Major-element and Li, Be compositional evolution of tourmaline in an S-type granite-pegmatite system and its country rocks: an example from Ikaria, Aegean Sea, Greece

2011 ◽  
Vol 49 (1) ◽  
pp. 321-340 ◽  
Author(s):  
D. C. Hezel ◽  
A. Kalt ◽  
H. R. Marschall ◽  
T. Ludwig ◽  
H.-P. Meyer
Quaternary ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 6
Author(s):  
Christopher Satow ◽  
Katharine M. Grant ◽  
Sabine Wulf ◽  
Hartmut Schulz ◽  
Addison Mallon ◽  
...  

The Eemian was the last interglacial period (~130 to 115 ka BP) to precede the current interglacial. In Eastern Mediterranean marine sediments, it is marked by a well-developed and organic-rich “sapropel” layer (S5), which is thought to reflect an intensification and northward migration of the African monsoon rain belt over orbital timescales. However, despite the importance of these sediments, very little proxy-independent stratigraphic information is available to enable rigorous correlation of these sediments across the region. This paper presents the first detailed study of visible and non-visible (cryptotephra) layers found within these sediments at three marine coring sites: ODP Site 967B (Levantine Basin), KL51 (South East of Crete) and LC21 (Southern Aegean Sea). Major element analyses of the glass component were used to distinguish four distinct tephra events of Santorini (e.g., Vourvoulos eruption) and possible Anatolian provenance occurring during the formation of S5. Interpolation of core chronologies provides provisional eruption ages for the uppermost tephra (unknown Santorini, 121.8 ± 2.9 ka) and lowermost tephra (Anatolia or Kos/Yali/Nisyros, 126.4 ± 2.9 ka). These newly characterised tephra deposits have also been set into the regional tephrostratigraphy to illustrate the potential to precisely synchronise marine proxy records with their terrestrial counterparts, and also contribute to the establishment of a more detailed volcanic history of the Eastern Mediterranean.


2020 ◽  
Vol 6 (17) ◽  
pp. eaaz0424 ◽  
Author(s):  
Andrea Giuliani ◽  
D. Graham Pearson ◽  
Ashton Soltys ◽  
Hayden Dalton ◽  
David Phillips ◽  
...  

Quantifying the compositional evolution of mantle-derived melts from source to surface is fundamental for constraining the nature of primary melts and deep Earth composition. Despite abundant evidence for interaction between carbonate-rich melts, including diamondiferous kimberlites, and mantle wall rocks en route to surface, the effects of this interaction on melt compositions are poorly constrained. Here, we demonstrate a robust linear correlation between the Mg/Si ratios of kimberlites and their entrained mantle components and between Mg/Fe ratios of mantle-derived olivine cores and magmatic olivine rims in kimberlites worldwide. Combined with numerical modeling, these findings indicate that kimberlite melts with highly variable composition were broadly similar before lithosphere assimilation. This implies that kimberlites worldwide originated by partial melting of compositionally similar convective mantle sources under comparable physical conditions. We conclude that mantle assimilation markedly alters the major element composition of carbonate-rich melts and is a major process in the evolution of mantle-derived magmas.


2016 ◽  
Vol 2 (2) ◽  
Author(s):  
Deny Setiady ◽  
Faturachman Faturachman

Granit tipe I dan Tipe S tersebar sepanjang Kepulauan Riau. Di Pulau Batam dan Pulau Bintan, yang menerus dari jalur granit Johor Penensular, Malaysia. Granit-granit tersebut menerus secara alamiah dari Provinsi granit Johor sebelah Timur menerus ke kepulauan Riau sampai Bangka Belitung. Ciri granit tipe I berwarna pink biotit hadir berwarna colat gelap, mempunyai komposisi kimia SiO2 antara 53% -76%, kandungan CaO Na2O yang tinggi, kandungan Sr tinggi dan Rb rendah. Ciri granit tipe S biasanya berwarna abu-abu, hornblenda jarang ditemukan, komposisi kimia SiO2 berkisar antara 66% - 76%, mempunyai kandungan CaO dan Na2O yang rendah, biasanya Sr rendah dan Rb tinggi. (Chappel dan white, 1983) Berdasarkan Analisa data megaskopis granit di pantai Pulau Batam sebelah utara (PBT-14) dan PBT-12, berwarna abu-abu dengan tekstur afanitik, mengandung orthoklase (45%), Quartz (20), Biotite (15), Hornblende (5%) dan Plagioclase (10%). sedangkan di tengah -tengah (PBT-13) berwarna kemerahan, ukuran butir menengah sampai kasar,mengandung Orthoklase, kuarsa, Plagioklas hal ini menunjukkan bahwa terdapat perbedaan tipe granit di Pulau Batam yaitu tipe I dan Tipe S. Sedangkan di Pulau Bintan sama dengan PBT-13 yaitu kemerahan, tekstur fanerik yaitu ciri dari tipe I. Berdasarkan analisa petrografis sampel di 3 lokasi di Pulau Batam terdiri dari plagioklas, orthoklas, kuarsa, biotit dan mineral opak. Demikian juga di Pulau Bintan tidak ditemukan hornblenda, kemungkinan tipe S Hal ini menunjukkan bahwa granit di daerah selidikan mempunyai tipe S, karena hornblenda tidak ditemukan. Kandungan senyawa SiO2 yang tinggi di P. Bintan (> 63,55%), kandungan CaO (< 0,99%), dan Na2O (< 3,02%) yang rendah, Serta unsur tanah jarang Sr (>4 ppm), yang tinggi, maka disimpulkan bahwa tipe granit di daerah Bintan adalah Tipe S. Di P. Batam Kandungan SiO2 yang tinggi ( > 71,39%), Kandungan CaO (0,14%- 3,48%), dan Na2O (< 3,33%) yang rendah, Serta unsur tanah jarang Sr (> 17 ppm), yang tinggi, maka tipe granit di daerah Bintan adalah Tipe S. Granites S and I Type are distributed throughout the archipelago, which lie immediately to the south of Johorein Peninsular Malaysia. These granites seem to form a natural continuation of the eastern province granites in Johor to Riau Archipelago until Bangka and Belitung Island. I Type Granite show pink colour in megascopis speciment, SiO2 composition between 53% - 76%, high content Cao and Na2O, higih content Sr and low content Rb. S type granite shows greeyish, no present hornblende, SiO2 composition between 53% - 76%, Low content CaO and Na2O, Granite in the eastern coast of Batam Island in (PBT-14 and PBT-12) are greeyish, afanitic texture is made up of an orthoclase, Quartz, Biotite, Hornblende and Plagioclase. While granite in the middle (PBT-13), reddish, medium to coarse grained, Orthoclase, quartz, Plagioclase. This description shows that granite in Batam is I type and S type, while in Bintan Island is I Type. Base on petrography's analysis in 3 location in Batam island Granite, greeyish, faneric texture, medium - coarse grained, holocrystalyne, hipidiomorfic - allotriomorfic. Orthoclase, quartz, Plagioclase, Biotite, Opaque Mineral. While granite in Bintan island are gray, faneric texture medium to coarse grain, holocristalyn - alotriomorfic, consists of Plagioclase, Orthoclase, quartz and Biotite. These analysis shows that Granit in Batam and Bintan island are S Type because hornblende is not found. Base on Chemist Analysis Major element in Bintan island consists of high content SiO2 (> 63,55), and CaO (< 0,99%), Na2O (< 3,02%) are low Content. Trace element is high content Strontium (>4 PPM ). These analysis shows that granite in Bintan island are S Type. Major element in Bintan island consists of high content SiO2 (>71,39%), and CaO (<0,14%), Na2O (<0,18% ) are low Content. Trace element is high content Strontium (> 17 PPM ). These analysis shows that granite in Bintan island are S Type.


Author(s):  
Nikolay Esin ◽  
Nikolay Esin ◽  
Vladimir Ocherednik ◽  
Vladimir Ocherednik

A mathematical model describing the change in the Black Sea level depending on the Aegean Sea level changes is presented in the article. Calculations have shown that the level of the Black Sea has been repeating the course of the Aegean Sea level for the last at least 6,000 years. And the level of the Black Sea above the Aegean Sea level in the tens of centimeters for this period of time.


2007 ◽  
Vol 7 (1) ◽  
pp. 253-260 ◽  
Author(s):  
T. Theodoulou ◽  
C. Memos

Limenoscope is a web based database aiming at promoting the cultural heritage regarding ancient Greek harbours and disseminate the relevant information equally to the general public and to researchers with an interest in that particular cognitive field. The scope of the project is the realization of a database, where one can search for concise information relevant to the historical role, the topography, the morphology, as well as the technical works and installations of ancient harbours in the Mediterranean and the Black Sea. The Database started off with the registration of harbours located in the Aegean Sea and Cyprus, dating from Archaic to Byzantine times. Special emphasis is laid on the bibliographical update of the data forms of the harbour sites, as well as on the related references in ancient literature. The database enables the locating of these sites on a general map, where photographs, plans etc. are also archived. The principles of the database structure are briefly presented along with an example, that of the harbour of Phalasarna, among the harbours registered therein.


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