land for the construction of a new residential complex Mar’inskii Park. This... 相似文献
17.
Adam Tomaových Ivo Gallmetzer Alexandra Haselmair Darrell S. Kaufman Borut Mavri
Martin Zuschin 《Sedimentology》2019,66(3):781-807
Carbonate sediments in non‐vegetated habitats on the north‐east Adriatic shelf are dominated by shells of molluscs. However, the rate of carbonate molluscan production prior to the 20th century eutrophication and overfishing on this and other shelves remains unknown because: (i) monitoring of ecosystems prior to the 20th century was scarce; and (ii) ecosystem history inferred from cores is masked by condensation and mixing. Here, based on geochronological dating of four bivalve species, carbonate production during the Holocene is assessed in the Gulf of Trieste, where algal and seagrass habitats underwent a major decline during the 20th century. Assemblages of sand‐dwelling Gouldia minima and opportunistic Corbula gibba are time‐averaged to >1000 years and Corbula gibba shells are older by >2000 years than shells of co‐occurring Gouldia minima. This age difference is driven by temporally disjunct production of two species coupled with decimetre‐scale mixing. Stratigraphic unmixing shows that Corbula gibba declined in abundance during the highstand phase and increased again during the 20th century. In contrast, one of the major contributors to carbonate sands – Gouldia minima – increased in abundance during the highstand phase, but declined to almost zero abundance over the past two centuries. Gouldia minima and herbivorous gastropods associated with macroalgae or seagrasses are abundant in the top‐core increments but are rarely alive. Although Gouldia minima is not limited to vegetated habitats, it is abundant in such habitats elsewhere in the Mediterranean Sea. This live–dead mismatch reflects the difference between highstand baseline communities (with soft‐bottom vegetated zones and hard‐bottom Arca beds) and present‐day oligophotic communities with organic‐loving species. Therefore, the decline in light penetration and the loss of vegetated habitats with high molluscan production traces back to the 19th century. More than 50% of the shells on the sea floor in the Gulf of Trieste reflect inactive production that was sourced by heterozoan carbonate factory in algal or seagrass habitats. 相似文献
18.
Earthquake catalogues for Romania supply for 11th–15th century earthquakes located in the region of Vrancea records that consist
of a complete set of parameters, including magnitude and depth. Scope of this paper is to verify the reliability and consistency
of these parameters with the informative background as explicitly referenced by the catalogues. After retrieving the original
sources they mention, the set of data appeared to be related almost exclusively to the Russian plain and too poor to be at
the very origin of the parameter assessment. Data for 19th–20th century earthquakes, such as instrumental locations and CMT
solutions, added to the understanding of the macroseismic response of the Russian plain to Vrancea earthquakes. On the one
hand, the investigation and analysis of historical earthquake records for the fourteen events listed by the catalogues in
the 11th–15th centuries has shown that for three earthquakes (1022, 1038, 1258) no primary sources could be traced, and three
more earthquakes (1091, 1170 and 1328) are attested only by scarcely reliable records and had to be classified as doubtful,
and one (1473) is simply a duplication of the 1471 event. On the other hand, the availability of data on recent earthquakes
that may be compared to historical ones in terms of macroseismic effects allowed the authors to agree with the previous catalogue
compilers’ solution with regard to both magnitude and depth of the past earthquakes for which do exist reliable primary historical
records. 相似文献
19.
In this research work, changes in concentration of the chosen chemical element in alluvial sediments have been used to estimate the relative age of floodplain deposits. The research concerning changes of chromium concentration in alluvial deposits was done in the Obra river valley near Międzyrzecz (Western Poland). Chromium was chosen because of its low ability to migrate in groundwater environment. Moreover, this chemical element was used in the process of dyeing textures in Międzyrzecz between the sixteenth and the nineteenth century. Confrontation of changes in chromium concentration and age of alluvial sediments (age estimated in years BP using radiocarbon method) have shown that the sediments with higher chromium contents are much older than the period of development of the weaving industry in Międzyrzecz. Therefore, it is not possible to use changes in chromium concentration to estimate relative age of floodplain sediments. Despite information in the literature about low migration ability of this chemical component (Macioszczyk and Dobrzyński in Hydrogeochemia: strefy aktywnej wymiany wód podziemnych. PWN, Warszawa, 2002; Ball and Izbicki in Appl Geochem 19:1123–1135, 2004) migration of chromium is so intensive that distinct changes in its concentration are observed even before the period of increased human activity.
相似文献
M. SłowikEmail: |
20.
《Quaternary International》1999,53(1):57-67
Data obtained in the early 20th century on the total phosphorus (TP) content in soil materials from the Pampean region have been processed and plotted on maps of the region. Approximately 1200 subsoil data and 1400 surface horizon data obtained using the same analytical method, have been processed. According to differences in phosphorus content, several areas have been demarcated. Limits and characteristics of these areas have been correlated with data from the more recent literature regarding the P distribution and with both mineralogical and sedimentological information on surface materials. Results suggest that a confluence of sediments from different provenances (i.e. the Andean Range, the Pampean Hills, and the Brazilian Shield) is found in the Argentine Pampean region. 相似文献