gold rush

a sudden happening that brings good fortune (as a sudden opportunity to make money); "the demand for testing has created a boom for those unregulated laboratories where boxes of specimen jars are processed like an assembly line"

1 करोड़ सरकारी कर्मचारियों और पेंशनरों के लिए 85,000 करोड़ रुपये का अप्रत्याशित लाभ ।

In 1848 - 1849, because of the Swarna Doud (California Gold Rush), this expansion was continued.