Theme: Not for the shallow - The first word in the theme answers can be the end of a phrase starting with DEEP.
38. Pool diving area ... and, literally, what the start of each answer to a starred clue can be : DEEP END
17. *The president's annual salary, e.g. : SIX FIGURES. Deep Six, I'm going with the naval use of the term for a measure of six fathoms; a depth suitable for burial at sea.
61. *Prince film featuring "When Doves Cry" : PURPLE RAIN. Deep Purple. It seems unclear what Prince meant by 'Purple Rain'. Deep Purple is a rock band but what I like best is the use in the opening line of this remake of "Star Dust" by Nino Tempo & April Stevens. Deep Purple
11. *"Sweet dreams" : "SLEEP TIGHT". Deep Sleep. 'Sleep tight' may just mean 'sleep soundly'.
29. *Scatterbrain : SPACE CADET. Deep Space, the final frontier.
Argyle here in the deep freeze. At least we didn't get the wind they were predicting. A musical Monday, not theme related though. Standard pinwheel grid, some standard crosswordese and some c/a from recent puzzles. All-in-all, a good day.
Across:
1. Diplomat Henry __ Lodge : CABOT. (1850 - 1924) or (1902–1985)(Jr. or II) He was the grandson of Henry Cabot Lodge.
6. Former Ford division, briefly : MERC. (Mercury, 1938 - 2011)
10. "Kindly let us know," on invites : RSVP. (French: répondez s'il vous plaît). And 10D. English translation of the start of 10-Across : RESPOND
14. Like a noisy stadium : AROAR
15. Length times width : AREA
16. Israeli airline : EL AL
19. Lily that's Utah's state flower : SEGO
20. Mary __ cosmetics : KAY
21. Agree silently : NOD
22. Avoid shipping out? : SHAPE UP. Ultimatum: Shape up or ship out!
24. Electrically connected : WIRED
26. Weds in secret : ELOPES
27. Kind of football kick : ONSIDE. Deliberately kicked short in an attempt to recover the ball.
30. Prairie dog or squirrel : RODENT
32. Brown photo tone : SEPIA
33. Long skirt : MAXI. Not demure when it is see-thru or has a thigh-high slit.
34. Carpe __: seize the day : DIEM
37. Hawaii's Mauna __ : LOA
41. Dean's list fig. : GPA. (grade point average)
42. How some audiobooks are recorded : ON CD
44. Prayer ending : AMEN
45. Autumn shade : OCHER
47. Pencil mark remover : ERASER
49. PC memos : E-NOTES
50. Say yes (to) : ACCEDE
52. Arabian Peninsula country : YEMEN
54. Thick fog metaphor : PEA SOUP
56. Prefix with east or west : MID
57. Comedian Margaret : CHO
60. X-ray units : RADs. (obsolete?)
64. "Understood" : "I SEE"
65. Flanged fastener : T-NUT
66. It's measured in degrees : ANGLE
67. "Why don't we?" : "LET'S"
68. "__-dokey!" : OKEY
69. 1971 Eric Clapton hit : LAYLA
Down:
1. Wine barrel : CASK
2. Operatic solo : ARIA
3. Squarish, as some cars : BOXY
4. Lummox : OAF
5. __ and Tobago: West Indies nation : TRINIDAD
6. "All in the Family" spin-off : "MAUDE"
7. Make a typo, say : ERR
8. "Cheers" actor Roger : REES. (1944 - 2015)
9. Redeemed, as casino chips : CASHED IN
12. Unclear : VAGUE. Purple Rain?
13. Lands heavily : PLOPS
18. 2000 Bush opponent : GORE
23. Pub potable : ALE
24. Nintendo game system : Wii
25. Window treatment : DRAPERY
27. Capital of Norway : OSLO
28. Gas used in signs : NEON
31. Team on the farm : OXEN
33. Viral video, e.g. : MEME
35. Fencing sword : EPEE
36. Fourth planet : MARS
39. Approach cautiously : EASE UP TO
40. Fait accompli : DONE DEAL
43. Puts on clothes : DRESSES
46. "Vaya __ Dios" : CON
48. Commotion : ADO
49. Actor Jannings : EMIL
50. Tax deadline month : APRIL
51. Put an end to : CEASE
53. "E" on a gas gauge : EMPTY
55. Rock genre : PUNK
57. Clever : CAGY
58. Sledding slope : HILL
59. Most fit for military duty : ONE-A
62. Regret : RUE
63. Genetic stuff : RNA
Argyle
Argyle