Strontium isotopes and sedimentology of a marine Triassic succession (upper Ladinian) of the westernmost Tethys, Spain

Chemical Stratigraphy, or the study of the variation of chemical elements within sedimentary sequences, has gradually become an experienced tool in the research and correlation of global geologic events. In this paper 87Sr/ 86Sr ratios of the Triassic marine carbonates (Muschelkalk facies) of southeast Iberian Ranges, Iberian Peninsula, are presented and the representative Sr-isotopic curve constructed for the upper Ladinian interval. The studied stratigraphic succession is 102 meters thick, continuous, and well preserved. Previous paleontological data from macro and micro, ammonites, bivalves, foraminifera, conodonts and palynological assemblages, suggest a Fassanian-Longobardian age (Late Ladinian). Although diagenetic minerals are present in small amounts, the elemental data content of bulk carbonate samples, especially Sr contents, show a major variation that probably reflects palaeoenvironmental changes. The 87Sr/86Sr ratios curve shows a rise from 0.707649 near the base of the section to 0.707741 and then declines rapidly to 0.707624, with a final values rise up to 0.70787 in the upper part. The data up to meter 80 in the studied succession is broadly concurrent with 87Sr/86Sr ratios of sequences of similar age and complements these data. Moreover, the sequence stratigraphic framework and its key surfaces, which are difficult to be recognised just based in the facies analysis, are characterised by combining variations of the Ca, Mg, Mn, Sr and CaCO3 contents

Discovery and settlement of Alaska coaster

Tsar Peter the Great ruled Russia between 1689 and 1725. Its domains, stretching from the Baltic Sea in the west to the Pacific Ocean in the east. From north to south, its empire stretching from the Arctic Ocean to the borders with China and India. Tsar Peter I tried to extend the geographical knowledge of his government and the rest of the world. He was also interested in the expansion of trade in Russia and in the control of trade routes. Feodor Luzhin and Ivan Yeverinov explored the eastern border of the Russian Empire, the trip between 1719 and 1721 and reported to the Tsar. They had crossed the peninsula of Kamchatka, from west to east and had traveled from the west coast of Kamchatka to the Kuril Islands. The information collected led to the first map of Kamchatka and the Kuril Islands. Tsar Peter ordered Bering surf the Russian Pacific coast, build ships and sail the seas north along the coast to regions of America. The second expedition found equal to those of the previous explorers difficulties. Two ships were eventually thrown away in Okhotsk in 1740. The explorers spent the winter of 1740-1741 stockpiling supplies and then navigate to Petropavlovsk. The two ships sailed eastward and did together until June 20, then separated by fog. After searching Chirikov and his boat for several days, Bering ordered the San Pedro continue to the northeast. There the Russian sailors first sighted Alaska. According to the log, "At 12:30 (pm July 17) in sight of snow-capped mountains and between them a high volcano." This finding came the day of St. Elijah and so named the mountain.

Civic Humanism and the Classical Tradition in the Early Republic of Chile

The first decades of the 19th century constituted a period of profound change for Chile, the principal results of which were to be seen in the consolidation of the process of independence from Spanish dominion in 1818. The consequences were not limited to a revolution of military and political nature; they also included a renovation of the cultural panorama -at least among the educated patriots who made an effort to distance themselves ideologically from the Monarchy-, with the implicit challenge of establishing a new order for Chile, based on legitimate and universally recognizable foundations. The inspirational framework for these efforts is usually associated with other revolutionary examples -France and the United States- that preceded the emancipation processes in Spanish America, as well as with the discourses of illustrated liberalism. As we will attempt to demonstrate in this study, a new reading of the texts written by the Creoles that lead the Chilean independence process may, nonetheless, also reveal the relevance of the classical tradition as a model for the configuration and legitimization of the first Republican projects that especially admired the ideals of Republicanism.