Breccia Research Papers - Academia.edu (original) (raw)

La Breccia di Slivia, affiorante circa 2 km a nord di Aurisina (Trieste), rappresenta la registrazione stratigrafica di un'importante fase tettonica verificatasi nell'area del Carso triestino durante il Campaniano... more

La Breccia di Slivia, affiorante circa 2 km a nord di Aurisina (Trieste), rappresenta la registrazione stratigrafica di un'importante fase tettonica verificatasi nell'area del Carso triestino durante il Campaniano superiore-Maastrichtiano. In tale periodo si è originata una depressione strutturale nei calcari di piattaforma di età santoniano-coniaciana, riempita da imponenti corpi di breccia derivati da smantellamenti e frane dei calcari incassanti. Questi depositi sono coevi alle facies schizoaline "liburniche" affioranti, con discreti spessori, nel Carso triestino meridionale e nel Carso goriziano settentrionale, mentre lungo la vicina fascia costiera il "Liburnico" è molto ridotto od assente e comunque generalmente limitato a termini basali del Paleocene. Infine, la depressione tettonica contenente la breccia è verosimilmente associata ad un significativo lineamento strutturale che sblocca e ripete la successione di piattaforma coniaciano-santoniana tra Slivia e S. Pelagio (a NE) ed Aurisina (a SW).

Öz: Phaselis antik kenti Antalya’nın güneybatısında Kemer ile Tekirova arasında deniz kıyısında yer almaktadır. Kentin tarihinin MÖ 691 yıllarına kadar gittiği söylenmektedir. Kentin jeolojik yapısında, Üst Kretase okyanus tabanı magmatik... more

Öz: Phaselis antik kenti Antalya’nın güneybatısında Kemer ile Tekirova arasında deniz kıyısında yer almaktadır. Kentin tarihinin MÖ 691 yıllarına kadar gittiği söylenmektedir. Kentin jeolojik yapısında, Üst Kretase okyanus tabanı magmatik kayaçlardan en son jeolojik dönemde (Kuvaterner) oluşmuş traverten – traverten breşi (Fanglomera) birimlerine kadar değişen birimler gözlenmektedir. Antik kentin ilksel ana yapı malzemesi (kesilmiş, boyutlandırılmış bloklar) traverten breşleridir. Jura yaşlı kireçtaşları (Tekedağı formasyonu kireçtaşları) neotektonik dönemde (Plio-Kuvaterner) yükselmiş ve bunların önüne düşen kayaç parçaları, faylardan gelen karbonatlı sularla taşlaşarak traverten breşlerini (Fanglomera) oluştur-muştur. Ayrıca antik kentin yerleşim alanında kalkarenitler ve gabrolar da görülmektedir. Phaselis antik kentinde ilksel olarak çevredeki kayaçlar (traverten breşleri, travertenler, kalkarenitler, serpantinler ve gabrolar), sonraki dönemlerde ise dışarıdan getirilmiş mermerler, limra ve limra breşleri de kullanılmıştır. Traverten breşleri ve diğer yapı malzemeleri tarih boyunca değişik bozuşmalara maruz kalmıştır. Traverten breşlerindeki bozuşmalar, şehrin ana yapı unsuru olduğundan önemlidir. Traverten breşlerinin bozuşmasındaki ana unsur breşlerin çimentosu olan malzeme ile ilgilidir. Çimento tamamen karbonattan olu-şursa bloklar oldukça dayanıklı olur, fakat bu bölgede çimentoya karışan kil malzemesi hava şartlarından etkilenerek bozuşmalara neden olmuştur. İleride restorasyon yapılması düşünüldüğünde, çevreden üre-tilecek traverten bloklarının çimentosuna bu anlamda özellikle dikkat etmek gerekecektir.
Anahtar sözcükler: Phaselis, Yapıtaşları, Breş, Limra, Mermer, Bozuşma
Abstract: The ancient city of Phaselis lies on the seafront between Kemer and Tekirova, southwest of Antalya. It is said that the city’s history dates back to 691 B.C. Geological feature of the city is formed ranging from the Upper Cretaceous magmatic rocks to in the last geological period (Quaternary) to the travertine - travertine breccia (Fanglomera) units. The primary main building material of the ancient city is the travertine breccias. The Jurassic limestones (Tekedağı formation limestones) have been elevated during the neotectonic period and Plio-Quaternary rocks, which were petrified with carbonated waters from the faults, and the travertine breccias (Fanglomera) were formed. Also calcarenites and gabbros are observed in the settlement area of the ancient city. In the ancient city of Phaselis, the surrounding rocks (travertine breccias, travertines, calcarenites, serpentines and gabbros) were firstly used, in later periods marbles, limestone and limra breccia were also used. Travertine breccias and other building materials have been subject to various alteration throughout the history. Alterations in travertine breccias are important because they are the main building element of the city. The main factor in the degradation of the travertine breccias is related to the cement material of the breccias. If the cement is completely carbonated, the blocks are highly resistant. However, the clay material added to the cement is affected by the weather conditions. Considering the future restoration, particular attention will be paid to the cement of the travertine blocks to be produced from the environment.
Keywords: Phaselis, Cut-Stones, Breccia, Limra, Marble, Alteration
 Jeoloji Yük. Müh., Competent Person (CP-Australia JORC), Doktora ögrencisi, Hacettepe Üniversitesi, Fen Bilimleri Enstitüsü, Jeoloji Bölümü, Ankara. ferdaoner@hotmail.com

The Mesoarchean Nuasahi chromite deposits of the Singhbhum Craton in eastern India consist of a lower chromite-bearing ultramafic unit and an upper magnetite-bearing gabbroic unit. The ultramafic unit is a ∼5 km long and ∼400 m wide... more

The Mesoarchean Nuasahi chromite deposits of the Singhbhum Craton in eastern India consist of a lower chromite-bearing ultramafic unit and an upper magnetite-bearing gabbroic unit. The ultramafic unit is a ∼5 km long and ∼400 m wide linear belt trending NNW-SSE with a general north-easterly dip. The chromitite ore bodies are hosted in the dunite that is flanked by the orthopyroxenite. The rocks of the ultramafic unit including the chromitite crystallized from a primitive boninitic magma, whereas the gabbro unit formed from an evolved boninitic magma. A shear zone (10–75 m wide) is present at the upper contact of the ultramafic unit. This shear zone consists of a breccia comprising millimeter- to meter-sized fragments of chromitite and serpentinized rocks of the ultramafic unit enclosed in a pegmatitic and hybridized gabbroic matrix. The shear zone was formed late synkinematically with respect to the main gabbroic intrusion and intruded by a hydrous mafic magma comagmatic with the evolved boninitic magma that formed the gabbro unit. Both sulfide-free and sulfide-bearing zones with platinum group element (PGE) enrichment are present in the breccia zone. The PGE mineralogy in sulfide-rich assemblages is dominated by minerals containing Pd, Pt, Sb, Bi, Te, S, and/or As. Samples from the gabbro unit and the breccia zone have total PGE concentrations ranging from 3 to 116 ppb and 258 to 24,100 ppb, respectively. The sulfide-rich assemblages of the breccia zone are Pd-rich and have Pd/Ir ratios of 13–1,750 and Pd/Pt ratios of 1–73. The PGE-enriched sulfide-bearing assemblages of the breccia zone are characterized by (1) extensive development of secondary hydrous minerals in the altered parts of fragments and in the matrix of the breccia, (2) coarsening of grain size in the altered parts of the chromitite fragments, and (3) extensive alteration of primary chromite to more Fe-rich chromite with inclusions of chlorite, rutile, ilmenite, magnetite, chalcopyrite, and PGE-bearing chalcogenides. Unaltered parts of the massive chromitite fragments from the breccia zone show PGE ratios (Pd/Ir = 2.5) similar to massive chromitite (Pd/Ir = 0.4–6.6) of the ultramafic unit. The Ir-group PGE (IPGE: Ir, Os, Ru) of the sulfide-rich breccia assemblages were contributed from the ultramafic–chromitite breccia. Samples of the gabbro unit have fractionated primitive mantle-normalized patterns, IPGE depletion (Pd/Ir = 24–1,227) and Ni-depletion due to early removal of olivine and chromite from the primitive boninitic magma that formed the ultramafic unit. Samples of the gabbro and the breccia zone have negative Nb, Th, Zr, and Hf anomalies, indicating derivation from a depleted mantle source. The Cu/Pd ratios of the PGE-mineralized samples of the breccia zone (2.0 × 103–3.2 × 103) are lower than mantle (6.2 × 103) suggesting that the parental boninitic magma (Archean high-Mg lava: Cu/Pd ratio ∼1.3 × 103; komatiite: Cu/Pd ratio ∼8 × 103) was sulfur-undersaturated. Samples of the ultramafic unit, gabbro and the mineralized breccia zone, have a narrow range of incompatible trace element ratios indicating a cogenetic relationship. The ultramafic rocks and the gabbros have relatively constant subchondritic Nb/Ta ratios (ultramafic rocks: Nb/Ta = 4.1–8.8; gabbro unit: Nb/Ta = 11.5–13.2), whereas samples of the breccia zone are characterized by highly variable Nb/Ta ratios (Nb/Ta = 2.5–16.6) and show evidence of metasomatism. The enrichment of light rare earth element and mobile incompatible elements in the mineralized samples provides supporting evidence for metasomatism. The interaction of the ultramafic fragments with the evolved fluid-rich mafic magma was key to the formation of the PGE mineralization in the Nuasahi massif.

Breccia are key elements of the polymetallic iron oxide copper-gold (Co-Ag-Bi-U) (IOCG) deposits worldwide. Their use is however difficult either in regional mineral exploration or in production mapping. Recent studies on breccias in... more

Breccia are key elements of the polymetallic iron oxide copper-gold (Co-Ag-Bi-U) (IOCG) deposits worldwide. Their use is however difficult either in regional mineral exploration or in production mapping. Recent studies on breccias in magmatic-hydrothermal systems show that genetic information may be determine from quantitative geometric parameters (shape and spatial organization of fragments) and composition. Breccia maturity could be determined from several parameters et could be use for targeting mineralization. In IOGC(U) ore deposits, breccias occurs in all geological environments and at different depths. Corroded breccia fragments and chaotic particle size distribution are more abundant than in other types of ore deposits, underlying the role of solution process in this class of deposits. Résumé Les brèches sont des éléments essentiels dans les gisements d'oxydes de fer polymétalliques à cuivre-or (Co-Ag-Bi-U). Leur utilisation reste cependant difficile, aussi bien en exploration régionale que lors de la cartographie au cours de la production. Les études récentes sur les brèches dans les systèmes magmatiques-hydrothermaux ont montré qu'il était possible d'obtenir de multiples informations génétiques à partir d'analyses géométriques détaillées sur la forme et l'organisation spatiale des fragments en tenant compte de la composition. La maturité d'une brèche peut se mesurer selon différents paramètres et peut servir de vecteur vers la minéralisation. Dans les gisements IOGC(U), les brèches apparaissent dans tous les environnements et à diverses profondeurs. Les fragments des brèches sont plus corrodés et la granulométrie est plus chaotique que dans d'autres types de gisements, ce qui souligne l'importance des processus de dissolution dans ces gisements.

Chicxulub Crater, formed ~66Ma ago by an asteroid impact on the southern Gulf of Mexico, is the best preserved of the three large multi-ring basins in the terrestrial record. The crater structure is characterized by a semi-circular... more

Chicxulub Crater, formed ~66Ma ago by an asteroid impact on the southern Gulf of Mexico, is the best preserved of the three large multi-ring basins in the terrestrial record. The crater structure is characterized by a semi-circular concentric ring pattern, marking the crater basin, peak ring, terrace zone and basement uplift. Analysis of a grid of 19 seismic reflection profiles using seismic attributes, marker horizons, contour surfaces and 3-D views is used to investigate the stratigraphy of the central zone. We used interactive software and routine applications to map the impact breccias, breccia-carbonate contact and post-impact carbonates. Four horizons marked by high-amplitude reflectors representing high-impedance contrasts were identified and laterally correlated in the seismic images. Complex trace attribute analysis was applied for petrophysical characterization. Surface contour maps of base and top of stratigraphic packages were constructed, which mapped the impactites and post-and pre-impact carbonate stratigraphy. Basin floor, marked by the contact between the impact breccias and overlying carbonates is shown by laterally discontinuous high-amplitude reflectors. Discontinuous scattered reflectors interpreted as the upper breccias beneath the crater floor, have an average thickness of ~300msm. The Paleogene sedimentary units are characterized by multiple reflectors with lateral continuity, which contrast with the seismic response of underlying breccias. The basal Paleocene sediments follow the basin floor relief. Upwards in the section, the carbonate strata are characterized by horizontal reflectors, which are interrupted by a regional unconformity. Onlap/downlap packages over the unconformity record a period of sea level change.

The epithermal Shila-Paula Au–Ag district is characterized by numerous veins hosted in Tertiary volcanic rocks of the Western Cordillera (southern Peru). Field studies of the ore bodies reveal a systematic association of a main E–W vein... more

The epithermal Shila-Paula Au–Ag district is characterized by numerous veins hosted in Tertiary volcanic rocks of the Western Cordillera (southern Peru). Field studies of the ore bodies reveal a systematic association of a main E–W vein with secondary N55–60°W veins—two directions that are also reflected by the orientation of fluid-inclusion planes in quartz crystals of the host rock. In areas where this pattern is not recognized, such as the Apacheta sector, vein emplacement seems to have been guided by regional N40°E and N40°W fractures. Two main vein-filling stages are identified. stage 1 is a quartz–adularia–pyrite–galena–sphalerite–chalcopyrite–electrum–Mn silicate–carbonate assemblage that fills the main E–W veins. stage 2, which contains most of the precious-metal mineralization, is divided into pre-bonanza and bonanza substages. The pre-bonanza substage consists of a quartz–adularia–carbonate assemblage that is observed within the secondary N45–60°W veins, in veinlets that cut the stage 1 assemblage, and in final open-space fillings. The two latter structures are finally filled by the bonanza substage characterized by a Fe-poor sphalerite–chalcopyrite–pyrite–galena–tennantite–tetrahedrite–polybasite–pearceite–electrum assemblage. The ore in the main veins is systematically brecciated, whereas the ore in the secondary veins and geodes is characteristic of open-space crystallization. Microthermometric measurements on sphalerite from both stages and on quartz and calcite from stage 2 indicate a salinity range of 0 to 15.5 wt% NaCl equivalent and homogenization temperatures bracketed between 200 and 330°C. Secondary CO2-, N2- and H2S-bearing fluid inclusions are also identified. The age of vein emplacement, based on 40Ar/39Ar ages obtained on adularia of different veins, is estimated at around 11 Ma, with some overlap between adularia of stage 1 (11.4±0.4 Ma) and of stage 2 (10.8±0.3 Ma). A three-phase tectonic model has been constructed to explain the vein formation. Phase 1 corresponds to the assumed development of E–W sinistral shear zones and associated N60°W cleavages under the effects of a NE–SW shortening direction that is recognized at Andean scale. These structures contain the stage 1 ore assemblage that was brecciated during ongoing deformation. Phase 2 is a reactivation of earlier structures under a NW–SE shortening direction that allowed the reopening of the preexisting schistosity and the formation of scarce N50°E-striking S2-cleavage planes filled by the stage 2 pre-bonanza minerals. Phase 3 coincides with the bonanza ore emplacement in the secondary N45–60°W veins and also in open-space in the core of the main E–W veins. Our combined tectonic, textural, mineralogical, fluid-inclusion, and geochronological study presents a complete model of vein formation in which the reactivation of previously formed tectonic structures plays a significant role in ore formation.

The copper-rich, tourmaline-bearing Donoso breccia pipe is one among more than 15 different mineralized breccias in the giant (>50 million metric tonnes of copper) Miocene and Pliocene Río Blanco-Los Bronces copper deposit in the high... more

The copper-rich, tourmaline-bearing Donoso breccia pipe is one among more than 15 different mineralized breccias in the giant (>50 million metric tonnes of copper) Miocene and Pliocene Río Blanco-Los Bronces copper deposit in the high Andes of central Chile. This breccia pipe, bracketed in age between 5.2 and 4.9 Ma, has dimensions of 500 by 700 m at the current surface 3,670 m above sea level. Its roots have yet to be encountered, and it is >300 m in diameter at the depth of the deepest drill holes. The Donoso breccia is, for the most part, monolithic, containing clasts of the equigranular quartz monzonite pluton which hosts the pipe. It is matrix supported, with between 5 and 25% of the total rock volume consisting of breccia-matrix minerals, which include tourmaline, quartz, chalcopyrite, pyrite, specularite, and lesser amounts of bornite and anhydrite. An open pit mine, centered on this breccia pipe, has a current production of 50,000 tonnes of ore per day at an average grade of 1.2% copper, and copper grade in the breccia matrix is significantly higher. Measured δ18O for tourmaline and quartz from the matrix of the Donoso breccia at different levels of the pipe range from +6.9 to +12.0‰, and measured δD in tourmaline ranges from –73 to –95‰. Temperatures of crystallization of these minerals, as determined by the highest homogenization temperatures of highly saline fluid inclusions, range from 400 to >690°C. When corrected for these temperatures, the stable isotope data indicate that fluids from which these breccia-matrix minerals precipitated were magmatic, with δ18O between +5.6 to +9.1‰ and δD between –51 to –80‰. These isotopic data preclude participation of a significant amount of meteoric water in the formation of the Donoso breccia. They support a model in which brecciation is caused by expansion of magmatic fluids exsolved from a cooling pluton, and breccia-matrix minerals, including copper sulfides, precipitated from the same magmatic fluids responsible for brecciation. Sericitic alteration of clasts in the breccia was also caused by these magmatic fluids. Different types of fluid inclusions imply that several different magmatic fluids were involved in formation of the Donoso breccia. These include high-temperature, highly saline, non-boiling fluids, trapped in inclusions that homogenize by halite dissolution, which probably exsolved from a magma cooling under relatively high (>1 kbar) lithostatic pressure conditions, consistent with geologic constraints. Other high-temperature, highly saline fluids are trapped in inclusions that homogenize by vapor-bubble disappearance and are spatially associated with vapor-rich inclusions, suggesting either phase separation (boiling) or simultaneous separation of immiscible brine and vapor from a magma cooling at lower hydrostatic pressure conditions. Both types of high-temperature, highly saline fluids circulated intermittently, as pressure fluctuated between lithostatic and hydrostatic conditions because of episodes of sealing and rebrecciation.

Through field and laboratory analyses, the cross-sectional structure and the grain size distribution of 10 strike-slip fault cores less than 1 m thick were studied. The fault cores are exposed in Jurassic platform limestone within the... more

Through field and laboratory analyses, the cross-sectional structure and the grain size distribution of 10 strike-slip fault cores less than 1 m thick were studied. The fault cores are exposed in Jurassic platform limestone within the Mattinata Fault zone located in the Adriatic–Apulian foreland of southern Italy. Each fault core consists of a breccia zone and a gouge zone, which differ in thickness and grain size distribution. Through the conventional sieving-and-weighting method, the grain size distribution of 20 samples of fault rocks was obtained. The distributions follow power-laws with fractal dimension (D) in the 2.00977–3.04008 range. Gouge D-values are proportional to the normalised thickness of the corresponding gouge zones. For a gouge D-value≈2.2, the thickness of the corresponding gouge zone is only about 3% of the fault core thickness, whereas for a gouge D-value≈3.0, the thickness of the corresponding gouge zone is almost 90% of the fault core thickness. Results from this study suggest that, with progressing fault displacement: (i) grain comminution in fault cores occurred mostly by early bulk fragmentation of grains and late grain abrasion; (ii) breccia zones were progressively incorporated into the adjacent gouge zones.

The Plinian Lower Pumice 2 (LP2) eruption (172 ka) was one of the first major caldera-forming eruptions of the Santorini volcanic complex (Greece). The eruption shows some striking similarities to the caldera-forming Late Bronze Age... more

The Plinian Lower Pumice 2 (LP2) eruption (172 ka) was one of the first major caldera-forming eruptions of the Santorini volcanic complex (Greece). The eruption shows some striking similarities to the caldera-forming Late Bronze Age (Minoan) eruption in terms of field, petrological and geochemical characteristics of its eruptive products, which are used to reveal the storage conditions of the LP2 magmas, pre-eruptive magmatic processes and the behaviour and degassing of volatiles prior to and during eruption.The LP2 eruption comprises four, predominantly rhyodacitic eruptive units (LP2-A, B, C, D). The lowermost unit of the Plinian LP2 deposits (LP2-A) consists of a basal phreatomagmatic bed (LP2-A1), which is overlain by three discrete pumice fall deposits (LP2-A2-1, A2-2, A3), the most prominent of which (LP2-A3) contains abundant, quench-textured scoriae that range in composition from basalt to basaltic andesite. The eruption proceeded with the deposition of pumice-rich pyroclastic flows (LP2-B) characterised by a lower, stratified and cross-bedded ignimbrite (LP2-B1) that may grade into a massive, non-welded ignimbrite (LP2-B2), a lithic-rich pumiceous breccia (LP2-C) and a co-ignimbrite lithic lag breccia (LP2-D).The main volume of rhyodacitic magma, which formed by fractionation of olivine, clinopyroxene, orthopyroxene, plagioclase, amphibole, Fe–Ti oxides, pyrrhotite and apatite from basaltic parental magmas and assimilation of crustal rocks, was held at mid-crustal levels (≤ 16 km depth), magmatic temperatures of 831 ± 12 °C and an oxygen fugacity slightly above the fayalite–magnetite–quartz (FMQ) oxygen buffer. Injection of ∼ 200 °C hotter mafic magma into the rhyodacitic reservoir and subsequent mingling and minor hybridisation with the resident magma helped to remobilise the rhyodacitic host magma and determined the final compositional range of the erupted products.Melt inclusion data show that sulphur concentrations were reduced to < 270 ppm in the rhyodacite, primarily due to partitioning of sulphur into pyrrhotite or, depending on temperature, a FeS-rich melt during magmatic differentiation at oxygen fugacities around the FMQ oxygen buffer. Sulphur concentrations in groundmass glasses of the LP2 pumices suggest that ∼ 43% of the remaining sulphur was released into the atmosphere during the LP2 eruption, the climatic effects of which are considered minor when compared to eruptions of more oxidised silicic arc magmas. Chlorine remained dissolved in the melt during magmatic differentiation prior to and during the LP2 eruption, indicating that chlorine emissions to the atmosphere were negligible.

Numerous palaeoenvironmental and archaeological studies from southern Arabia (Yemen and Oman) have revealed strong relations between phases of human settlements and climate change linked to the Indian monsoon system. Analyses on... more

Numerous palaeoenvironmental and archaeological studies from southern Arabia (Yemen and Oman) have revealed strong relations between phases of human settlements and climate change linked to the Indian monsoon system. Analyses on speleothems, cave fills, lacustrine deposits and palaeo-mangroves have shown that during the Early to Mid-Holocene, a humid Optimum culminated around 9000-8000 cal BP. New results on inland speleothems and cave sediments fromthe Jebel Qara (southern Oman) are crucial in our depiction of Early and Mid-Holocene climatic evolution and cultural dynamics of the region. These aspects are discussed here, based on new archaeological surveys, excavations, geoarchaeological and micromorphological studies, aiming to better understand connections with Terminal Pleistocene and Early Holocene autochthonous cultures of southern Arabia. Our results suggest that the final Pleistocene was marked by strong aridity, which promoted a widespread thermoclastism within rock shelter and deposition of aeolian sand; in contrast, the transition towards the Holocene is marked (since c.12,000 cal BP) by a progressive increasing in environmental humidity, which permitted the formation of thick strata of peridesert loess. After this phase, the environmental humidity of the Jebel increased and permitted the existence of a large community of land snails; the latter were exploited by Early Holocene hunter-gatherers who lived in the rock shelters between c. 10,500e9500 cal BP and left consistent accumulations of land shells (escargotières). The maximum of Holocene humidity was reached between 9000 and 8000 cal BP; regional aquifer were recharged and the deposition of calcareous tufa at the entrance of caves started, lasting up to c. 4500 cal BP. C and O stable isotopes from calcareous tufa highlights, in accordance with several regional records, the progressive decline of the intensity of the Indian Ocean monsoon and the transition towards arid conditions. In this phase, the area was abandoned and archaeological communities possibly relocated along the coast of central and southern Oman, where they exploited the mangrove environment.

Öz: Phaselis Antalya’nın yaklaşık 55 km güneybatısında yer alan bir ören yeridir. Kentin yapılarında yapı taşı olarak traverten breşi kullanılmıştır. Bu breşleri oluşturan taneler Jura yaşlı kireçtaşlarının (Tekedağı formasyonu... more

Öz: Phaselis Antalya’nın yaklaşık 55 km güneybatısında yer alan bir ören yeridir. Kentin yapılarında yapı taşı
olarak traverten breşi kullanılmıştır. Bu breşleri oluşturan taneler Jura yaşlı kireçtaşlarının (Tekedağı formasyonu
kireçtaşları) yamaç molozu olarak birikmiş yığışımlardan oluşmuştur. Kentin Büyük Hamam, Hellenistik Tapınak
ve hamam yapılarında da ana malzeme olarak traverten breşlerinden düzgün olarak kesilmiş bloklar kullanılmıştır. Geç Antikçağ’da kentin depremler nedeniyle onarımlar veya yeniden yapılan duvar ve binalarda ise ilksel
bloklar ve bunların kırılmış parçaları ve çevreden bulunmuş her türlü moloz kullanılmıştır. Bu taşlar genellikle
kumtaşları (kalkarenitik), çört, serpantin, gabro ve bazalt olarak belirlenmiştir. Bu kayaçlar içinde jeolojik olarak
bu bölgede rastlanmayan kuvarsit ve şistlerin bulunması ilginçtir. Ayrıca genellikle çatı kaplaması olarak kullanılan kayraklara rastlanması da bunların limanlararası ticaret yoluyla getirilme olasılığını düşündürmektedir.
Hellensitik tapınakta yapılan kazılar sırasında ortaya çıkarılan sütunlarda gözlenen fosillerden, bu sütunların
olası olarak Üst Kretase yaşlı neritik kireçtaşlarından üretildiği gözlenmiştir. Bu tür oluşumlar bölgeye en yakın
Finike yöresindeki Limyra kireçtaşlarıdır. Phaselis kentinin ana yapı malzemesi olan traverten breşlerinin üretildiği ocak alanı şehrin Hellenistik akropolis ile Antalya-Kumluca Otoyolu’nun güneyindeki alan olarak belirlenmiştir. Bu alanda yapı taşının üretildiği ocak aynaları gözlenmiştir. Doğu Nekropolis alanındaki anıt mezarda
kullanılan traverten breşlerinin yanı sıra yapay olarak üretildiği kanısına varılan bazı sütunlar da belirlenmiştir.
Abstract: Phaselis is a historical site located about 55 km southwest of Antalya. Travertine breccia was used as
the building stone in the city buildings. The grains forming these breccias are composed of accumulated
deposits as slope debris of Jurassic limestones (Tekedağı formation limestones). In the large baths, Hellenistic
temple and bath structures of the city, blocks cut properly from travertine breccias were used as the main
material. In the Late Antiquity, the city was repaired due to earthquakes or rebuilt walls and buildings, while
the primary blocks and their broken pieces and all kinds of debris found from the environment were used.
These stones are generally sandstones (calcarenitic), chert, serpentine, gabbro and basalt. Interestingly, these
rocks contain quartzites and schists that are not geologically encountered in this region. In addition, the
presence of slate, which is generally used as roofing, suggests the possibility of bringing it through inter-port
trade. It was observed that these columns were probably produced from Upper Cretaceous neritic limestones.
Such formations are Limyra limestones in the Finike region closest to the region. The quarry area where
travertine breccias, the main building material of Phaselis was produced, was determined as the area to the
south of the Antalya-Kumluca motorway and the Hellenistic acropolis of the city. Quarry pit benches in which
the building stone was produced were observed in this area. In addition to the travertine breccias used in the
monumental tomb in the East Necropolis, some columns were found to be artificially produced.

Geological mapping and geochemical analyses combined with 40K- 40Ar ages for lavas from the Late Miocene to Quaternary La Purísima volcanic field (Baja California Sur) provide evidence for five volcanic events. These, in turn, may reflect... more

Geological mapping and geochemical analyses combined with 40K- 40Ar ages for lavas from the Late Miocene to Quaternary La Purísima volcanic field (Baja California Sur) provide evidence for five volcanic events. These, in turn, may reflect plate interactions in the region. The oldest event (event 1), prior to 11 Ma, corresponds to the emission of normal to K-rich calc-alkaline lavas, exposed as large mesas in the eastern part of the studied area and as pyroclastic breccias and volcaniclastic sediments to the west. It is associated with the end of the Comondú arc activity resulting from subduction of the Farallon and Guadalupe plates. Between 10.6 and 8.8 Ma (event 2), magnesian andesites and tholeiites were emplaced. At 5.5 Ma (event 3) and 2.5 Ma (event 4) small volumes of magnesian andesites erupted in the central and southern parts of the volcanic field. Finally, between 1.2 Ma and Holocene (event 5), numerous basaltic and magnesian andesitic fissural and central emissions resulted in the formation of strombolian cones and associated lava flows, mainly distributed within a NNW-SSE trending graben located SE of the town of La Purísima. Magmatic events 2 to 5 occurred well after the supposed end of the subduction event. Their geochemical characteristics are still typical of subduction-modified sources and possibly indicate partial melting of hot slab and formation of an asthenospheric window due to a slab rupture event which followed ridge-trench collision, prior to the continental breakup of the Gulf of California extensional province.

The formation of volcanic–sedimentary interaction features in extreme arid environments is not a commonly described process. Specifically the occurrence of dynamically mixed sediments and juvenile igneous clasts as peperites, for water... more

The formation of volcanic–sedimentary interaction features in extreme arid environments is not a commonly described process. Specifically the occurrence of dynamically mixed sediments and juvenile igneous clasts as peperites, for water has been considered one major important factor in the processes of magma dismantling and mingling with unconsolidated sediment to form such deposits. The study area, located in south Brazil, shows a sequence of lava flows and intertrapic sandstone layers from the Paraná Basin, associated with the formation of clastic dykes, flow striations, peperite and ‘peperite-like’ breccias. Four processes are suggested for the genesis of the peperites: (a) fragmentation of the flow front and base; (b) sand injection; (c) dune collapse; (d) magma cascade downhill. The continued flow of a lava, while its outer crust is already cooling, causes it to break, especially in the front and base, fragments falling in the sand and getting mixed with it, generating the flow front ‘peperite-like’ breccia. The weight of the lava flow associated to shear stress at the base cause sand to be injected inwards the flow, forming injection clastic dykes in the cooled parts and injection peperite in the more plastic portions. The lava flow may partially erode the dune, causing the dune to collapse and forming the collapse ‘peperite-like’ breccia. The shear stress at the base of a flowing lava striates the unconsolidated sand, forming the flow striations. The sand that migrates over a cooled, jointed lava flow may get caught in the cavities and joints, forming the filling clastic dykes. These deposits are analogous to those found in the Etendeka, NW Namibia, and show that sediment–lava interactions in arid settings are widespread throughout the Paraná-Etendeka province during the onset of flood volcanism.

20.5.2008 Monthermé………………………………………………………………….. 2 Revin …………………………………………………………………….…. 4 Rocroi ………………………………………………………………………. 5 Fepin ………………………………………………………………….…….. 5 Quarry von Vireux ………………………….……………………………… 6 Le Mur de Vireux-Molheim... more

20.5.2008 Monthermé………………………………………………………………….. 2
Revin …………………………………………………………………….…. 4
Rocroi ………………………………………………………………………. 5
Fepin ………………………………………………………………….…….. 5
Quarry von Vireux ………………………….……………………………… 6
Le Mur de Vireux-Molheim …………………………………..……………. 7

Öz: Phaselis Antalya’nın yaklaşık 55 km güneybatısında yer alan bir ören yeridir. Kentin yapılarında yapı taşı olarak traverten breşi kullanılmıştır. Bu breşleri oluşturan taneler Jura yaşlı kireçtaşlarının (Tekedağı formasyonu... more

Öz: Phaselis Antalya’nın yaklaşık 55 km güneybatısında yer alan bir ören yeridir. Kentin yapılarında yapı taşı olarak traverten breşi kullanılmıştır. Bu breşleri oluşturan taneler Jura yaşlı kireçtaşlarının (Tekedağı formasyonu kireçtaşları) yamaç molozu olarak birikmiş yığışımlardan oluşmuştur. Kentin Büyük Hamam, Hellenistik Tapınak ve hamam yapılarında da ana malzeme olarak traverten breşlerinden düzgün olarak kesilmiş bloklar kullanılmıştır. Geç Antikçağ’da kentin depremler nedeniyle onarımlar veya yeniden yapılan duvar ve binalarda ise ilksel bloklar ve bunların kırılmış parçaları ve çevreden bulunmuş her türlü moloz kullanılmıştır. Bu taşlar genellikle kumtaşları (kalkarenitik), çört, serpantin, gabro ve bazalt olarak belirlenmiştir. Bu kayaçlar içinde jeolojik olarak bu bölgede rastlanmayan kuvarsit ve şistlerin bulunması ilginçtir. Ayrıca genellikle çatı kaplaması olarak kullanılan kayraklara rastlanması da bunların limanlararası ticaret yoluyla getirilme olasılığını düşündürmektedir. Hellensitik tapınakta yapılan kazılar sırasında ortaya çıkarılan sütunlarda gözlenen fosillerden, bu sütunların olası olarak Üst Kretase yaşlı neritik kireçtaşlarından üretildiği gözlenmiştir. Bu tür oluşumlar bölgeye en yakın Finike yöresindeki Limyra kireçtaşlarıdır. Phaselis kentinin ana yapı malzemesi olan traverten breşlerinin üretildiği ocak alanı şehrin Hellenistik akropolis ile Antalya-Kumluca Otoyolu’nun güneyindeki alan olarak belirlenmiştir. Bu alanda yapı taşının üretildiği ocak aynaları gözlenmiştir. Doğu Nekropolis alanındaki anıt mezarda kullanılan traverten breşlerinin yanı sıra yapay olarak üretildiği kanısına varılan bazı sütunlar da belirlenmiştir.
Abstract: Phaselis is a historical site located about 55 km southwest of Antalya. Travertine breccia was used as the building stone in the city buildings. The grains forming these breccias are composed of accumulated deposits as slope debris of Jurassic limestones (Tekedağı formation limestones). In the large baths, Hellenistic temple and bath structures of the city, blocks cut properly from travertine breccias were used as the main material. In the Late Antiquity, the city was repaired due to earthquakes or rebuilt walls and buildings, while the primary blocks and their broken pieces and all kinds of debris found from the environment were used. These stones are generally sandstones (calcarenitic), chert, serpentine, gabbro and basalt. Interestingly, these rocks contain quartzites and schists that are not geologically encountered in this region. In addition, the presence of slate, which is generally used as roofing, suggests the possibility of bringing it through inter-port trade. It was observed that these columns were probably produced from Upper Cretaceous neritic limestones. Such formations are Limyra limestones in the Finike region closest to the region. The quarry area where travertine breccias, the main building material of Phaselis was produced, was determined as the area to the south of the Antalya-Kumluca motorway and the Hellenistic acropolis of the city. Quarry pit benches in which the building stone was produced were observed in this area. In addition to the travertine breccias used in the monumental tomb in the East Necropolis, some columns were found to be artificially produced.

Recent studies on shallow-level arcuate intrusions have identified numerous examples of horizontal mineral fabrics. These are commonly interpreted as reflecting considerable lateral flow during magma emplacement, thus querying established... more

Recent studies on shallow-level arcuate intrusions have identified numerous examples of horizontal mineral fabrics. These are commonly interpreted as reflecting considerable lateral flow during magma emplacement, thus querying established 'semi-vertical'ring-dyke models. We question the recent lateral emplacement model proposed for the Palaeocene Slieve Gullion Ring-complex, NE Ireland, where the absence of steep fabrics in parts of the ring-complex has been used to support a shallow, semi-horizontal ...