Cryptic crossword No 3,799

Across

1. Mountain group for settling South American camelids (7)
2. Originators of Gothic art movement unified tonal spectrum (5)
3. Peer unexpectedly dispatched to host Republican and act as an ambassador? (9)
4. Used to fill in a gap, I'm cast inappropriately (6)
5. Synthesis of morphine not as crystalline mirror images (13)
6. Express decision about girl on degree course (10)
7. Old English spinner consumes drink in play (5,4,4)
8. Former vagabond settled in Caribbean islands is exuberant (9)
9. Observed the old rector who cuts up wood? (6)
10. Setter's introduced to fat landowner (5)
11. Hand is buried in opal mine (4)
12. Icy cloud's composed of oxygen gas, right? (4)
13. Lean over Yorkshire river given a post to hang on to (7)
14. No love for two-wheeled vehicle, adequate and that’s being kind (10)

Down

1. Sounds strangely silent (6)
2. Composer is rash, losing the head (4)
3. Crash into posh car touring Eastern Australia and stop (4-3)
4. Extreme concentration from leaders of Soviet Union's preliminary exploratory rocket at Io being pulled in by Saturn (15)
5. Generous merchant with a notion to wind up (7)
6. IKEA gin and pop cocktail is a dodgy purchase (3,2,1,4)
7. Old cello left scratched by Tiddles initially - he's not a big cat! (6)
8. Reportedly, the French cake is delivered smoothly and uncut (6)
9. Monkey some teased in market (8)
10. Function is embedded in experimental remote equipment to show how far one has gone (8)
11. Place to sit and negotiate an agreement (6)
12. Island united with a state (4)
13. Electronic tool to locate an attractive male? (4,6)
14. Thoughtfully one helps to find direction over island and rest finally by cathedral town (15)