Geochemical maps of the Fal Estuary system

In the linear maps for the estuary as a whole, it is clear that the sediments in Restronguet Creek have the highest levels of contamination, particularly for arsenic, copper and zinc. Values for lead and tin are also highest in Restronguet Creek, but Calenick Creek also has elevated lead concentrations, and tin is elevated in concentration above the dominant levels in Carrick Roads in the Penryn River, Calenick Creek and the Truro River, as well as in Restronguet Creek. Note that samples included in this study and collected in the early 1980's from the area around the mouth of Restronguet Creek were not analysed for lead. When we compare the linear maps for the estuary as a whole with the log plots we see that the log maps reveal greater variability. Arsenic, copper and zinc concentrations are highest in Restronguet Creek and reveal a clear contaminant plume, issuing from Restronguet Creek and flowing south along the western side of the estuary towards Mylor Creek. The upper parts of the River Fal, to the east of the confluence with the Truro River and St. Just Creek have the lowest levels of arsenic, zinc and copper contamination. In the River Fal this is because all of the sediments in this area are china clay mine waste which has low levels of arsenic etc. The maps showing the distribution of lead show that there is also elevated concentrations of lead in Calenick Creek as well as Restronguet Creek. Tin distribution is more variable. Restronguet Creek still has the highest levels of contamination, but Calenick Creek, the Truro River and Tresillian River all have elevated levels of tin when compared with the main part of Carrick Roads.

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Linear Values				Logarithmic Values
		Arsenic				Arsenic
		Copper				Copper
		Lead				Lead
		Tin				Tin
		Zinc				Zinc