Chapter 24.1, Problem 3R

Summary Introduction

To explain:

The site out of x, y, and z, which would be added to refine the boundary, between Silurian period and Ordovician period on the map given below.

Given:

Table 1 given below shows the ratio between the ²⁰⁶Pb and ²³⁸U and the estimated age of the sites given.

Introduction:

According to the data given in tables and radioactive isotope dating, the sites formed during the Ordovician and Silurian periods of the geological timescale are given as below:

Site 1, 2, 4, 5, 8, 9, and 10 were formed during the Ordovician period of the Palaeozoic era having estimated age from 443.7 to 488.3 million years ago

Site 3 and 6 were formed during the Silurian period of the Palaeozoic era having estimated age from 416 to 443 million years ago.