POLLEN AND PALEOSALINITY ANALYSES FROM A HOLOCENE TIDAL MARSH SEQUENCE, CAPE MAY COUNTY, NEW-JERSEY
POLLEN AND PALEOSALINITY ANALYSES FROM A HOLOCENE TIDAL MARSH SEQUENCE, CAPE MAY COUNTY, NEW-JERSEY
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DOI：
10.1016/0025-3227(72)90033-3
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发表时间：
1972-01-01
期刊：
影响因子：
2.9
通讯作者：
MEYERSON, AL
中科院分区：
文献类型：
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作者：
MEYERSON, AL
丹尼斯溪潮汐沼泽的沉积物类型，SPM古盐度值和花粉光谱的评价表明，沼泽环境的波动与海平面上升的速度。海平面的上升引发并伴随着沉积不是恒定的，而是在丹尼斯河序列所代表的整个时间段内不断变化的。大约3000年前，海平面上升首先影响了丹尼斯河地区。最初，存在开放的水域环境，随后是互花米草的发展。海平面上升速度的减缓使淡水环境移到已形成的沼泽之上，后来海平面上升速度的加快又造成了海侵，再次形成了沼泽地区。紧邻主要支流的地区对海侵及其波动的反应程度大于远离主要支流的地区。因此，从沼泽系统中分离出来的岩心可能不包含该地区发生的所有事件的完整记录。一次主要的海侵发生在大约1800年B.P.。因此，以前发表的海平面上升曲线似乎显示的是平均值，并不能反映实际的波动。人类在该地区定居的证据在花粉记录中非常清楚。在花粉光谱中，菊科植物的涌入表明该地区的森林砍伐，使这些杂草植物变得丰富。16号岩芯中藜科植物的高比例是沼泽开沟的结果。丹尼斯溪潮汐沼泽地层学的阐明以及该地层学与邻近地区的对比表明，所采用的方法实际上对这种类型的研究是有效的。花粉分析可与其他方法结合用于确定当地植被。此外，SPM古盐度技术是有效的在一个单一的垂直序列，其中有没有变化的沉积物的源区。通过这种方法获得的盐度值可能不准确，但是，建立的趋势是非常有价值的古生态学的解释。
Evaluation of sediment types, SPM paleosalinity values, and pollen spectra for the Dennis Creek Tidal Marsh indicates fluctuation of marsh environments related to rate of sea-level rise. The rise of sea level which initiated and accompanied the deposition was not constant, but rather changed throughout the period of time represented by the Dennis Creek sequence.Prior to about 3000 years ago rising sea level first affected the Dennis Creek area. Initially, an open water environment existed, followed by the development of aSpartina alternifloramarsh. A decrease in the rate of sea-level rise allowed a fresh-water environment to move out over the established marsh.A later increase in the rate of sea-level rise produced a marine transgression again establishing the marsh area. Areas immediately adjacent to major tributaries responded to the transgressions, and fluctuations therein, to a greater degree than those areas further away from major tributaries. Thus, isolated cores from a marsh system may not contain the complete record of all that has happened in the area.A major transgression of the sea occurred at around 1800 years B.P. This transgression is also indicated by changes in pollen spectra of sediments from Barnstable, Massachusetts. Thus, previously published curves for sea-level rise appear to show mean values, and do not reflect actural fluctuations.The evidence of man's colonization of the area is quite clear in the pollen record. The influx of the Compositae in the pollen spectra for the cores indicates the deforestation of the area, allowing these weed plants to become abundant. The high percentages of the Chenopodiaceae in core # 16 is the result of ditching of the marsh.The elucidation of the stratigraphy of Dennis Creek Tidal Marsh and the correlation of this stratigraphy with adjacent areas indicates that the methods utilized are, in fact, valid for this type of study. Pollen analysis can be utilized for the determination of local vegetation in conjuction with other methods. Also, the SPM paleosalinity techniques is valid within a single vertical sequence, where there has been no variation in the source area of the sediment. The salinity values obtained by this method may not be exact; however, the trends established are extremely valuable in the interpretation of paleoecology.