# Grain-size distribution dataset of lagoonal and riverine coastal placer deposits along the southeastern coast of Sri Lanka

## TL;DR

This paper presents a dataset of grain size distributions from coastal sediments in Sri Lanka to study sediment dynamics and mineral deposits.

## Contribution

The study provides a detailed grain size dataset for lagoonal and riverine placer and non-placer sediments along a 70 km Sri Lankan coastline.

## Key findings

- Placer sediments show coarse-skewed leptokurtic to platykurtic fine sand distributions.
- Non-placer sediments are characterized as medium sand-grained.
- The dataset aids in understanding deposition environments and transportation dynamics.

## Abstract

The dataset contains grain size data of placer and non-placer sediments in lagoonal and riverine beaches of southeastern part of Sri Lanka. A total of 124 swash sediment samples were collected from a 70 km long coastline with an interval of 500 m. Placer sediments in the area mainly have mineralogy of ilmenite, zircon and almandine while non-placers are quartz, albite and calcite. After dry sieving, the grain size distribution (GSD) analyses were carried out on each sample using the Gradistat Excel template. Placer deposits result coarse-skewed leptokurtic to platykurtic fine sand distributions while non-placers are medium sand-grained. The dataset can be used to interpret the deposition environment and transportation dynamics. Further, they can be used to study the southwestern coastline of the Bay of Bengal, juvenile crust sediments of Grenvillian age, alongshore and fluvial sediment dynamics, depositional and erosion processes, geohazards assessments and heavy mineral deposits.