(Table 1) Gypsum, pyrite and glauconite at DSDP Hole 36-329

Authigenic gypsum, pyrite, and glauconite are disseminated throughout an unusually long (346 m) Miocene section of mixed biogenic carbonate and diatomaceous ooze drilled on the Falkland Plateau at DSDP Site 329 (water depth, 1519 m). The present organic carbon content of the sediment is low, ranging between 0.1 and 0.7%. Gypsum occurs as euhedral single or twinned crystals of selenite up to 5 mm in diameter, sometimes in the form of gypsum rosettes. These crystals are intact and unabraded, comprising up to 4% of the washed sample. The authigenic nature of the gypsum is demonstrated by the presence of diatoms and radiolarians embedded within the gypsum crystals.
The gypsum co-occurs with pyrite and glauconite in these samples. The pyrite occurs as framboids, foraminiferal infillings, rods, and granular sheetlike masses composed of pyrite octahedra. The glauconite occurs as foraminiferal infillings and as free grains. The gypsum and pyrite were identified by energy-dispersive X-ray analysis and scanning electron micrographs. Some of the gypsum has grown on pyrite, indicating that it precipitated after the pyrite, perhaps in response to a change in pH conditions. The formation of the mineral suite can be explained by current models of in situ sulfide and sulfate precipitation coincident with diagenesis and oxidation of much of the original organic carbon.

自生石膏（authigenic gypsum）、黄铁矿（pyrite）与海绿石（glauconite）呈浸染状分布于福克兰高原（Falkland Plateau）深海钻探计划（Deep Sea Drilling Project, DSDP）329站位钻获的厚度达346米的异常深厚中新统混合生物成因碳酸盐-硅藻软泥剖面中，该站位水深1519米。沉积物现今有机碳含量较低，介于0.1%至0.7%之间。透石膏（selenite）以自形单晶或孪晶形式产出，粒径可达5毫米，偶见玫瑰状石膏集合体；此类晶体完整无磨蚀痕迹，占洗选后样品总质量的比例最高可达4%。石膏的自生成因可通过包裹于其晶体内部的硅藻与放射虫得以佐证。
本批样品中，石膏与黄铁矿、海绿石共生。黄铁矿呈草莓状集合体、有孔虫充填物、棒状以及由黄铁矿八面体构成的粒状片状团块产出；海绿石则以有孔虫充填物及游离颗粒形式存在。研究通过能量色散X射线分析（energy-dispersive X-ray analysis）与扫描电子显微照片（scanning electron micrographs）确认了上述三种矿物的属性。部分石膏附着于黄铁矿之上生长，表明其沉淀时间晚于黄铁矿，或与pH环境变化相关。该矿物组合的形成可通过现有原位硫化物与硫酸盐沉淀模型解释，该过程与成岩作用及原始沉积物中大部分有机碳的氧化作用同步发生。