Tanaris 45 - 47
Once in Gadgetzan(1) turn in Tran'rek and accept all the quests. From here head east to (2). Kill 10 Wastewander Bandits, 10 Theifs, and collect 
5 Wastewander Water Pouches. Return to Gadgetzan when you're done and refresh "Wastewander Justice". From Gadgetzan head further east to Steamweedle Port(3), Turn in "Stoley's Debt" and accept the quests here. Now head to (4) and kill 8 Wastewander Rogues, 6 Assassins, and 10 Shadowmages.
Also patrolling around in this area is Caliph Scorpidsting(5). Kill him and loot his head. When you're finished continue southeast to the Pirates(6). Here you need to kill 10 Southsea Pirates, 10 Freebooters, 10 Dockworkers, 10 Swashbucklers, Collect 
20 Pirate Hats (Drops from any pirate), grab 
Stoley's Shipment(7), and kill Andre Firebeard(8). Andre Firebeard sits in the middle of the pirate area, and the stolen cargo is in the right building on the third floor upon entering the Pirate "Fort". Once you complete all the quests return to Steamwheedle Port and turn in all of your quests. Grab the followup "Deliver to MacKinley". From There head west back to Gadgetzan and refresh your quest supply.
From Gadgetzan head west to "Gadgetzan Water Survey"(9). Use the 
Untapped Dowsing Widget in the pool and run from the mobs that come out. Return to town and refresh your quest. Accept the followup "Noxious Lair Investigation" then head south to Marvon Rivetseeker(10). Accept "Gahz'ridian" then head southwest to the Dunemaul Compound(11). Here you need to kill 10 Dunemaul Brutes, 10 Enforcers and Gor'marok the Ravager(12). Gor'marok is in the cave at the southern end of this encampment. When you're done head directly south to the Southmoon Ruins(13).
Here you'll want to collect 
30 Gahz'ridian. Once you have all 30 head west to Thistleshrub Valley(14). Here you need to kill Thistleshrub Dew Collectors for a 
Laden Dew Gland, 8 Gnarled Thistleshrub and 8 Thistleshrub Rootshapers. Once you're done these two quests head north to "Noxious Lair Investigation"(15). Kill the insects here until you get 5 insect parts. Once you're done return to gadgetzan. Turn in all of your quests and do the followup to the Dew gland "In Good Taste". Accept the followup for that aswell.
From here hearth to the Crossroads and fly to Orgrimmar. Hop the Zeppelin to Grom'gol and fly to Kargath. From Kargath head west into Searing Gorge. Thorium point is in the Northern section of Searing Gorge.
Save 15 silk for Searing Gorge.