It said a 91m intersection grading 0.48 grams per tonne 3E returned from a 350m step-out hole "is the most significant zone of metal accumulation (grade-width basis) intersected to date", and supportive of a new geological model that pointed towards a "large untested search space".
Caspin is awaiting the results of a further six holes from Serradella - previously called XC-22 - before starting follow-up drilling.
Yarawindah Brook is in the region where Chalice Mining has had huge PGE-nickel-copper success, with Chalice a substantial shareholder in Caspin.
Meanwhile, drilling and soil sampling is continuing at Caspin's Mount Squires gold-copper project near the tri-border regions of WA, Northern Territory and South Australia.
That work will continue through till mid-July.
Caspin started the June quarter with A$11 million cash.
Shares in Caspin were up 10.5% to 47.5c in morning trade, capitalising the company at $35.5 million.
