Isotopic Ages Database

SE Asia: isotopic ages of igneous and metamorphic rocks

Much of SE Asia and the SW Pacific is and has been the site of volcanic activity throughout the Cenozoic and for much longer. There is clear need for good dating of the igneous rocks as a step towards understanding the plate tectonic history of the region, the causes of  different types of magmatic activity, reasons for its initiation and cessation, the character of magmatism, to identify only a few reasons. For use in some of our projects we have compiled a database of ages which are now in GIS format. Many of the ages are published, although some are in difficult-to-find publications. There are also quite a number of ages in research theses, unpublished reports, and shown on published maps. We have tried to incorporate these in the databases. Currently, age data are compiled for Indonesia and parts of Malaysia, New Guinea, the Philippines, and the Philippine Sea Plate.


One of the aims in producing the database was to consider the distribution of igneous activity in the context of the plate tectonic history of the region. Another aim of the database was to assess the quality and distribution of ages in the region. Examination of the ages shows that many must be considered of dubious quality as they are poorly located geographically and stratigraphically, some lack errors and some information on methods. Most are K�Ar dates, and there are few age determinations by other methods.

We have made these databases available for two principal reasons. First, to save others the work of compilation so that time can be used more usefully for other research on the region. Second, because we wish to improve the dating database for the entire region. We hope that this can be achieved by others adding their own data to this data set. We shall update this page with new data which we compile, and any other age data submitted to this site.

Pdf description file                                         Download File

MapInfo datasets (zip file)                          Download File

Database Files in dbf format (zip file)    Download File

We would welcome additional data to be added to these datasets which will then be made available via this web page. Most formats are acceptable, although most convenient would be either MapInfo tables in 1the forms used here, or dbf/xls files formatted as the dbf format files. An empty Excel worksheet can be downloaded here for input of new data [download template].

Please send any new data or enquiries to Robert Hall (