University of New Hampshire University of New Hampshire Scholars' Repository
New England Intercollegiate Geological NEIGC Trips Excursion Collection
1-1-1973
Pointe Verte to Tide Head, Chaleaur Bay Area, New Brunswick
Greiner, H.
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Recommended Citation Greiner, H., "Pointe Verte to Tide Head, Chaleaur Bay Area, New Brunswick" (1973). NEIGC Trips. 192. https://scholars.unh.edu/neigc_trips/192
This Text is brought to you for free and open access by the New England Intercollegiate Geological Excursion Collection at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in NEIGC Trips by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. TRIP A-7, by H. Greiner, The University of New Brunswick.
POINTE VERTE TO TIDE HEAD, CHALEUR BAY AREA, NEW BRUNSWICK
INTRODUCTION
Silurian and Devonian sedimentary, extrusive and intrusive rocks of northern New Brunswick occupy the southwest-trending Chaleurs Bay Synclinorium (Poole, W. H., and John Rodgers, 1972). These sediments and volcanics were deposited adjacent to an island arc system with a core of Ordovician and older rocks which had been deformed by the Taconic Orogeny (Bird, J. M. and Dewey, J. F., 1970). This ancient land mass, named “Mirami- chia” by Rodgers (1971, p. 1159), was the source of sediment and the site of volcanoes in the Lower, Middle and Upper Silurian and into the Lower and Middle Devonian. Deep-water turbidite accumulations, probably beginning in the Middle Ordovician (with argillaceous limestone or “ribbon rock” of the Matapedia Group), and continuing through the Silurian, prevailed to the west in the Campbellton-Matapedia area. For much of the area there is a remarkable repetition, almost cyclical in character, in the Middle to Upper Silurian and in thQ Lower Devonian. In both an initial, marine, calcareous siltstone or silty limestone is succeeded by basalt flows, followed by ter restrial redbeds or (for the Devonian) very near-shore sedimenta tion, and ending with orange felsitic extrusions. (Fig. 1.) Middle Devonian sedimentary rocks of the Campbellton Form ation are lacustrine, intermontane conglomerates, sandstones and shales, with a rich fish and plant biota, and a close association with tuffs and agglomerates. The youngest consolidated rocks are redbed conglomerates of Pennsylvanian age, the Bonaventure Formation, which lie with conspicuous angular unconformity on older rocks. They are al most flat-lying, and only rarely faulted. Deformation was in shallow-depth zones and mainly Acadian, although local granitic to gabbroic intrusions occurred as well. Folds are open, and two fault systems dominate, one north-trend ing, the other to the east or northeast. Metamorphism is sub- greenschist (zeolites in Devonian palagonite tuffs are not uncom mon), and contact metamorphism minimal. Axial-plane cleavage is present in many of the Silurian and Devonian pelites. Appala
58 chian deformation was apparently limited to gentle warping; shal- low-zone faulting took place in the Dalhousie area, as well. The Ordovician-Silurian contact is probably an angular uncon formity (Fig. 2 and 3). Otherwise all formational contacts of Si lurian units in the Petit Rocher-Charlo areas (but probably not in the West Campbellton) are conformable or disconformable. In deed, the Silurian-Devonian boundary itself appears to be one of conformity, and lies somewhere within a calcareous siltstone- mudstone sequence. As might be expected, facies chnge can be great (Fig. 4). Contacts between the various Devonian sedimentary formations are in general more complex, with much- injection and extrusion of igneous rocks, and interfingering and “pinching-out” of units. The Archibald Settlement Felsites in the Charlo area are con spicuously unconformable, as, indeed, is the Bonaventure Con glomerate.
LOG AND STOPS MILEAGE FRIDAY, OCTOBER 12, 1973 0.0. in tersection at King Avenue and Main Street, Bathurst. Turn left onto Route 11. 2.4 Tetagouche River. Middle Ordovician graptolite locale ca. one mile upstream in graphitic slate and chert of the Tetagouche Group. 3.5 Vi mile west to graptolite site. 3.8 Pillow basalt flows, probably Devonian. 6.1 Grants Brook. Ordovician Tetagouche metasedimenta- ries. Just beyond, cross Rocky Brook-Millstream Fault zone into Silurian siltstone, shale-limestone rocks. Gaspe visible across Chaleur Bay. 9.7 Nigadoo River. Silurian.
14.4 STOP 1 — Limestone Point. Silurian sedimentary rocks lie with probable unconformity on Elmtree (-Teta gouche) phyllite, quartzite, etc., and are unconformably overlain by Devonian andesitic flows. The Silurian sec tion here begins with Lower (but probably not lowest) Silurian redbed rudites, tentatively named the “Pointe
59 G AS P E
Upsalquitch
DEVONIAN mudstone , shple
Rafting \ Ground
Sugarloaf
Dacite SILURIAN
MIDDLE ORDOVICIAN to LOWER SILURIAN ( G AS P E
Campbellton
f.nmnbellton Formation X n / r X X X X X X X x X X X X andesite, tuff . etc X X X 1f \ A X X x x X X X X
X X X X X X X 1 ^ - X X X x X X X
Sugarloaf
Dacite
v v granite, v x
v v felsite
Balmoral Gabbro Dalhousie CHALE UR
BA Y
Stewart x Andesite East Charlo
v \B ry o n' <7 v V~"hiash| v ^ v vvCreek L v Archibald vFelsite^ \ Fm
Nash Creek i Fm.
Charlo Charlo Granite v Granite v
Balmoral ^ Gabbro
62 SCHEMATIC PANEL DIAGRAM
FACIES AND FORMATIONS
CHALEUR BAY COASTAL AREAS
NORTHERN NEW BRUNSWICK
(THICKNESS APPROXIMATE)
East Charlo
I 2 3 MILE 1 2 3 KILOMETE Belledune
Belledune , Point
Bonaventure Fm______Sunnyside Fm ______
Belledune Fm
New Mills Conglomerate amygdaloidal porphyry Chapel Poinl Sandstone
Nash Creek Antinouri Limestone Granite Pointe Verte Redbeds
Elmtree Group
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o a • s 5 < l ! Z TD •• -O : CO c ~ c S I o ? Is o o o o c « £ o CO in ? o s| • o o o c E 0) m m E o a> d 0 E a> CO -x q k. in • J - > o J ( o o c «n O in I a , b • H CNJ O 13 o C - < 55 \ 6 OQ • H a> c v o 10 _ *n (/) e t IA O' — y UJ CJ UJ e t _J *« £3 ^ o 4> r , UJ a u J* o £ >K o * o a> > CO e t c o c o * o o C7» c £ o z < < o o E c/> < % X q . a O CL S.- et D w jt: o O £ . 3 c r n< et Z 1 £ < o O ^UJ L ^ CD <_> U J cr D is 2 0 q : uj > w o UJ 1 O £ if) tf) * - J o 5 " o o < et o o i t K (f> o O u j h- £ CD £ O C/3 CD S a CO £ O 03 CD 03O £ O 0 £ • 03H £ O > CD Q 1 £ •r~i03 £ 0 } i £ • *—•05 o > T5O o CO D > > H U« 0 J I f ) o I f) <0 65 66* 59’ 66° 52' LOWER DEVONIAN (?) OR LATER Felsic intrusive and extrusive rocks gronite . granodiorite, felsite .feldspar porphyry .docite stocks, and reloted dykes and sills LOWER,MIDDLE AND UPPER SILURIAN AND LOWER DEVONIAN Greenish - weathering micoceous. silty mudstone and shale, calcareous siltstone and minor conglomerate 2o Thick to medium-bedded sondstone and siltstone, with basal ond mterbedded con glomerate UPPER ORDOVICIAN (?) TO LOWER SILURIAN M a t a p e o ia g r o u p Dork bluish-grey, dense,calcareous argillite la Uncleaved' banded"limestone ond dork shale Foult .with escorpment I SCALE IN MILES 4 7 *5 3 ’ 6 6 *5 9 ’ 66*52' Fig. 4 Ordovician-Silurian-Devonian contact relations, Resti- gouche River estuary, New Brunswick. Verte Redbeds,’ with minor andesitic flows, and is suc ceeded by typical, widespread, nodular “pitroek” lime stone, roughly equivalent to the Gaspe La Vieille Form ation of upper Llandovery-YVenlock age. This is the Nash Creek Limestone. Especially interesting here are the intense slump folds penecontemporaneous with deposition of the sediment. Time permitting, a side trip up the Madran road to the railroad crossing to see a small gabbroic neck — the probable source for the andesite flows — and, farther on, to view the Elmtree metasedimentaries will be made. 6 6 15.5 Dark greenish-grey basalts, etc., begin. 17.5 Green Point crossroad. Silurian, as before. 22.4 Smelter. Lead and zinc. 23.3 Church at Turgeon. 23.6 STOP 2 — At Turgeon the conspicuously jointed "Chapel Point” reddish sandstones (which, nearby, can be seen resting on the Nash Creek Limestone) is succeeded by mafic, amygdaloidal porphyry which contains large phe nocrysts of feldspar. Boulders of this porphyry, as well as of many other igneous rocks, and of the Nash Creek Limestone, can be found in the • succeeding New Mills Conglomerate, a typical fanglomerate. Plucked “rip-up" limestone clasts are common, sorting is poor. Such structureless, unsorted conglomerates have been said to indicate surge deposition within a fanglomerate. 27.8 Belledune River; Lower Devonian fossiliferous siltstone w in river. 28.3 Cross fault into probable basal Silurian (Llandovery) redbeds. 30.7 Turn right onto dirt road (just before bend, Rte. 11), and proceed to shore at Flanagan’s house. STOP 3 — Fault zone at creek: to west, Nash Creek siltstone, Bryant Point basalt, New Mills Conglomerate, with associated mafic intrusions; to east (right), “Pointe Verte Redbeds” in a finer, partially marine, crossbedded facies, grading into (overturned) fossiliferous Nash Creek Limestone at Quinn Point. All steeply dipping, with the Bonaventure Formation in angular unconform ity above. Paleobathymetric analysis of the Nash Creek shows three of the five depth-zone indicators of Ziegler (1965) are present; the shallowest (Lingula, of the Welsh strata) is replaced by algal heads, here. Carboniferous tropical weathering (Rodgers, John, pers. comm.) is prevalent. 33.6 Jacquet River Provincial Park. Bonaventure redbeds. 34.7 Jacquet River Bridge; Bonaventure on east Bank. 38.1 Again Silurian. 40.0 Road to Dickie Cove. 67 I? Z UJ CO X5* 2* X? o C •O • z O UJ OC x> UJ c o Z O T3 o z o H- © < o X3 z o U) < UJ 2 Z u c o (/) A z O T3 z c l 2 ■o o o O UJ UJ UJ a: 9 K z s c o UJ o E »- a CL 2 T> < < 2 03 u. < CE1 5 *- 0. K 9 2 cn < z o o O 2 §• O I* o CL o o 3 UJ -J UJ (E « ® o c UJ CO UJ Z. o c 03 u O C/3 Z © o c X3 c n o H © X> < X) © *o © C X) •« 2 w - CO O © S i S w-* c o o .£ o • o ® © c o E X? O f> ft o o < § o c -K x> o © ° o ~ o CD « €> o a, ^ -o c © CO o r> > o X? © ■ f ; < c u c c to © -I •» s o to X3 i s o O c t - a -J © - u X3 o UJ c © 03 CD UJ o c a: X5 cn CD O O h X3 c© c 7> io C/) © o 0 . XJ X) © o X3 o I 7* C o 2 c c TD 0 - o o i i o o • • c n lO £ < CL E 8 o 3 X o II 13 1 8 I g o O CL H- ? 5 o ® X3 3 3 ^ .O 3 T3 CL § c r a: O < - { O c C 6 0 8 f © UJ O o s U ^ e> X - 1 O o ■o to CL O 5 I s o UJ O o UJ 3 CD &? u CD O 2 © < ft UJ I © o ° . o y— CL o o h - ft « c/3 o CL il o CD < o o u UJ CL CL 3 3 * 2 5 ^ J; ° o UJ < < o CL o > h - o £ o UJ O 10 c 6 Q5 ^ ^ o -J cn o 2 II -J < -J < K UJ < 3 03 >- cn H < 1 cn cn Q o 2 u< CL UJ 03 I * a © © © £ o UJ CL o CL 68 STOP 4 — Nash Creek Formation in a ripple-marked, worm-burrowed calcareous siltstone facies. Note the kame ridge. 43.6 New Mills and Federal Salmon Pond. STOP 5 — Bryant Point-New Mills contact. Bus proceeds to Cove at Thrum Island. Heron Island with flat-lying Bonaventure offshore. Archibald Settlement -(Devonian) rhyolite forms hills inland. 48.9 River Charlo. Bonaventure forms bedrock. 50.2 Approaching ridge of Devonian gabbro. 54.0 Turn off Route 11 at Co-op Centre to power plant. STOP 6 — The Lower Devonian (Helderberg) Dalhousie Group consists of shallow-water, fossiliferous shales and limestone with intercalated andesites, basalt flows, tuffs, etc. Basal calcareous shales are poorly exposed, along strike trilobites of Helderberg (Gedinnian) age have been found. The palagonite tuff above contains a zeolite (an- alcime) assemblage (Mossman and Bachinski, 1972). Columnar jointing and (rare) amethystine-quartz-filled geodes are exhibited in the basic flows, which probably originated from vents at Dalhousie and Sugar Loaf Mountain. 55.5 Back on Route 11. Proceed through Dalhousie. 56.5 Devonian andesites. 56.7 Ferry road to Gaspe. Upper Devonian Escuminac Formation across bay. 59.1 to 59.4 Devonian volcanics dipping to north. 71.7 Sugar Loaf Mountain overlooking Campbellton ahead. 74.6 South end of Interprovincial Bridge to the Gaspe. OVERNIGHT' in Campbellton (40 Winks Motel). SATURDAY, OCTOBER 13, 1973 0.0 Campbellton. 0.9 Turn right into lumber yard and park vehicles. 69 STOP 1 — Walk down to shore and examine Campbell- ton Formation (Middle Devonian) with fish (Cephalas- pis, Climatius, C heir acanthus, Gyracanthus, Dolioclus, Mesacanthus, etc.) and plant (Psilophyton, sensu lata, Wm. Forbes, pers. comm.) remains, and ostracods inter- bedded in tuffs, etc. 6.0 Tide Head. Turn off onto Route 17 (left). Glaciofluvial terraces. 11.0 Flenlevit. Devonian basalts, etc. from ca. Mile 8.0. 11.7 STOP 2 — Limestone-pebble conglomerate, orange felsite of Upper Silurian or Lower Devonian age. 15.0 STOP 3 — DANGEROUS right-angle bend; park just be fore it. Pentamerid (Conchidium?) zone; probably Mid dle or Upper Silurian. 15.5 Rafting Ground Road. Possible detour to Restigouche River and Matapedia Group. 23.9 Upsalquitch River crossing. 25.5 STOP 4 — Deformed (near fault) basal Silurian (?) sand stone and shale, with (0.5 Miles farther) smashed and contorted Matapedia argillite. Continue Route 17 to St. Leonard and Route 2 (Trans-Canada Highway) to Fred ericton. 70