【摘要】 大量地质地球化学证据表明,晚泥盆世丹池盆地內有热水活动。热水活动使盆地内的碳酸盐沉积物发生了准同生硅化作用,淋虑溶蚀作用及广泛准同生重结晶作用。与一般灰岩受热重结晶作用中δ¹³C值的变化相反,在准同生重结晶灰岩中,方解石的结晶程度愈高,则δ¹³C值反而愈大。我们认为这是碳酸盐不饱和的热水溶液对碳酸盐沉积物中轻碳同位素(¹²C)优先淋滤的结果。更多还原

【Abstract】 Many lines of geological and geochemical evidence show that there did occur hydrother-mal fluid activity in the Late Devonian Danchi Basin. As a result, carbonate sediments suffered leaching, dissolution and silicification.In the sub-syngenetic recrystalline limestone there has been found a positive correlation between the recrystallinity of calcite and the S13C value, i.e., the greater the recrystallinity, the higher the 613C value. This may be due to preferential leaching of light carbon isotope (12C) out of carbonate sediments by hydrothermal fluids.更多还原