The Tectonic History of The Hat Creek Coal Deposit (2008).

 

A Tectonic History of The Hat Creek Coal Deposit.

(2008)

By

George Stuart Green, B.A. Geol.

© 2008 George S.Green

ISBN: 978-0-9919761-1-9 (html)

 

(top page 2)

A Tectonic History of The Hat Creek Coal Deposit (2008)

First written in 1992 and titled; A Tectonic History of The Hat Creek Coal Deposit. © 1992 George S. Green. All Rights Reserved

In 2008, the 1992 version was revised, updated and titled; A Tectonic History of The Hat Creek Coal Deposit (2008). © 2008 George S. Green. All Rights Reserved. The text of which follows.

Please note:

Pages 3-26 inclusive, and all of the tables and figures appearing in this work have been re-printed from my earlier 1992 paper. However, Figure 6 in (1992) became Figure 4 in (2008), with Figure 4 in (1992) becoming Figure 5 in (2008). New material on pages 27-28 (inclusive) was added in 2008, with page 30 (2008) slightly revised from page 28 (1992) in order to render the statements there to be more accurate. Additional (endnote) references have been added in support of any new material.

 

(top page 3)

Acknowledgements

I wish to thank Energy, Mines and Resources Canada (GEOS magazine), B.C. Hydro Power and Authority, the B.C. Ministry of Energy, Mines and Petroleum Resources, and the Geological Survey of Canada for their permission to use and/or otherwise cite the reference material used in producing this paper.

 

(top page 4)

INTRODUCTION

From July of 1977 to September of 1978 the author mapped the structural geology revealed by two large trenches cut into B.C. Hydro's Hat Creek coal deposit #1; and logged several thousand feet of core taken from the deposit. In the winter of 77-78 the writer engaged in a complete re-evaluation of the geological and geophysical data generated on the deposit.

An extensive evaluation and correlation of more then three hundred geophysical logs run on the property produced a number of cross sections, structure contour and geological maps; and a mastered working hypothesis relevant to the tectonic history of the structural deformation of the coal.

In short, the geological data and the deformation geometry indicate that Deposit # 1 was deformed as the result of compressional forces impinging upon the property, relatively speaking from a northerly direction. Additional research indicates that this deformation most likely occurred during the late Miocene or early Pliocene when several episodes of regional tectonic activity affected this part of south central British Columbia.

 

(top page 5)

 

(top page 6)

Location, access and topography

 

The Hat Creek valley is located approximately 30 kilometers west of Cache Creek, British Columbia. It is accessible via Highway 12 which joins Highway 97 at a point some 10 kilometers north of the town of Cache Creek.

The valley is roughly 10 kilometers long, 2.3 kilometers wide and trends almost due north/south; with Hat Creek proper flowing to the north (Figure 1). The valley is nearly surrounded on all sides by mountains that range in elevation from 1,500 to 2,000 meters. The sides of the valley consist of gently sloping and rolling hills that increase in steepness as the tree line is reached at about 1,400 meters.

 

(top page 7)

Geology

Table #1 lists a sequence of stratigraphic units occurring in the area under review.

Strata of the Permian Cache Creek Group represent the oldest rock strata in the vicinity of the Hat Creek coal deposit (Deposit #1). The Cache Creek Group is divided into the Marble Canyon Formation above, and the Greenstone Sequence below. As per Table #1, the Marble Canyon Formation is made up of marble, limestone and argillite. It forms the Pavillion Mountains to the north and the Cornwall Hills to the southeast of the coal deposit. The Greenstone Sequence is exposed to the northeast of the deposit and forms the Trachyte Hills (Figure 1).

To the west of Deposit #1 is the Mount Martly Stock. The Mount Martly Stock is composed mainly of granodiorite, and is believed to be Cretaceous in age(1). The contact relationship with the Marble Canyon Formation is believed to be fault related, although it is possible that some prior intrusive or contact metamorphic relationship existed before its present disposition and hence the generation of the marble portion of the Marble Canyon Formation.

 

(top page 8)

 

(top page 9)

 

(top page 10)

The Spences Bridge Group is Cretaceous in age and is composed of andesitic and dacitic lavas, basalt, rhyolite, tuff breccia and conglomerate(2). The Spences Bridge Group can be found in the Clear Range Mountains which form the western boundary of the Hat Creek valley. Its lower contact with the Mount Martly Stock is reportedly erosional(3). Its upper contact indistinct, unconformable(4).

Stratigraphically above the Spences Bridge Group there occurs an (essentially) early Eocene sedimentary assemblage that has been divided into three formations; the Coldwater Beds (referred to as the Coldwater Formation for purposes of this paper). The Coldwater Formation is overlain by the Hat Creek Formation; and the Hat Creek Formation is overlain by the Medicine Creek Formation. It is believed that these formation designations were developed and applied during (and as a result of) B.C. Hydro's 1974 - 75 exploration program.

For purposes of this paper, these strata will be regarded as definitive formations, and the names as generated will be applied to facilitate discussion.

The lowest sedimentary formation recognized therefore at Hat Creek is the Coldwater Formation. The Coldwater Formation is believed to be middle Eocene in age(5) (possibly late Paleocene to early Eocene).* It is made up of poorly consolidated sandstone, siltstone, claystone, pebble conglomerate and (regionally) minor coal. It is approximately 1,372 meters thick(6). Its lower contact was never penetrated by drilling. It may be resting (locally) upon the Spences Bridge Group.

Above the Coldwater Formation is the Hat Creek Formation. It too is considered to be middle Eocene in age, yet may be late Paleocene to early Eocene.* The Hat Creek Formation consists mainly of coal with interbedded layers of siltstone, claystone, sandstone, and pebble conglomerate. It is approximately 550 meters thick and sits conformably upon the Coldwater Formation. The Hat Creek Formation is further divisible into six identifiable members; (from top to bottom they are) the A-1 coal member; the A-2 rock member; the B-1 coal member; the C-1 rock member; the C-2 mixed rock and coal member; and the D-1 coal member. (These are discussed in detail later on in this paper under Stratigraphy of Deposit #1).

 

(top page 11)

Above the Hat Creek Formation is the Medicine Creek Formation. The Medicine Creek Formation is made up of a rather uniform composition of siltstone and claystone. Its semi-consolidated nature causes it to break down rapidly upon exposure to weathering and consequently there are few exposures of it in the Hat Creek area. An upper contact for this formation has not been located(7).Drilling data does indicate that the thickness of the Medicine Creek Formation exceeds 200 meters(8).The formation is considered to be middle Eocene in age (9) yet may be late Paleocene to early Eocene. Its lower contact with the Hat Creek Formation is sharp and conformable.

Above the Medicine Creek Formation is the Finney Lake Formation. The Finney Lake Formation consists of lahar, andesite and dacite lava flows, and minor sandstone and conglomerate(10).The Finney Lake Formation reportedly forms an angular unconformity upon tilted Medicine Creek and Hat Creek sediments(11). This would tend to suggest that the Finney Lake Formation is much younger than the Eocene Hat Creek and/or Medicine Creek formations.

Additional Miocene basalt flows(12),cover the land to the northeast of the Hat Creek deposit(13).Many of these basalt flows consist of, vesicular and amygdaloidal basalt of varying compositions(14).Referred to as the Chilcotin Group Basalts(15),these Miocene basalts reportedly occur at the 1,800 meter elevation on Tsil-tsalt Ridge, just to the north of Hat Creek, in the Pavillion Mountains. They rest unconformably, upon the (Permian) Marble Canyon Formation(16).They apparently occur as well at the 1,000 meter elevation, just to the east of the Hat Creek coal deposit(17);indicative therefore, of some 800 meters of post Miocene displacement. (Discussed further under Tectonic History).

Lastly, Pliestocene glaciation has occurred throughout the Hat Creek valley, and numerous thick deposits, of glacial till now cover much of the valley floor. These deposits have been studied by B.C. Hydro and arranged according to pre and post glacial features(18).A large landslide occupies an area just to the west of the coal deposit(19).

*See;The age of the coal (to follow)

 

(top page 12)

Stratigraphy of Deposit #1

Based upon an evaluation of geophysical and lithological data(20),the Hat Creek Formation has been subdivided into six members, sometimes referred to as horizons or zones. Beginning from top to bottom they are; the A-1 coal member; the A-2 rock member; the B-1 coal member, the C-1 rock member, the C-2 mixed rock and coaly shale member, and finally, the D-1 coal member.

The A-1 coal member ranges in thickness from 170 to 200 meters. It is made up of numerous seams of coal with interbeds of siltstone, sandstone, claystone, and minor thin (2 to 10 cm) beds of volcanic ash (tuff). Individual coal seams tend to thin in a southwesterly direction while thickening in a northeasterly direction. The upper contact of the A-1 coal member represents the upper contact of the Hat Creek Formation with the overlying Medicine Creek Formation. The contact is sharp and conformable. The lower contact of the A-1 coal member with the A-2 rock member is gradational and conformable.

The A-2 rock member ranges in thickness from 0 to 30 meters. It consists mainly of siltstone, claystone, and minor sandstone. The A-2 rock member thins out completely in a northeasterly direction and as such it is completely missing as a rock member from between the overlying 'A' and the underlying 'B' coal members. This shows evidence of strong facies change activity occurring at the time of the deposition of the coal, with a source area to the southwest of the deposit. The contact with the underlying B-1 coal member is sharp and conformable.

The B-1 coal member ranges in thickness from 45 to 85 meters. It consists primarily of coal with thin layers of carbonaceous claystone, coaly shale, and minor thin beds of volcanic ash (tuff). The B-1 coal member thins in a southwesterly direction while thickening in a northeasterly direction. The contact of the B-1 coal member with the underlying C-1 rock member is sharp and conformable.

The C-1 rock member ranges in thickness from 10 to 60 meters. It consists of siltstone, fine grained sandstone, and minor pebble conglomerate. It is distinguished from the underlying C-2 rock member by the absence of any coaly shale beds. The contact of the C-1 rock member with the underlying C-2 rock member is gradational and sometimes difficult to locate in the geophysical logs.

 

(top page 13)

(top page 14)

The C-2 rock member ranges in thickness from 40 to 80 meters. It consists mainly of coaly shale, carbonaceous claystone, siltstone, and minor sandy siltstone. The C-2 rock member gradually thickens in a southwesterly direction. The quality and thickness of the coaly shale portions of this member increase in a northeasterly direction. This member and the overlying C-1 rock member show evidence of strong and rapid facies change activity occurring at the time of the deposition of the coal, with a source area existing to the southwest of the deposit. Throughout the Hat Creek Formation, no facies change activity is indicated as occurring from a northerly direction. The lower contact of the C-2 rock member with the underlying D-1 coal member is sharp and conformable.

The D-1 coal member ranges in thickness from 60 to 120 meters. It consists mainly of coal with minor interbeds of carbonaceous claystone. The coal is bright and hard, and of the many individual members within the Hat Creek Formation, the D-1 coal member represents the most competent member within the formation. The D-1 coal member thins in a southwesterly direction and thickens in a northeasterly direction. All coal bearing members within the Hat Creek Formation thicken in a northeasterly direction and indicate that the more stable environment for the deposition of the coal existed to the northeast of the deposit.

Stratigraphic and structural evidence indicates that the Hat Creek deposit extended further to the northeast of its present location(21).With respect to the coal deposit itself, the immediate eastern and northeastern margins of the deposit have been folded, faulted, uplifted and subjected to erosion. The D-1 coal member has been folded, faulted and uplifted to a sub-crop position beneath glacial till.

 

(top page 15)

The Age of the Coal

A number of palynology studies have been conducted in an effort to determine the age of the Hat Creek coal deposit(22).Additional research has endeavored to use potassium argon methods of dating on the rhyolite and dacite lava flows(23),and a number of age dates have been generated.

The stratigraphic evidence associated with these lava flows, indicates that they are younger than the strata comprising the Hat Creek Formation, i.e. these volcanic flows appear to be resting unconformably upon tilted Hat Creek strata. Given this stratigraphic positioning and potassium argon dates ranging from 43.6 to 49.9 to 51.2 million years, it would seem that the age of the coal could be, as some palynology studies suggest, late Paleocene to early Eocene (roughly 56 to 60 million years). The volcanic activity, from which the potassium argon dates were taken, having occurred, some 5 to 12 million years after the deposition of the coal and the overlying sediments.

Alternately, the rhyolite (and dacite) sampled could represent volcanic events which occurred after the deposition of the Coldwater yet contemporaneous with the deposition of the coal. This could account to some degree for the origin of some of the ash beds (tuff) found within the coal, with the present disposition of the rhyolite being the result of slumping or slide activity.

The structural disposition of the Finney Lake Formation resting unconformably upon tilted Medicine Creek and Hat Creek sediments(24),suggests a much younger age for the Finney Lake Formation than that of any rhyolite occurring in the same area as the Finney Lake Formation. The Finney Lake Formation may be therefore, a post Eocene, possibly a Miocene geological feature(25).

 

(top page 16)

Structural Geology of Deposit #1

The structural geology of deposit #1 is characterized by a large asymmetrical syncline. Referred to as the Hat Creek Syncline, its axis strikes almost due north/south, with a plunge of 17 to 20 degrees to the south. The west limb of the Hat Creek Syncline dips eastward at 30 to 35 degrees. The east limb dips westerly at 25 to 35 degrees in the north end of the deposit and increases to 70 to 80 degrees to the west at the southern end of the deposit.

There are several faults in deposit #1 especially affecting the eastern flank of the deposit. Three of the more prominent faults affecting the eastern flank of the deposit are; the Creek Fault, the Finney Fault, and the Harry Lake Fault. There are several minor adjustment faults associated with these faults (Figure 2).

The Creek Fault is essentially, a faulted anticline. It is a reverse fault. Relevant to the Creek Fault, the eastern block uplifts portions of the 'D' coal horizon to a sub-crop position. The Creek Fault strikes N 15/E and dips 70/E. The Creek Fault postdates and displaces the Finney Fault (Figure 2).

The Finney Fault postdates the Hat Creek Syncline and precedes the Creek Fault. It strikes N 25/E and dips 75 to 80/NNW. It truncates the Hat Creek Syncline at the southern end of the deposit (Figure 2).

The Harry Lake Fault is contemporaneous with the Creek Fault. It runs sub-parallel to the Creek Fault and strikes N 15/W and dips at 70 to 80/E. It too is a reverse fault and displaces the Finney Fault, as evidenced via drill hole DDH 128 and DDH 164.

There are two identifiable faults in the west limb of the Hat Creek Syncline. They are the Aleece Lake East Fault and the Aleece Lake West Fault. The Aleece Lake East Fault is a low angle (relative to bedding plane) reverse fault. It strikes N 25/E and dips roughly 65 to 70/ESE.

The existence of this fault was first recognized in April of 1977* and was subsequently confirmed when Trench 'A' was cut into the west limb of the deposit in June of 1977.

* See Endnote # 28

 

(top page 17)

The Aleece Lake East Fault and two other reverse faults, which split off from the Aleece Lake East Fault were also exposed when Trench 'A' was cut into the deposit. There is strong indication (slickensides) of right lateral strike slip movement associated with these faults.

The Aleece Lake West Fault is also a reverse fault. It strikes roughly N 35/E and dips at about 70 to 80/NNW. It developed as a counter element to the movement along the Aleece Lake East Fault. As the two faults merge together, the Aleece Lake East Fault appears to override the Aleece Lake West Fault. When seen in cross section, this looks like an upside down 'Y' (Figure 3).

 

(top page 18)

 

 

(top page 19)

 

(top page 20)

Tectonic History

Although the general character of the south central B.C. interior may in part be explained by block faulting and the development of horst and graben type structures, the local structural geology of Deposit #1 and to some degree the rest of the Hat Creek valley, may be explained more clearly as being the result of compressional tectonic forces.

Although the valley may have been a graben type structure that existed prior to or concurrent with the deposition of the coal, the faulting now evident within the deposit took place after the deposition and folding of the coal, and must therefore be post Eocene in age, probably Miocene.

Just to the north of Deposit #1 and in fault contact with Deposit #1(26)the Pavillion Mountains, composed of limestone of the (Permian) Marble Canyon Formation rise 1,000 meters above the floor of the Hat Creek valley (Figure 1). The relative displacement between the Permian limestone of the Marble Canyon Formation and the Eocene coal of the Hat Creek Formation is in excess of 2,000 meters. This large scale displacement (very clearly post Eocene displacement) combined with a wedging effect created by the presence of the Trachyte Hills and Cornwall Hills to the east of the deposit, assisted in the production of the necessary compressive mechanism required to cause the folding and subsequent high angle reverse faulting currently displayed throughout the deposit.

It is quite likely therefore, that the rising Pavillion Mountains* were responsible for plunging the Hat Creek Syncline 17 to 20 degrees to the south. In relative terms, the Pavillion Mountains rose up on a wedge shaped fault structure(27)and more or less plowed into Deposit #1 like the prow of a ship slamming into a dock (Figure 4).

Apparently, the entire region under went a period of post Miocene uplift; the result of which caused the Hat Creek valley and the Pavillion Mountains to rise. Only the Pavillion Mountains rose at a rate somewhat faster than the rate at which the valley rose. The effect of this differential displacement caused the coal in Deposit #1 to become compressed. This compression being reflected in the high incidence of strike slip, bedding plane and high angle reverse faulting clearly evident within the deposit.

 

(top page 21)

 

(top page 22)

The high angle reverse faulting in both limbs of the Hat Creek Syncline (the Aleece Lake Fault in the west limb(28) and the Harry Lake and Creek faults in the east limb); the low angle bedding plane or thrust faulting, as well as the overturning of portions of the A-1 coal horizon(29),and the right lateral strike slip nature of much of this faulting (in the west limb of the syncline) (left lateral in the east limb) points to the presence of strong compressive forces impinging upon the deposit, relatively speaking from a northerly direction.

The presence of thick Miocene basalt flows regionally suggests that some quite strong tectonic activity certainly took place during the Miocene(30).The small portion of basalt mapped as Miocene located near the top of the Pavillion Mountains(31)tends to indicate that the elevations of the Hat Creek Valley and the Pavillion Mountains during or just prior to the Miocene were relatively equal. The Pavillion Mountains may only be a late Miocene or early Pliocene geological feature.

Furthermore, it should be pointed out that the source area for the strong facies change activity affecting the A-2, C-1 and C-2 rock units of the Hat Creek Formation existed to the southwest of the deposit and no such facies change activity occurs from a northerly direction. This also tends to indicate that the Pavillion Mountains most likely did not exist at the time of the deposition of the Eocene coal of the Hat Creek Formation.

Some research considers the basalt located on top of Tsil-tsalt Ridge to be Eocene in age(32).Even if this turns out to be the case, this too tends to indicate the Pavillion Mountains most likely did not exist at the time of the deposition of the coal. Since these Eocene basalts would likely be contemporaneous with those occurring near the floor of the Hat Creek Valley, the elevation of the (current) tops of many of the ridges forming the Pavillion Mountains must have been relatively equal at or about the time of the deposition of these Eocene basalts.

It is possible that subsequent uplift of the Pavillion Mountains could have occurred during the Oligocene, with the structural deformation of the Hat Creek coal deposit occurring at that time.

* See author's note, final page.

 

(top page 23)

Additional information:

Research conducted in the early 1980's on the Anahim Volcanic Belt north of Hat Creek(33)locates a source and dated sequence of events which support the contention that a significant degree of regional uplift (or general rise of the region) occurred during the Miocene and Pliocene epochs. The existence of several lava flows throughout the region indicates a number of periods of tectonic activity occurring over a significant length of time.

From an examination of this information it appears that two arch systems were formed; each of which resulted in extensive volcanic activity along the crest of each of these arches. One was a north/south arch; the other was an east/west arch.

The north/south arch runs from Tascha Lake in the north to Cache Creek in the south. The Chilcotin Basalts may be associated with this north/south (crustal) arch. The east/west arch runs from Clearwater in the east to Bella Coola in the west, and is known as the Anahim Volcanic Belt (Figure 5).

This crustal arching preceded the volcanic activity generated along the crest of the axis of each of these systems. It was this tectonic activity (regionally) which caused the Pavillion Mountains and the Hat Creek Valley (as a whole) to rise; with the Pavillion Mountains rising at a rate somewhat faster than the rate at which the valley rose and therefore, pressing in upon the coal and causing the structural deformation of the deposit.

The Pavillion Mountains appear to be situated on the southern tip of the axis of the north/south Tascha Lake/Cache Creek arch. The Pavillion Mountains would in part, seem to be a product of tectonic activity along this system. Figure 5-A illustrates how both large scale normal faulting, as well as large scale reverse faulting could be produced along such a system. Figure 5-B illustrates how this activity appears to have impacted upon the coal in Deposit #1 at Hat Creek.

Table #3 presents a comprehensive geochronological order or sequence of events, relevant to the tectonic activity that has affected the area regionally, as well as locally.

 

(top page 24)

(top page 25)

(top page 26)

 

(top page 27)

 

(top page 28)

Hat Creek Update (2008)

In my earlier (1992) work on the tectonic history of the Hat Creek coal deposit, I presented an hypothesis that stated that there was in effect, some 6,000 feet (1,830 m) of displacement between the Permian limestone of the Pavillion Mountains and the Eocene sediments of the Hat Creek coal deposit. The evidence gathered at Hat Creek during the 77-78 exploration program supports this hypothesis.

The property was caught up in a general, post Eocene uplift of the region; with the deformation of the coal deposit having occurred at this time; due mainly to the differential rates of rise between the strata containing the coal and that of the limestone of the Pavillion Mountains(34).There is additional evidence to support this hypothesis.

This evidence comes from a coal deposit beneath the town of Princeton, British Columbia. Princeton is some 126 miles (153 klm) to the south of Hat Creek. At Princeton, there is another Eocene coal deposit. The deposition and disposition of this coal deposit is similar to that of the Hat Creek deposit.

The Princeton coal deposit sits beneath the town of Princeton. The town itself and the valley it is located in, sit at about 2,000 feet (610 m) above sea level. The coal beneath Princeton has been age dated as being Eocene(35) probably Late Paleocene to early Eocene. It is the same age as the Hat Creek coal.

The coal at Princeton is contained within the lower portions of the Allenby Formation(36).The coal seams are composed within a series of anticlines and synclines some of which strike to the northwest. At the southern extent of the Princeton coal deposit, the Allenby Formation is contained within a northeast by southwest trending syncline(37).Strata within the syncline plunge to a degree sufficient to contain some 4,800 feet (1,464 m) of the Allenby Formation beneath the valley floor(38).This puts some of the coal down to about 3,000 feet (915 m) below the valley floor.

About 20 miles (25 klm) to the northwest of Princeton, just west of the community of Coalmont, and to the south of the community of Tulameen, there sits the Tulameen Coal Deposit. This coal is also contained within strata of the Allenby Formation(39).

(top page 29)

It is the same age coal; and an extension most likely of the same coal deposit that occurs at Princeton; yet it sits exposed in outcrop upon a plateau up Blakeburn Creek at about the 4,000 foot elevation (1,219 m)(40). At this location, this Eocene coal deposit outcrops some 2,000 feet (610 m) 'above' the valley floor(41).

At Princeton the coal seams dip to 3,000 feet (915 m) below the valley floor. The total amount of displacement between these two (contemporaneous) coal deposits is about 5,000 feet (1,525 m). Just about the same degree of displacement (1,830 m) that has occurred at Hat Creek. The faulting responsible for this may be either normal or reverse faulting, it does not matter.

This is another example of large scale displacement having occurred sometime after the lithofication and deformation of these Eocene coal deposits at these two (separate) locations (Hat Creek and Princeton). Now we have two locations where the geology of which suggests, that there was some very strong deformation of the region taking place; possibly during the Miocene and/or Pliocene epochs when considerable volcanic activity took place throughout much of central and south central British Columbia. Miocene lava flows cover much of this region. This (Miocene) tectonic activity, complete with lava flows, even extends down into Washington, Oregon and northern California.

My original (77-78) hypothesis as regards the Hat Creek property seems all the more correct and confirmed.

 

(top page 30)

Figures and Tables

Figure #1: Hat Creek location map, NTS 1:250,000

Figure #2: Hat Creek Coal Deposit #1 geology. Drawing by George Green, data courtesy B.C. Hydro. Original geology by George Green and H. Kim.

Figure #3: Hat Creek Coal Deposit #1 geological cross section. Drawing by by George Green, data courtesy B.C. Hydro. Original geology by George Green and H. Kim.

Figure #4: Geology Map. Marble Canyon and Hat Creek Canyon faulting. Drawing by George Green, data courtesy B.C. Hydro. Original geology by George Green and H. Kim.

Figure #5: Anahim Volcanic Belt Location Map. Drawing by George Green, data taken from GEOS Magazine, Vol. 12, No. 3, Energy, Mines and Resources Canada.

Figures: Figures 5-A and 5-B are cross sectional representations for 5A &5B illustrative purposes. Concept and drawings by George Green.

Table #1: Table of Formations. Drawing by George green, data courtesy B.C. Hydro, B.C. Ministry of Mines and the Geological Survey of Canada.

Table #2: Hat Creek Formation, Stratigraphic Column. Drawing by George Green, data courtesy B.C. Hydro.

Table #3: A Geochronological Order, sequence of events, outlining the comparative tectonic histories of the Hat Creek deposit with the surrounding region. Concept and design by George Green.

 

(top page 31)

Author's note

After the completion of this paper, it was noticed that the Pavillion Mountains (named as such in this work) were in other sources (maps) identified as the Pavillion Range. Additionally, in some sources, a southwest portion of these mountains, nearest to the Marble Canyon, were identified as the Marble Range.

During 77-78 exploration effort, it was common to refer to both of these mountain ranges as the Pavillion Mountains. That name stuck with me and I used it here rather liberally before I noticed the difference.

So, for clarification, the term Pavillion Mountains is an inclusive term referring to both the Marble Range and the Pavillion Range as one unit of mountains.

 

(top page 32)

Endnotes

(1)Dawson, G.M., 1895; Kamloops Map Sheet, B.C. Report, Geological Survey of Canada.

(2)Church, N., 1975; Geology of The Hat Creek Basin, B.C. Summary of Field Activities. B.C. Department of Mines.

(3)Duffell, S. and McTaggart, K.C.. 1951; Ashcroft Map Area, B.C. Memoir 262, Geological Survey of Canada.

(4)Duffell, S. and McTaggart, K.C., 1952; (as per above). See also; McKay, B.R., 1925; Hat Creek Coal Deposit, Kamloops District, B.C. Summary Report, part A. Geological Survey of Canada.

(5)Church, N., 1975 (as per above). Note; see also my commentary on the age of the coal following, "The Stratigraphy of Deposit #1" in this text.

(6)Church, N., 1975 (as per above). Also; Hoy, T., 1975, Geology of a Tertiary Sedimentary Basin Northeast of Hat Creek. Summary of Field Activities, B.C. Department of Mines.

(7)Church, N., 1975; (as per above).

(8)B.C. Hydro, DDH #139, Cross Section 'W'. Open Files 141-146. B.C. Ministry of Energy, Mines and Petroleum Resources.

(9)Church, N., 1975; (as per above). Also, Rouse, G., 1977; via B.C. Hydro 77-78 Hat Creek exploration program.

(10)Church, N., 1975; (as per above).

(11)Church, N., 1975; (as per above).

(12)Dawson, G. M., 1895; (as per above).

(13)Fraser River Map 1386 A, Sheet 92, Geological Survey of Canada.

(14)Read, P.B., 1990-23, Cretaceous and Tertiary Stratigraphy and Industrial Minerals, Hat Creek, B.C., (NTS 92I/12,13,14), (1:25,000), a single sheet.

(15)Read, P. B., 1990-23, (as per above). Also; Read, P.B., 1988-29; Tertiary Stratigraphy and Industrial Minerals, Fraser River, Lytton to Gang Ranch, B.C. (1:25,000) a single sheet map. B.C. Ministry of Energy, Mines and Petroleum Resources.

See also Read, P.B., 1988-30; Tertiary Stratigraphy and Industrial Minerals, Cache Creek (92J/14), (1:25,000) a single sheet map. B.C. Ministry of Energy, Mines and Petroleum Resources.

(16)Dawson, G.M., 1895; (as per above).

(top page 33)

(17)Dawson, G.M., 1895; (as per above).

(18)McCullough, P.T., 1978; via B.C. Hydro's 77-78 Hat Creek exploration program. Also; Golder Associates, geotechnical studies for B.C. Hydro, 77-78 exploration program and subsequent work; B.C. Ministry of Energy, Mines and Petroleum Resources, open files #140-146.

(19)Golder Associates, geotechnical studies. (As per above).

(20)Original work by G. Green (this author) and H. Kim. B.C. Hydro 77-78 Hat Creek exploration program.

(21)Fraser River Map 1386 A, Sheet 92; Geological Survey of Canada.

(22)Rouse, G., 1977; B.C. Hydro 77-78 exploration program. Also, Hopkins, W. S., 1980; Palynology of the 75-1006 Core Hole, Hat Creek Coal Basin, B.C. Ministry of Energy, Mines and Petroleum Resources. (I.S.P.G.) Open File Report #547. (This reference by way of Church, N., 1985, Volcanology and structure of Tertiary Outliers in South Central British Columbia. B.C. Ministry of Energy, Mines and Petroleum Resources.

(23)Church, N., 1975; Geology of The Hat Creek Basin, B.C., Summary of Field Activities, B.C. Department of Mines.

(24)Church, N., 1975; (as per above).

(25)The Finney Lake Formation was considered Miocene at the time of the 77-78 Hat Creek exploration program. However, see my commentary under "Tectonic History" in this text.

(26)Read, P.B, 1990-23; Cretaceous and Tertiary Stratigraphy and Industrial Minerals, Hat Creek, B.C. (NTS 92I/12,13,14), (1:25,000), a single sheet map.

(27)Read, P.B., 1990-23; (as per above). Also, Golder Associates, geotechnical studies for B.C. Hydro, 77-78 Hat Creek exploration program. B.C. Ministry of Energy, Mines and Petroleum Resources, open files #140 - 146.

This fault line was indicated by the work of Golder Associates in 1977-78. It forms a wide angle 'V' shape in plan view, with the apex of the 'V' pointing into the Hat Creek deposit. The left wing of the 'V' strikes northwesterly through the canyon separating the Mount Martly Stock from the Pavillion Mountains. The right wing of the 'V' strikes northeasterly down the Hat Creek canyon. Given the structural deformation of the Hat Creek coal deposit, it is reasoned that the plane of this fault (the right wing) dips north/northwesterly into and beneath (?) the Pavillion Mountains. The left wing dips (although it may be steeper) it dips north/northeasterly into and beneath (?) the Pavillion Mountains. It may have been activity along this structure that enabled the body of the Pavillion Mountains to rise up, and into the Hat Creek coal deposit (Figure #4).

(top page 34)

(28)Hughes, J., 1977; The Structural Geology of The West Limb of The Hat Creek Syncline, April 1977; for B.C. Hydro's 77-78 Hat Creek exploration program.

(29)B.C. Hydro, DDH #77-242, Cross Section 'T' (as discovered by this author in 1977)

(30)Fraser River Map 1386 A; Sheet 92, Geological Survey of Canada. Also; Parsnip River Map 1424 A, Sheet 93, Geological Survey of Canada.

(31)Dawson, G.M., 1895, Kamloops Map Sheet; B.C. Report, Geological Survey of Canada. Also; McKay, B.R., 1925, Hat Creek Coal Deposit, Kamloops District, B.C. Summary Report, part A, Geological Survey of Canada.

(32)Fraser River Map 1386 A; Sheet 92, Geological Survey of Canada.

(33)Rogers, G. C., and Souther, J.G., 1983, Hotspots Trace Plate Movements. GEOS Magazine, Volume 12, No. 2, Spring issue, Department of Energy, Mines and Resources Canada.

(34)Green, G. S., 1992, A Tectonic History of The Hat Creek Coal Deposit. See this paper, current text, pages 19 -21.

(35)Petroleum Geology Paper 2004-1, Coalbed Gas Potential in British Columbia. Ministry of Energy and Mines, Oil and Gas Division, Resources Development and Geosciences Branch. July 2004. Pages 43-46.

(36)McMechan, R. D. (1976), Princeton Basin, Geological Fieldwork 1975, B. C. Ministry of Energy, Mines and Petroleum Resources, Paper 1976-1, pages 99-103.

(37)McMechan, R. D. (1983), Geology of the Princeton Basin, B.C. Ministry of Energy, Mines and Petroleum Resources, Paper 1983-3.

(38)Shaw, W. S. (1952), The Princeton Coalfield, B. C. Geological Survey, Paper 52-12.

(39)Petroleum Geology Paper 2004-1, Coalbed Gas Potential in British Columbia. Ministry of Energy and Mines, Oil and Gas Division, Resources Development and Geosciences Branch. July 2004. Pages 51-54.

(40)Evans, S. H. (1978), Tulameen Coal Basin; Geological Fieldwork 1977, B.C. Ministry of Energy, Mines and Petroleum Resources, Paper 1978-1, pages 83-85.

(41)Evans, S. H. (1983), Geology of the Tulameen Coal Basin; Geology in British Columbia 1977-1981, B.C. Ministry of Energy, Mines and Petroleum Resources, pages 76-87.

THE END

Return to: My research papers list.