论文部分内容阅读
雷州半岛西南部沿海的古珊瑚礁,是广东大陆沿岸唯一被保存下来的发育在中更新世玄武岩滩地上的典型珊瑚岸礁.该区的地壳垂直运动自新第三纪以来为沉降区,到全新世中期才处于相对稳定状态,近数十年是轻微下降区.我们于1993～1995年间先后3次考察了灯楼角(20°13′N,109°56′E)和水尾村(20°24′N,109°52′E)的古珊瑚礁,前者礁平台(礁坪)最宽处约1km,长逾2km,后者礁平台宽约0.5km,长约1km.是研究全新世高海面较理想的地区之一.1 古海面标志物及其确切位置研究古海平面变化最重要是要找到能真正代表当时海平面的位置,并能测定标志物的高程和年龄.经多年研究认为,以大型块状滨珊瑚构成的礁顶面,是研究古海面的最好标志物.南海礁区单个礁体的礁顶面,宽度从几十米到千米以上;长度从几百米到几千米,其礁平面很平坦,高差很小.由于珊瑚只能在水下生长,其实际生长上限在大潮低潮面下1m深,珊瑚礁顶面记录着海平面的确切位置,珊瑚样品又是多种测年方法的上选材料,因而珊瑚礁顶面是古海面的极好标志物.
The ancient coral reefs along the southwestern Leizhou Peninsula are the only preserved coral reefs in the middle Pleistocene basalt beach along the Guangdong coast.The vertical movement of the crust in this area has been a subsidence since the Neogene. The mid-term period was relatively stable, with a slight decrease in recent decades. From 1993 to 1995, we investigated the light house angle (20 ° 13’N, 109 ° 56’E) and Shuiwei Village (20 ° 24’N, 109’52’E). The former reef platform (reef flat) is about 1km wide and over 2km long and the latter is about 0.5km long and about 1km long. It is a study of the Holocene high sea surface One of the most ideal regions.1 Ancient Sea Surface Marker and Its Exact Location The most important change of the ancient sea surface level is to find the position that can truly represent the current sea level and to determine the elevation and age of the marker.After years of research, Large lumps of coral reef top, is the study of the ancient sea surface markers.Restore reefs in the South China Sea reefs the top surface, width from tens of meters to more than kilometers; length from a few hundred meters to several thousand Rice, the reef plane is very flat, the height difference is very small due to corals can only grow underwater, the actual The upper limit of growth is 1m deep below the tidal tide and low tide surface. The top of coral reefs record the exact sea level. Coral samples are the top selection materials for various dating methods. The coral reef top is therefore an excellent marker of ancient sea surface.