Tourmaline Composition of the Kı¸sladag Porphyry Au Deposit,Western Turkey: Implication of Epithermal Overprint

The Kışladağ porphyry Au deposit occurs in a middle Miocene magmatic complex comprising three different intrusions and magmatic-hydrothermal brecciation related to the multiphase effects of the different intrusions. Tourmaline occurrences are common throughout the deposit, mostly as an outer alteration rim around the veins with lesser amounts disseminated in the intrusions, and are associated with every phase of mineralization. Tourmaline mineralization has developed as a tourmaline-rich matrix in brecciated zones and tourmaline-quartz and/or tourmaline-sulfide veinlets within the different intrusive rocks. Tourmaline was identified in the tourmaline-bearing breccia zone (TBZ) and intrusive rocks that had undergone potassic, phyllic, and advanced argillic alteration. The tourmaline is present as two morphological varieties, aggregates of fine crystals (rosettes, fan-shaped) and larger isolated crystals and their aggregates. Four tourmaline generations (tourmaline I to IV) have different compositions and substitutions. Tourmaline I in TBZ and INT#1 is distinguished by the highest Fetot and enriched in Fe3+. Tourmalines II and III occur as fine aggregates, accompanied by the formation of isolated crystals and are characterized by lower Fetot and Fe3+. Tourmaline IV is characterized by the lowest Fetot, enriched in Cl, and has the highest proportion of X-site vacancy among all the tourmalines. Tourmaline I may be attributed to the potassic stage in INT#1 and early tourmaline in TBZ. Tourmalines II and III from INT#1 and the TBZ could be referred to the phyllic stage. The low Fe content in tourmaline is caused by the simultaneous deposition of sulfide minerals. Tourmaline IV from the TBZ and tourmaline II from INT#3 are distinguished by the high X-site vacancy proportion up to the formation of X-site vacant species as well as enriched in Cl; they can be attributed to the argillic stage of the hydrothermal process. The textural and especially chemical data of the tourmaline from the Kışladağ Au deposit provide information on the physico-chemical conditions during the porphyry to epithermal transition and subsequent epithermal overprinting

Trace Anomaly in Quantum Spacetime Manifold

In this paper we investigate the trace anomaly in a spacetime where single events are de-localized as a consequence of short distance quantum coordinate fluctuations. We obtain a modified form of heat kernel asymptotic expansion which does not suffer from short distance divergences. Calculation of the trace anomaly is performed using an IR regulator in order to circumvent the absence of UV infinities. The explicit form of the trace anomaly is presented and the corresponding 2D Polyakov effective action and energy momentumtensor are obtained. The vacuum expectation value of the energy momentum tensor in the Boulware, Hartle-Hawking and Unruh vacua is explicitly calculated in a (rt)-section of a recently found, noncommutative geometry inspired, Schwarzschild-like solution of the Einstein equations. The standard short distance divergences in the vacuum expectation values are regularized in agreement with the absence of UV infinities removed by quantum coordinate fluctuations.Comment: 15pages, RevTex, no figures, 1 Tabl

Fluid Inclusion Characteristics of the Kışladağ Porphyry Au Deposit, Western Turkey

The deposit occurs in a mid-Miocene monzonite magmatic complex represented by three different intrusions, namely Intrusion 1 (INT#1), Intrusion 2 (INT#2, INT #2A), and Intrusion 3 (INT#3). Gold mineralization is hosted in all intrusions, but INT#1 is the best mineralized body followed by INT#2. SEM-CL imaging has identified two different veins (V1 and V2) and four distinct generations of quartz formation in the different intrusions. These are: (i) CL-light gray, mosaic-equigranular quartz (Q1), (ii) CL-gray or CL-bright quartz (Q2) that dissolved and was overgrown on Q1, (iii) CL-dark and CL-gray growth zoned quartz (Q3), and (iv) CL-dark or CL-gray micro-fracture quartz fillings (Q4). Fluid inclusion studies show that the gold-hosted early phase Q1 quartz of V1 and V2 veins in INT#1 and INT#2 was precipitated at high temperatures (between 424 and 594 °C). The coexisting and similar ranges of Th values of vapor-rich (low salinity, from 1% to 7% NaCl equiv.) and halite-bearing (high salinity: >30% NaCl) fluid inclusions in Q1 indicates that the magmatic fluid had separated into vapor and high salinity liquid along the appropriate isotherm. Fluid inclusions in Q2 quartz in INT#1 and INT#2 were trapped at lower temperatures between 303 and 380 °C and had lower salinities between 3% and 20% NaCl equiv. The zoned Q3 quartz accompanied by pyrite in V2 veins of both INT#2 and INT#3 precipitated at temperatures between 310 and 373 °C with a salinity range from 5.4% to 10% NaCl eq. The latest generation of fracture filling Q4 quartz, cuts the earlier generations with fluid inclusion Th temperature range from 257 to 333 °C and salinity range from 3% to 12.5% NaCl equiv. The low salinity and low formation temperature of Q4 may be due to the mixing of meteoric water with the hydrothermal system, or late-stage epithermal overprinting. The separation of the magmatic fluid into vapor and aqueous saline pairs in the Q1 quartz of the V1 vein of the INT#1 and INT#2 and CO2-poor fluids indicates the shallow formation of the Kışladağ porphyry gold deposit

Çöpler (Erzincan, İç-Doğu Anadolu) Porfiri-Epitermal Altın Yatağında Arjilik Alterasyona İlişkin Mineralojik Kanıtlar (Mineralogical Evidences on Argillic Alteration in the Çöpler Porphyry-Epithermal Gold Deposit) (Erzincan, East-Central Anatolia)

Çöpler porfiri-epitermal altın yatağı, Tetis Alpin-Himalaya orojenik kuşağında açılmalı tektonizma sonucu gelişen orta Eosen yaşlı plütonik sokulumlarla ilişkili bir altın yatağıdır. Plütonik kayaçlar (granodiyorit porfir, diyorit porfir) Geç Paleozoyik-Mesozoyik yaşlı metapelit ve metakarbonat kayaçlar içerisine sokulum yaparak porfiri-epitermal bir Cu-Au yatağı oluşturmuş ve hidrotermal alterasyon zonlarının (potasik, fillik, propilitik, arjilik) gelişimine neden olmuştur. Bu çalışmada, önceki araştırmacılarca yerel ve sınırlı alanda geliştiği belirtilen süperjen alterasyonun aksine, geniş yayılım sunan arjilik alterasyon zonlarının mineralojik-petrografik özelliklerinin ortaya konulması amaçlanmıştır. Bu kapsamda, optik ve taramalı elektron mikroskop (SEM ve SEM-EDS), X-ışınları kırınımı (XRD), O-H izotop jeokimyası ve K/Ar yaş tayini incelemeleri gerçekleştirilmiştir. Aşırı killeşmiş granodiyorit porfirlerde bile, ilksel porfiritik doku izlenebilmekte, ince-kristalli kil ve kuvarslar homojen ve yer yer mikrolaminasyonlar şeklinde gözlenmektedir. Simektit ve karışık-tabakalı illit-simektit (I-S) mineralleri yapraksıtüysü, illit ve kaolinitler levhamsı biçimler sergilemektedir. Kuvars ve jarositler özşekilli kristaller, kristobalitler kurtçuk görünümlü, bu çalışmada ilk kez belirlenen krandallitler ise ince-taneli granüler topluluklar şeklinde gözlenmektedir. Arjilik zona ait örnekler fillik zona yakın iç kesimlerde (ileri arjilik zon) kuvars + I-S, kuvars + krandallit + jarosit ve kristobalit, dış kesimlerde (arjilik zon) ise kuvars + simektit + kaolinit birliktelikleri sergilemektedir. Simektitler dioktahedral bileşime sahiptir (d060<1.500 Å, oktahedral Al=1.47-1.66). I-S mineralleri yüksek illit bileşenli (I85-S15) ve R3 tipi ara tabakalanmaya sahip olup, oktahedral Al ve yapraklar arası K içerikleri sırasıyla 1.66-1.71 ve 0.58-0.75 arasında değişmektedir. I-S’lerin O-H izotop bileşimi, düşük sıcaklık koşullarında ve magmatik suyun baskın olduğu bir oluşumu işaret etmektedir. Jarosit içeren örneğin K/Ar yaş verisi (43.6 ± 1.0 My), arjilik alterasyonun plütonik sokulum sırasında veya hemen sonrasında (<1 My) başladığına işaret etmektedir. Elde edilen bulgular, Çöpler porfiriepitermal altın yatağında geniş yayılım sunan, düşük sıcaklık (<200 ºC) ve asidik koşullarda gelişmiş, alüminyum fosfat ve demir sülfat minerallerinin de geliştiği bir arjilik alterasyonun varlığını ortaya koymaktadır. (The Çöpler porphyry-epithermal gold deposit is associated with middle Eocene intrusive rocks related to an extensional tectonic phase in the Tethyan Alpine-Himalayan orogenic belt. The intrusive rocks (granodiorite porphyry and diorite porphyry) were emplaced into Late Paleozoic–Mesozoic metapelite and metacarbonate rocks creating the porphyry-epithermal Cu-Au deposit and hydrothermal alteration zones (potassic, phyllic, propylitic, argillic). The mineralogic-petrographic and geochemical properties of the extensive argillic alteration zones (not supergene alteration described previously) were determined by optical and scanning electron microscopy (SEM and SEM-EDS), X-ray diffraction (XRD), O-H isotope geochemistry and K-Ar dating. Within the primary porphyritic texture, fine-grained clay and quartz crystals are present as homogeneous and partly micro-laminations in the more intensely argillized granodiorite porphyry. Smectite and mixed-layer illite-smectite (I-S) minerals exhibit flaky/sponge-like and fibrous shapes, respectively, whereas illites and kaolinites show platy/tabular crystal shapes. Quartz and jarosite have euhedral crystals, cristobalites and crandallites (first determined here) are shown as worm-like and fine-grained granular aggregates, respectively, developed within the pores indicating direct precipitation from the hydrothermal fluids. The samples from the argillic zone display quartz + I-S in the inner parts (advanced argillic zone) close to phyllic zone, whereas quartz + smectite + kaolinite associations are towards outer parts (argillic zone). Smectites have a dioctahedral composition (d060<1.500 Å, octahedral Al=1.47-1.66 a.p.f.u). I-S minerals have a high illite component (I85-S15) with R3 type ordering of interlayering. The tetrahedral Al and interlayer K contents are 1.66-1.71 and 0.58-0.75, respectively. Oxygen and hydrogen isotope composition of I-S indicate the low temperature conditions from the magmatic water dominant fluids. K/Ar age data from jarosite-bearing sample (43.6±1.0 My) indicates that the argillic alteration started during or shortly after (<1 Ma) the plutonic intrusion. The data demonstrate the argillic alteration was widely distributed and developed under low temperature (<200 ºC), acidic conditions in association with the aluminum phosphate and iron phosphate minerals.

Are there Local Minima in the Magnetic Monopole Potential in Compact QED?

We investigate the influence of the granularity of the lattice on the potential between monopoles. Using the flux definition of monopoles we introduce their centers of mass and are able to realize continuous shifts of the monopole positions. We find periodic deviations from the $1/r$-behavior of the monopole-antimonopole potential leading to local extrema. We suppose that these meta-stabilities may influence the order of the phase transition in compact QED.Comment: 11 pages, 5 figure

Optimizing fire station locations for the Istanbul metropolitan municipality

Copyright @ 2013 INFORMSThe Istanbul Metropolitan Municipality (IMM) seeks to determine locations for additional fire stations to build in Istanbul; its objective is to make residences and historic sites reachable by emergency vehicles within five minutes of a fire station’s receipt of a service request. In this paper, we discuss our development of a mathematical model to aid IMM in determining these locations by using data retrieved from its fire incident records. We use a geographic information system to implement the model on Istanbul’s road network, and solve two location models—set-covering and maximal-covering—as what-if scenarios. We discuss 10 scenarios, including the situation that existed when we initiated the project and the scenario that IMM implemented. The scenario implemented increases the city’s fire station coverage from 58.6 percent to 85.9 percent, based on a five-minute response time, with an implementation plan that spans three years

On "full" twisted Poincare' symmetry and QFT on Moyal-Weyl spaces

We explore some general consequences of a proper, full enforcement of the "twisted Poincare'" covariance of Chaichian et al. [14], Wess [50], Koch et al. [34], Oeckl [41] upon many-particle quantum mechanics and field quantization on a Moyal-Weyl noncommutative space(time). This entails the associated braided tensor product with an involutive braiding (or $\star$-tensor product in the parlance of Aschieri et al. [3,4]) prescription for any coordinates pair of $x,y$ generating two different copies of the space(time); the associated nontrivial commutation relations between them imply that $x-y$ is central and its Poincar\'e transformation properties remain undeformed. As a consequence, in QFT (even with space-time noncommutativity) one can reproduce notions (like space-like separation, time- and normal-ordering, Wightman or Green's functions, etc), impose constraints (Wightman axioms), and construct free or interacting theories which essentially coincide with the undeformed ones, since the only observable quantities involve coordinate differences. In other words, one may thus well realize QM and QFT's where the effect of space(time) noncommutativity amounts to a practically unobservable common noncommutative translation of all reference frames.Comment: Latex file, 24 pages. Final version to appear in PR

Pruning Algorithms for Low-Dimensional Non-metric k-NN Search: A Case Study

We focus on low-dimensional non-metric search, where tree-based approaches permit efficient and accurate retrieval while having short indexing time. These methods rely on space partitioning and require a pruning rule to avoid visiting unpromising parts. We consider two known data-driven approaches to extend these rules to non-metric spaces: TriGen and a piece-wise linear approximation of the pruning rule. We propose and evaluate two adaptations of TriGen to non-symmetric similarities (TriGen does not support non-symmetric distances). We also evaluate a hybrid of TriGen and the piece-wise linear approximation pruning. We find that this hybrid approach is often more effective than either of the pruning rules. We make our software publicly available

Genome-Wide Transcriptional Reorganization Associated with Senescence-to-Immortality Switch during Human Hepatocellular Carcinogenesis

Cataloged from PDF version of article.Senescence is a permanent proliferation arrest in response to cell stress such as DNA damage. It contributes strongly to tissue aging and serves as a major barrier against tumor development. Most tumor cells are believed to bypass the senescence barrier (become "immortal") by inactivating growth control genes such as TP53 and CDKN2A. They also reactivate telomerase reverse transcriptase. Senescence-to-immortality transition is accompanied by major phenotypic and biochemical changes mediated by genome-wide transcriptional modifications. This appears to happen during hepatocellular carcinoma (HCC) development in patients with liver cirrhosis, however, the accompanying transcriptional changes are virtually unknown. We investigated genome-wide transcriptional changes related to the senescence-to-immortality switch during hepatocellular carcinogenesis. Initially, we performed transcriptome analysis of senescent and immortal clones of Huh7 HCC cell line, and identified genes with significant differential expression to establish a senescence-related gene list. Through the analysis of senescence-related gene expression in different liver tissues we showed that cirrhosis and HCC display expression patterns compatible with senescent and immortal phenotypes, respectively; dysplasia being a transitional state. Gene set enrichment analysis revealed that cirrhosis/senescence-associated genes were preferentially expressed in non-tumor tissues, less malignant tumors, and differentiated or senescent cells. In contrast, HCC/immortality genes were up-regulated in tumor tissues, or more malignant tumors and progenitor cells. In HCC tumors and immortal cells genes involved in DNA repair, cell cycle, telomere extension and branched chain amino acid metabolism were up-regulated, whereas genes involved in cell signaling, as well as in drug, lipid, retinoid and glycolytic metabolism were down-regulated. Based on these distinctive gene expression features we developed a 15-gene hepatocellular immortality signature test that discriminated HCC from cirrhosis with high accuracy. Our findings demonstrate that senescence bypass plays a central role in hepatocellular carcinogenesis engendering systematic changes in the transcription of genes regulating DNA repair, proliferation, differentiation and metabolism