Bulletin of the Geological Society of Greece

Published by National Documentation Centre (EKT)
Print ISSN: 0438-9557
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Triple joining at a block from the walls of Sarmizegetuse Region
Exemplification of the chamfering technique used limestone blocks at Tilisca city
Spread according to an amazing plan of defense, at the foot of stately heights, at the blunted peaks or on their oblong ridges, the Dacian fortifications and the villages of some blooming communities are proof of an extraordinary technique of space planning and of setting up of construction works, proved by their variety, richness and monumental character. Raised of large and averagesize limestone blocks, these fortified areas impress not only by the chosen position, by the extraordinary building techniques, in accordance with the most up-to-date principles of strength, equilibrium and waterproofing, but also by iron processing workshops and time measuring devices. This type of buildings implies today, as it did then, specialists in designing, skillful workers for the execution, but more especially experience in construction works. The discovered fortifications and walls totalize at each of the cities about 200,000 m3 of stone, which indicates vast building rock mining, opening-up and rock stripping, splitting of the blocks out of the mother-rock, shaping workshops, efficient ways of transport and an advanced organization of the "building site".
 
In this study, all samples from Tortonian to Early Pliocene sediments of Zvernec-Vlora and Kavaja-Durres regions within Peri-Adriatic Foredeep (PAF) of Albania containing Globorotalia acostaensis were studied qualitatively and quantitatively. Based on these analyses resulted that G. acostaensis have changed coiling ratio direction during G. acostaensis and G. obliquus extremus Zone of Tortonian, differently from that known in Mediterranean area up to now. This is not a short time interval, which more exactly is from the first appearance of G. acostaensis to first appearance of G. suterae, at the upper part of G. extremus Zone. Another documented and explaining unconformity here is related with beginning of Pliocene sediments. There are at least four alienating sinistral and dextral coiling changes in G.acostaensis populations. Also in this work is given the history of the study of G acostaensis and which maybe causes that this species in Mediterranean province and especially in our country is used relatively late as zonal marker species. The main object of stratigraphers and paleontologists has been finding a successive section, with uninterrupted sedimentation, possibly for the longest geological time. Regarding to this phenomenon could be explained resulting unconformity between coiling ratio changes in Globorotalia acostaensis of the present study and other studies carried out in Mediterranean area on this occasion up to now. It is difficult to understand here the resulting unconformity during the main part of Tortonian age, which prolonged more than 2 m.y. Another resulting unconformity discovered at the Miocene/Pliocene boundary of the Kavaja-Durres regions is very significant. In these regions was discovered an earlier Pliocene sedimentation than known up to now according to resulting alternations of coiling direction of Globorotalia acostaensis prior to Pliocene Sphaeroidinellopsis Acme zone. These data are in favour of those based on the isotopie stratigraphy, which give a new definition at 5.32 M.Y. Miocene/Pliocene boundary instead of 5.1 or 5.2 M.Y. given previously based on absolute age. Coiling changes, in our case that of G. acostaensis are in response to changing climates or alternation of different cold and warm water populations resulting from changes in the boundaries between water masses as at the beginning of the Pliocene when the water masses of the Atlantic Ocean overflowed the Mediterranean area. Here is also proposed to correct the Neogene paleoclimatic curve referring, for the interval of G. acostaensis range distribution.
 
This paper intends to give the characterization of Quaternary loose deposits, near and along the sea coast zone, by evaluating lithological-geologic parameters, depositional environments and the tectonic subsidence. The main objectives are: - The lithologic-facial zone by mapping of lithologie composition and facies distribution. - The Quaternary basin analyses by interpreting depositional sequences of third order, where system tracts (lowstand, shelf wedge, transgressive and highstand) are individualized. - The present fluvial processes and delta configuration (Shkumbin, Seman).
 
Investigated area and its surrounding district consist of volcanic rocks. The Sanduklu volcanic are mainly composed of lavas, tuffs and tuffits. Using to K-Ar age method, the age of Sanduklu Lavas have been dated and ranged from 14 ± 0.3-8.0 to ± 0.6 Ma (Ercan, 1986).On the basis of diagrams Si02-(K20+Na20), Log (Zr/ TiO2*0.0001)-SiO2, Nb/Y-Log (Zr/TiO2*0.0001) and Ti02-Zr lavas are thrachyandesite, phonolitic tefrite, basaltic andésite, basaltic thrachy-nephelinite, andésite and dacite. Tuffs have been widely zeolitizated and dominant zeolite minerals are chabazite and phillipsite. Three phillipsite form were determined. These are potassiumsodium-aluminum-silicate hydrate, sodium-aluminum-silicate hydrate and potassium-calcium-silicate-silicate hydrate. The chemical and technological tests of zeolitic tuffs, altered lavas and tuffits were carried out and they are suitable to trass standards in cement industry.
 
Frakulla diapir is one of the studied diapirs in Albania. It is located in the western part of Albania. The Serravallian to Pliocene sediments belongs to the uppermost part of the Adriatic Basin, which is included in the central Mediterranean Basins group. Some anticline and syncline structures are indicated in the western part of Albania. These structures are placed in a linear way forming some structural ranges with SSE-NNW axis direction. Frakulla is one of these structures as a part of Vlora-Panaja-Frakkull range (Fig. 1). Based on the surface geology, well data and the interpretation of the seismic sections results that this structure is formed as a consequence of the mud diapir growth. This diapir is complicated with tectonic faults in both western and eastern flanks, which dip with angle 45-90° The southern and northern ends of the structure are clearly seen in the seismic sections and a number of wells penetrated these ends. We think that the Frakulla structure is a typical mud diapir surrounding in all directions by many gas sandstone beds. These sandstones are formed in a deltaic environment during the Messinian (Globorotalia conomiozea zone). Some factors affected the quantity of hydrocarbon accumulation are discussed in this paper like: structural character of the area, pattern and complexity of faulting around and over the mud diapir, depositional environment, rate of growth of the diapir and time of uplift. We think that the presence of gas accumulation in Frakulla area is as a consequence of a favorable interrelation of these factors
 
There are studied too many samples from Ionian Zone (geological outcrops and drilling wells) and Koma depression containing Larger Foraminifers, Lepidocyclina (Eulepidina) subgenus. For their study, determination to species level, biometrie and counting measurements known in literature are used. According to proposal (for Mediterranean region) we suggest that in south Albania also can be separated the following species and subspecies: - Lepidocyclina-(Eulepidina) formosoides DOUVILLE R. - Lepidocyclina-(Eulepidina) dilatata (MICHELOTTI) - Lepidocyclina-(Eulepidina) dilatata (MICHELOTTI) var concentrica SILVESTRI For the specimens of microsphaeric generation (B-Form, diameter more than 5 centimeter) maintained the typological concept of classification and were attributed to the species Lepidocyclina (Eulepidina) elephantine LEMOINE and DOUVILLE (1904). They are given briefly the deposition conditions of the shells of this subgenus in flysch (Ionian Zone and mollasic deposits (Korria depression) Middle Oligocene- Lower Miocene age. The paper has been accompanied by means 3 plates.
 
Albania is one of the most karst-developed countries in Europe. Karst phenomena are related to soluted carbonate formations which cover of about 7300 km2 of Albanian territory and with sulfate evaporates rocks, which outcrop of about 500 km2. Typically alpine relief of average altitude 708 m above the sea level and high horizontal splitting are favorable for karst development. Karst and geological sites of karst origin are widespread mainly in Albanian Alps and in Ionian zone. In Albanides there are determined surfaces and underground karst forms which belong to the Neo-Pliocene-Quaternary age and deep karst forms belonging to the paleokarst in old formations. The most widespread karst forms in carbonate rocks there are valleys, caves, cones etc., while into salt rocks there are formed many karstic lakes and depressions. Up to now there are determined about 80 karstic caves, nice karst fields, valleys, plains, which represent geological sites of karst origin.
 
The Periadriatic Depression includes the western Lowland of Albania from Vlora to Ulqini. The Periadriatic basin, formed after the main folding and thrusting of Ionian zone, is filled with molasses deposits. The molasse formation building this Depression is made up by Middle Miocene up to Pliocene sediments. The Periadriatic Depression extends on its eastern and southern bordes over folded and thrusted structures of the Ionian and Kruja Zones. The folding and thrusting of Periadriatic Depression is finally due to the Early Pleistocene compressional phase that is evidenced by some important structural unconformities. The Periadriatic Depression is built by some linear relatively narrow anticlines, superimposed over thrust or backthrust faults, and wide synclines. The Mio-Pliocene anticlinal folds generally do not outcrop with all their tectonic elements (flanks,periclines). The positive structures of western coastal part are well expressed on the relief; so, the anticlines here build hills while the synclines are buried under Holocene plains between them. The structural and neotectonic features are evidenced in the seismic lines
 
Ambient noise measurements of a dense mesh (about 100mX100m) were performed within the historical center of the city of Thessaloniki (Northern Greece), that was strongly affected by the 20/6/1978 destructive earthquake. The data were processed using the horizontal-to-vertical spectral ratio technique. Fundamental frequencies and corresponding amplitudes for each site were calculated. Selected cross-sections in the city - with respect to fundamental frequency - compared with already available theoretical and experimental 2D approximation results show very good agreement. Contour maps were produced for both fundamental frequency and corresponding (h/v) amplitude for the historical center of the Thessaloniki city, which were compared with existing geotechnical and geological data and found to be satisfactorily correlated. Damage distribution due to 20/6/1978 earthquake seems to be quite consistent with fundamental frequency spatial distribution taking into account that the majority of the affected buildings were of six to nine stories. The aforementioned results encourage the use of ambient noise measurements along with the (h/v) spectral ratio technique as a non-expensive and fast tool in microzonation studies to be carried out in urban environments.
 
Top-cited authors
C. B. Papazachos
  • Aristotle University of Thessaloniki
Emmanuel M. Scordilis
  • Aristotle University of Thessaloniki
George Karakaisis
  • Aristotle University of Thessaloniki
Dimitrios George Panagiotopoulos
  • Aristotle University of Thessaloniki
D. Papanikolaou
  • National and Kapodistrian University of Athens