more. lava, is very interesting. It is about 200 feet higher, and covered with dense brush, as is all the country in this vicinity. The greater part of the hill is formed of a coarse tuff, whose fragments stand out in sharp relief on the surface of the huge projecting, bowlder-like masses. The matrix, which is darker and softer, weathers out, leaving the surface of the rock covered with a great variety of fragments. Some are scoriaceous or amygdaloidal, others are very coarsely crystalline and porphyritic with feldspar or hornblende. Some of the fragments are themselves tufaceous, containing large masses of hornblende in a dioritic matrix. On the southern end of the hill, a great variety of dikes intersect the tufa. This is in all probability the neck of an old volcano, but appears to have no relation to the modern lavas near it. Owing to the exceeding difficulty of traversing these hills, the exact relations of the formations were not About 10 miles east of Temecula, near the point where ascertained. the creek takes a turn to the southeast and enters a cañon, there has been another lava eruption, but the time at my disposal did not permit me to examine it. A great variety of rocks are exposed along the road from Elsinore to Menifee Valley. For nearly 2 miles east of the station the rock is a white, glassy diorite, with an excess of feldspar. At the point where the road crosses the railroad, metamorphic schists appear, The rock is a fine, dark mica felsite. It is so compact that it breaks with a conchoidal fracture. A great irregularity in strike and dip exists; the average strike is a little west of north, dip northeast. As far as the top of the grade, the rocks are in part metamorphic and part dioritic There are many dikes; some fine-grained granites, others micaceou diorite porphyrites. The hills along the west side of Menifee Valley seem to be mostly metamorphic, with some bunches and veins of granite of the mountainous region lying south of the road from Temecula to San Jacinto is granite or diorite, excepting a strip of micaceous schist and gneisses near Glen Oak Valley. These strike northwest toward No opportunity was given me to examine the mountainous regions comprised in the San Jacinto range. The line of hills lying northeas come town and having a northwest direction are composed largely gneiss and mica schist, with some bodies of white crystalline limestone In the line of strike these hills finally disappear north of San Jacint Lake, under Quaternary clays and gravels, which form rather an abrup Lise from the San Jacinto Valley and extend northerly to the San Ber nardino Mountains. The deposits show a great deal of disturbance. part of them may be Tertiary. Dikes of dark, heavy diabase and diori are common about the sulphur springs north of San Jacinto. The hills for a distance of 3 miles north of Elsinore are formed slate and mica schists; strike north 70° west, dip vertical to 45° eas This is a continuation of the same series of rocks exposed on the road Menifee. A lenticular body of limestone occurs in these slates about miles north and east of Elsinore. It is highly metamorphosed, ficult to draw the line between eruptive and metamorphic rocks. It has gray to dark color, and is traceable for 500 or 600 feet. At been shown before that lamination is no sure indication of sedimentary spot a stratum of quartzite divides it. It was carefully examined structure. About 4 miles from Elsinore granit Lake Elsinore is bordered on the west by a high and rugged granite fossils, but none were found. rocks appear, followed by dark diorites in the vicinity of the Gange. In the mountains west of Elsinore the granite which cuts off The Pinacate district, taken as a whole, is rath the metamorphic rocks on the Santa Ana range is again replaced by Hope Mine. peculiar. At first sight it seems to be formed of granite, dark diori the Metamorphic Series, which are here very greatly altered. They strike gneiss, mica schist, and other metamorphic rocks, arranged in the me a little west of north and dip vertical or at a steep angle to the east. irregular manner. The belt of metamorphics northeast and east of Elsinore is terminated on an irregular east and west line by these granitic bodies, which inclose portions of the schists, and extend into the main body as long, dike-like arms. In the vicinity of the Good Hope Mine the strata of metamorphic rocks inclosed in the granitic rocks have a north and south strike, and are traceable for a mile or The veins of the Good Hope Mine are in a dike of light-colored biotite granite. It has considerable width on the surface, 100 feet or more, but below ground some distance it is not over 12 feet. On the surface it is greatly decomposed and cut by numerous small veins, which are so scattered that they hardly pay for working. Below they unite to form larger veins, generally one on the foot and another nearer the hanging wall. The latter is more irregular, often running out at a small angle. The foot wall, a dark compact diorite, is very regular. The walls are separated by well-defined clay seams from the vein matter, the decomposed granite. Clay seams also separate the different veins.' The foot wall diorite forms the country rock indefinitely eastward. The hanging wall is a fine, dark brown mica schist. The quartz is generally friable, and the granite vein matter much decomposed. The quartz at a depth of 300 feet carried one third of the gold in the sulphurets. A small amount of silver is also found. This vein is located for over a mile; direction a little east of north, dip 65° west. It is remarkable that there is no barren quartz; all the ore pays for working. In the lower workings the veins become more regular. Menifee. The Good Hope is the first mine in this district to reach a paying basis, and that has succeeded in finding a regular, defined quartz ledge. About 3 miles northwest is another vein, which has an east and west direction. It seems to lie wholly in granite, save for a narrow stratum of mica schist on one wall. The vein is located for a mile, but no extensive development has yet been made on it. On the hills, a short distance southwest, is an old Mexican mining camp. Many small veins are found in the vicinity, generally in a dark micaceous diorite. There are also bunch-like masses of coarse white granite, blending into gneiss and the gneiss into mica schist. The strike is exceedingly irregular, changing from north and south to east and west in the course of a few feet. Toward Elsinore mica schist, quartzose, and feldspathic rocks replace the greater portion of the granite. For some distance the schists are cut up by dikes of fine-grained granite, running in different directions, and small bunches of the same rock, often only a few feet across, but sharply differentiated from the schists. Judging from the exposure here, I think we might say that at the time of the metamorphism the action was so intense as to change the sedimentary rocks to mica schists and gneisses and through these to squeeze the liquified portions of the same formation in dikes and fissures. Small fragments of mica schist were noticed in the eruptive masses. In a region like this it is often dif The boundary of the granite is very irregular, and masses outcrop in the metamorphics near the main contact line. Much of this crystalline rock perhaps more truly belongs to the diorites. ains west of the creek. At the terra cotta works a drill was sunk over ceous diorite, decomposed to a great depth, but very tough when fresh. This is followed by syenite. A mile up the cañon, near the western edge of this rock and wholly inclosed in it, is a small mass of jasper schist and a lenticular body of semi-crystalline limestone. No traces of fossils were found in it. West of the syenite is another diorite dike. Thos Then follows banded jaspery rocks, sometimes verging on micaceous felsite or quartzites. There are also some slates, and all are often greatly contorted; strike north to northeast. North of the cañon these rocks extend to the summit, while south the Santiago Peak, the highest of the range, and the ridges leading up to it from the east, consist of a coarse quartzose granite, with but little if any triclinic feldspar. A variety of dikes occur near the the summit north of the cañon, among them hornblende porphyry, porphyritic granite, and syenite. Fossils were found on the ridge leading up to the summit, north of Cold Water Cañon. They occur in a grayish rock, apparently a fine micaceous felsite. They are poorly preserved, on account of the extreme degree of metamorphism to which the rocks have been subjected. The rocks have become so altered by pressure that they will not break on the lines of bedding, but perThe fossils consist of impressions of a small bivalve shell. Only about a dozen specimens could be found. The sils. These are the first fossils reported from the metamorphic rocks of rocks are more altered than any others I have ever seen carrying fos the Santa Ana range. These fossils when determined will give a clue to the age of the metamorphic gold-bearing rocks of this portion of the State, and also of the granite, concerning which much diversity of opinion has existed. The new silver mines lie just north of the San Diego County line, and west of the divide, a position which brings them into Orange County. The formations in which the veins occur vary from a dark brown felsite, often micaceous, to a finely banded quartzose rock. The latter is very compact, and often almost massive. In places hard, blocky argillites appear. The two or more veins found here carry galena bearing silver, and also much magnetite and iron sulphurets, with some of the baser metals. The veins are characterized by a dark red gossan cap on or near the surface. Carbonates are found in this. These deposits exist as impregnations along a fissure, which is not very strongly pronounced The ore is usually quite massive. The little gangue present is calcite Not enough development has been made here at the time of my visit to show how extensive the deposits are. The metamorphic rocks extend north along the mountains, forming the summit and eastern slope for number of miles. Granite borders them on the west toward San Juan through to Silverado Cañon. At some time this Elsinore basin opened the head of Temescal Creek. Gravel-topped hills lie along the mount out through the Temescal Valley, but now a low divide separates it from 600 feet without reaching the bottom of the basin. The Cheney Coal Mine is located 5 miles northwest of Elsinore, in the same basin. The beds dip to the west and southwest, having clay below, and sandstone followed by clay above. The coal is 7 to 8 feet thick, generally solid but in places showing a parting in the middle. A great deal of faulting and found to contain interesting geological features. A fine opportunity has taken place, but there seems to be no system about it. The throw is given for the study of the relation of the granite to the extensive of the faults sometimes amounts to 30 feet, often disturbing the pitch porphyry intrusives. For 2 miles east of Temescal Creek no eruptives the vein, and making it greater. The strata evidently belong to the appear; the rocks being wholly of the Metamorphic Series, with expos Miocene-Tertiary, for a little farther down the valley fossils of that agres of highly altered sandstones, clay shale, conglomerates, ate expos are found. This old Tertiary valley, undoubtedly an arm of the sea ing northwest and dipping southeast at 45° to 50°. About 3 miles up opened into the large valleys of San Bernardino and Los Angeles Cour the cañon the argillaceous rocks are replaced by a coarse granite, rich in ties, and extended southerly to Temecula; though south of Elsinore the mica and quartz. This is the prevailing rock up the cañon for 2 miles, Tertiary is covered by Quaternary gravels. The depth is unknown, but and it apparently extends much farther east. It shows a great the width is quite narrow, being from 1 to 2 miles. Not more than appearance; much of it contains large crystals of flesh cold variation quarter of a mile northeast of the coal mine the metamorphic rock clase. In this granite, particularly on the north side of the cañon, there quachward the mountains are formed of a quartz feldspar porph miles from the mouth of the cañion, there are rectilinear dikes of finequartzites, and hard, blocky argillites outcrop. East of Temescal Creeple dikes of many kinds of rocks. Large dikes of beautiful diorite por phyrites, both light and dark colored, appear in places. At one spot 4 of a dark gray color; at times it blends into portions not distinct grained granite, intersecting each other like artificial stone fences. For porphyritic. hills north show nothing but metamorphic schists. The porphyry in the distance of a mile east, after the granite begins in the cañon, the the mountains south does not reach the cañon. The great mass of this on the east flank of the Santa Ana range and extends north to Cold Wate Dawson Cañon, which heads in the Temescal Mountains, was explored The miles north of the San Diego County line granite appears as Cañon. Between Temescal Creek and the mountains is a broad, slop rock is dark, but in the vicinity of the granite it is lighter colored and gravel iles south of the Temescal Post Office there is an outcrop of is a gray, hard rock, of almost conchoidal fracture, and faint feldspar resting on the Tertian Two so sandstone carrying Miocene fossils. It dips southwest at an angle of 30 crystals. The granite near the contact is usually sharply defined, and Extensive clay banks of various colors and nearly horizontally bedde has a faintly porphyritic appearance at times. The line of junction of lie along the flanks of the mountains both east and west of the cree the two formations is sharply defined, not only lithologically, but physAn interesting series of rocks is exposed up Cold Water Cañon.ically. It is difficult to say which is the older. No granite appears in cañon has been eroded near the northern termination of the gran dikes in the porphyry, but there are many dikes of a porphyry-like portion of the Santa Ana Mountains. The first rock exposed is ་ appearance, resembling the light-colored porphyry in the granite itself. The line of junction is very irregular, and it is certain that the two formations do not belong to the same eruptive mass. East of the head of Dawson Cañon there is another outcrop of consid erable extent of metamorphic rock, micaceous felsites, and other dark schists. A mile west of the Gavilan Mines is a high conical peak formed of coarse, dark diabase. The mines of this district are in white biotite granite, continuous with that of the Pinacate district. The metamorphic rocks south of Dawson Cañon strike east and west, dip north, and extend in a westerly direction nearly to Temescal Post Office. North of the cañon, 2 miles from its mouth, there are a number of outcrops in vein-like forms and in bunches, of a black crystalline material, evidently tourmaline, identical with that at the Temescal Mine. These occur in the metamorphic sandstone and shales. The next large cañon in the Santa Ana range north of Cold Water Cañon shows highly disturbed Tertiary strata at its mouth, dipping away from the range at a high angle. They are soft, white clayey deposits, containing small nodules of selenite. The first of the older rocks exposed in the cañon is a horn blende porphyry, with variations to a granular diorite. For 3 miles up the cañon the only rocks seen are crushed and silicified ones of the Metamorphic Series. They dip, as a usual thing, at a high angle to the east, though in spots it is to the west or horizontal. Quartzose sandstones prevail, with blocky argillitic rocks and conglomerates. Near the summit there are dikes of green tufaceous porphyries. Temescal Valley is underlaid by clays of a great variety of colors. They are being used very extensively for the coarser kinds of pottery and drain pipe. The Miocene deposits of the valley dip westward from the Temescal range, and instead of also dipping away from the Sants Ana Mountains basin-like, they dip west into the latter range. The dip of these beds 3 miles south of South Riverside is 5° to 10° southwest tiary. The Tertiary formation consists of clays in various conditions of Bunches of granite outcrop in the metamorphic rocks along the east side of Temescal Creek north of Dawson Cañon. At the dam of the San Jacinto Company there is a large outcrop of the beautiful diorite porphyrite, similar to that seen in Dawson Cañon. This extends northwesterly along Temescal Creek toward South Riverside, where it is quarried. It makes an excellent and durable building stone, being compact and free from much mica or hornblende. West of this is a narrow strip of coarse granite, followed by diabase. North of Mr. Hoag's ranch, and west of the dam, is a dike of black porphyry. Westward the crystalline rocks are overlaid by the Tertiary. The dam commenced across the Temescal Creek at this point, where it enters the cañon, was intended to have been extended down to the bedrock, and thus bring to the surface the water which flowed beneath the surface channel. The diorite porphyrite is followed on the east by black porphyry. Geology of the Temescal Tin District.-The Temescal Tin Mine is located in the northern part of the San Jacinto grant, and about 5 miles southeast of South Riverside. This portion of the grant consists of rolling hills. On the west is a large body of porphyry, extending nearly to the Temescal Creek. The first rock exposed along the road to the mine east of the creek is a and as the Santa Ana Mountains are approached the dip increases, and dark flinty one. This is followed by a body of black porphyry, with white at a distance of a fourth of a mile, up to the metamorphics, it varies feldspar crystals. The porphyry is about a mile across, and is followed from 45° to vertical. The strata are not exposed all the distance across on the east by massive black crystalline rock, and that by a felsite. the valley, but there is no sign of a fold or overthrow; everything seems These rocks are soon replaced by granite, in which there are dikes of to point to a gradually increasing dip. This is indicative of an eleva fine-grained, highly quartzose granite. Little black veinlets of tourmation of the region toward Temescal, or a sinking of the Santa Ana line aggregates are very numerous in the granite, extending through all Mountains. This is undoubtedly the fault line which follows the range the rock up to the porphyry. They have a northeast direction. The for such a long distance south. Several thin seams of coal outcrop for a material forming them is the same as the gangue of the tin veins. A distance of 10 miles along the base of the mountains. They have been half mile south of the road is a cañon. Here the porphyry is seen opened in a number of places and all the strata found dipping into the extending up to the granite. The granite is greatly broken near the mountains. The coal seams are often only a few hundred feet away contact, and though there is no blending of one into the other, there is a from the metamorphics, and dip toward them at a very regular angled confused mixture of broken portions of both rocks. Bunches and dike450. Judging from the position of the strata it is not probable that the like bodies of granite are inclosed in the porphyry. The little veinlets coal underlies the valley, and as it is so close to the mountains, formed of tourmaline seem to have replaced the feldspar and mica, leaving the wholly of rocks of the Metamorphic Series, it cannot be of great extent quartz. These veins grow larger toward Cajalco Hill. Just west of the I believe that appearances point to the whole of the coal beds having works is a great mass of the black veinstone, the gangue of the tin ore. been eroded, save the limited, steeply inclined portion at the foot of the This rises in high, rugged croppings, and covers an area of about 300 by 250 mountains. A crowding of the strata against the mountains during feet. This is the greatest body of vein matter to be seen in the district. the movements along the fault line, have given rise to the steep di The tin deposit worked lies in an eastern prolongation of this cropping. The highest portion of the Tertiary beds has an elevation of 1,500 feet The course of the veins is north 45° east, dip 65° to 70° northwest. The A very even, gently sloping plain extends from this elevation toward country rock is a coarse hornblendic biotite granite. The vein has the South Riverside. It is formed of unconsolidated wash from the moun usual character of mineral deposits, swelling at times to a width of 8 feet, ains, deposited on and dipping in the opposite direction from the Ter and then contracting to much less. The highest grade ore is found in ་ the narrower portions, where it is sometimes almost pure tin oxide, quartzose portion of the vein matter often blends into the granite walls, distance of 2 miles northwest from the mine, extending into the porphyry, which replaces the granite in that direction. The granite extends eastward for many miles. The general geological features which obtain here are: A semi-circular area of granite over 2 miles in diameter, surrounded on the northwest and south by porphyries and joined on the east to a great body of granitic rocks extending indefinitely in that direction. Around the border of this granite protuberance are many dikes of a fine-grained granite. Cutting through the granite in a northeast and southwest direction are the black tourmaline veins, which form the gangue of the tin ore when it is present. Tin occurs here under conditions different from any other known deposit. Tin veins are almost always found in granitic formations, but such an extensively developed tourmaline veinstone is remarkable. The direction of the fissure system shown here is an uncommon one in California. The veinstone, together with the associated metals, has probably resulted from a process of sublimation along lines of fracture, removing those portions of the granite easily affected, over a large area, as at Cajalco Hill, and in the immediate contact completely replacing it with alco massive aggregate of minute tourmaline crystals. Thanks are due to the manager, Captain Harris, for the facility freely about. afforded me for examining the mine, the works, and the country abeely North of South Riverside the Tertiary beds dip at a small angle to the north. The Santa Ana River has cut its course through the hills at the northern end of the Santa Ana Mountains. No outcrop of the and there are bodies of evidently granitic origin wholly inclosed in the vein matter. A careful study of the vein matter, and its relation to the walls, shows that it is simply a portion of the granite, in which the feld spar and dark silicates, hornblende, and mica have been removed and tourmaline substituted. The quartz has the same character and color as that in the granite, and many transition stages in the process are shown. Where the action has been more intense, near and along the metamorphic rocks appears in the cañon. The Tertiary strata no longer fissures, the quartz has been wholly removed and the tourmaline depos dip toward the west, but in the Chino hills north of the river show a ited, together with the tin. Cajalco was the center of this action. veins decrease in size farther away. anticlinal arch. Along the south side of the river the beds dip 70° northeast; farther west, near the heart of the range, they dip 60° At the time of my visit the mine had been opened to a depth of 180 southwest, strike north 30° west. Near the upper end of the cañon there feet, by two working shafts. The total length opened on the vein is 300 are fault lines dipping toward the range, which show an elevation of feet. Two levels have been run and work was in progress on the third the hanging wall. Bedrock Cañon is the first large one which opens The main ore body lies in the center of the workings, and extends down to the Santa Ana River from the western slope of the mountains. The ore milled averaged 5 per cent of tin pposite the mouth of this cañon the greatest amount of water appears ward in the dip of the veins. oxide, though large portions, as before stated, are very high grade. The the bed of the river, indicating the presence of hard rock only company has also prospected Cajalco Hill by tunnel and open cuts, and little distance below. Coal veins are located near the head of this one or more of the veins south by shafts. At the time of my visit two cañon, one 700, the other one 1,300 feet above the river. They dip only of Husband's pneumatic stamps were in operation. They weigh 900 few degrees to the southwest. They are exposed on cliffs facing the pounds each, and drop one hundred and thirty-five times per minute. as mere bunches on the surface. These veins closely resemble the main mountains to the northeast. Below them are very hard sandstones without great disturbance, while the gypsum mines farther down on the South and southeast of the works are many bunchy veins of the black carrying fossils, probably Cretaceous. One prospect shows a number of tin gangue. They often carry considerable iron. They extend, generally teams within a width of 8 feet. The widest is 29 inches, the othe nearly parallel, in a northeast and southwest direction. Some appe Their position, lying so flat high on the mountains, indicates an uplift The other prospects show only one 39-inch seam. vein at Cajalco Hill, and are due to the same action, and it has bee flank of the mountains dip at a high angle to the southeast. It may supposed that many of them will be found to carry tin, though it is no be that all of the coal deposits of the western slope of the Santa Ana present on the surface. About 2 miles south the granite is replace Mountains belong to the Cretaceous, and have been greatly separated by The granite about the works, and especially toward the contact with the opened in Gypsum Cañon, 2 miles south of the river. The beds have a by a banded feldspar porphyry. This cuts off the tourmaline veins porphyry, is cut by many dikes of a fine-grained granite, having an faulting and folding. A deposit of white, granular gypsum has been thickness of or 10 feet. At one spot a large mass of crystalline excess of quartz and feldspar. Associated with the porphyry are strat dolomite was found. The deposits run with the strata, north and south, of metamorphic rocks, of a hard, dark, quartzose character. A quart and dip west 60°. As we approach Olive, the few croppings seen still of a mile northwest of the mine is a bunch-like outcrop of porphyr dip south or southwest, but at a less angle. South of the mouth of carrying silver and copper carbonate. The black veins outcrop for Silverado Cañon a line of hills extends north and south, bordering the Santa Ana Plain. The western portion of these hills is formed of basalt considerably decomposed. The basalt varies from scoriaceous to finegrained and compact. Its eastern edge was seen to rest on Miocene sandstones, and it dips west at a small angle, perhaps 10°. The lava seems to have been squeezed up in fissures, judging from the way in At some places which it outcrops. Its greatest elevation is 800 feet. the sandstones, where not covered with lava, have been silicified, turned to quartzite, or rendered granitic in appearance. This may be due to an intrusive neck of lava, or more probably to the action of thermal springs. gangue. north of Silverado, and extending in a southerly direction for 7 or 8 miles. The Quincy Mine is one of the most northern ones. vein has a width of 2 feet; the ore, silver-bearing galena in a calcite The It carries but little base metal of any kind. The ore has a peculiar appearance, the galena being distributed through the gangue in little leafy crystals or aggregates. The fissure is well defined and regular, with a pale green syenitic rock on the hanging wall, and a dark diorite on the foot wall. This hanging wall rock weathers to a light gray color, producing a rock known as porphyry among the miners. South of this mine a side vein carries much antimony. The Quincy has been opened along a length of 500 feet. The ore is quite uniform, producing one eighth in concentrates. The Quincy camp has an elevation of 2,300 feet. South of Silverado Cañon, in Silver and Pine Cañons, a great amount of work was done during the former excitement. The sides of the steep, rocky cañons are fairly honey-combed with tunnels, which were undertaken without sufficient prospecting, and, of course, never struck anything. The New York Mine spent much money, but did not prove a success. West is the Princess, and farther still, about 1,200 feet above the cañon, is the Blue Light Mine, on which much work has been done and rich ore taken out. The mines south of the cañon are in a feldspathic rock, which weathers white. It is undoubtedly an intrusive porphyry, for traces of feldspar crystals are to be seen. The mines are characterized by a large amount of zinc-blende, iron pyrites, and not a large percentage of lead, making them more difficult to reduce. The porphyry is mineralized in many places where no traces of the precious metals occur. Litigation and poor management seem to be the chief factors in stopping work in this district. Though some of the ore runs into hundreds of dollars to the ton, the most of it is medium to low grade. An interesting fold of the Tertiary strata was observed at the entrance of Santiago Cañon. The sandstones and conglomerates on the eastern side dip to the northeast at an angle of 30°, while those on the west side dip in the opposite direction. The valley has been eroded in the summit of an anticlinal. The rocks of the eastern side rise again against the side of the mountains, thus forming a synclinal. Up the cañon the sandstones on the west maintain a southwest dip of 45° to 50°, and strike north 40° west. The cañon finally leaves the anticlinal, and the Toward the summit of the hill, rocks dip southwest on both sides. north of the Harris Coal Mine, the dip increases to 70°, but on the top they turn so that the strata lie horizontal. Here they consist of clay shale. The strata at the coal mine swing around, and one mile northeast they strike north and south and dip west. This hill seems to form the southern termination of the anticlinal ridge north of Santiago Cañon. Southeast of this point there is a simple monoclinal fold or slope away from the older rocks of the high mountains. There has apparently been a fault extending northwest in this anticlinal ridge, bringing up the clay shales which farther south were shown to belong About a mile and a half down the cañon from the old Silver Post to the Cretaceous. Harris Coal Mine shows a seam 18 inches wide, shale There is a fault of Office, and in a cañon coming in from the south, is a cropping of dark, forming the foot wall and sandstone the upper. The sandstone at the mouth of Silsomewhat argillaceous limestone inclosed in shales. The limestone does 200 feet cutting this coal seam. A half mile up the not seem to have been highly metamorphosed, yet the fossils which it verado Cañon dips south 30°, forming bold cliffs. contains are almost obliterated. The faint impressions are those of coral cañon there are heavy beds of clay shale inclosed in the sandstone. Cretaceous fossils appear in the shales, as well as in a coarse sandstone stems, stromatopora, and some other low forms of life. This sandstone is replaced by conglomerates farther down the cañon is a cropping of brecciated marble. Half a mile near the contact with the underlying Metamorphic Series. The sand points, particularly on the north side of the cañon, there are great masses At many none rises to a height of 2,500 feet, with bold, almost perpendicular of apparently conglomeritic character, but with a crystalline structure. cliffs facing the mountains. Portions of the sandstone containing the The matrix has a green to brown color, and in it are imbedded pebbles of the same degree of fineness, but often distinguished by much brighter of bowlder-like inclusions, and are evidently eruptive tuffs. Above these the water holds much lime in solution, and extensive tufas are frequently The first crystalline rocks met are dark and fine grained, with traces red, purple, and green colors. In this cañon, as in others of this range, which underlies them. fossils are often very much hardened. are green, dioritic rocks. These intrusives are followed for several miles to be seen. The basal members of the Cretaceous at the mouth of In other places thin layers of sandstone and shale are wonderfully con and those into shales; dip 55° away from the mountains in the highest by sandstone and shale, in which the stratification is often obliterated Silverado Cañon consist of conglomerates passing up into sandstone, torted. The dip is at a high angle either east or west. In the vicinity ridge, but in the course of a quarter of a mile becoming much less. The of the old Silverado Camp there are dikes and bunches of a green dio change in dip is very sharp, giving the appearance of a fault. ritic rock. The mines in the Silverado district are again being devel A cañon which enters Silverado Cañon from the northeast near its oped to some extent. The mineral belt is about 2 miles wide, and mouth was followed up nearly to its head for the purpose of investigating extent of dikes of greenish to blackish rocks, often showing distin dark porphyry. Beyond this the stream has cut a deep cañon through hornblende crystals. The dip of the metamorphic rocks is east abou an immense conglomerate of porphyritic and quartzose pebbles. The 45°. There is one main mineral vein located, beginning about a mi porphyritic pebbles are dioritic and part red and black porphyries. |