Geological map of the C astro chrom.i te dep osit, (U. S • Geological Urve y B ull. in preparation). Geologic sketch map of the Klamath Mountains M showing their genera. areas of rock ultraraa fik out-.
IN TEE PACI F'I G COA;JT REGION
Rynearson who collaborated on the early parts of this investigation, as well as Dr. In laboratory investigations 1. about 300 thin sections of rocks from different loeolites were examined.
GEOLOGY
The gene r a l geology of the K lama th mount ain re E)ion of northern cal a lif or nif:i a n southwestern. Other chromite deposits are found in the northern part of the Seiad quadrangle where sohlierenband and injection type orebodies occur in a northwesterly direction.
SKETCH MAP OF GENERALIZED AREAS
THE OF
KLAMATH ·MOUNTAINS ULTRAMAFIC ROCK
SHOWING OUTCROPS
Locally, due to an increase in the percentage of the rho.ml:th pyroxene, enstatite, the dunite grades into saxonite peridot;tte. However, the texture of the original rock is well preserved, and unless it is b 1:1 dly.
MIIN""ER A LOGY
Little correlation has been found between the color of the chromium content of or2o3 in the chromite molecule, although the deep red chromium usually contains a greater percentage of cr2o3 than the yellow mineral. Much of the evenly distributed chromium in the Pacific coast deposits is fine-grained, and few deposits have been found here.
1 TELLURIUM
SODIUM
TITANIUM
Each curve shows a minimlllll corresponding to the mlnir:mm shown by nickel and nt nearly the same position in the time sequence. However, the curves for each element, although based on minor dnta, do suggest that the minor element content of the chromite molecule is a regular variation arranged in the tim e of crystallization. sequence proposed in this paper; The variation is thought to reflect differences in the conditions of deposition and crystallization.
ALTEHATION
Flattening::: and lengthening of the eye muscles is parallel to thf3 dl:p and stroke 01' tho bun and inr; in the chromite with which the spheres are associated. Exposures are limited and the boundaries of the ore body are unknown. The accompanying plan of the works clearly indicates the random distribution of the ore bodies.
The bulk of the ore consists of lenticular high-grade bodies of chromite distributed entirely by serpentines. They are almost always in a completed zone and are often damaged or broken off after placing the ore. This direction is different from the core of the larger textural feelings of the Santa Lucia Runge.
COMBINED TERNARY DIAGRAMS OF PHASE EQUILIBRIA IN THE SYSTEM
A small amount of t1umine destroys this immiscibility, when the ferrous-ferric iron ratio is a b out 1:1 a minimum4.ril of at least 6-oercent A l O.
If cooling occurs during this interval, the part of the mass will be slightly aggravated. This type of deposl t is common in the intrusives of the coastal ranges of California. rrhe deposits of the Twin S isters r a n g e east of. p. 79. The rest of the ma s will appear much the same as before, except for additional concentrations of chromite in local areas with consequent ~ rcity elsewhere.
It is believed that the result of the predictable forces approaches an equilibrium state consisting of a layer of olivine and small amounts of chromite in the base of the magma chamber, cnre rlain. This ideal condition is rarely attained in nature, except perhaps in the stratifo.rm deposits, and the degree of deviation from equilibrium conditions determines the characteristics of the ore deposit formed. EaoP, chromite precipitation is investigated.in the evidence that indie at what stage in the process of cooling or crystallization of the ul tran1afic.
CHROMITE DEPOSITS OF GRANT COUNTY, OREGON
P. THAYER
CHROMITE DEPOSITS OF GRANT COUNTY, OREGON A PRELIMINARY REPORT
Dry Camp Mine (33).-- The Dry Camp Mine is in the southern part of swi sec. Although the belt in both deposits dips 45° to 75° S., the deposits are very shallow. Marks & Thompson Mine (27).--The Marks & Thompson mine is located in the northern part of the second SWt.
Celebration mine (52).--The Celebration mine is about 500 feet south of the East Fork of Pine Creek, in the northwest corner of sec. Howard Prospect (26).--The Howard prospect is 3,500 feet northeast of the Dry Camp mine, near the center of sec. Prospect west of Pine Creek (58).--The prospect well west of Pine Creek, in the middle of the Si sec.
GEOLOGIC MAP OF THE MARKS THOMPSON CHROMITE DEPOSIT
PLAN OF THE RAY MINE
In small irregular bundles and stringers of higher grade chromite occurring outside the main body of spotted ore, only vertical linear structure is visible. It is encased in dunite, which grades into olivine within a few centimeters of the ore. Reed (13) and Campbell mines (14).--The Reed and Campbell properties are among the prospect~ in NEi sec.
Silver Lease Mine (10).--The Silver Lease Mine is about 3 miles northwest of John Day near the center of the western edge of the. The ore remaining in the glory hole consists only of small lenses and a shell of chromite perhaps 3 feet thick, lying against the gabbro (?) dike. The main ore block is west of the gabbro (?) which evidently cuts square across the original chromite lens.
PLAN AND CROSS SECTION OF THE SILVER LEASE CHROMITE DEPOSIT
Hankins Mine (Spring and Chrome Ridge) (45).--The Hankins Mine, described by Allen as the Spring and Chrome Ridge Mine, is in the northeast. Delores Prospects (47).--The Delores Prospects are on a bare serpentine ridge between Deer Creek and the South Creek of Killer Creek, in sec. Total shipments amounted to about 50 tons of ore, said to average 54 percent chromium oxide.
In the lower trim, the fine-grained brown chrome plating on the serpentine-polished surfaces is extremely prominent. Prospects near Bull Spring (61).--Three prospects are situated in the vicinity of Bull Spring, which is situated near the common corner of the seconds. The workings are on the serpentine which forms a bare ridge northwest of the road between Murderers Creek and the South Fork of Murderers Creeko No chrome except that forming thin coatings on smooth surfaces was seen in place, although a few small patches of black ore friable was found in landfills.
CHROMITE DEPOSITS IN THE SEIAD QUADRANGLE
CHROMITE DEPOSITS IN THE SEIAD QUADRANGLE SISKIYOU COUNTY, CALIFORNIA
Interest in the chromite resources of the district has revived in recent years. Landslides in the peridotite and serpentine are numerous, and two of the smaller chromite deposits are in landslides. The relationship of the nodules to the foliation of the peridotite could not be determined.
On the above assumptions, indicated reserves, in tons, of the Seiad Creek deposit, averaging 35 percent chromite, are estimated in the table below. Red Butte Claim (Veta Grande).--The Red Butte claim is now known as the Veta Grande claim of the Rustless Mining Corporation. Liberty Claim (Cerro Colorado).--The Liberty claim is now the Cerro Colorado claim of the Rustless Mining Corporation.
ONARY TR1i:NDS AND V ARIANTS l.1
SYSTEMATIC DESOIUPTI ONS
Plate I
Glyezmeri~ veatohii anae 40
Plato II
ABS TRACT
INTROD UCTION
STATEMENT OF PROBLEM
MWTIIOD OF INVESTIGATION
In the investigations cited above as well as in the present study, certain qualifications must be met before the results are obtained and the conclusions made can be considered justified. l) The species Qt tbe genera ohosen for examine- t:i.on. must be represented by an abundance of individuals in all stages throughout its geological range. structural differences observed on two given specimens are small and - i ndi'1idu&l variations are often niialaading. It is clear that the course in evolution of an ohar• .. actor can only be determined when the relative stratigi-aphic age or position or individual stage& in the modification of these teatu:re 1$ known. once the tx-end and rate or .. evolution is determined• strati gre.phio OQrrelations can be established with even greater certainty. .. preserved or carefully prepared spet- :men must be used. aonclusions based on poor preservation. or fragmentary rnaterials are often not valid since tbe evo•. lutionary changes can be masked or completely destroyed. This separate ration was made (1) because it was clear early in the investigation that a sample with a thickness or convexity of shell ef about 6 mm.
EVOLUTIONARY T:RENDS .AND VARIA NTS
STRATIGRA PHY
Member IV
The exposures occur along the valleys or little cow creek, svedje creek, egnonne, kloverå, old cow creek and south cow creek. The entire seot1on is probably more than 4000 feet in thieknees and includes some of the earl1•. In the present study attention is directed to the upper parts sinee, glyczmer,1,.s veatch11 ~edtHpsensis.
Although there is no stratigraphic basis for the division, other than the abundance of coarse conglomerate in the lower half, the division is recognized because it is not a.
While there is no stratigraphic basis for this division except an abundance of earse conglomerate in the lower half• the division is recognized because ot a. . r recognizable modlfi.tation in the evolutionary trends ot . one. veatehii reddingens1s,. Member :rv is a series of dark•gr. ay anddy shale and shaly sandstone with s few thin coarse sanct.atone beds. .. 2'Q00 f e et Af lag fortning 8 monooline in which the stl'ata dips to the west away from the m.mounta.in:;h It is essenti.,. . ally consists of $endstone, except for a severe C)onglom;. on the basis of measurements ot .. veatchi1 reddi;igensis, the localities are grouped into. an op pe r and a lower limb. n:this cUvision does not, however, reoeier firmly au.pii O;rt from the pal-0ontological cal e v1 .. denee, since only four specimens are r~orded from op per zone. It is recognized here to indicate possible evolutionary advances in Q:• veatc hii dU:rin. occurrences of .Q• veatchii in the Santa Ann MOUl').tains are grouped into three zones. similar g ro 1 _iplng of these beds in .. suggested by th<&· relationship ot other parts of.
The lower part of - G• -- ve.atchi1 - --- in the Santa Ana Mountains is located in the upper half of the Holz Member ot. The roes at the Tuscan springs are different from the continuation of those found in the section exposed to Chico creek, and consist for the most part of pebbly or silty sandstones. It is particularly fortunate that we encounter the type and species of G-vea tcb.ii.
