FLC UNSURE OF LOCATION OF DISPLACED THRESHOLD WHEN LNDG AT NIGHT.

Narrative

ENRTE TO ORF THE ATIS INDICATED RWY 5 AS THE ACTIVE WITH A DISPLACED THRESHOLD. WE WERE CLRED FOR A VISUAL AND CONTACTED THE TWR AT 5 DME. I COULD SEE THE RWY BUT AT THAT POINT COULDN'T SEE WHAT SPECIFIC MARKINGS WERE IN PLACE TO INDICATE THE BEGINNING OF THE OPEN PORTION OF THE RWY. THE TWR CTLR APPEARED TO BE CAUGHT A LITTLE OFF GUARD WHEN I ASKED WHAT SPECIFIC MARKING INDICATED THE DISPLACED THRESHOLD. I MENTIONED THAT I SAW THE GREEN BAR AT THE BEGINNING OF THE RWY (FULL LENGTH) AND A SET OF GREEN LIGHTS OFFSET FROM THE END. THEY WERE THE ONLY CLUE AT THAT POINT WHERE THE DISPLACED THRESHOLD WAS. ALL THE NORMAL LIGHTS AT THE APCH END WERE ON AND I BELIEVE THE RWY EDGE LIGHTS WERE ON FOR THE ENTIRE LENGTH (INCLUDING THE CLOSED PORTION). TWR SAID THERE WERE SOME RED LIGHTS BUT THE ONLY ONES I SAW WERE BEFORE THE BEGINNING OF THE FULL LENGTH. I ADVISED THAT WE WERE UNSURE AT THAT POINT OF WHERE THE OPEN RWY BEGAN AND TO 'WATCH US REAL CLOSE' -- HOPING THAT HE WOULD ADVISE US IF IT APPEARED THAT WE WERE GOING TO LAND SHORT. AS WE GOT CLOSER; I COULD SEE THE CONSTRUCTION WORK OFF TO THE R AND ASKED IF THE RWY BEGAN JUST BEYOND THE CONSTRUCTION -- NO ANSWER. WE TOUCHED DOWN APPROX 750 FT BEYOND WHAT ALL 3 CREW MEMBERS THOUGHT WAS THE DISPLACED THRESHOLD. I ADVISED THE TWR AS WE TURNED OFF THAT I BELIEVED THE MARKINGS (LIGHTING) WAS INADEQUATE AND WAS INDIRECTLY HOPING THAT THE TWR WOULD ACKNOWLEDGE THAT WE; IN FACT; LANDED ON THE OPEN PORTION; BUT HE ONLY ACKNOWLEDGED OUR XMISSION. I WAS ALSO TRYING TO PASS ON OUR CONCERN FOR THE LACK OF CONCLUSIVE MARKINGS SO THAT THEY COULD PROVIDE ADDITIONAL GUIDANCE FOR SUBSEQUENT LNDG ACFT. AT THIS POINT IN TIME; I BELIEVE THAT WE DID; IN FACT; LAND AT THE APPROPRIATE POINT. BUT THE LACK OF REINFORCEMENT AND MARGINAL MARKINGS LEAVES AN ELEMENT OF DOUBT. SAFETY IS OUR PRIMARY CONCERN FOR OUR ACFT AND; IN THIS CASE; FOR GND CONSTRUCTION PERSONNEL. I WOULD PREFER MORE DISTINCTIVE MARKINGS AND LIGHTING AS WELL AS SPECIFIC GUIDANCE FROM TWR CTLR AND FOLLOW-UP GUIDANCE (ESPECIALLY WHEN SPECIFICALLY REQUESTED). WE TOOK OFF THE NEXT AFTERNOON AND COULD NOW SEE THE MARKINGS INDICATING THAT WE DID LAND ON THE OPEN PORTION. HOWEVER; THE CONCERNS STILL EXIST. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THIS RPTR THOUGHT THAT NOTAM AND ATIS SVC WAS OK BUT WAS UNHAPPY WITH THE PHRASEOLOGY USED BY THE CTLR. COM BREAKDOWN. SUPPLEMENTAL INFO FROM ACN 211901: CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR SAID THAT CONSTRUCTION WAS COMPLETE AND DISPLACED THRESHOLD HAS BEEN REMOVED.