The Fengjia barite–fluorite deposit in southeast Sichuan is a stratabound ore deposit which occurs mainly in Lower Ordovician carbonate rocks. Here we present results from fluid inclusion and oxygen and hydrogen isotope studies to determine the nature and origin of the hydrothermal fluids that generated the deposit. The temperature of the ore‐forming fluid shows a range of 86 to 302 °C. Our detailed microthermometric data show that the temperature during mineralization of the fluorite and barite in the early ore‐forming stage was higher than that during the formation of the calcite in the late ore‐forming stage. The salinity varied substantially from 0.18% to 21.19% NaCl eqv., whereas the density was around 1.00 g/cm3. The fluid composition was mainly H2O (>91.33%), followed by CO2, CH4 and traces of C2H6, CO, Ar, and H2S. The dominant cation was Na+ and the dominant anion Cl‐, followed by Ca2+, SO42‐, K+, and Mg2+, indicating a mid–low‐temperature, mid‐low‐salinity, low‐density NaCl–H2O system. Our results demonstrate that the temperature decreased during the ore‐forming process and the fluid system changed from a closed reducing environment to an open oxidizing environment. The hydrogen and oxygen isotope data demonstrate that the hydrothermal fluids in the study area had multiple sources, primarily formation water, as well as meteoric water and metamorphic water. Combined with the geological setting and mineralization features we infer that the stratabound barite–fluorite deposits originated from mid–low‐temperature hydrothermal fluids and formed vein filling in the fault zone.

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From January 1978 to February 1999, 120 patients (42 males and 78 females) with cardiac myxoma (115) or myxosarcoma (5) underwent surgical excision or biopsy. There were 5 early postoperative deaths (mortality, 4.2%). Seventy-three survivors were followed up for 0.75 to 20.25 years (mean, 9.42 years); they comprised 4 myxosarcoma patients who all had recurrence or metastasis, and 69 myxoma patients who had no evidence of recurrence or metastasis. Neither familial myxoma nor Carney complex was found. The 5 cases of myxosarcoma and 18 randomly selected cases of myxoma were evaluated for proliferative activity, metastatic potential, and oncogene products by immunohistochemistry. The expression of p53 and Bcl-2 was similar in both groups. Overexpression of proliferating cell nuclear antigen and low expression of nm23 in myxosarcoma are consistent with the high rate of recurrence and metastasis of this tumor. Surgical resection of sporadic myxoma is a safe and effective treatment with satisfactory early and long-term results. However, the prognosis of myxosarcoma is still disappointing. Regular echocardiography and chest radiography or computed tomography are necessary for early detection of recurrence or metastasis of myxosarcoma.