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1.
Lechaion, the western harbor of ancient Corinth, was an artificial harbor excavated in a marshy area and connected to the open sea through a channel with revetment walls. It was probably the most important harbor of this type in antiquity, and one of the most important harbors in Greece for more than one millennium. Yet, the date of construction of this harbor is a matter of debate; 600 B.C., ca. 44 B.C., and A.D. 350 are the most probable dates. Geomorphological and biological investigations, in combination with AMS radiocarbon dating of exposed marine shells found in the walls of the channel leading to the inner basin of the harbor indicate that the channel was open to the sea before a seismic land uplift that probably occurred sometime in the fifth to third century B.C. These data indicate that the construction of the harbor began in ca. 600 B.C., the period of Corinthian expansion to the Ionian Sea and southern Italy. © 1996 John Wiley & Sons, Inc.  相似文献   

2.
Although the ancient site of Utica has been studied since the 19th century, the location of its harbors remains unresolved as they were buried under sediments as the Mejerda delta prograded and left Utica 10 km inland. Using relief data and a coring survey with sedimentological analysis, we identify the dynamics of the delta's progradation, which produced a double system of alluvial fans. These show that the ancient bay of Utica silted up faster and earlier than was thought, probably before the end of the Punic period. Combined with the radiocarbon dates from coring, this suggests that the harbor lay on the north‐western side of the Utica promontory, communicating with the sea by a marine corridor west of the northern compartment of the delta. As the infilling of the ancient bay progressed, this corridor narrowed until it disappeared completely in the early 5th/mid‐6th century A.D., when a peat bog developed on the northern side of the promontory, sealing the fate of Utica as a port. This relative environmental stability ended in the 9th–10th century A.D. when about 4 m of sediment, probably of fluvial origin, covered the peat bog, leaving the site more than 4.5 m above the local sea level.  相似文献   

3.
The Roman Villa on the Marina di Equa (Vico Equense, Sorrento Peninsula, Italy), built in the first century A.D., is an important coastal site where the geological effects of the A.D. 79 eruption of Vesuvius are combined with archaeological remains, thus representing an interaction of both human and natural events. At this site, a patrician Roman villa, located at the outlet of a steep V‐shaped valley on the northern flank of a ridge in the Lattari Mountains, was completely destroyed by the A.D. 79 eruption and by subsequent mud/debris flows and floods. During these catastrophic events, the villa was rebuilt twice, in the second and third centuries A.D., as shown by archaeological evidence on the beach. A marine geophysical survey was conducted to study the unexplored portion of this archaeological site. A geographical information system (GIS) analysis of integrated geophysical survey data has identified and mapped (in two and three dimensions) the major underwater archaeological structures on and below the seabed in the villa harbor. A map of the ancient port of the Roman villa has been created by correlating the submerged remains with the construction phases of the villa.  相似文献   

4.
Historical and archaeological data are used to test geological claims that, in the fourth to sixth centuries AD, the Eastern Mediterranean experienced an unusual clustering of destructive earthquakes (the ‘Early Byzantine Tectonic Paroxsym’). A review of historical accounts of a notable earthquake at this time, that of 21 July AD 365, indicates that this event destroyed nearly all the towns in Crete and was followed by a tsunami which devastated the Nile Delta. The AD 365 event was also probably responsible for reported or observed destruction in ancient towns of west Cyprus and Libya. This earthquake is most likely to be identified with a Hellenic Arc subduction-zone event of ‘great’ (M>8) magnitude, as testified by up to 9 m of uplift in western Crete dated by previous geological studies to around this time. Historical and archaeological data also support the hypothesis that the fourth to sixth centuries AD was a period of abnormally high seismicity in the Eastern Mediterranean. The high seismicity rates of this period may reflect a reactivation of all plate boundaries in the region (Dead Sea Transform, East Anatolian Fault, North Anatolian Fault, Hellenic Arc, Cyprus Arc Fault).  相似文献   

5.
Lechaion's ancient harbor is now a coastal swamp filled with sediments. Two natural factors explain the harbor's abandonment: (1) tectonic uplift during historical times and (2) the location of the harbor basin in a serpentine depression protected from the sea. Although it undoubtedly functioned as a very efficient sediment trap, only modest sedimentation rates (<1 mm/yr) have been measured in the basin. This paradox suggests that the basin was dredged and that the extracted sediments were dumped, forming a number of mounds around the harbor edges. The transition from marine organics to silt is dated to 750–400 cal. B.C. and precedes the 1.2 m uplift of the harbor at around 340 B.C., which underscores the minimal impact of tectonic forcing factors. The presence of fine‐grained sediments is consistent with an increasingly protected environment. The macrofauna indicate a low‐energy environment enriched with organic matter and brackish conditions. All data suggest that this environment became isolated from the sea. Although a seismic uplift around 340 B.C. played a partial role in the evolution of the harbor, it is not the sole natural forcing agent involved in the silting up of the basin. © 2012 Wiley Periodicals, Inc.  相似文献   

6.
Literature of the ancient Chola Dynasty (A.D. 9th–11th centuries) of South India and recent archaeological excavations allude to a sea flood that crippled the ancient port at Kaveripattinam, a trading hub for Southeast Asia, and probably affected the entire South Indian coast, analogous to the 2004 Indian Ocean tsunami impact. We present sedimentary evidence from an archaeological site to validate the textual references to this early medieval event. A sandy layer showing bed forms representing high‐energy conditions, possibly generated by a seaborne wave, was identified at the Kaveripattinam coast of Tamil Nadu, South India. Its sedimentary characteristics include hummocky cross‐stratification, convolute lamination with heavy minerals, rip‐up clasts, an erosional contact with the underlying mud bed, and a landward thinning geometry. Admixed with 1000‐year‐old Chola period artifacts, it provided an optically stimulated luminescence age of 1091 ± 66 yr and a thermoluminescence age of 993 ± 73 yr for the embedded pottery sherds. The dates of these proxies converge around 1000 yr B.P., correlative of an ancient tsunami reported from elsewhere along the Indian Ocean coasts. © 2011 Wiley Periodicals, Inc.  相似文献   

7.
Sanguinet lake is separated from the Atlantic Ocean by a wide Holocene coastal dunes system in SW France. The present day lake level is 21 m above mean sea level (msl). It formed when aeolian sand closed the mouth of the small La Gourgue river which gradually became a lagoon and then a lake. Dated sub‐lacustrine archaeological remains (human settlements, canoes, and wooden architectural structures), as well as paleoenvironmental evidence (drowned tree stumps and lagoonal deposits exposed on the beach) are used to interpret the formation and chronology of lake level rise during the past 4000 years. Around 2000–1650 B.C., the river flowed into a lagoon or an estuary which connected with the ocean west of the present Sanguinet Lake. Its level was affected by the tide, which ranged between 2 m below and 3 m above msl. The accumulation of aeolian sand before 1500–1000 B.C. began to close the connection with the sea. At this time, the elevation of the surface of the lake water was approximately 5 m above msl, but it still remained connected to the ocean. Around 1000 B.C., the lake level rose quickly by 1 to 2 m during a period of renewed mobility of the coastal aeolian sand, and continued to rise slowly until about 100 A.D. when there was a gradual closure of the lake outlet. This rise forced people who were living on the lake shore and along the rivers to move to higher land along the valley. The nearby Gallo‐Roman site of Losa was settled at the end of the 1st century B.C.; then the final blocking of the outlet occurred because of spit growth as a result of north‐south littoral drift accompanied by the deposit of aeolian sand. This led to the lake level rising rapidly. Consequently, Losa was abandoned in the 3rd century A.D. and ruins of its temple (at 17 m above msl) were submerged in the 6th century. Further oscillations of the lake level probably correspond to water table fluctuations before it became stable at around 1000 A.D. The highest lake level (23.35 m) was reached during the 18th century as a consequence of modern dune formation, and thus was artificially reduced to 21 m in 1840 by construction of an overflow channel. © 2008 Wiley Periodicals, Inc.  相似文献   

8.
The ancient harbour of Fréjus, located in a Holocene ria, has been the subject of a research program in archaeology and, notably with regards to the sedimentary environment at its foundation. A core was extracted in the middle of the basin of Fréjus harbour. The objective is to understand the paleogeographical evolution of the pre-harbour and Roman harbour environments. The sedimentological and biostratigraphical proxies enabled us to: (1) confirm Texier's (1849) hypothesis in which the pre-harbour environment comprised a marine bay blocked by an artificial quay (Gébara and Morhange, 2010). Excoffon et al., 2006 and Devillers et al., 2007, demonstrate the presence of a rocky coast (butte Saint-Antoine), at the time of the harbour's foundation, which it has been progressively transformed into a sandy coast due to the sedimentary input of Argens delta. This study permitted: (2) to confirm the date of foundation of Fréjus’ harbor; and (3) to show different phases of protection. Indeed, the harbour facies attests to a euryhaline lagoon (B1 and B3) which was gradually transformed into a freshwater lake (B4) due to the progradation of the Argens. Low sedimentation rates (ca. 0.5 mm/year), between the end of the last century BC until seventh century AD is consistent with the dredging of the harbour basin.  相似文献   

9.
对龙羊峡形成的初步认识   总被引：5，自引：0，他引：5  
从地貌和新构造的角度实际考察了龙羊峡，建立了共和盆地和龙羊峡地区构造抬升和变形的几何模型。根据模型笔者认为，黄河溯源侵蚀到达贵德盆地之后，龙羊峡西段由海拔3000m的夷平面封闭共和古湖，共和盆地周围的水体流向共和古湖；峡谷东段拉吉玛、罗汉堂地区已进行溯源侵蚀，水体向东流向贵得盆地。共和运动发生时，共和盆地作为一个完整的次级刚性活动块体被向东挤出和向东南微量顺时针旋转，同时，盆地的西端垂直构造抬升的幅度大于东端，共和古湖的水体重心向东偏移，水面越过海拔3000m的夷平面，向东流向贵德盆地，流水作用在两个盆地之间快速下切形成现今的龙羊峡。  相似文献   

10.
S.C. Stiros 《Geoarchaeology》1998,13(7):731-741
Archaeological and biological evidence indicates that the approximate sea level position of A.D. 150–250, the period of construction of the ancient harbor of Aigeira (Gulf of Corinth, Greece), can be identified at the height of 4 m above present sea level. The exposed ancient structure permits a direct observation of harbor construction techniques of the Roman period and study of the Late Holocene uplift of the area, characterized by a terrace staircase morphology. The harbor uplift is related to a series of earthquakes, one of which was possibly responsible for the demise of Aigeira in the 3rd century A.D. The corresponding rate of uplift is estimated to 2.4–3.0 mm/yr; it is consistent with available radiocarbon data and is among the highest uplift rates ever recorded in normal faulting environments. © 1998 John Wiley & Sons, Inc.  相似文献   

11.
An extensive rescue excavation has been conducted in the ancient harbor of ?stanbul (Yenikap?) by the Sea of Marmara, revealing a depositional sequence displaying clear evidence of transgression and coastal progradation during the Holocene. The basal layer of this sequence lies at 6 m below the present sea level and contains remains of a Neolithic settlement known to have been present in the area, indicating that the sea level at ~ 8-9 cal ka BP was lower than 6 m below present. Sea level advanced to its maximum at ~ 6.8-7 cal ka BP, drowning Lykos Stream and forming an inlet at its mouth. After ~ 3 cal ka BP, coastal progradation became evident. Subsequent construction of the Byzantine Harbor (Theodosius; 4th century AD) created a restricted small basin and accumulation of fine-grained sediments. The sedimentation rate was increased due to coastal progradation and anthropogenic factors during the deposition of coarse-grained sediments at the upper parts of the sequence (7th-9th centuries AD). The harbor was probably abandoned after the 11th century AD by filling up with Lykos Stream detritus and continued seaward migration of the coastline.  相似文献   

12.
Shuttle Radar Topography Mission (SRTM) data, with ground‐based geologic investigations, define the geographic position of the relict Canopic channel in Egypt's NW Nile delta. Two sinuous channel segments south of Abu Qir Bay are observed on a radar image: a more sinuous trace (36 km in length) west of Idku lagoon, and an eastern one (˜20 km), reaching the lagoon's southeast corner. Sediment cores recovered along channel traces show sand‐rich deposits (to > 4 m thick) beneath the surface, in contrast with silty muds in areas away from channels. Historic and archaeological findings indicate that the Ptolemaic Roman city of Schedia once lay directly along the Canopic that channeled water from the 3rd to 2nd centuries B.C. until ˜5th century A.D., after which Nile water was displaced to the east via Bolbitic and, later, Rosetta branches. Identification of buried, but well‐defined, Canopic channels provides baselines for renewed archaeological exploration in this delta sector. © 2006 Wiley Periodicals, Inc.  相似文献   

13.
A systematic archaeoseismological study indicates that at least three earthquakes occurred between 400 B.C. and A.D. 600, causing destruction to numerous ancient monuments in Sicily. Evidence for these earthquakes comes from the collapse style of buildings (toppled walls, column drums in a domino‐style arrangement, directional collapses, etc.), and the exclusion of other likely causes for such effects. Dating of inferred earthquakes is based on coins (accurate to within 5–10 years), pottery (accurate to within 50–200 years), and other artifacts. The oldest documented earthquake occurred between 370 and 300 B.C. and caused the collapse of two Greek temples in Selinunte. This otherwise poorly documented event was probably also the cause of extensive destruction in northeastern Sicily in the first century A.D. Destruction of some sites may be assigned to an earthquake that occurred between 360 and 374 and correlates with the A.D. 365 seismic sequence known from historical sources. This study covers a wider region and provides a more precise dating of earthquakes than previous studies. Although it focuses on a certain period (4th–3rd centuries B.C., 4th–7th centuries A.D.), it indicates that the period before A.D. 1000 is not a period of seismic quiescence in Sicily as was previously believed, but to a period characterized by strong and destructive earthquakes. © 2009 Wiley Periodicals, Inc.  相似文献   

14.
《Quaternary Research》1986,25(2):177-188
The recent discovery of a post-Roman-aged marine calcarenite terrace, at an altitude of 7 to 8 m at the ancient harbor of Akhziv, supports the hypothesis of oscillatory tectonic movements along the coastline of Israel during the late Holocene. The marine to estuarine origin of this terrace is indicated by the presence within it of a biocoenosic, sea-marginal to estuarine, assemblage of well-preserved molluscs consisting of taxa tolerating brackish-water, together with a few fresh-water specimens. The transgressive marine sediments onlap and overlie a 2700-yr-old middle Iron Age (Phoenician) tomb, which was built on a dark clay layer, containing a middle Bronze HB (3750 yr B.P.) settlement. In post-Roman times the coastal zone at this site, both east and west of the present coastline, was first subjected to tectonic subsidence of a few meters, and was then tectonically uplifted to its present altitude.  相似文献   

15.
A 38‐km‐long ancient aqueduct channel that served Roman Ephesos, Turkey was dislocated vertically over 3 m by a single seismic event on a normal fault. A new channel was constructed downstream from the fault in Roman times, next to and partly on top of the original channel. Archaeological investigations and study of carbonate deposits suggest a causative seismic event in the second half of the second century CE, probably in 178 CE, after the original channel had functioned for <35 years. The ?çme Tepe fault was identified as responsible for the displacement and may still constitute a seismic and tsunami hazard for the Turkish west coast, specifically for the city of Ku?adas?. Ancient aqueducts, of which more than 1400 are presently known, are a promising and almost untapped archive for archaeoseismic studies, especially in the Mediterranean area.  相似文献   

16.
The northern Tien Shan is the northern front of the Himalayan mountain belt, which resulted from the collision between the Indian and Eurasian Plates. This region encompasses the most active seismic zones of the orogen, which generated the strongest (M > 8) earthquakes. Since there are scarcely any written accounts, the only way to trace back strong earthquakes is the paleoseismologic method. Since 1984 we have been studying the northwestern Issyk Kul’ basin, where there are differently directed anticlines, which constitute the Kungei meganticline. Here, several active tectonic structures (faults, folds) are located, whose development was accompanied by strong earthquakes. Our field studies of 2008 in the Iiri-Taldybulak Valley, along the adyrs (foothills) of the Kungei-Ala-Too Range, revealed two unknown historical earthquakes. The first one, which occurred along the southern rupture in the late 7th century A.D., gave rise to a seismic scarp; the latter broke through the river floodplain and a tash-koro (ancient settlement). The second one, which occurred along the northern rupture in the late 9th century A.D., increased the height of the seismic scarp, existing on the Early Holocene and older terraces. Note that this region already records a strong seismic event around 500 A.D. Archeologic data have revealed one more strong earthquake, which took place in the 14th century A.D. Note that the above-mentioned strong seismic events are coeval with the decline of the nomadic cultures (Wusun, Turkic, Mogul) in the northern Tien Shan and Zhetysu (Semirech’e).  相似文献   

17.
This study examines the hydrodynamics of the Roman harbor of Portus during the Trajanic period (second century A.D.). We have evaluated the impact of the north‐eastern channel on water circulation and sediment resuspension within the harbor in relation to the problem of sediment infilling. We used a 2D numerical model to compute the distribution of the depth‐averaged current velocity, bed shear stress, and kinetic energy induced by each of the four prevailing local winds. First, the results confirm the persistent conditions for sediment infilling over the entire western harbor basin, even when the north‐eastern channel is operational; these conditions being present for 61.3% (40.3%) of the summer period and up to 68% (44.2%) of the winter period in the south‐western harbor basin. Second, the results show that favorable conditions for navigation occur in the central basin, leading to the landing installations, under the S 180°, SE 135°, and NE 22° winds when the north‐eastern channel is operational; these conditions being present for 21% of the summer period and 51.3% of the winter period. Inversely, the access to the landing installations with both channels operating remains affected by sediment infilling, for 40.3% of the summer period and 16.7% of the winter period.  相似文献   

18.
纳木错湖相沉积与藏北高原古大湖   总被引：11，自引：2，他引：11       下载免费PDF全文
藏北高原古湖岸线分布广泛，湖相沉积与湖成地貌发育，目前，在纳木错沿岸可清晰地划分出4-6级湖岸阶地，最高湖相沉积高出现代湖面150m，沿岸堤可多达50条，雄曲-那曲谷地是连接纳木错盆地与其以西的仁错-久如错盆地的分水谷地，也是构成纳木错2湖岸阶地顶部的第四纪湖相沉积，构成宽谷的谷底，从最高湖岸线的分布与湖相沉积物、湖成地貌等标志综合判定，古大湖泊的面积要比现代湖泊面积大数十倍，末次古大湖的时代发生于末次冰期间冰段。  相似文献   

19.
The Luni Plain, which faces the northern Tyrrhenian Sea, underwent major landscape changes over the last 3000 years. The coastline shifted south and west, separating the ruins of the ancient Roman colony of Luni (founded in 177 BC) from the sea by means of a new coastal plain. The precise location of the coastline during the main settlement phase as well as during the city's decline has never been established, although partial and qualitative scenarios have been suggested by various authors. According to these authors, an indentation of the coastline west of the city formed a major water basin, along the shores of which traces of pre-Roman settlements exist; near the city, two minor basins were present, suitable for hosting harbour structures. The city of Luni was famed for its harbour (Portus Lunae), from which the marbles quarried in the Apuan Alps, used to build many of the monuments in Rome, were delivered. The traces of its port, however, are scattered and uncertain.Newly available subsurface data are presented, associated with a revision of unpublished archaeological evidence of the ancient city topography. Progress in palaeoenvironmental reconstructions at Luni has been possible thanks to the collection and analysis of ancient and recent cores, supported by radiocarbon dates, as well as the interpretation of archaeological findings suitable as markers for sea-level recognition. The main environmental changes in the area have been refined: since a few centuries before the colony was founded, the Luni plain had been characterized by a complex architecture of swamps and marshes limited by dune ridges and fluvial sand bars. The positions of these landforms were not fixed, but shifted, mainly depending on the spatial relationship between the coastline and the river mouths.Determining the precise position of the Roman coastline is useful to constrain the area in which archaeological surveys should be concentrated in order to identify the harbour location. Moreover, some of these results have been used to infer altitude constraints on the sea-level position in Roman times: preliminary data are shown for constructing a Late Holocene local sea-level curve in the area.  相似文献   

20.
东濮盆地蒸发岩的成因   总被引：19，自引：0，他引：19  
李任伟  辛茂安 《沉积学报》1989,7(4):141-148
东濮盆地第三纪蒸发岩含大量芒硝、钙芒硝等矿物；石盐岩具有低的溴含量，都低于30ppm，部分接近或低于10ppm；硬石膏岩硫同位素的δ34S的范围从+3.31到+37.5,大大超过现代及第三纪海洋硫酸盐的数值。上述资料表明，东濮盆地第三纪蒸发岩可能为非海相成因。  相似文献   

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