eventSource
Ingredient to acquire events
Example
<fdsnEvent>
    <originTimeRange>
        <startTime>
            2015-01-01T00:00:00.000Z
        </startTime>
        <endTime>
            2015-01-31T23:59:59.999Z
        </endTime>
    </originTimeRange>
    <magnitudeRange>
        <min>6.0</min>
    </magnitudeRange>
</fdsnEvent>
    Places this can be found
delayedEventSource contains this directly
eventArm contains this directly
similarEvent contains this directly