Formacje metalogeniczne w utworach kredowych na obszarach platformowych Europy i na terenach przyległych

Abstract

W epikontynentalnych i śródlądowych utworach kredy na obszarze Europy i na terenach przyległych wyróżniono formację żelazonośną (RFN, Wielka Brytania, Francja, Polska, obszar chopiorski, obrzeżenie Uralu), fosforytonośną (polska, Bułgaria, basen paryski, Belgia, obszar wiatsko-kamski, saratowski, brański, kurski, Turcja, Syria, Jordania) i boksytonośną (Francja, obrzeżenie tarczy ukraińskiej, obszar górnotobolski) oraz inne surowce mineralne jak: rudy manganu, tytanu, strontu, glaukonit, surowce skaleniowe, krzemionkowe, bentonity i kaoliny. METALLOGENIC FORMATIONS OF THE CRETACEOUS IN PLATFORM AREAS OF EUROPE AND THE ADJACENT ONESThe paper presents general characteristics of metallogenic formations of strata of platform Cretaceous cover in Europe and adjacent areas. In sections of epicontinental and inland basins there are differentiated the iron-, phosphate-, and bauxite-bearing formations as well as occurrences of mineral raw materials not assigned to any formations, e.g. ores of manganese, tithanium, strontium, and other metals.In the Cretaceous times, the epicontinental basin was connected by narrow seaways with the Tethyan sea and, in the west, the northern Atlantic, being delineated by the Scandinavian landmass in the north. It was subdivided by islands and shoals into several separate subbasins, differing in development of strata of individual stages. The origin of iron ores and phosphates was related to times of transgressions and regressions.Major iron ore deposits are known from the area of F.R.G.: Salzgitter and Haverlahviese (Hauterivian- Albin), Oberpfalz-Auerbach (Cenomanian), and Peine-Ilsede (Santonian) and Damme (Campanian). They represent oolitic-detrital deposits, formed in result of erosion of older rocks in the course of origin of salt domes. Phosphates originated in Poland and Bulgaria in the Albian, and the Paris Basin and Belgium in the Maastrichtian. In areas of the East-European Platform, the Aptian and older Lower Cretaceous rocks are developed in marine and continental facies, and the Albian - in marine sandy-glauconitic ones. The extent of the shallow epicontinental sea was the greatest in the Late Cretaceous. Formation of iron ores continued in the vicinities of Orel (Chopiorskoye deposit) from the Cenomanian to Maastrichtian, in result of weathering of carbonate rocks in a land area. Phosphates are found in several horizons of the Cretaceous, especially the Valanginian-Santonian, in the Viatsk-Kam, Saratov, Briansk, and Kursk areas.Iron and bauxite deposits were formed at the margin of the Urals, in western part of the western Siberian platform.In areas of the North African Platform, sedimentation of continental rocks continued from the Triassic to Cenomanian, to be broken in the Late Cenomanian by a marine transgression which came from the Mediterranean Sea. The Upper Cretaceous and Tertiary are represented by marine sediments.In the Early Cretaceous, the major part of the Arabian Platform was emerged. The exception was here the Mesopotamian Basin, in which marine sediments were accumulated. In the Late Cretaceous (Albian) to Paleogene times, there took place sedimentation of marls and dolomites as well as marly limestone rocks of the shallow-marine facies, with phosphate-bearing horizons in Turkey, Syria, Jordan and Israel.