Taxonomic study of Ordovician (Llanvirn-Caradoc) Radiolaria from the Southern Uplands (Scotland, U.K.)

11 Pages·1999·3 MB·English

by  Taniel Danelian

Taxonomie study of Ordovician (Llanvirn-
Caradoc) Radiolaria from the Southern Uplands
(Scotland, U.K.)
Taniel DANELIAN
Department of Geology and Geophysics.
The University of Edinburgh, West Mains Road, Edinburgh EH9 3JW (U.K.)
Laboratoire de Micropaléontologie,
Université Pierre et Marie Curie, CNRS-ESA 7073,
C. 104, T. 15-25, 4 place Jussieu, F-75252 Paris cedex 05 (France)
[email protected]
Danelian T. 1999. — Taxonomie study of Ordovician (Llanvirn-Caradoc) Radiolaria from the
Southern Uplands (Scotland. U.K.), in De Wever P. & Caulet J.-P. (eds), InterRad VIII.
Paris/Blerville 8-13 septembre 1997. Geodiversitas 21 (4) :625 ‘635.
ABSTRACT
Over 100 years ago, Hinde (1890a, b) described Radiolaria in thin sections
from Ordovician chert.s of the Southern Uplands of Scotland and established
for the First time the presence of the group in the Early Palaeozoic.
Radiolarians from the Southern Uplands hâve now been successfully cxtrac-
tcd by hydrofluoric acid ieaching and the systematic palaeontolog)^ ot some
of the yieldcd morphorypes is discusscd herein. The studied fauna corne
from two outerops of radiolarites: one at upper Hawkwood Burn and the
KEYWORDS orher north-west of the village of Crawford. Amongst the radiolarians cxtrac-
Radiolaria,
Ordoviciaa, red from the latter ourcrop, the généra Imnihlguttii and Prdtoccratoikiscum
Llanvirn, are common. The presence of the spccies hianihiguttti diffusa (Hinde),
Caradoc,
Inanibigiitîa (?) minuta Wang and înanihigutta sp. cf. verrucultt (Nazarov)
Southern Uplands,
Scotland, allows the corrélation of the Crawford fauna with ihc Haplcntactinm juncta-
United Kingdoni, Jnanigîitta unica assemblage in Nazarov s (1988) biozonation, of upper
laperas Océan,
Llanvirn (Llandeilian)-Caradoc âge, and with the assemblage documenred by
Caledonides,
radiolarian chert. Wang (1993) in China, of earliest Caradoc âge.
GEODIVERSITAS • 1999 • 21 (4) 625
Danelian T.
RÉSUMÉ
Etude taxonomique des radiolaires ordoinciens (Llanvirnien’Caradocien) de
Southern IJplands (Écàsse^ R. U.).
Des radiolaires ordoviciens ont été extraits à l’acide fluorhydrique des radio-
larites de Tunicé structurale des Southern Uplands en Écosse. Étudiés en
lame-mince il y a plus d’un siècle (Hinde b) ceux-ci oui servi comme
témoin de la présence certaine de ce groupe dans Je Paléo/oiquc inferieur. La
faune ici étudiée vient de deux affleurements: riin des radiol.iikcs rouges
brunâire.s à Hawkvvood Burn, l'autre des radiolaritcs grises qui affleurent au
nord-ouest du village de Crawfdrd. La paléontologie sysrémariqiie de cer¬
taines formes intéressantes est ici discutée. Les genres Inanihtgutra et
MOTS CLÉS
Radiolairfs, Protoceratoîkiscum sont communs parmi les radiolaires extraits des radiol.i-
Ordovicien, rites de Crawford. La présence des espèces Inanibigutta dijfusa (Hinde)»
Llanvirnicn,
fnanihigutta (?) minuta Wang et Inanibigutta sp. cf. verrucula (Na^arov)
CamdoaVn,
l.cojwe. permet la corrélation de la faune de Crawfoid avec l’association
Royaume Uni, Haplenracîintd junaa-Inaniguna unica de la biozonation de Nazarov (1988),
radîolarites,
d’âge Llanvirnien supérieur (Llandeilien)-Caradocien, ainsi qu’avec l’associa¬
Océan lapetus,
Calédonides. tion décrite par Wang (1993) en Chine, d’âge Caradocien basal.
INTRODUCTION known and most of them represent carbonate
platform/slope environments (Fortey ôé
Despite significant improvements in our under- Holdsworrh 1971; Nazarov Popov 1980:
standing of Palaeoxoic Radiolaria over the last Webby èic Blom 1986; Renz 1990; Wang 1993).
35 years, Early Palaeo/oic assemblages are still Radiolaria of oceanic affinitv are common, but
poorly documented (Noble Sc Aîtehison 1995). less wcll picservcd, in rocks of deep water origin
As a rcsiilr, our knowledge of the early stages of such as radiolarites (ribbon radiolarian cherts
évolution of ihi.s significant planktonic group with shaly intcrvals) which are ofren associated
remains limitcd, 1 he oJdest radiolarian fossils with remnants ot oceanic crust in accretionary
corne from late Cambrian shallow-water lime- prisms of ancient subduction zones. Thcy reflect
stones ol China» front which one species bas rhe significant biogeocheinical rôle that
been reccntly described (Dong et al. 1997). Radiolaria staried to play in the océans (i.e. the
Diversification markedly increased during the silica q^cle) from the Early Palaeozoic.
Ordovician and from the limited work that has rhe occurrence of r.tdiolarians in cherts of the
been donc so far, it is clear thaï radiolarian cvolu- Southern Uplands terrane (Fig. I ) has been
tionary change during ihis time was more rapid known for over a ccncury. It was on material
than prcvioLisly bclieved (Renz 1990). The group from this région that Hinde (1890a, b) first esta-
has thereforc rhe potential co bccomc a valuable blishcd the definite presence of Radiolaria in the
biostratigraphic tool for chc yct poorly explorcd Early Palaeozoic. Outerops of radiolarian cherts
Early Palaeozoic interval, with an increasing were extensivdy discussed by Peach & Home
number of easily identifiable, diagnostic taxa (1899), wlio were responsible for a major map-
(Aitchison ôé Noble 1997; Aitchison 1998; ping compilation of tho goology of Southern
Aitchison et ai 1998). Scotland. Radiolaria from the Southern LIplands
There are relanveiy few localities in the world hâve also been reported by Nicholson (1889)
where well-preserved Ordovician assemblages are and Smith (1900). The techniques available at
626 GEODIVERSITAS • 1999 • 21 (4)
Taxonomy of Ordovician Radiolaria from the S. Uplands
Fjg. 1. — Geological outline of the Southern Uplands. Based on McAdam étal. (1993).
that time only allowed for study of Radiolaria in
LEADHILLS
thin section, which provided very lirnited infor¬ graptolite conodont greywacke SUPEHGROUP
zones zones
mation on iheir morpliology. Tliis wa.s naturally ü Bur.
the case for the single previous taxonomie work O " MOFFAT
< SHALE
of Radiolaria trom the Southern Uplands (Hinde c<üe Aur. gracilts GBOUF»
1890b) in which 23 new spccics wcrc described. ansennus 1
Recügnising rhe potential of ladiolarian studics 2 Llandeil. s 0.
DC Zi
in the Southern Uplands, a number of radiolar- > ê
2 O
ian chcrc outerops hâve alteady been examined 3 Aber.
J
and the results briefly reported (Danelian & ی
Fenn. O
Clarkson 1998). This paper foenses on the syste- ? ^ U,
O
mbaasreied sotund ym oofd seomn ier aodfi othlaer iyaincl dtcadx omnoorjpnhyo t(yep.ge.s, ZLcUr . Whit. 0 V a e radio(cid:9632)l ari^t e 1cüe
Nazarov & Popov 1980; Nazatov 1988). It Mor. lava
attempis to link matrix-free forms to the species
described originally by Itinde and to gradually
Fig. 2. — Simplified stratigraphy for the Lower-Middle
build a detailed and integrated picture of the Ordovician of the Southern Uplands. focusing on the Crawford
radiolarian assemblages occuring in these historic- Group. Lithostratigraphic terminology according to Floyd (1996).
Chronostratigraphy and biostratigraphy from Fortey et al.
ally important Scottish localities. (1995).
GEODIVÊRSITAS • 1999 • 21 (4) 627
Danelian T.
Fig. 3. — Geological map of the studied localities. A, north-west of the village of Crawford ^after Leggett & Casey 1980); B, at
Hawkwood Burn (after Clarkson étal. 1993).
STRATIGRAPHICAL FRAMEWORK BIOSTRATIGRAPHICAL DISCUSSION
The Southern Uplands consist largely of The fauna discussed herein were extracred from
Ordoviciiin and Silurian sedimenrary rocks of two chert samples, onc from an outerop along
deep-w:Uer origin. The oldest rocks at ihe base of the lowcr part of a trackside cutting, north-west
the succession are composed mainly of basaltic of the village of Crawford (National Grid
lavas, radiolarian chcjts and siliceous mudstoties. Référencé NS 941 215; Figs 1, 3A) and che other
A formai lithostratigraphy for the Ordovidan has from radiolarites cropping oui at upper
recently been defined by Floyd (1996). The lavas Hawkwood Burn (NS 972 248), a cributary of
and radiolarites are part ol the Crawford Group the Wandei Burn (Figs 1, 3B). Samples were pro-
of Arenig-Llanvirn âge (stfuu Fortey étal. 1995), cesscd with the laboratory technique of hydro-
although based on recent conodont evidence the fluoric acid (Dumitrica 1970; Pessagno &
Group probably extends into ihc Caradoc Nowport 1972).
(Armstrong al. 1990, 1996). The overlying At Hawkwood Burn, the r;tdiolarian cherts are of
graptoliiic shalcs of the Moffat Shale Group red-brownish colour and were recently descrihed
(Caradoc-LUndovery) are in turn succeeded by by Clarkson et al. (1993). From the base of thèse
the greywackc successions of the Leadhills cherts a conodont launulc of lare Llanvirn
Supergroup (Fig. 2). (Llandeilian)-earliest Caradoc âge was reponed
üntil rccendyv che varions outerops of radiolarian (Armstrong 1990, 1996). Alrhoiigh nidiola-
cherts in the Southern Uplands were considered rian préservation here does not allow any confi¬
as being part of a single concinuous stratigraphi- dent identification of established species, the
cal sequence, spanning the Arenig and Llanvirn, fauna seem to be comparable lo rhe Haplentac-
and ovcrlain by the early Caradoc [Nemagiaptus thiia juncta'InanigHtta unicn assemblage of
gradlis graptoliie biozone) Moffat Shale Group Nazarovs biozonation (Llandeilian-Caradoc;
(Leggett 1978, 1987), However Armstrong rr rfA Nazarov 1988; Nazarov & Ormiston 1993),
(1996), after an extensive révision, suggested thar which i.s consistent with the age given on the
radiolarian cherts could reprc.sent rwo distinct basis oi conodonts..
sedimenrary events: one during ihc mid Arenig In the second locality, ncar the village of
{Oepikodus evae conodont biozonc), and onc of Crawford, the radiolarites are mainly greeni.sh-
latest Llanvirn to earliest Caradoc âge {Pygodus grey in culour. No biostratigraphic data other
anserinus conodont biozone). than that provided by the radiolarians exist for
628 GEODIVERSITAS • 1999 • 21 (4)
Taxonomy of Ordovician Radiolaria from the S. Uplands
the âge of this oiitcrop. The presence of the MEASURëMENT.S (one specimen). — Diameter of che
genus Protoceratoikiscum is important because it flattened part of the outer shell, 133-136 pm: dianic-
cer ol rhe elongated part of the outer .shell, 152-
suggests a Llanvirn-Caradoc iiiterval {sensu
154 pm; length of main spines, 40-50 pm; diameter
Fortey et ai 1995) as a First approximation for
of inner shell, 63-66 pm.
the âge of these chcrts (Daiiclian & Clakson
1998). lhe présence of ihe specLes Inanibigutta Description
diffiisay established hercin (Fig. 4A-D), now A nearly spherical outer shell bearing six radia-
allows the corrélation of tlic Crawford tauna ting main spines positioned with hexagonal sym-
vvith lhe Haplentiictinia junvta-lnanigutta unica metry. The outer shell is perforated by circulât to
assemblage of Nazarov’s biozonation of late oval pores of varions dimensions. The main
Llanvirn (Llandeilian)-Caradoc agc. Morcover, spines are robust. rod-like, and gently tapering
the identification of Inünlhigutîa (?) minuta distally. They are almost half che length of the
(Fig. 4F-G) and inanibigutta sp. cf. /. vetrucula diameter of che outer shell. A nuniber of needle-
(Fig. 4H) allows tfie corrélation of the Crawford like sccondary spines cover ihc surface of rhe
assemblage with the one docuinented by Wang outer shell. The inner shell is relarively small,
(1993) from the Pingliang Formation, dated as perforated and linked to the outer .shell through
of carliest Caradoc âge (commun interval be- radial beams that continue as main spines out-
tween the N. gracilis and P. anserinus biozones). side the outer shell. Its position is eccentric in rela¬
tion to the center of the outer shell (Fig. 4C-D).
SYSTEMATIC PALAEONTOLOGY Remarks
The eccentric position of the inner shell was
Subclass RADIOLARIA Muller, 1858
pointed out by Nazarov (/// Nazarov & Popov
Superorder POLYCYSTINA Ehrenberg, 1838
1980) and can be observed on the holotype illus-
entend. Ricdel, 1967
traced by Hinde (1890b), which is obviously a
Order SPUMELLAHIA Ehrenberg, 1857
section through an équatorial plan encompassing
Family InaniguTTIDAE
four s'pines. Only one specimen in our sample
Nazarov & Ormiston, 1984
was identifiable with certamty. NeverchelesSj
several orher naturally broken but incomplète
Genus Inanibigutta Nazarov, 1988
specimens may bclong to this species (Fig. 4E).
The dimensions of our specimen correspond pre-
Inanibigutta Nazarov, 1988: 56. — Nazarov &
cisely co the ones ineasured by Hinde (1890b).
Ormiston 1993: 35.
However, Nazarov (in Nazarov & Popov 1980)
Typf SPECIRS. — Entactinosphaera aksakensis Nazarov, accepted a largcr variabÜicy of sîze for this spe¬
1975. cies, especially as far as the length of spines ïs
concerned. The latrer author also mencioned that
Inanibigutta diffusa (Fïinde, 1890b) a spongiform texture was observed on the outer
(Fig. 4A-D) shell of somc of his specimens from Kazakhstan.
Suutroplegtna diffiLKum Hindt, 1890b: 50, pl. 4, fig. 4.
Entactinosphaera ? diffusa (Hinde) - Nazarov Popov
Inanibigutta (?) minuta Wang, 1993
1980: 37, 38, rexi-hg. 16, pL 2, fig. 4, pl. 13, fig. 8.
Inanibigutta dijftisa (blinde) - Nazarov 1988, fig. 31. (Fig. 4F-G)
OcCL’RKENCF.. — Middic Ordovician (l.landcilan lo Inanibigutta minuta Wang, 1993: lÜO, pl. 6, figs 9-
Lower Caradoc) Bestomakskaya Suite, Eastern 12.
Kazakhstan, southwestern foothills of the Chingiz
Range, Chagaii River (Nazarov & Popov 1980); Occurrence. — Middle part of the Pingliang
Broughron Hcights, Peehlcshire, Southern Uplands Formation, Gansii Province, China (Wang 1993);
(Hinde 1890b); grey radiolarites of the Crawford grey radiolarites of the Crawford track, Southern
track, Southern Uplands, this study. Uplands, this study.
GEODIVERSITAS • 1999 • 21 (4) 629
Danelian T.
Fig. 4. — Scanning électron micrographs of radiolaria extracted from cherts of the Southern Uplands. A-D, Inanibigutta diffusa
(Hinde), different views of the same specimen; C-D, view of Internai structure after the Shell was broken with a razor:
E, ? Inanibigutta diffusa (Hinde); F-G, Inanibigutta (?) minuta Wang; H, Inanibigutta sp. cf. /. verrucula (Nazarov): I. Inanibigutta sp.
cf. I. aksakensis (Nazarov); J, Inanibigutta (?) sp. A. Scale bar: A, 82 pm; B, 89,5 pm; C, 106 pm; D, 70 pm; E, 76 pm; F. G, 94 pm;
H, 124 pm; I. 83 pm; J, 129 pm.
630 GEODIVERSITAS • 1999 • 21 (4)
Taxonomy of Ordovician Radiolaria from the S. Uplands
Remarks figs 4-8, pl. 21, fig. 1 (noc 2). - Nazarov & Popov
The observed morphotypes are identical to 1980: 35, 36, text*fig. 15a-b, pl. 3, figs 8, 9, pl. 8,
fig. 6, pl. 1 K figs 8, 9.
Inanibigiitta minuta as described and illustrated
Inanibigutta aksakensis (Nazarov) — Nazarov 1988,
by Wang C1993). They possess nearly spherical
tcxt-lig. 17, pl. 10. fig. 7-8. — Nazarov & Ormiston
outer shellswith nunierous sccondary spines, dis- 1993: 36, pl. 3, fig. 1.
tally tapcring main spines with apophyses in
their proximal pan and both the outer shell and Ot.]CURRENCE. — Grey radiolarites of the Crawford
track, Southern Uplands, this study.
main spines hâve appropriate dimensions. Never-
theless, the attribution of this species to Inanibi'
Remarks
gutta is questionable because in neither the
This morphotype has distally tapcring main
type-series (holotype and paratypes), nor in our
spines, small secondary spines on rhe perforated
material has the exact number of main spines
outer shell and an inner spherical shell (diameter:
cvcr bccn observed.
70 pm approxinvately) comparable lo /. aksaken¬
sis. Howcver, the sizc of the omet shell (diameter
Inanibigiitta sp. cf. L VeiTucula
less than 150 pm) is nearly hall the size ol the
(Nazarov in Nazarov &L Popov, 1976)
larter species. The holotype of L aksakensis in
(Fig. 4H)
Nazarov’s (1975) work is the specimen illustrated
Entactinosphacra verrucula Nazarov in Nazarov & on pl. 21, fig. 1 (see pl. 3, fig. 8 in Nazarov àc
Popov, 1976: 408-409, fig. id. — Nazarov & Popov Popov 1980).
1980: 38-39, texr-fig. 17, pl. 3. fîg. 6, pl. 11, fig. 6.
Inanthigutta verrucula (Na/.arov) — Nazarov 1988,
fig. 31. — Wang 1993: 100, pl. 6, figs 2-3, 5-8.
Inanibigutta (?) sp. A
OcrURRHNCH. — Middle part of the Pingliang (Fig. 4J)
Formation, Gansu Province, China (Wanç, 1993);
grey radiokrites of ihe Crawford track, Southern Occurrence. — Red-brown radiolarites at
Uplajids, thb .siudy. Hawk\vood Biirn, Southern Uplands, this study.
Remarks Description
The illustrated specimen is comparable to /. ver- The outer shell is a nearly perfect sphere perfora¬
rucula as described originally by Nazarov (1976). ted by relarively large circular pores. It also bears
The spherical outer shell (diamcter: 185 pm) is small secondary spines, Two thin rod-like main
perforated by angular to subanguLir pores and spines, positioned along an axis and almost half
bears short conoidal sccondar)'^ spines, as wcll as the length of rhe diameter of the outer shell, dis¬
main spines (length of intact spine: 174 pm). play a few thorn-shaped apophyses,
Mowever, it ddfers as main spines are capering
rather than cylindrical and apophyse.s tend to be Remarks
clustercd ncar the proximal part of the spines. The nature of the thin rod-like main spines dis-
My material rescmbtes Wang s (1993) spccimens tinguishes this morphotype from ail other
in ail respects, d'his species can bc distinguished Tnanigurridae. The exact number of spines and
from L (?) minuta Wang by the larger size of its internai srructurc of the shell are unknown.
outer shell, of diameter usually grcatcr than
180 pm, and by the longer main spines
(> 150 pm).
Genus Inanigutta Nazarov & Ormiston, 1984
Inanibigutta sp.
cf L aksakensis (Nazarov, 1975)
Inanigutta Nazarov & Ormiston, 1984: 72, 86. —
(Fig. 41) Nazarov 1988: 56.
Entactinosphaera aksakensis 1975: 68, pl. 16, Type species. — Entactinia unica Nazarov, 1975.
GEODIVERSITAS • 1999 • 21 (4) 631
Danelian T.
hmnigiitta (?) sp. K ^Oriundogutta 1993
(Fig. 5A) (Fig. 50
OccURKtNCF.. — Grev radiolaritcs of the Crawford ? Oriundogîitta bella Wang, 1993: 101, pl. 9, figs 1-
track, Southern Uplands, this study. 13.
Occurrence. — Grey radiolaritcs of the Crawford
Description
track, Southern Uplands, this study.
Small inaniguttid with six robiist main spines,
four of chem situated on an équatorial plane and
Re.marks
the other two along an axis perpendicular to it.
Alchough only six spines are visible, their distri¬
The four équatorial spincs are themselves posi-
bution and angle on the spherical shell suggests
tioned along two axes, perpendicular to each
that thcir total number is possibly cight.
other. Ail spines are rod-like, gently tapering dis-
tally. Thcir bases are large, perforared and joined
to the outer perforated shell in such a way as to Inaniguttid (?) gen. et sp. indet.
give a bîpyramidal outlinc. No secondary spines (Fig. 5D-E)
are visible on the surface of the outer shell.
Occurrence. — Grey radiolaritcs of the Crawford
track, Southern Uplands, chis study.
Remarks
Uncertainty regarding generic assignement is due
Description
to die unknown internai structure ol this morpho-
.Star-shaped shell, Icnricular in cros.s*secrion, bea-
type.
ring five n»bust conical spines. I be shell is perfo-
raied by numerous pores ol varions sîzcs and
Genus Oriundogutta\^^T.2xov^ 1988 shapes (subangular, oval), Pores near the base of
the spines are disiinctly larger and elongated,
encompassing part ol the spine. The internai
Oriundogutta Nazarov, 1988; 57- - Nazarov & structure is unknown.
Ormiston 1993: 36, text-fig. 7h.
Type SPECIES. — Astroentactinia ramificans Nazarov,
Order ALBAILLELLARIA Deflandre, 1953
1975.
emend. Holdsvvorth, 1969
iOriundopitta riisti Family Ceratoikiscidae Holdsworth, 1969
(Ruedeniann & Wilson, 1936)
(Fig. 5B) Genus P}‘otoceratoikîscum
Goto, Umeda & Ishiga, 1992
? Heliosphaera riisti Ruedemann & Wilson, 1936:
1572, pi, 5. figs 13-^15, 31, pl. 7> % 8. Protoceratoikîscum Goto-, Umeda àc Ishiga, 1992: 165.
? Astroentitetinia ? riisti (Ruedcmanit & Wilson) —
Nazarov ÔC Popov 1980: 46, text-fig. 24, pl. 12, Type SPECIES. — Protoceratoikiscum chinocrystallus
figs 10-11, Goto, Umeda & Ishiga, 1992.
Occurrence. — Red-brown radiolaritcs at Hawk-
wood Burn, Southern Uplands, this snidy. Protoceratoikisctim sp.
aff. P, similistellatum Li, 1995
Remarks (Fig. 5F-G)
The size of the outer shell (diamerer 150 pm
aff. Protoceratoikisctmi similistellatum Li, 1995: 337,
approximately) and the presence of stout and
pl. 2, figs 2, 4.
thinner spines are comparable to O. rüsti.
Doubts regarding taxonomie assignement remain Occurrence. — Grey radiolaritcs of the Crawford
owing to uncertainty about the internai structure. track, Southern Uplands, this study.
632 GEODIVERSITAS • 1999 • 21 (4)
Taxonomy of Ordovician Radiolaria from the S. Uplands
Fig. 5. — Scanning électron nnicrographs of radiolaria extracted from cherts of the Southern Uplands. A. Inanigutîa (?) sp. K;
B. ? Oriundogutta rüsti (Ruedemann & Wilson); C, ? Oriundogutta bella Wang: D E, Inaniguttid (?) gen. et sp. indet.;
F'G, Protoceratoikiscum sp. aff. P. similistellatum. Scale bar: A. 51 pfT»; B. 79 pm; C, 73 pm; D. 65 pm; E, 72 pm; F. 63 pm; G.
66.5 pm.
Description morphotype is comparable to the species descri-
Three to four spincs distributcd radially along a bed by Li (1995). However, it differs in its smal-
semi-circle forrned by rwo to threc rows of arches 1er size and the smallcr angle between adjacent
joining the spincs. Spincs taper gently distally, spincs. Only incomplète .specimens were encount-
but aiso towards the centre very rapidly. ered in the yiclded matcrial.
RE MARKS Acknowledgements
From the presence of arches between spines this Financial support from the Royal Society of
GEODIVERSITAS • 1999 • 21 (4) 633
Danelian T.
Edinburgh (B. P. Granr) is gratefully acknowled- et Géographie, Série de Gétdogie 14 : 45-124.
ged. The author is inosr indebted to E. K. N. Ehrenberg C. G. 1838. — Über die Bildung der
Rreidefclscn ünd des KreidemergcLs durch unsichr-
Clarksoii for having iatroduced him to the stu-
bare Organi.srncn. Abhandlungen der Koniglichen
died outcrops and J. Floyd for discussion on the
Akaderme des Wissenschaften in Berlirr. 59-147.
geolog)' of the scudied areas. Many rhanks also ro — 1857. — Über die organischen Lcbcn.storincn în
J. C. Aicchison and fi J. Noble for hcipfui coiti- unerw'artet grossen Fiefen des Mittelmeeres.
ments on the manuscript, S. Zatsepin for hclp Koniglich Preiissisthc Akadcmic der Wissenschaften
zii Berlin: 538-570.
with translation of Russian liierature and M. Lee
l'loyd J. D. 1996. — Lithostracigraphy of the
for helpfui advice and assistance with SEM
Ordovician rocks in the Southern Uplands;
images. This is a contribution to IGCP No. 410 Crawford Group. Moffai Shale Group. Leadhills
“The Great Ordovician Biodiversification Supergroup. Transaettons of the Royal Society of
Event”. liatnhwgh: Earth Sciences 86: 153-165.
Fortey R. A. îR Holdsworrh B. K. 1971. — The
oldest known wcll preserved Radiolaria. Bollettirio
délia Sücicta Paleontvlôgiça Italiana I U: 35-41,
REFERENCES fortey R. A.» Flarpcr D. A. T., Ijigham ). K., Owcn
A. W. & Riisheon A. W A. 1995. — A révision of
Aitchison J. C. 1998. — A new Lovvrr Ordovician Ordovician sc-iles and stages from the hisrorical
(Arenigian) radiolarian fauna from the Ballantrac type area. Geolo^calMagttzine \}il: 15-30.
Complex, Scorland. Scottish journal of Geolog' 34: Goto H.. Umeda M. ik Ishiga If. 1992. — Late
73-81. Ordovician Radiolarians from the Fachlan Fold
Aitchison J. C. & Noble P. J. !997. — Early Belr, Southea.stern Ausrralia. Memoirs ofthe Famlty
Palaeozoic radiolarian biosrracigraphy. Inter- of Sciences, Shhmne Univcrsiiy 1G\ 145-170,
Rad VIII, ParisIBiervillt, 8-!} Septembtr 1997. Flindc CF J. 1890a. — Speeimen.s and microseopic
Abstract volume'. 7. sections ot Radiolarian Chert from the (Ordovician
Aitchison J. C., Flood P. G. i!c Malp.is J. 1998. — strata (= l.landeilo-Catrailoc) of the Southern
Lowermost Ordovician (ha.sal Trenudoc) radiolar- Uplands of S'coiland. Journal of the Gcological
ians from the Little Port Complex, western Society, Proceedin^: 111, 112.
Newfoundland. Gcolo^ical Maçifzine 135 (3): — 1890b. — Noies on Radiolaria from rhe Lower
413-419. Palaeozoic rocks (Llandcilo-Caradoc) of the South
Armstrong Fl. A., (Jarkson F- N. K. & Owcn A. W. of Scotland. Annals and Magazine of Natural
199(1. — A new Power Ordovician conodonr fau- Ilhtory. 40-59.
nule from the Northern Belr of the Southern ! lüldswoi'th B. K. 1969. — Namuriati Radiolaria of
Uplands. Scottîsh Journal of Geolog 26: 47-52. (hc gciiuv Ceratoikhtum from Staffordshire and
Armstrong FI. A.. Owcn A. W., Sennton C. T., 19erby.sbire, England. Micropaleontology 15:
Clarkson E. N. K. & Taylor C. M. 1996. — 221-229.
Evolutitin of the Noi thern Bc|t» Southern Uplands: Li H. 1995. — New gcncra and spccics of Middic
implications for ihe Southern IJpl.mds conrroversy. Ordovician Nassellaria and Albaillellaria from
JourPialof the GeologkaI Society 153 ) 97-205. Batjingsit Qüan mountains. China. Sdentia
Clarkson E- N- K., Fiatper D. À. T., Owcn A, W. &: Gcologica Sintca 4: 331 -346.
Tayli>r C. M. 1993. — Biggar: 180-191, in Lcggett j. K. 1978. — Eustacy and pelagk régimes in
McAdam A. 19., Clarkson E. N. K. & Sione P. the lapeius Océan during che Ordovician and
(eds), Scottish Borders Geology. Scottish Academie Silurian. Farth and Planciary Science Letters 41:
Press, Edinburgh.- 16.3-169.
Danelian T. & Clarkson E. N. K. 1998. — — 1987. — The Southern Uplands as an accrc-tionary
Ordovician radiolaria from hedded chert.s of the prism: the importance of analogues m reconsrruc-
Southern Llplands. Scottish journal of Gcoloiçy ring palaeogeograpliy. Journal of the Geological
34(2): 133-134. Society^ London 144: '^37-752.
Deflanda- G. 1953. — Radiulaircs fossiles: 390-436, in l.eggcrr J. K. tR ('a.scy D. M. 1982. — The Southern
Grasse P. P. (ed.). Traite de Zoologie Anatomie, Uplands Accrerionary l'risnt: Implications for
Systérmtîique, Biologie^ Volume I (2). Masson. Paris. Controls on ^rructural development of subduction
Dong X., Knoil A. H. & l.ipps J. H. 1997. — Latc complexes, m Wattkins J. S. &: Drake C. L. (eds),
Cambrian Radiolaria from Hunan journal Stutlies in Continental Margin Geology, Memoirs
ofPnleon(ologyl\ (5l: 753-758. of the American Association of Petroleum Ceologists
Dumitrica P. 19*^0. — Crj'plocephalif and crypto- 34: 377-393.
thoracic Nassellaria in some Mesozoic deposits of McAdam A. D, Clarkson E. N. K. & Stone P.
Romania. Revue Roumaine de Géologie, Géophysique 1993. — Scottish Borders Geology. Scottish
634 GEODIVERSITAS • 1999 • 21 (4)