 <unk> or <unk> of europium in minerals relative to other rare earth elements is known as the europium anomaly . Europium is commonly included in trace element studies in <unk> and <unk> to understand the processes that form igneous rocks ( rocks that cooled from <unk> or <unk> ) . The nature of the europium anomaly found helps reconstruct the relationships within a suite of igneous rocks . 
