SHANGHAI, Oct. 21 (SMM) – LME base metal prices overnight closed with sharp declines. Ongoing European debt crisis and concerns over China's slower demand growth continued to depress market sentiment. LME zinc prices plunged as of the morning session. Due to concerns that economy will experience double-dip recession and weather Europe will be able to resolve its debt crisis, LME zinc prices hit a new low for the year at USD 1,718/mt. Finally, LME zinc prices closed at USD 1,740/mt, down USD 91/mt. SHFE three-month zinc contract prices should move between RMB 13,700-14,000/mt today, with spot premiums rising to RMB 350-450/mt.