Abstract

The nature and distribution of heavy minerals along beach placers have been studied along the coastal part of Podampata, Eastern Coast of Odisha, India. The primary objective of this study was to assess the heavy mineral placers along the NE–SW direction, the nature of the high background radiation area, and the geomorphic agents controlling the beach sediment distribution. In-situ total radiation counts were obtained using a Micro R survey meter, and the individual activity of ²³²U (in µg/g), ²³⁴Th (in µg/g), and ⁴⁰K (in %) of the collected samples were measured with Gamma surveyor II instrument. The sediment characterization was undertaken using grain size statistical parameters, which shows dominant influence of river and wind actions on the sediments and their high transportation and modification rates. Nature of radioactive anomalies observed is due to the decays of ²³²U and ²³⁴Th. The meandering nature and subsequent erosion, primarily at the outer curvature of the river, seems to have primarily contributed to the heavy mineral deposition. The high wind velocity during the frequent cyclonic events could have a significant influence on distribution and transport of heavy minerals observed. The mixed geomorphic agents operating in the study area influence the distribution of heavy minerals along the NE–SW direction.

Research Highlights

1. 1.

   The higher abundance of Th is basically along the outer curvature of the meandering part as compared to the U and K occurrences.

2. 2.

   Fine sand sediments with negatively skewness contains higher abundance of radioactive= elements.

3. 3.

   The meandering pattern of Rusikulya River along due to beach action, primarily fluvial and aeolian activity plays an important role in the distribution of the sediments along the coast.

中文翻译：

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印度奥里萨邦东海岸 Podampata 沿岸富含放射性的海滩沉积物的粒度分析

摘要

已经在印度奥里萨邦东海岸的 Podampata 沿海地区研究了沿海滩砂矿的重矿物的性质和分布。本研究的主要目的是评估沿 NE-SW 方向的重矿物砂矿、高背景辐射区的性质以及控制海滩沉积物分布的地貌因素。使用 Micro R 测量仪获得原位总辐射计数，  ²³² U（以 µg/g 为单位）、  ²³⁴ Th（以 µg/g 为单位）和 ⁴⁰所收集样品的 K（以 % 计）是用 Gamma 测量仪 II 仪器测量的。沉积物表征是使用粒度统计参数进行的，这表明河流和风作用对沉积物的主要影响及其高运输和改性率。观察到的放射性异常的性质是由于²³² U 和²³⁴th。蜿蜒的自然和随后的侵蚀，主要是在河流的外曲率处，似乎是造成重矿物沉积的主要原因。频繁的气旋事件期间的高风速可能对观测到的重矿物的分布和运输产生重大影响。研究区的混合地貌因子影响重矿物沿 NE-SW 方向的分布。

研究亮点

1. 1.

   与 U 和 K 事件相比，Th 的丰度较高基本上沿着曲折部分的外曲率。

2. 2.

   具有负偏度的细砂沉积物含有较高丰度的放射性元素。

3. 3.

   由于海滩作用，主要是河流和风成活动，Rusikulya 河的蜿蜒模式在沿海沉积物的分布中起着重要作用。