摘要:
巨砾石是颗粒直径大于256 mm的沉积物。巨砾石海滩(Boulder beach)是一种少见的海岸类型,形成条件特殊,与砾石海滩(2~60 mm)沉积动力特征不同,是具有旅游价值和学术价值的资源。对海南万宁大花角巨砾石海滩的调查研究结果表明,海滩主要是由直径500~1 000 mm、磨圆、光滑的巨砾石排列而成的,剖面平滑,宽40 m,高9 m,海滩坡度13°。与普陀岛的巨砾海滩相比,本海滩更为典型,海滩巨砾石磨圆更好、宽度更大、海滩低潮至高潮之间高度更大,海滩形态也更完好。它的形成与海岸岬湾地形、地质条件、高能波浪等有关。巨砾石磨圆极好、表面光滑,但是粒径比一般鹅卵石大1~2个数量级。巨砾石海滩与砾石滩在沉积特征和动力地貌特征不同,是不同类型的海滩。
Abstract:
Boulder beaches are different from gravel beaches in terms of sediments and morphodyanmics, as a kind of special scenery, which attracts tourists. In this paper, we select a case from Dahuajiao, Wanning city of the Hainan Island to report its occurrence and characteristics. The boulder beach is composed of rounded boulders in size of 0.5~1.0 m. Storm waves were the force to move the boulders trimly along the base of the beach. The beach profile is rather smooth, which is 40 m in width and 9 m in height from the low water level to the top of the beach. The slope of the beach is around 13°.The beach was formed by high energy waves, based on specific geological background and geomorphologic factors. It is important to highlight the unique boulder beaches that sometimes were regarded as pebble and cobble beaches. As a tourist resource, the special boulder beach is more attractive than common gravel beaches.
下载: