Are you looking for a site with magma at the surface? Do you also want it to have iron ore, flux, and a brook? Do you want to top it all off with an obsidian mountain rising up out of the plain and overlooking the volcano?

Look no further. There's an area of savannah biome (with the sedimentary layers underneath it) about 4x2 embark tiles to the north; the brook is in the southwest and the magma pipe is in the southeast, topping out 17 Z-layers higher than the brook. Between the two is an obsidian mountain with a main peak rising another 11 levels above the magma pipe.

Generated in vanilla DF 31.25 with advanced settings to encourage high volcanism next to sedimentary biomes.

This is the archived save from the moment that the first generation arrived at the site. Embark equipment and skills are from the Lazy Newb Pack pre-generated set.

Stonesense screenshot of wagon site and magma pipe:


DFProspector results:

Base materials:
SOIL : 19638
STONE : 953510
FEATSTONE : 42364
OBSIDIAN : 8397
VEIN : 90900
MAGMA : 159364

Layer materials:
GRANITE : 158170
SCHIST : 133436
SLATE : 101210
GABBRO : 95514
RHYOLITE : 94901
MUDSTONE : 86783
OBSIDIAN : 73981
PHYLLITE : 71151
QUARTZITE : 59044
ANDESITE : 35095
SLADE : 31580
DACITE : 19896
SILT_LOAM : 19638
BASALT : 18359
DIORITE : 4101
MARBLE : 1869
>>> TOTAL = 1004728

Vein materials:
TETRAHEDRITE : 23270
COBALTITE : 12337
ORTHOCLASE : 11943
ALUNITE : 10881
GALENA : 6225
NATIVE_COPPER : 4367
HEMATITE : 3829
EMERALD : 1924
VIOLET SPESSARTINE : 1862
OPAL_PINFIRE : 1571
RAW_ADAMANTINE : 1281
GREEN ZIRCON : 1167
PRASE : 997
RED PYROPE : 969
RED BERYL : 808
PYROLUSITE : 752
CRYSTAL_ROCK : 658
SALTPETER : 647
CITRINE : 513
ALMANDINE : 483
GOSHENITE : 452
BONE OPAL : 411
BLACK ZIRCON : 404
HORNBLENDE : 403
BLACK PYROPE : 401
NATIVE_ALUMINUM : 326
PYRITE : 269
TIGER IRON : 261
PINEAPPLE OPAL : 260
QUARTZ_ROSE : 254
RHODOLITE : 251
MILK QUARTZ : 227
PINK GARNET : 205
BROWN ZIRCON : 195
PRASE OPAL : 154
HONEY YELLOW BERYL : 138
TURQUOISE : 136
REALGAR : 130
FORTIFICATION AGATE : 115
STIBNITE : 105
MORION : 100
RESIN OPAL : 99
RED ZIRCON : 79
PIPE OPAL : 57
AMETHYST : 55
RUTILE : 53
BRIMSTONE : 47
MOSS OPAL : 40
CAT'S EYE : 27
SMOKY QUARTZ : 24
AQUAMARINE : 10
GREEN TOURMALINE : 9
>>> TOTAL = 92181

Shrubs:
GRASS_WHEAT_CAVE : 170
MUSHROOM_HELMET_PLUMP : 167
BUSH_QUARRY : 157
MUSHROOM_CUP_DIMPLE : 141
POD_SWEET : 130
GRASS_TAIL_PIG : 85
BERRIES_PRICKLE : 56
BERRIES_STRAW_WILD : 37
GRASS_LONGLAND : 35
ROOT_HIDE : 30
WEED_BLADE : 19
BERRIES_FISHER : 2
>>> TOTAL = 1029

Wood in trees:
TUNNEL_TUBE : 198
GOBLIN_CAP : 193
SPORE_TREE : 171
ACACIA : 146
BLACK_CAP : 99
FUNGIWOOD : 94
NETHER_CAP : 84
BLOOD_THORN : 83
WILLOW : 4
MAPLE : 1
CHESTNUT : 1
BIRCH : 1
>>> TOTAL = 1075




It also has - and this is an HFS spoiler so don't read unless you want to know ahead of time - a demon temple.