"FIELD NOTES FOR SURFACE OUTCROPS, MINE, AND PROSPECT DUMPS"	
				
				
FIELD_ID	LATITUDE	LONGITUDE	ROCK_TYPE	ROCK_DESC
GSA_001	37.6193	-90.6249	Rhyolitic tuff	"Pilot Knob--tuff that underlies the so-called upper ""aglomerate""  iron ores and the thinnly bedded hematite ores.  The thinnly bedded tuffs are replaced by hematite ore."
GSA_010	37.4502	-90.5421	Rhyolite	"(GSA-SEG Brown stop #3)  Lower campground tuff (Ylc) of Brown, 1988.  Rhyolitic ash flow tuff which underlies the Lake Killarney tuff.  Dark-maroon, dense, porphrytic rhyolite of Marble Creek Campground"
GSA_011	37.4709	-90.4342	Lake Killarney rhyolitic tuff	"(GSA-SEG Brown stop #4) Top of Arnett Mountain.  Thin veneer of Lake Killarney Tuff (sampled material ) rests on top of  tuff of Marlow Mountain ( Brown, 1988), which was intracaldera fill material from the Marlow Mountain caldera.  Dark purplish-grey to maroon colored welded rhyolitic tuff, with flattened pumice and 12-14 % phenocrysts of mostly alkali feldspar."
GSA_012	37.4784	-90.4152	Rhyolitic tuff	"(GSA-SEG Brown stop #5; Rock Pile Mtn Quad).   Tuff of Marlow Mtn  (Brown, 1989 SEG guidebook) Ponded intracaldera fill material.  Maroon-colored welded rhyolitic tuff with ~8% phenocrysts of quartz and alkali feldspar, lithic clasts and aggregates of iron oxides."
GSA_013	37.4633	-90.4054	Rhyolitic tuff	"(GSA-SEG Brown stop #6; crest of Little Grassy Mtn, west of parking lot, North entrance to Rockpile Mtn Wilderness).  Tuff of Copper Mountain (Brown, 1989 guidebook).  Dark purple rhyolite clasts in lighter maroon-colored welded rhyolite tuff.  Autobrecciated ash flow tuff with devitrified volcanic glass shards."
GSA_014	37.4668	-90.3841	Rhyolitic tuff	"(GSA-SEG Brown stop #7; Rockpile Mtn Quad).  Tuff of Jones Hollow (Brown, 1989 guidebook).  Strongly welded rhyolitic tuff (10% phenocrysts) with flattened pumice ratio 4-6 inches long by 0.25 inch thick."
GSA_015	37.4412	-90.346	Granite dike	"(GSA-SEG Brown stop #9) Hypabyssal granitic dike cutting rhyolite. Megacrysts of quartz, feldspar, and rapakivi feldspars set in medium-grained matrix.  Equivalent to Butler Hill Granite?"
GSA_016	37.4411	-90.3462	Rhyolite	"(GSA-SEG Brown stop #9) Host black rhyolite.  Tuff breccia with red rhyolite clasts in black (70% SiO2) rhyolite matrix.  Map unit Ybr (black rhyolite and breccia; Brown 1989 guidebook).  Location estimated from description in guidebook, mileage off relative to described location of pond and mapped logging roads."
GSA_017	37.4637	-90.2094	Andesite	(GSA-SEG Brown stop #10; Cottoner Mtn).  Black porphyritic andesite with <10% phenocrysts of altered plagioclase (1-5 mm in diameter).
GSA_018	37.5578	-90.4432	Silvermine Granite	(GSA-SEG stop #3-2 Silvermine district).  Silvermine Granite taken ~200 feet east of Einstein adit (from foundation of old mill site) Lat-Long locaiton approximate.
GSA_019	37.5577	-90.4438	Vein in Silvermine Granite	"(GSA-SEG stop #3-2 Silvermine district).  Vein with topaz, flourite, quartz in Silvermines Granite.  Host  greissenized  granite has secondary k-spar with trace of desiminated sulfides, now oxidized.  Taken from outcrop uphill from Einstein adit.  Lat-long location approximate."
GSA_002	37.6189	-90.6243	Rhyolitic tuff	(GSA-SEG field trip stop #3) Pilot Knob area.  Sample of purple rhyolite tuff.
GSA_020	37.5578	-90.443	Vein in Silvermine Granite	"(GSA-SEG stop #3-2 Silvermine district).  Vein with open-space filling of epidote, actinolite, flourite, and topaz in Silvermine Granite.  From Einstein mine dump."
GSA_021	37.5578	-90.443	Ore from Einstein mine	(GSA-SEG stop #3-2 Silvermine district).  Ore material from Einstein mine dump with sphalerite+chalcopyrite+quartz+topaz.
GSA_022	37.5578	-90.443	Ore from Einstein mine	(GSA-SEG stop #3-2 Silvermine district).  Sample of sphalerite+chalcopyrite from Einstein mine dump (Gary Sidder's sample=GBS22).
GSA_023	37.6669	-90.6482	Graniteville Granite	Graniteville Granite (with polished surface).  From  Missouri Red  quarry east of US 21 ~1 mile north of turnoff for Elephant Rocks State Park.
GSA_003	37.6186	-90.6246	Rhyolitic tuff with iron oxide replacement	(GSA-SEG field trip stop #4).  Bedded tuff replaced by iron oxide.  Less iron oxide replacement than at GSA-1.  Unit is lateral equivalent to that mined along front part of mine (at stop 4). 
GSA_004	37.6205	-90.6328	Siderite-quartz from Lower Pilot Knob	Lower Pilot Knob dump.  Siderite+quartz from ore (rare occurance).
GSA_004A	37.4132	-90.5824	Rhyolitic tuff	"(GSA-SEG stop #1)  Tile-red tuff  (Ytr) of Brown, 1988.  Tile-red color (diagnostic feature), fine-grained densely welded tuff with plagioclase and alkali feldspar phenocrysts.  Eliptically shaped lithophysae.  Basal lithophysal zone"
GSA_005	37.4143	-90.584	Rhyolitic tuff	"Tuff at Crane Pond (Ycp) of Brown, 1988."
GSA_006	37.4145	-90.5427	Ryholite of Mountain View	"(GSA-SEG stop #2) Ryholite of Mountain View (Ymv) of Brown, 1988.  Flow-banded rhyolite with <6% phenocrysts of alkali feldspar and quartz. "
GSA_007	37.4205	-90.5405	Rhyolite	"(GSA-SEG stop #2)  Upper ridge ryholite (Yur) of Brown, 1988. Lithic ttuff with beautiful red lithic clasts in fine-grained tuff matrix. "
GSA_008	37.4227	-90.5444	Rhyolite	"(GSA-SEG stop #2)  Upper ridge rhyolite (Yur) of Brown, 1988.  Red  upper ridge tuff  with characteristic color and texture. "
GSA_009	37.4227	-90.5444	Andesite	"(GSA-SEG stop #3)  Lower andesite  (Yla) of Brown, 1988.  Trachyandesite south of Marble Creek campground."
IGCP1_1	37.7291	-90.4275	Butler Hill Granite	"(IGCP stop #1-1) Butler Hill Granite.  Biotite-granite microperthite holocrystalline course-grained rapakivi granite.  Forms central pluton in Bultler Hill caldera and surrounded by ring intrusions (Stono Mtn, Silvermines, Slabtown, and Knblick Granites)."
IGCP1_2	37.6634	-90.3855	Knoblick Granite	"(IGCP stop #1-2) Knoblick Granite of the ring intrusion suite of Kisvarsani.  Medium-grained biotite-hornblende granite with alkali-feldspar porphyries.  Metaluminous granite with assessory minerals of zircon, apatite, magnetite. Granite intrudes ash-flow aphanitic rhyolite."
IGCP1_3	37.6067	-90.3391	Slabtown Granite	(IGCP stop #1-3) Slabtown Granite of the ring intrusion suite of Kisvarsanyi.  Fine-grained amphibole equigranular granite.  Thought to be a subvolcanic/hypabysal intrusion; thought to be oldest of this ring complex.
IGCP2_1A	37.697	-90.541	Breadtray Granite	(No IGCP stop number). Breadtray Granite.
IGCP2_3	37.5204	-90.8355	Munger Granite	(IGCP stop #2-3) Taum Sauk Power Plant area.  Munger granite  hypabyssal intrusion along the margin of the Taum Sauk caldera.
IGCP2_3A	37.5204	-90.8355	Taum Sauk rhyolitic tuff	(IGCP stop #2-3) Taum Sauk Power Plant area.  Taum Sauk rhyolitic ash flow tuff.
IGCP2_4	37.6669	-90.6482	Graniteville Granite	(IGCP stop #2-4) Graniteville Granite.  Course-grained equigranular muscovite-biotite alkali granite.  Accessories of flourite+pyirte+topaz+alunite+monazite common.  Eva Kisvarsanyi classified this as a high heat producing granite suite (HHP) with U potential.
IGCP3_1	37.8309	-90.2326	Gneiss	Hawn State Park.  Older pre-volcanic gneiss--basement?  Course-grained foliated hornblende-biotite tonalitic to granodioritic gneiss
IGCP3_2	37.8319	-90.2327	Rhyolite dike	Hawn State Park.  Porphyritic (megacrystic) rhyolite dike.
IGCP3_3	37.8328	-90.2326	Gneiss	Hawn State Park. Foliated biotite granodiorite gneiss.
IGCP4	37.5663	-90.3502	Grassy Mountain Ignimbrite (rhyolite)	(IGCP stop #1-4) Grassy Mountain Ignimbrite. Ryolite erupted from the Butler Hill caldera.  Outcrop has basaltic dike cutting rhyolite.
IGCP5	37.5578	-90.443	Einstine mine	(IGCP stop #1-5) Silver Mine Recreational Area; Einstein mine area.
IGCP5A	37.5702	-90.4626	Mafic-granitic magma mingling	(No IGCP stop number).  Tiemann Shut-in at Mill Stream Gardens Conservation Area. Evidence of mafic-granitic magma mixing on polished outcrops along St. Francois River.  Mafic  pillows  with lobate margins in Silvermine Granite suggests mafic magma present during emplacement of the Silvermine ring intrusion.  Is  the mafic phase evidence for the source of heat for generating the crustal melts?
MGS28_1	37.5288	-90.6772	Dark Purple rhyolite-Ketcherside Mtn	Dark purple rhyolite on Ketcherside Mountain.
MGS28_4	37.5283	-90.6748	Black rhyolite-Ketcherside Mtn	Black rhyolite on Ketcherside Mountain.
MGS31_2	37.517	-90.6747	Black rhyolite-Ketcherside Mtn	Dark gray to black fine-grained ash fall tuff from Ketcherside Mountain.
MGS37_2	37.5114	-90.6776	Royal Gorge Rhyolite-Ketcherside Mtn	Royal Gorge Rhyolite on Ketcherside Mountain; flow-banded K-spar bearing ignimbrite.
MGS37_3	37.5136	-90.6769	Royal Gorge Rhyolite-Ketcherside Mtn	Royal Gorge Rhyolite on Ketcherside Mountain; flow-banded K-spar bearing ignimbrite.
MGS37_4	37.514	-90.6767	Royal Gorge Rhyolite-Ketcherside Mtn	Royal Gorge Rhyolite on Ketcherside Mountain; flow-banded K-spar bearing ignimbrite.
MGS38_3	37.5681	-90.6979	Royal Gorge Rhyolite-Russell Mtn	Royal Gorge Rhyolite on Russell Mountain flow-banded K-spar bearing ignimbrite.
MGS38_4	37.5686	-90.6979	Royal Gorge Rhyolite-Russell Mtn	Royal Gorge Rhyolite on Russell Mountain flow-banded K-spar bearing ignimbrite.
MGS38_6	37.5695	-90.6978	Royal Gorge Rhyolite-Russell Mtn	Royal Gorge Rhyolite on Russell Mountain flow-banded K-spar bearing ignimbrite.
MO88_001	37.6318	-90.6455	Jasperoid breccia-Cedar Hill iron prospect	Jasperoid breccia from Cedar Hill iron deposit.
MO88_002	37.6318	-90.6455	Polymict breccia-Cedar Hill iron prospect dump	Polymict breccia from Cedar Hill iron mine dump.
MO88_003	37.6318	-90.6455	Hematite-replacement of host rhyolite-Cedar Hill iron prospect	" Ore  of hematite replacement of host rhyolite from Cedar Hill iron mine dump, west side of mountain."
MO88_004	37.477	-90.6219	"Trachyte, Crane Loookout tower"	Trachytic volcanic flow
MO88_005	37.6194	-90.6251	Clastic rock with hematite matrix-Upper Pilot Knob	"Bedded ash-rich horizons interlayered with cobble- to pebble-size clasts of rhyolite.  Fine-grained ash horizons seem to be replaced by hematite.  Cross beds, ripple marks, rain drops, mudcracks indicate shallow aqueous environment.  Syn-depositional with exhalative iron-oxide hydrothermal fluids in near shore caldera mote lake?"
MO88_006	37.6191	-90.6248	Rhyolite clasts replaced by hematite-Upper Pilot Knob	Top of Pilot Knob see clasts of hematite in sedimentary breccia and clasts replaced by hematite indicating syn- to post-ore sedimentation.  Iron mobility during diagensis as well as post-ore sedimentation.
MO88_007	37.6191	-90.6249	Banded iron ore-Upper Pilot Knob	Banded iron ore-Upper Pilot Knob iron deposit.
MO88_008	37.6191	-90.6249	Rain-drop depressions in banded hematite sediment-Upper Pilot Knob	Rain-drop depressions in banded hematite sediment-Upper Pilot Knob.
MO88_009	37.6995	-90.6394	Magnetite + actinolite ore-Iron Mountain	Magnetite + actinolite ore sample from Iron Mountain iron deposit.
MO88_010	37.6995	-90.6394	Magnetite+actinolite+apatite	Presumed ore grade sample of magnetite+actinolite+apatite from Iron Mountain iron deposit.
MO88_011	37.9659	-90.9988	"Trachyte, Floyd Tower"	Trachyte from Flyod Tower area.
MO88_012	38.0414	-90.9194	Trachyte from Indian Creek mine dump	Trachyte sample from Indian Creek mine dump materials.
MO88_015	37.6195	-90.6243	Top of Pilot Knob: Hematite clasts in water-lain conglomerate	Top of Pilot Knob: Iron-rich clasts in water-lain conglomerate.
MO88_016	37.6196	-90.6335	Brecciated host rock with calcite and flourite in matrix	Brecciated host rock with calcite and flourite in matrix from Lower Pilot Knob mine dump.
MO88_017	37.6196	-90.6335	Andesite host rock from Lower Pilot Knob dump	Host volcanic rock (andesite) from Lower Pilot Knob mine dump.
MO88_018	37.6196	-90.6335	Magnetite ore	Magnetite ore from Lower Pilot Knob mine dump.
MO88_019	37.6196	-90.6335	Altered host rock from Lower Pilot Knob dump	Magnetite-altered host rhyolite from Lower Pilot Knob mine dump.
MO88_020	37.6196	-90.6335	Ore breccia with magnetite clasts	Breccia with ore-stage magnetite cemented by chlorite and calcite from Lower Pilot Knob mine dump.
MO89_004	37.6992	-90.6395	Grassy Mountain Ignimbrite (Iron Mt)	Grassy Mountain Ignimbrite host for Iron Mountain iron deposit.  Maroon rhyolite porphyry with 8 percent broken phenocrysts of feldspar>quartz and flattened pumice and lithic fragments.
MO89_005A	37.6992	-90.6395	Grassy Mountain Ignimbrite (Iron Mt)	Grassy Mountain Ignimbrite rhyolite host for Iron Mountain iron deposit.
MO89_005B	37.6992	-90.6395	Green alteration veins in Grassy Mountain Ignimbrite (Iron Mt)	Quarry (Hayes Cut) is east of the underground iron ore body (west of trap rock operations).  Flows dip east so these flows would overlie buried old mine workings (and ore).
MO89_006	37.6997	-90.6402	Hematite vein in host rhyolite	Iron Mountain: Beautiful hematite (altered magnetite?) veins cross cutting host rhyolite. First nice cut along old road.
MO89_007	37.6997	-90.6402	Host rhyolite clasts in hematite ore	Iron Mountain: Host rhyolitic clasts invaded by hematite (altered magnetite?).
MO89_008	37.6997	-90.6402	Large apatite? (or altered amphibole) in hematite	Iron Mountain: Large apatite(?) or altered amphibole in hematite ore.
MO89_009	37.6997	-90.6402	Quartz vein in hematite clast	Iron Mountain: Late-stage quartz vein cutting lithic clast in ore breccia.
MO89_010	37.6997	-90.6402	Apatite(?)/altered amphibolie and hematite	Iron Mountain: Apatite(?)/altered amphibolie and hematite.
MO89_011	37.6997	-90.6403	Deep read apatite(?)/altered amphibole crystals	Iron Mountain: Deep read apatite(?)/altered amphibole crystals.
MO89_012	37.6997	-90.6403	Interstital quartz within hematite ore	Iron Mountain: interstital quartz within hematite ore for possible fluid inclusion work.
MO89_013	37.6698	-90.6403	Quartz pod within hematite ore	Iron Mountain: quartz pod within hematite ore.  See beautiful 8 inch long blades of actinolite that form basketball-shaped pod.
MO89_114	37.6113	-90.6489	Shepherd Mountain Rhyolite host to iron deposit	Sepherd Mountain: Dark maroon welded fresh rhyolite with 15 percent flattened pumice up to 1.5 ft long; 10-15 percent feldspar phenocrysts with some broken. Unit shows flow layering dipping N50E-34S.  Interpreted as rhyolitic ignimbrite.
MO89_115	37.6106	-90.6464	Quartz+magnetite-Shepherd Mountain iron deposit dump	Shepherd Mountain: Ore deposit is steeply dipping magnetite vein cutting host rhyolite.  Mine workings 200ft long 50ft wide and strike N50E-80SW.  Ore course grained magnetite with trace (<1 percent) pyrite.  Phylosicicates in vugs (late stage gauge mineral). Very simple system.  Alteration of host limited to margins of magnetite vein and is reddening of host.
MO89_116	37.6102	-90.647	Massive magnetite ore-Shepherd Mountain iron deposit dump	Massive magnetite ore-Shepherd Mountain iron deposit mine dump.
MO89_117	37.6102	-90.647	Massive magnetite ore with rhyolite clast-Shepherd Mountain iron deposit dump	Massive magnetite ore with rhyolite clast-Shepherd Mountain iron deposit mine dump.
MO89_118	37.6102	-90.647	Altered host rock-Shepherd Mountain iron deposit	Altered host rhyolite 1 ft from magnetite ore vein.  Alteration extends only 10-15 ft out from vein-Shepherd Mountain iron ore deposit.
MO89_119	37.6063	-90.646	Hematite+quartz fragment in Shepherd Mountain Rhyolite	Hematite+quartz fragment in Shepherd Mountain Rhyolite.  Implies at least some ore formation was pre-volcanism here.
MO89_120	37.6074	-90.6482	Mafic xenolith in host rhyolite host-Shepherd Mountain iron deposit	Mafic xenolith in host rhyolite host-Shepherd Mountain iron deposit.
MO89_121	37.6075	-90.6477	Massive magnetite ore-Shepherd Mountain iron deposit dump	Massive magnetite ore-Shepherd Mountain iron deposit mine dump.
MO89_122	37.6076	-90.6473	Catclastic breccia on southern margin of iron ore vein-Shepherd Mountain 	Shepherd Mountain deposit: Catclastic breccia on southern margin of iron ore vein-Shepherd Mountain 
MO89_123A	37.5913	-90.6574	Rhyolite ash flow tuff	Unit Yr of Pratt and others (1979).  Dark maroon colored ash flow tuff with lithic fragments of dark brown to black mafic volcanics. Phenocryts ~10 percent with no flattened pumice fragments.
MO89-123B	37.5912	-90.6573	 Mafic  lithic clast in rhyolite 	"More mafic lithic clast in rhyolite.  Unit overlies Shepherd Mountain Rhyolite (unit Ys of Pratt and others, 1979)."
MO89_124	37.5961	-90.6584	Rhyolite ash flow tuff	Unit Ys of Pratt and others (1979).  Shepherd Mountain Ryholite (Cedar Bluff Rhyolite).  Brownish-maroon crystal-rich ash flow tuff with broken plagioclase phenocrysts (20-40 percent) with occasional more mafic clasts.
MO89_125	37.6288	-90.6419	Rhyolite ash flow tuff breccia of Cedar Hill area	Rhyolite tuff breccia with angular red and black fragments (pebble to boulder sized) with maroon-colored tuff matrix.  Locally silicified matrix with boxwork texture of open space filling.  Quartz and epidote veins. Cedar Hill area: parked at Baptist Church walked NNE along outcrop. Unit Ys Pratt and others (1979).
MO89_126	37.6294	-90.6424	Banded rhyolite ash flow tuff on Cedar Hill	Flow-banded rhyolite with dark to black fine-grained rhylite lithic clasts and flattened pumice.  Flow foliation 270-N16E.
MO89_127	37.6331	-90.647	Polymict rhyolite breccia on Cedar Hill	Poorly shorted matrix-supported polymict breccia from Cedar Hill.  Matrix is welded tuffaceous rhyolite tuff.  Area relatively unmineralized.  May be intra-cauldera tuff breccia deposited within or adjacent to the cauldera margin.
MO89_128A	37.6331	-90.647	Polymict rhyolite breccia on Cedar Hill	Same as MO89_127 sampled to thin section to characterize matrix material. Poorly shorted matrix-supported polymict breccia from Cedar Hill.  Matrix is welded tuffaceous rhyolite tuff.  Area relatively unmineralized.  May be intra-cauldera tuff breccia deposited within or adjacent to the cauldera margin.
MO89_128B	37.6331	-90.647	Polymict rhyolite breccia on Cedar Hill	Same as MO89_127 sampled to thin section to characterize matrix material. Poorly shorted matrix-supported polymict breccia from Cedar Hill.  Matrix is welded tuffaceous rhyolite tuff.  Area relatively unmineralized.  May be intra-cauldera tuff breccia deposited within or adjacent to the cauldera margin.
MO89_129	37.632	-90.6464	Hematite-replacement of host rhyolite-Cedar Hill iron deposit	Cedar Hill mine dump: Hematite replacement of polymict rhyolite breccia matrix with highly altered clasts.
MO89_130	37.632	-90.6464	Hematite-cemented rhyolite breccia with jasperoid-Cedar Hill iron deposit	Cedar Hill deposit: Hematite-cemented rhyolite breccia with jasperoid replacement of rhyolite clasts-Cedar Hill iron deposit.
MO89_131	37.632	-90.6464	Hematite+jasperiod+argillic alteration of rhyolite breccia-Cedar Hill	Cedar Hill deposit: Hematite+jasperiod+argillic alteration of rhyolite breccia.
MO89_132	37.632	-90.6464	Massive hematite+jasperoid epithermal breccia replacement-Cedar Hill iron deposit	Cedar Hill deposit: Hematite-rich fluids invaded and replaced pre-existing intracauldera breccia.  No apatite--this was an epithermal deposit.
MO89_133	37.632	-90.6464	Massive hematite ore-Cedar Hill iron deposit dump	Cedar Hill deposit: Hematite ore with remnant rhyolite breccia clasts.
MO89_134	37.574	-90.7021	Russel Mountain Rhyolite	Dark maroon fiamme-rich rhyolite ash flow tuff of Russel Mountain (east of Taum Sauk lookout tower).
MO89_135	37.5734	-90.6982	Royal Gorge Rhyolite	Flow-banded rhyolite with bands oriented N0E-vertical.  Royal Gorge Rhyolite.  Taking field trip guide down Taum Sauk trail.
MO89_136A	37.5792	-90.6861	Wildcat Mountain Rhyolite (breccia)	Heterolithic rhyolite breccia with tuffaceous matrix.
MO89_136B	37.5792	-90.6861	Rhyolite clast within Wildcat Mountain Rhyolite	Massive clast of the predominant dark maroon rhyolite called Wildcat Mountain Rhyolite.
MO89_137	37.5682	-90.7203	Taum Sauk Moutain Rhyolite	Float of Taum Sauk Mountain Rhyolite.  Dark maroon with 5-10 percent broken quartz+feldspar phenocrysts.  Characteristically NOT flow banded.
MO89_138	37.5922	-90.5746	Lake Killarney rhyolitic tuff	Dark reddish purple rhyolite tuff (not flow-banded like Grassy Mountain ignimbrite).
MO89_139	37.5854	-90.5831	Grassy Mountain Ignimbrite	Grassy Mountain Ignimbrite characterized by flow banded pumice horizons. Dark purplish-brown color with 20-25 percent quartz-k-spar broken phenocrysts.
MO89_140	37.6144	-90.6064	Ironton Hollow Rhyolite	"Dark purple phenocryst-poor flow-banded rhyolite (3-5 percent phenocrysts).  Flow-banding highly folded.  Pilot Knob is maded as this unit, buth I didn't see this on Pilot Knob."
MO93_001	37.5705	-90.6975	Royal Gorge Rhyolite	Russell Mountain (SW of Ironton).  Royal Gorge Rhyolite.  Flow-banded rheological rhyolitic flow with Z-folds in flow foliations.  Flow banding looks to be pumice and frothy tops of flows.
MO93_010	37.5235	-90.6662	Stromatalites	Stromatalite horizons with chert and algal laminants within the Ketcherside Tuff. Exhalative deposit with algal matts growing near vents. Beds are horizontal.  
MO93_011	37.5437	-90.6455	Ketcherside Tuff	Small waterfall on creek.  Rhyolitic ash-flow tuff (broken quartz) and aglomerate at base of Ketcherside Tuff.  Thought location is at margin of Taum Sauk Caldera.
MO93_012	37.5079	-90.6612	Rhyolite	Light pinkish gray massive rhyolite porphyry (k-spar).  Dark net veining in matrix.
MO93_120	37.5373	-90.6801	Lamott Sandstone	Cambrian Lamott Sandstone pebbles.
MO93_121	37.5347	-90.6789	Royal Gorge Rhyolite	Flow-banded Royal Gorge Rhyolite with angular 1-4 inch diameter lithic fragments
MO93_122	37.533	-90.6792	Rhyolite	"Flow-banded rhyolite with less pumice and lithic fragments (as in Royal Gorge Rhyolite). Aphanitic groundmass, with highly variable grayish red to reddish brown color"
MO93_123	37.5326	-90.6796	Hydrothermal rhyolite breccia	Iron-cemented hydrothermal breccia with flow-banded rhyolite.  Breccia is simple with angular clasts of rhyolite up to 4 inch diamter in matrix of hematite + magnetite.  Mapped as Royal Gorge Rhyolite
MO93_124	37.5325	-90.6801	Brecciated Royal Gorge Rhyolite	Brecciated subangular to subrounded flow-banded rhyolite clasts.  Could be megabreccia along caldera margin or fault zone (or hydrothermal phreatomagmatic breccia?).  Matrix is fine-grained (rock flour).
MO93_125	37.5308	-90.6803	Royal Gorge Rhyolite	Brecciation seems to die off to the east.  Numerous high angle fractures filled with iron oxide mineral(s) 1/8 inch wide x 5 feet long.  Flow banding is folded and contorted.
MO93_126	37.5298	-90.6785	Rhyolite	"Dark reddish gray rhyolitic tuff (k-spar>quartz).  Phenocrysts <20 percent, some broken.  Mapped as  Black Rock."
MO93_127	37.5286	-90.6778	Rhyolite	Dark red lithic rhyolitic tuff.  Approximately 25 percent phenocrysts (both euhedral and broken) of k-spar>>quartz.  Matrix of fine-grained dark red rhyolite with dark aphanitic lithic fragments.
MO93_128	37.527	-90.6768	Rhyolite	Purple rhyolitic tuff (=Taum Sauk Rhyolite?).  First signs of flattened pumice in float.  Flow-banded porphyritic rhyolite.
MO93_129	37.5261	-90.6758	Lithic rhyolitic tuff	Aphiric fine-grained welded lithic tuff.  Blackish red <5 percent phenocrysts of k-spar and quartz with 5 percent lithic rock fragments with strong epidote alteration. (so-called Black Rock of Charlie Robertson MGS).
MO93_013	37.5083	-90.6611	Rhyolite	Light pinkish gray massive rhyolite porphyry (k-spar).  25-30 % phenocrysts.
MO93_130	37.525	-90.6763	Rhyolite tuff	Crystal lithic rhyolitic ashflow tuff.  (15 percent k-spar; 2-5 percent alkali feldspar; 1 percent quartz; 5-7 percent lithic fragments).
MO93_131	37.5224	-90.683	Rhyolite	Purple rhyolitic tuff (=Taum Sauk Rhyolite?).  First signs of flattened pumice in float.  Flow-banded porphyritic rhyolite.
MO93_132	37.5216	-90.6802	Flow-banded rhyolite	Autolithic cobble-sized lithic fragments plastically deformed in crystal-lithic tuff (Purple Rhyolite of Charlie Robertson MGS).
MO93_133	37.5216	-90.6826	Rhyolite tuff	"Air-fall tuff.  Series of 6inch thick moderately sorted bed sets of lighter lithic-rich course-grained horizons iwht finer aphanitic purple-colored tuff.  Tops upward, dips east.  Basal part would beds are  Black Rock .  Bedding 098, 12 SE."
MO93_134	37.5226	-90.6855	Rhyolite	Typical purple rhyolitic tuff with black fine-grained angular lithic fragments.  Approximately 25 percent phenocrysts; 5-8 percent dark fragments; 1-5 percent flow-banded autolithic rhyolite fragments.
MO93_135	37.5272	-90.6822	Flow-banded rhyolite	Float of flow-banded crystal-lithic rhyolite tuff mixed with Cambrian Lamott Sandstone.  Approximately 10-15 percent phenocrysts (k-spar>quartz) in rhyolite.
MO93_136	37.5405	-90.6514	Cuthbertson Mountain tuff	"Dusky red to blackish red fresh Cuthbertson Mountain tuff with minor flattened pumice (stongly welded).  Phenocrysts 5 percent k-spar, 1 percent quartz."
MO93_137	37.5352	-90.6576	Cuthbertson Mountain tuff	"Cuthbertson Mountain tuff.  Nice open outcrop near creek.  Flattened pumice foliation 150, 15SW."
MO93_138	37.528	-90.6614	Cuthbertson Mountain tuff	Float of Cuthbertson Mountain tuff with white tuff.
MO93_139	37.5275	-90.6614	Cuthbertson Mountain tuff	Bedded Cuthbertson Mountain tuff.  
MO93_014	37.5133	-90.6593	Ketcherside Tuff	Ketcherside Tuff. Copper prospect dumps NE side of  Gap .  Well layered waterlain tuffacous sediment.  Graded bedding & laminar bedding alternating with sand-sized tuffaceous and clay-sized (green biotite and amphibole?) horizons.  Mineralitaion reported to be malachite and minor Cu sulfides (not seen).  Note: mineralization at Upper Pilot Knob and Cuthbertson Mtn restricted to waterlain Ketcherside Tuff time interval-most favorable horizon for mineralization.
MO93_140	37.5272	-90.6621	Cuthbertson Mountain tuff	"Good outcrop of Cuthbertson Mountain tuff with flattened pumice and lithic fragments.  Phenocrysts 5 percent k-spar, 1-5  percent black lithic fragments.  Flattening = 120, 38 SW."
MO93_141	37.5232	-90.6692	Cuthbertson Mountain tuff	"Cuthbertson Mountain tuff.  Flattened pumice foliation 0, 15 NE"
MO93_142	37.5221	-90.6709	Cuthbertson Mountain tuff	"Cuthbertson Mountain tuff.  Seems to be a transition zone to  Purple tuff .  Flattening = 0, 15 NE. Blackish-red to graysih red aphanitic rhyolitic welded tuff. Phenocrysts 7 percent k-spar, 3-5 percent quartz.  <20 percent pumice and lithic fragments."
MO93_143	37.5237	-90.6715	Cuthbertson Mountain tuff	"Cuthbertson Mountain tuff.  Dusky red, 5 percent k-spar, 7-9 percent lithic fragments"
MO93_144	37.5221	-90.6744	 Purple tuff  rhyolite	"Crystal lithic rhyolitic  tuff with lithic clasts of Cuthbertson Mountain tuff, 20-30 percent k-spar phenocrysts in a moderately reddish brown to purpl-colored matrix.   Purple tuff  younger than Cuthbertson Mountain tuff"
MO93_145	37.5191	-90.6755	Rhyolite	Royal Gorge tuff is beneath  Purple tuff  on northwest corner of Ketcherside Gap area.  Are  Purple tuff  and Royal Gorge tuff coeval?
MO93_146	37.5211	-90.6705	Cuthbertson Mountain tuff	"Lithic-rich zone in Cuthberston Mountain tuff.  20 percent white lithic fragments in welded tuff.  Flattened pumice oriented 310, 28 NE"
MO93_147	37.5133	-90.6593	Ketcherside tuff	"Bedded silicious banded malachite-bearing tuffaceous siltstone with malachite dessiminted and cross-cutting bedding (epigenetic). Bedding = 320, 15 NE. Gary Sidder sampled the outcrop."
MO93_148	37.5136	-90.6588	Ketcherside tuff	Ketcherside tuff here is a tuffaceous siltsone.  Block at drill collar is crystal-lithic tuff with flattened pumice (Royal Gorge Rhyolite).
MO93_149	37.5125	-90.6614	 Purple tuff  rhyolite	 Purple rhyolite  and Royal Gorge Rhyolite float.
MO93_014A	37.5133	-90.6593	Tuffaceous sandstone	Dirty  sandstone with quartz sand and honey-colored lusterous mineral (sphalerite?) in matrix.  Sulfide weathering on surface.
MO93_014B	37.5133	-90.6593	Waterlain tuffaceous sediments	Pink and green layered waterlain tuff with actinolite+biotite horizons (Ketcherside Tuff).
MO93_014C	37.5133	-90.6593	Ketcherside Tuff with malachite	Malachite-bearing bedded tuff (Ketcherside Tuff).  Best cut on east end with 2 drill collars exposed.  Ubiquitous malachite staining along fractures and dessiminated in tuffaceous sediment.
MO93_015	37.5101	-90.6581	Rhyolitic tuff	Grayish-pink K-spar porphyritic rhyolitic tuff with massive texture (similar to MO93-13).  20-30% broken phenocrysts (K-spar>>qtz).
MO93_150	37.5121	-90.661	 Purple tuff  rhyolite	"Crystal-rich tuff of  Purple tuff  unit with faint flow banding and broken crystals.  Pale grayish to blackish red matrix with 15 percent albite, 5 percent quartz phenocrysts and 1 percent lithic fragments."
MO93_151	37.5117	-90.6647	Royal Gorge Rhyolite	"Flow-banded densly welded ignimbrite with pale red matrix.  Phenocrysts 10 percent albite, 5 percent quartz, 2 percent k-spar. Ignimbrite with flattened insitu degassing textures and flattend pumice."
MO93_153	37.5154	-90.6643	Cuthbertson Mountain/Ketcherside Gap tuff contact	"Waterlain bedded tuff with ripple marks (Ketcherside).  Bedding = 270, 10 N. Contact zone between Cuthbertson Mountain (on top) and Ketchershide Gap (beneath) tuffs. Royal Gorge Rhyolite beneath the Cutherberston Mountain tuff."
MO93_155	37.5146	-90.6659	Royal Gorge Rhyolite	Royal Gorge Rhyolite.
MO93_016	37.512	-90.666	Royal Gorge Rhyolite	"Royal Gorge Rhyolite.  Distinctive light and dark pink flow-banding in rhyolite tuff.  10-15% K-spar phenocrysts.  See folding in flow banding.  Strike on banding=205, 50NE."
MO93_160	37.517	-90.6613	Ketcherside Gap tuff	"Ketcherside Gap tuff is tuffaceous siltstone and mudstone.  Lacks silicification associated with mineralization.  Sample taken is unmineralized representation of unit.  Bedding = 290, 5 NE."
MO93_161	37.5132	-90.6566	Lamott Sandstone	Cambrian Lamott Sandstone conglomerate.
MO93_162	37.4487	-90.5412	Andesite	"Unit upper andesite (Yua) of Brown, 1988.  Andesite from Marble Creek campground south of Highway is subcrop of dark purplish black andesite with ~15 percent plagioclase phenocrysts.  Epidote alteration common"
MO93_163	37.4499	-90.5372	Rhyolitic tuff	"Unit Lower Campground rhyolitic tuff (Ylc) of Brown, 1988."
MO93_164	37.4409	-90.559	Andesite	"Unit Andesite from Marble Creek campground (Yua) of Brown, 1988.  Outcrop is north of Highway on east side of knob west of campground.  Sample is very fresh."
MO93_165A	37.4813	-90.5877	Grassy Mountain Ignimbrite (rhyolite)	"Grassy Mountain ignimbrite.  Dark red aphanitic matrix. Lacks pumice and fiammes normal to unit.  ~25 percent total phenocrysts (15 percent k-spar, 10 percent quartz) and 2 percent mafic lithic clasts."
MO93_165B	37.4811	-90.5893	Grassy Mountain Ignimbrite (rhyolite)	Basal part of Grassy Mountain ignimbrite with darker red aphanitic matrix.
MO93_165C	37.4809	-90.59	Lake Killarney rhyolitic tuff	Lake Killarney tuff.  Good sample for chemistry.
MO93_017	37.5116	-90.665	Purple Rhyolite	(Location approximate).   Purple rhyolite .  Massive K-spar porphyry with maroon aphanitic matrix and minor flow banding.
MO93_018	37.5113	-90.6635	Royal Gorge Rhyolite	"Royal Gorge Rhyolite.  Distinctive light and dark pink flow-banded rhyolite ignimbrite. Flow banding= 312, 70NE."
MO93_019	37.5068	-90.6689	Royal Gorge Rhyolite	Royal Gorge Rhyolite.  Distinctive light and dark pink flow-banded rhyolite ignimbrite.
MO93_002	37.5482	-90.6645	Gasconade weathered residuum	Along railroad cut.  Varigated shales and cherts looks to be weathering residuum from the Gasconade Fm.  Steeply dipping to the northwest.  Precambrain basement exposed beneath residuum.
MO93_020	37.5035	-90.6668	Alkali porphyry granite	Megacrystic alkali porphyry granite.  See flow alignment of K-spar porphyries.  Intruded along Taum Sauk Caldera margin.
MO93_003	37.5341	-90.6681	Rhyolitic tuff	"Purplish-gray welded rhyolitic tuff with quartz phenocrysts (no k-sp) with rounded and embayed margins.  Angular black lithic fragments (~15-25 %).  Flattened lithic fragment strike=278W, 45N."
MO93_004	37.5321	-90.6663	Rhyolite	Pillow structure in rhyolite--subaqueous lava flow?  2 foot long oblate pillow with epidote enrichment along rinds (photo).
MO93_005	37.5318	-90.6659	Rhyolite	Light gray massive aphanitic ryholite. Characterized by lack of visible phenocrysts. Veins of late quartz and pyrite.
MO93_006	37.537	-90.6644	Rhyolitic lithic tuff	Lithic tuff with monolithic rounded rhyolitic clasts (2-4 inches in diamter). Agglomerate?
MO93_007	37.5339	-90.6618	Bonneterre Dolomite	Cambrian Bonneterre Dolomite.
MO93_008	37.537	-90.654	Ketcherside Tuff	"Ketcherside Tuff(?)  Flow-banded rhyolitic tuff with broken quartz phenocrysts, flattened pumice, and flow banding.  Strike of flow banding 125, 22SW"
MO93_009A	37.5405	-90.6504	Manganese ore	Manganese ore sample.  Epithermal sinter deposit with clasts of host Ketcherside Tuff with carbonate cement and red jasper matrix. Ketcherside Tuff host to the Cuthbertson Mountain manganese desposit.  Ketcherside Tuff thought to be beneath the Cuthbertson Mountain Tuff.  Distinctive waterlain tuff with ripple marks and x-beds.  Correlated with Upper Pilot Know host rocks.
MO93_009B	37.5405	-90.6504	Jasperoid	Sinter deposit.  Jasperoid with banded texture.
PKMO_100	37.6197	-90.6326	Magentite vein in breccia (skarn)	"Lower Pilot Knob mine dump: Magnetite vein in actinolite-quartz(+calcite+chlorite) breccia, similar to Pea Ridge amphibole zone rocks."
PKMO_101	37.6197	-90.6326	Altered host rhyolite	Lower Pilot Knob mine dump: Silicified rhyolite breccia with magnetite and minor quartz in matrix.  Rhyolitic clasts were reddened (k-spar?) before introduction of magnetite. Siderite in matrix with magnetite.  Similar to Kratz Springs and Pea Ridge.
PKMO_102	37.6197	-90.6326	Rhyolite breccia	Lower Pilot Knob mine dump: Rhyolite breccia with angular rhyolite clasts that were previously reddened and silicified in a matrix of actinolite+quartz+siderite+magnetite.
PKMO_103	37.6197	-90.6326	Magentite breccia (ore)	Lower Pilot Knob mine dump: Ore sample to slab.  Magnetite+apatite+quartz+pyrite+flourite+siderite stable.  White quartz subangular clasts in magnetite+apatite ore.
PKMO_104	37.6197	-90.6326	Massive quartz	Lower Pilot Knob mine dump: Massive quartz with actinolite+chlorite+flourite.  Same generation (?) quartz as in PKMO-103.  Pre-magnetite ore in paragensis.
PKMO_105	37.6197	-90.6326	Magnetite breccia	"Lower Pilot Knob mine dump: Heterolithic magnetite breccia with siderite vug-filling matrix. Clasts of altered rhyolite wall rock, magnetite+fragments of siderite in matrix."
PKMO_106	37.6197	-90.6326	Magnetite breccia	Lower Pilot Knob mine dump: Clasts of magnetite ore set in matrix of magnetite+quartz+apatite. Sample of quartz+magnetite.
PKMO_107	37.6207	-90.6327	Rhyolite breccia	"Lower Pilot Knob mine dump: Silicified host rhyolite breccia (Yar generation from Pratt, 1979). Alkali rhyolite lithic breccia or flow breccia.  Walking east along haul road to the old mill foundations on the north side of Pilot Knob outcrops of flow-banded rhyolite brecciated and hydrothermally altered (argillic + chalcedony (quartz) and yellow staining from weathered sulfide.  Possible low-temperature hydrothermal .alteration associated with ore deposit."