31:
38:
886:, the area surrounding the former Mount Pleasant mine has been a major focus of the company. Research is ongoing, and focuses on the two most likely candidates: the McDougall Brook Granitic suite (MBG) and the Mount Pleasant Granitic suite (MPG). In June 2011, the owners moved their corporate offices from Toronto to Fredericton with the intent of refocusing efforts onto getting the mine running again by 2012.
804:
791:, basalt and pumice-ridden tuff. Pebble to cobble sized conglomerate is also seen complementing the volcanic rock, and parts seem to come from older formations. The basalt is characterized by large crystals (up to 2 cm (1 in)). The tuff are characterized by their reddish-brown color and abundant fossil-pumice. The formation is very rare exposed and of interest to
292:. The volcano is north-south trending in its elliptical shape, with minimum dimensions of 13 by 34 kilometres (8 mi × 21 mi) as outlined by regional gravitational and magnetic studies. The northern half of the volcano has since been covered by depositional rock strata. The caldera is bounded to the east and west by fused
716:. The crystal structure inside the pumice are larger than those outside, indicating that significant mechanical breakage during the eruption in which they were deposited. The exposed part of this layer is located around the southern base of the main caldera, and is colored ochre (light orange) on the diagram.
784:. One rhyolite unit appears to overlie the McDougall Brook Granite formation. The tuff is littered by clasts from the Seelys and McDougall Brook Granite formations. The tuff also appears to be layered. It is colored dark orange on the map, and the exposed part partially rings the north of the volcano.
845:
Inc. holds 102 prospective claims covering approximately 1,600 hectares (4,000 acres) and 405 hectares (1,000 acres) of surface rights at Mount
Pleasant, dominating the local extraction rights. It is situate close to infrastructure and potential employees. With a population of 50,000, Fredericton is
692:
rocks are very common in places and one sandstone-conglomerate lava flow can be found. The sedimentary breccia is dominated by pebble to boulder size angular metasedimentary stratas, and a few crystal tuff layers that contain about 1% biotite, the only such high amount of a typically trace
858:
was regularly transported through Saint John by means of a provincial highway for shipment to Europe. The mine site is accessible via all-weather roads from
Fredericton, Saint John and St. George. Electricity is provided by the New Brunswick transmission grid and water from a pump house located on
560:
The exocaldera sequence consists of, in ascending stratigraphic order, the Hoyt
Station Basalt, Rothea Formation, South Oromocto Andesite, Carrow Formation and Bailey Rock Rhyolite. The first and last flow units have the least extent, evidence of erosional activity after their formation but before
870:
hosted a small field trip to the caldera and the nearby Mount
Pleasant Mine and Clarence stream deposit. The trip was divided into three stages: the Mount Pleasant Caldera, the Mount Pleasant Mine, and the Clarence Stream deposits. The field crew described two trenches that seemed to outline the
487:
felsic lavas that are distributed across five different layers. The late
Caldera-Fill Sequence contains rocks that are similar to those of the outflows of the other, older layers, and comprises two formations and two relatively minor intrusive lava flows. The volcanic flows are generally
352:. As a result, gases tend to become trapped at high pressure within the magma. When the magma approaches the surface of the Earth the rapid off-loading of overlying material causes the trapped gases to decompress rapidly triggering explosive destruction of the magma and spreading
444:
The eruptive history of the Mount
Pleasant Caldera can be divided into three stages of activity: the exocaldera sequence, the intracaldera sequence, and the late caldera-fill sequence. These can further be subdivided into strata based on their depth below the surrounding rock.
719:
The Seelys formation, next in the order, consists of lithic tuff and pumice-littered lithic lapilli-tuffs, banded, pumiceous, crystal tuff, and densely welded crystal tuff. The basalt contains clasts of both the
Scoullar Mountain andesite and Little Mount Pleasant formation.
579:(well-worn, consolidated volcanic ash). It is only directly exposed at the surface in one area, as a tuff on an extended solidified multi-age lava flow that extends northeast from the northern section of the volcano, colored green in the diagram at right.
516:. The various stages of fractionation are continually interrupted by eruptions, and have allowed scientists to recognize seven stages of caldera development. The genesis of the caldera is related to a period of lithospheric thinning that followed the
672:(chemically weathered rock) separates the Bailey Rock Rhyolite formation from the overlying Caldera-Fill Sequence-era rocks. The exposed part of the flow overlies part of the Carrow formation, and is colored pink in the diagram above-right.
602:
lava flow and another lithic tuff unit. It can be found exposed in a limited region, encompassing the flank of the Hoyt
Station basalt, colored light yellow in the diagram at right; it also peeks out closer to the volcano twice.
680:
The
Intercaldera Sequence is divided into, in ascending order, the Scoullar Mountain formation, Little Mount Pleasant formation, Seelys formation, and McDougall Brook Granite formation. In addition, there are felsic
1125:"Petrochemical evolution of subvolcanic granitoid intrusions within the late Devonian Mount Pleasant Caldera, southwestern New Brunswick, Canada: comparison of Au versus Sn-W-Mo-polymetallic mineralization systems"
777:. Two types of breccias have been identified, and older and more common felsic series, and a younger neutral phase. The porphyries making up the rocks were emplaced at the pre-existing volcanic margin.
762:
The Late
Caldera-Fill sequence includes the Mount Pleasant Porphyry, the Big Scott Mountain formation, and the Kleef formation. The ages of the rocks are not well-established, but they are most likely
770:. In addition the Intracaldera sequence is cut into multiple intrusions of varying origins. Many of the intrusions are thought to have formed without eruption, when mineral deposits "leaked."
582:
The next oldest layer is the Rothea formation. It can be divided into three major lava flow layers. The lower member consists mainly of unwelded (unjoined), but heavily compacted,
754:
is the main mineral phase in all three of the flows. Parts of the feldspar porphyry are hydrothermally altered. The deposit is extensively exposed, and is colored red on the map.
773:
The Mount Pleasant Porphyry formation occurs as dykes and small rock areas that have been associated with local breccia. The dyke structures seem to indicate multiple periods of
104:
780:
The Big Scott Mountain formation consists of rhyolite of variable composition, lapilli-tuff, and crystal tuff. Most of the rhyolites are characterized by large amounts of
637:
at the top. The flow is littered with abundant flows from the Seelys (in the intercaldera sequence) and Rothea (earlier) formation towards the southeast, but in the north
645:, predominate. The lower part of the formation consists of unwelded and highly compacted lapilli tuff with abundant amounts of pumice fragments. A basalt and basalt-clad
535:. The only intracaldera rocks with this much biotite is volcanic strata within sedimentary breccia of and a tuff unit near the Scoullar Mountain formation (Intracaldera).
688:
The first sequence in the order is the Scoullar Mountain formation. The layer is characterized by sedimentary breccia and interbedded andesitic lava. In addition felsic
564:
The first and oldest layer is the Hoyt Station basalt formation, which is composed of at least two flow units. There are two types of rock associated with the basalt,
625:
The Carrow formation is a predominantly fine-grained redbed (consisting of typically red sedimentary rocks) unit that has a grade ranging from pebbles and cobble in
653:, around 350 million years ago. The exposed part of the formation forms a long band around the South Oromocto Andesite formation, and is colored brown on the map.
606:
The next layer, the South Oromocto Andesite formation, is composed of at least three flow units, with basalt flows being the most extensive. Only one exhibits a
1299:
428:
Mount Pleasant lies along the southwestern margin of the caldera complex. Two mineralized zones, termed the Fire Tower Zone and the North Zone, occur within
541:
occurs only in two flow units: the South Oromocto Andesite of the Exocaldera sequence, and the Scoullar Mountain formation of the Intracaldera sequence.
1169:"Granitic Intrusions Of the Mount Pleasant Caldera, Southwestern New Brunswick: Petrochemical Characteristics and Implications for Gold Mineralization"
860:
850:, with a population of 70,000, which lies about 80 km (50 mi) o the southeast. Mount Pleasant is also only 65 km (40 mi) from the
425:. Fractionation was continually interrupted by eruption of material from the roof zone such that seven phases of caldera growth have been recognized.
701:. The exposed portion of the flows loosely flank the slopes of the volcano on the left and right, and are represented by bright orange on the map.
374:, several gold deposits have been recorded in the past. The positive early results have created great interest for gold-finding efforts, and the
30:
879:
878:, announced the results of a 2007 - early 2008 diamond drilling program on the west side of Mount Pleasant. Along with the development of the
1284:
404:
810:
wire. The rare element, used in flat-panel televisions, computers and smart phones, is one of the key mined resources at Mount Pleasant.
313:
rocks of the Saint George Batholith bound part of the southern margin of the caldera. Rocks within the summit itself date back to the
1252:
587:
384:
intrusions within the caldera complex include the McDougall Brook Microgranite and the somewhat younger Mount Pleasant Granite. Gold
1193:
818:
was first discovered on the mountain in 1937. The focus of exploration over the years has shifted from tin-base metals to porphyry
492:. The stratigraphic subdivision is supported by geochemical and mineralogical analyses, which indicate that the basaltic rocks are
1006:
448:
The Intercaldera Sequence comprises formations that crop out from overlying flows in triangularly shaped area, and includes thick
1124:
418:
732:
is very common. The formation is colored the lightest orange on the map, and swathes across the main body of the caldera.
649:
occurs near the top of the formation in some places. A dated locality from the top of the formation has been dated to the
834:, a rare element that is important to new technologies such as LCD screens and solar cells, computers and smart phones.
1279:
962:
1229:"Geodex Announces Base Metal, Tin and Indium assays from four prospects in the Mount Pleasant Camp, New Brunswick"
851:
144:
50:
1228:
1294:
1200:
867:
963:"Stratigraphy and eruptive history of the Late Devonian Mount Pleasant Caldera Complex, Canadian Appalachians"
900:
697:-ridden lapilli-tuff section near the believed top section additionally has a 1% composition of the mineral
97:
1194:"Report on the UNB SEG Student Chapter field trip to Intrusion-related deposits of southern New Brunswick"
685:
and one mafic dyke that intrude the Scoullar Mountain and Little Mount Pleasant formations, respectively.
895:
795:, as it contains many of the possibly gold-bearing intrusive areas. It is colored light blue on the map.
750:. The grain size of the porphyry and the size and abundance of feldspar increases inward. Amphibole with
668:
older stratas. This layer is unique for it bridges the exocaldera and intracaldera sequences. A layer of
551:
and overlies the Carrow formation, but is intruded by the intracaldera McDougall Brook Granite formation.
468:
the above layers and are typically located along caldera margin faults. The Exocaldera Sequence contains
90:
1289:
847:
527:
The relative position of the Exocaldera and Intracaldera sequences is based on several observations:
704:
The next layer is the Little Mount Pleasant formation, which is composed of crystal tuff and banded
1168:
407:
1080:
660:, and is characterized by an absence of angular crystals and pumice derivatives. In places its
626:
565:
200:
586:
lapilli-tuff and crystal tuff strata. The middle member consists of rock ranging from nearly
432:
about 1 kilometre (1 mi) apart. The volcanic necks are defined by magmatic-hydrothermal
245:
166:
590:
tuff at the base to crystal tuff near the top. The top section of the middle unit contains
285:
281:
8:
1204:
375:
371:
188:
1167:
Xueming Yang; David R. Lentz; Steve R. Mccutcheon; MCLEOD; J. Malcolm (March 27, 2003).
1010:
982:
743:
544:
The exocaldera Carrow formation contains clasts from the intracaldera Seelys formation.
367:
85:
960:
986:
767:
497:
961:
McCutcheon, S. R.; S. R. McCutcheon; H. E. Anderson; P. T. Robinson (January 1997).
656:
The last formation in the later, the Bailey Rock Rhyolite formation, is composed of
512:
flow units, are thought to have originated from high-end crystallization inside the
1166:
1136:
974:
871:
relationship between the volcanic rock and the possibly gold-rich intrusive areas.
792:
747:
689:
493:
1122:
875:
638:
517:
505:
391:
and veins cut the McDougall Brook Microgranite and its volcanic wall-rock, while
303:
277:
268:
in the northern Appalachian Mountains. It sits relatively near to the coastline.
265:
261:
173:
728:
increase in size and abundance yoward the top. Biotite is virtually absent, but
682:
363:
314:
159:
978:
1273:
763:
650:
642:
513:
429:
422:
249:
235:
193:
148:
119:
106:
54:
814:
Mount Pleasant has a long history of exploration and development in mining.
855:
569:
521:
449:
353:
341:
217:
927:
883:
842:
838:
736:
607:
484:
823:
708:. The tuff is characterized by, recrystallized pumice with microscopic
595:
392:
329:
300:
293:
1123:
Yang, Xue-Ming; Lentz, David R.; McCutcheon, Steve R. (July 1, 2003).
531:
The upper part of the Rothea formation (Exocaldera) contains about 1%
774:
713:
698:
669:
665:
619:
548:
465:
345:
306:
rocks of the local Digdeguash and Flume Ridge geological formations.
837:
The Mount Pleasant mine is located 80 km (50 mi) south of
693:
mineral outside of Rothea formation in the Extracaldera sequence. A
819:
781:
725:
705:
661:
634:
630:
615:
591:
538:
501:
477:
469:
400:
337:
310:
297:
257:
1141:
827:
751:
739:
709:
646:
611:
572:
532:
457:
433:
396:
388:
381:
241:
238:
205:
831:
807:
788:
729:
721:
694:
622:
in the flow. It forms a thin band around the Rothea formation.
599:
583:
509:
480:
461:
414:
385:
370:. In southwestern New Brunswick, which is part of the Canadian
349:
325:
289:
253:
152:
75:
58:
803:
618:
near the top of the layer indicate that this was a period of
489:
473:
321:
568:
ranging in particle size from small pebbles to cobbles, and
657:
576:
453:
360:
333:
815:
735:
The McDougall Brook Granite formation consists mostly of
260:
calderas, and its formation is associated to a period of
496:-derived and have, unusually, relatively intraplate (or
344:
rich in the mineral. Silica-rich magma does have a high
317:, and show multiple fill sequences late in its history.
504:
flows were probably derived from basaltic magma by the
276:
The large elliptical feature is dated back to the late
410:
are related to the multiphase Mount Pleasant Granite.
830:
deposits, and then to porphyry tin deposits, and now
280:, and is partially covered in the north by overlying
854:. When the mine was last producing - 1983 to 1985 -
787:The final formation, the Kleef formation, includes
1118:
1116:
932:Adex Mining Mount Pleasent Caldera mining overview
508:of the magma material. The relatively rare, more
1271:
1085:Geological description of Mount Pleasant Caldera
1113:
922:
920:
918:
916:
874:On June 25, 2008, Geodex Minerals Ltd., a gold
1253:"Mount Pleasant may see mining activity again"
1087:. Canada Department of Natural Resources. 2009
641:rocks, which are sedimentary rocks exhibiting
37:
841:, the provincial capital. The mining company
757:
1300:Landforms of Charlotte County, New Brunswick
1098:
913:
882:tungsten-molybdenum-copper project north of
1075:
1073:
1071:
1069:
1067:
1065:
1063:
1061:
1059:
1057:
1055:
1053:
1051:
1049:
1047:
742:, a borderline feldspar (sometimes quartz)
366:have recently raised great interest among
1191:
1187:
1185:
1162:
1160:
1158:
1045:
1043:
1041:
1039:
1037:
1035:
1033:
1031:
1029:
1027:
348:, and therefore does not flow easily like
1221:
1140:
500:) type chemical affinities. The multiple
417:sections are associated with episodes of
973:(1). Cambridge University Press: 17–36.
802:
675:
1182:
1155:
1024:
1272:
1135:(2). the Atlantic Geoscience Society.
1104:
555:
956:
954:
952:
950:
948:
378:has proven to be an ideal candidate.
328:, as indicated by a large amounts of
1234:. Geodex Minerals Ltd. June 25, 2008
746:, and minor amounts of fine-grained
547:The exocaldera Bailey Rock Rhyolite
1171:. The Geological Society of America
439:
13:
1285:Extinct volcanoes of North America
945:
256:. It is one of few noticeable pre-
14:
1311:
244:complex, located in the northern
324:produced by Pleasant is rich in
80:Approx. 248 m (814 ft)
36:
29:
1245:
594:. The top member consists of a
1201:Society of Economic Geologists
999:
868:Society of Economic Geologists
1:
1192:Lafontaine, Jonathan (2005).
1109:(1 ed.). Academic Press.
967:Cambridge Geological Magazine
906:
901:Volcanology of Eastern Canada
846:important to the mine, as is
460:layers, and intermediate to
7:
896:List of volcanoes in Canada
889:
866:On September 25, 2005, the
852:Canada–United States border
464:igneous rocks that tend to
264:thinning that followed the
91:List of volcanoes in Canada
10:
1316:
758:Late Caldera-fill sequence
561:the next deposited layer.
419:fractional crystallization
309:Late Silurian to Devonian
271:
1280:Calderas of New Brunswick
1255:. CBC News. June 16, 2011
1107:Encyclopedia of Volcanoes
979:10.1017/S0016756897006213
798:
216:
211:
199:
187:
182:
172:
158:
140:
135:
120:45.5003750°N 66.7545306°W
96:
84:
74:
69:
23:
18:
1081:"Mount Pleasant Caldera"
421:in a high-level, zoned
125:45.5003750; -66.7545306
811:
232:Mount Pleasant Caldera
44:Mount Pleasant Caldera
19:Mount Pleasant Caldera
1295:Polygenetic volcanoes
806:
676:Intracaldera sequence
246:Appalachian Mountains
167:Appalachian Mountains
282:Middle Mississippian
928:"Property Overview"
793:economic geologists
556:Exocaldera sequence
376:Mount Meager massif
372:Alleghenian orogeny
368:economic geologists
116: /
1105:Lipman, P (1999).
812:
359:Intrusion-related
234:is a large eroded
70:Highest point
1290:Devonian calderas
1007:"Image or region"
934:. Adex Mining Inc
356:over wide areas.
228:
227:
1307:
1264:
1263:
1261:
1260:
1249:
1243:
1242:
1240:
1239:
1233:
1225:
1219:
1218:
1216:
1215:
1209:
1203:. Archived from
1198:
1189:
1180:
1179:
1177:
1176:
1164:
1153:
1152:
1150:
1149:
1144:
1129:Atlantic Geology
1120:
1111:
1110:
1102:
1096:
1095:
1093:
1092:
1077:
1022:
1021:
1019:
1018:
1009:. Archived from
1003:
997:
996:
994:
993:
958:
943:
942:
940:
939:
924:
861:Piskahegan River
748:quartz monzonite
658:porphyritic lava
539:Andesitic strata
520:in the northern
440:Eruptive history
248:of southwestern
224:All-weather road
220:
162:
145:Charlotte County
131:
130:
128:
127:
126:
121:
117:
114:
113:
112:
109:
51:Charlotte County
40:
39:
33:
16:
15:
1315:
1314:
1310:
1309:
1308:
1306:
1305:
1304:
1270:
1269:
1268:
1267:
1258:
1256:
1251:
1250:
1246:
1237:
1235:
1231:
1227:
1226:
1222:
1213:
1211:
1207:
1196:
1190:
1183:
1174:
1172:
1165:
1156:
1147:
1145:
1121:
1114:
1103:
1099:
1090:
1088:
1079:
1078:
1025:
1016:
1014:
1005:
1004:
1000:
991:
989:
959:
946:
937:
935:
926:
925:
914:
909:
892:
801:
760:
678:
639:metasedimentary
629:at the base to
558:
518:Acadian Orogeny
506:crystallization
442:
304:metasedimentary
278:Devonian Period
274:
266:Acadian orogeny
218:
160:
124:
122:
118:
115:
110:
107:
105:
103:
102:
65:
64:
63:
62:
61:
48:
47:
46:
45:
41:
12:
11:
5:
1313:
1303:
1302:
1297:
1292:
1287:
1282:
1266:
1265:
1244:
1220:
1181:
1154:
1112:
1097:
1023:
998:
944:
911:
910:
908:
905:
904:
903:
898:
891:
888:
800:
797:
759:
756:
677:
674:
616:hematite bands
557:
554:
553:
552:
545:
542:
536:
441:
438:
430:volcanic plugs
408:mineralization
315:Upper Devonian
273:
270:
226:
225:
222:
214:
213:
209:
208:
203:
197:
196:
191:
185:
184:
180:
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170:
169:
164:
156:
155:
142:
138:
137:
133:
132:
100:
94:
93:
88:
82:
81:
78:
72:
71:
67:
66:
49:
43:
42:
35:
34:
28:
27:
26:
25:
24:
21:
20:
9:
6:
4:
3:
2:
1312:
1301:
1298:
1296:
1293:
1291:
1288:
1286:
1283:
1281:
1278:
1277:
1275:
1254:
1248:
1230:
1224:
1210:on 2011-05-25
1206:
1202:
1195:
1188:
1186:
1170:
1163:
1161:
1159:
1143:
1138:
1134:
1130:
1126:
1119:
1117:
1108:
1101:
1086:
1082:
1076:
1074:
1072:
1070:
1068:
1066:
1064:
1062:
1060:
1058:
1056:
1054:
1052:
1050:
1048:
1046:
1044:
1042:
1040:
1038:
1036:
1034:
1032:
1030:
1028:
1013:on 2008-10-24
1012:
1008:
1002:
988:
984:
980:
976:
972:
968:
964:
957:
955:
953:
951:
949:
933:
929:
923:
921:
919:
917:
912:
902:
899:
897:
894:
893:
887:
885:
881:
877:
872:
869:
864:
862:
857:
853:
849:
844:
840:
835:
833:
829:
825:
821:
817:
809:
805:
796:
794:
790:
785:
783:
778:
776:
771:
769:
768:Mississippian
765:
764:Late Devonian
755:
753:
749:
745:
741:
738:
733:
731:
727:
723:
717:
715:
711:
707:
702:
700:
696:
691:
686:
684:
673:
671:
667:
663:
659:
654:
652:
651:Late Devonian
648:
644:
643:metamorphosis
640:
636:
632:
628:
623:
621:
617:
613:
612:Calcite veins
609:
604:
601:
597:
593:
589:
585:
580:
578:
574:
571:
567:
562:
550:
546:
543:
540:
537:
534:
530:
529:
528:
525:
523:
519:
515:
514:magma chamber
511:
507:
503:
499:
495:
491:
486:
482:
479:
475:
471:
467:
463:
459:
455:
451:
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431:
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423:magma chamber
420:
416:
413:The numerous
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343:
342:igneous rocks
339:
335:
331:
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295:
291:
287:
286:Pennsylvanian
283:
279:
269:
267:
263:
259:
255:
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250:New Brunswick
247:
243:
240:
237:
236:Late Devonian
233:
223:
221:
219:Easiest route
215:
210:
207:
204:
202:
201:Mountain type
198:
195:
194:Late Devonian
192:
190:
186:
181:
177:
175:
171:
168:
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154:
150:
149:New Brunswick
146:
143:
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134:
129:
111:66°45′16.31″W
108:45°30′01.35″N
101:
99:
95:
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89:
87:
83:
79:
77:
73:
68:
60:
56:
55:New Brunswick
52:
32:
22:
17:
1257:. Retrieved
1247:
1236:. Retrieved
1223:
1212:. Retrieved
1205:the original
1173:. Retrieved
1146:. Retrieved
1142:10.4138/1175
1132:
1128:
1106:
1100:
1089:. Retrieved
1084:
1015:. Retrieved
1011:the original
1001:
990:. Retrieved
970:
966:
936:. Retrieved
931:
880:Sisson Brook
876:venture firm
873:
865:
856:tungsten ore
836:
813:
786:
779:
772:
761:
734:
718:
703:
687:
679:
664:composition
655:
627:conglomerate
624:
605:
598:, typically
596:fine-grained
581:
566:conglomerate
563:
559:
526:
522:Appalachians
450:volcanic ash
447:
443:
427:
412:
405:polymetallic
380:
358:
354:volcanic ash
340:, and other
319:
308:
275:
231:
229:
161:Parent range
884:Fredericton
859:the nearby
843:Adex Mining
839:Fredericton
737:porphyritic
690:pyroclastic
633:laced with
608:porphyritic
485:porphyritic
189:Age of rock
123: /
98:Coordinates
1274:Categories
1259:2013-12-25
1238:2019-05-14
1214:2009-04-16
1175:2010-06-07
1148:2009-04-16
1091:2009-04-15
1017:2009-03-16
992:2009-04-15
938:2009-04-16
907:References
848:Saint John
824:molybdenum
403:and later
393:molybdenum
330:ignimbrite
301:turbiditic
294:Ordovician
987:129124992
775:intrusion
714:amphibole
699:amphibole
670:saprolite
620:degassing
610:texture.
584:pumiceous
456:), thick
346:viscosity
136:Geography
76:Elevation
890:See also
820:tungsten
782:pyroxene
744:porphyry
726:feldspar
710:crystals
706:rhyolite
666:intrudes
662:rhyolite
635:calcrete
631:mudstone
592:pyroxene
549:intrudes
502:andesite
478:alluvial
470:ash flow
434:breccias
401:tungsten
389:breccias
382:Granitic
338:rhyolite
311:granitic
298:Silurian
258:Cenozoic
239:volcanic
212:Climbing
174:Topo map
141:Location
828:bismuth
752:apatite
740:granite
647:mudflow
600:reddish
588:aphyric
573:lapilli
533:biotite
498:hotspot
481:redbeds
476:lavas,
472:tuffs,
466:intrude
458:breccia
397:bismuth
288:Period
272:Geology
262:crustal
242:caldera
206:Caldera
183:Geology
86:Listing
985:
832:indium
808:Indium
799:Mining
789:redbed
730:zircon
722:Quartz
695:pumice
570:lithic
510:felsic
494:mantle
483:, and
462:felsic
415:felsic
386:quartz
350:basalt
326:silica
290:strata
254:Canada
178:021G07
153:Canada
59:Canada
1232:(PDF)
1208:(PDF)
1197:(PDF)
983:S2CID
683:dykes
490:mafic
474:mafic
364:veins
322:magma
766:and
724:and
712:and
614:and
577:tuff
454:tuff
361:gold
334:tuff
320:The
284:and
230:The
1137:doi
975:doi
971:134
816:Tin
296:to
1276::
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977::
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822:-
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399:-
395:-
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