TY - JOUR N2 - The Panorama Point Beds represent a subfacies of the Early to Middle Permian Radok Conglomerate, which is the oldest known sedimentary unit in the Prince Charles Mountains, MacRobertson Land, East Antarctica. This unit records clastic sedimentation in fresh−water depositional system during the early stages of development of the Lambert Graben, a major structural valley surrounded by crystalline highlands in the southern part of Gondwana. It contains common siderite precipitated through early diagenetic processes in the swamp, stagnant water, and stream−flow environments. There are two types of siderite in the Panorama Point Beds: (1) disseminated cement that occurs throughout the sedimentary suc− cession; and (2) concretions that occur at recurrent horizons in fine−grained sediments. The cement is composed of Fe−depleted siderite (less than 90mol%FeCO3)with an elevated con− tent of magnesium, and trace and rare earth elements. It has negative δ13CVPDB values (−4.5 to −1.5‰). The concretions are dominated by Fe−rich siderite (more than 90mol% FeCO3),with positive δ13CVPDB values (+1 to +8‰). There are no noticeable differences in the oxygen (δ18OVPDB between −20 and −15‰) and strontium (δ87Sr/86Sr between 0.7271 and 0.7281) iso− topic compositions between the siderite types. The cement and concretions developed in the nearsurface to subsurface environment dominated by suboxic and anoxic methanic degrada− tion of organic matter, respectively. The common presence of siderite in the Panorama Point Beds suggests that fresh−water environments of the Lambert Graben were covered by vegetation, starting from the early history of its development in the Early Permian. L1 - http://journals.pan.pl/Content/108307/PDF-MASTER/article-p169.pdf L2 - http://journals.pan.pl/Content/108307 PY - 2010 IS - No 2 EP - 194 KW - Antarctica KW - Prince Charles Mts KW - Radok Conglomerate KW - Permian KW - siderite KW - fresh−water environment A1 - Krajewski, Krzysztof P. A1 - Gonzhurov, Nikolai A. A1 - Laiba, Anatoly A. A1 - Tatur, Andrzej PB - Polish Academy of Sciences PB - Committee on Polar Research DA - 2010 T1 - Early diagenetic siderite in the Panorama Point Beds (Radok Conglomerate, Early to Middle Permian), Prince Charles Mountains, East Antarctica SP - 169 UR - http://journals.pan.pl/dlibra/publication/edition/108307 T2 - Polish Polar Research ER -