ites . ▁Ext ensive ▁lo ess ▁sequences ▁were ▁depos ited ▁during ▁a ▁cool ▁period ▁ 2 . 5 ▁to ▁ 2 . 3 ▁million ▁years ▁ago ▁and ▁the ▁most ▁prominent ▁pale os ol ▁formed ▁between ▁ 6 1 5 ▁and ▁ 4 7 0 ▁hundred ▁thousand ▁years ▁ago . ▁ ▁The ▁start ▁of ▁the ▁Hol oc ene ▁( 1 0 ▁to ▁ 8 ▁thousand ▁years ▁ago ) ▁is ▁recorded ▁as ▁a ▁warm ▁and ▁wet ▁time ▁in ▁central ▁China , ▁most ▁likely ▁from ▁the ▁mel ting ▁of ▁snow ▁and ▁ice ▁off ▁the ▁Tib et an ▁Pl ate au . ▁A ▁decrease ▁in ▁the ▁area ▁of ▁lo ess ▁depos its ▁shows ▁that ▁the ▁Hol oc ene ▁Cl im atic ▁Opt imum ▁occurred ▁across ▁central ▁China ▁ 8 ▁to ▁ 5 ▁thousand ▁years ▁ago . ▁ ▁H ain an ▁and ▁the ▁South ▁China ▁Sea ▁ ▁The ▁island ▁province ▁of ▁H ain an ▁is ▁located ▁off ▁the ▁South ▁coast ▁of ▁China ' s ▁main land . ▁It ▁was ▁separated ▁from ▁the ▁main land ▁by ▁t ect onic ▁rif ting ▁and ▁coast al ▁er os ion . ▁The ▁parts ▁of ▁the ▁South ▁China ▁Sea ▁that ▁China ▁claims , ▁formed ▁by ▁the ▁evolution ▁of ▁contin ental ▁rif ting ▁into ▁ocean ic ▁spread ing ▁during ▁the ▁mid ▁C en oz o ic . ▁There ▁are ▁numerous ▁sea ▁mount s ▁and ▁island ▁carbon ate ▁re ef s ▁that ▁have ▁developed ▁on ▁hor st s ▁formed ▁during ▁the ▁extension . ▁ ▁C rat ons ▁and ▁or ogen ies ▁ ▁China ▁has ▁three