Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Training / Qualification
Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Chart Or Publication; Human Factors; Procedure
The clearance was to TERAX UA304 VIR direct.  Once established on Airway UA304 ATC cleared us to 7000 feet. In VMC condition the captain decided to start a descent. There was no arrival in the FMC to SLVR. We looked at the area chart and there was UA304 depicted on the chart with a crossing for SALBI; at FL170.  Nothing on the en route chart. During the descent ATC consistently enquired about our altitude and distance from the VIR VOR. He then came back and reported us too low for the area and advised us to climb. We were VMC the entire time; so we leveled off and delayed the descent. We later found out they have a generic arrival in the Jepp charts with no identification or name identifying the chart itself [20-2].  Next time we must take a delay at the departure field and make sure we review the all the arrivals in the Jepp. Even though the FMC does not pull one up or ATC does not even assign you an arrival by name.
First Officer reports being cleared to FL070 by SLVR ATC with no crossing restrictions or arrival procedure mentioned. ATC indicates to the crew that they are too low during the descent and levels off. After landing an arrivals page; which the crew believed to be an area chart; is discovered in the Chart manual but no arrivals exist in the FMC.