D. ____________ orebodies in sediments are very important producers of
many different metals, especially base metals and iron. These orebodies
include such host rocks as ______________, ___________, ___________,
and _________.The base metals in such deposits are not only copper, but also
silver and ________ deposits.
E. There are two principal types of deposit to be found in volcanic rocks,
_______ filling deposits and __________ massive sulphide deposits. They
can be divided into three classes of deposit: (a) ____________, (b) zinc-
copper, and (c) copper.
F. _________deposits are formed by the removal of non-ore material from
________. For example, the ___________- of silica and alkalis from a
nepheline-syenite may leave behind a surface ________ of hydrous
aluminium oxides
G. ______________is a process which may affect most orebodies to some
degree. After a deposit has been formed, _________ and __________ may
bring it within reach of circulating ground waters. This may _________-some
of the metals out of that section of the orebody above the water table. This
can lead to a considerable enrichment in metal values.
2. Look at the following statements and the list of orebody deposits. Match
each statement with the corresponding deposit.
1. Pipes can be of various types and origins.
2. The most common type of tin deposits occur in sheeted veins.
3. The major metals found in skarn deposiots are iron, graphite, talc and
uranium.
4. Concordant orebodies in sediments are very important producers of many
different metals.
5. The infilling of veins consists of an intergrowth of ore and gangue
minerals.
6. Copper is not the only base metal that occurs in such deposits.
7. These deposits can be referred to as stratiform.
8. Uranium is a by-product in Witwatersrand goldfields.
9. An example of this deposit can be diamonds in kimberlites or
orthomagmatic in nickel-copper deposits.
10. Theses deposits are extremely irregular in shape, such as tongues.
11. The following host rocks- shales, argillites, slates- are important in the
formation of concordant orebodies.