Around 34 to 23 million years ago (Mid Tertiary), this rock was covered by shallow sea; an ideal environment for Nummulites of the foraminifera class. These small single celled organisms have calcite shells with internal spiral coils divided into chambers.
Once foraminifera die their shells accumulate on the sea floor to form limestone.
Nummulite is from the Latin meaning “little coin”, they are also known as “Angel’s coins”. Descendants of these fossilized foraminifera can still be found living in today’s oceans.