鹭。tage。。，，。。。ev。nia。。ystem by W . Ziegler and G ．K lapper Th e S ubc om m is sio n on D ev on ian S tr at ig rap h y h a s f orm a ll y ag re ed up on th e n om en c la tu re f or sev en S tan d ard S t ag es o f th e D e von ian S ys tem . A ba sa l b oun d ar y str a to typ e is d e scr ib ed in th i s ar ti c le f or th e E if e lian S t ag e , c o in ci de n t wi th th e b as e of th e M idd l e D evon i an S er i es . C r it er ia f or r ec ogn i zin g a Givetian-Frasnian Stage boundary （＝base of Upper M O D e von ian Se ri es ) an d a F ra sn i an -F am enn i an S ta ge bo un d ar y are al so o u tl in ed ． F u tu re w ork wi ll c om - p le te th e d ef in it ion o f ba sa l b oun d ar y st ra to t yp es f o r e a c h S t a g e . In trod uc tio n A nnual m eetings of the Subcom m ission on D evonian Stra- tigraphy (SD S) have been held since its foundation in 1973, w ith im portant decisions sum m arized here on stratigraphic standards being m ade in 1979, 1981, 1982 and 1983; these have now been form ally ratified by lU G S. E ach of these m eetings, associated w ith field excursions to the D evonian of m any countries, stim ulated a w ealth of D evonian research throughout the w orld. A n earlier account in Episodes (Ziegler and K lapper, 1982) sum m arized the SD S decisions then taken; certain diagram s in that paper are repeated here so as to m a ke this a cc ou nt se lf-co n ta in ed . D evonian Stage N am es T he agreed Stage nam es of the D evonian System (see accom panying article by Bassett) are as follow s: U pper D evonian 一 F am ennian 一 F rasn ia n M id dle D e von ian 一 G iv etia n 一 E if e lia n L o w e r D e v o n ia n 一 E m s ia n 一 Pragian 一 L o c h k o v i a n W ith the exception of the low er lim it of the Lochkovian 厂厂帐 Stage, w hich coincides w ith the low er boundary of the D evonian System (M cLaren, 1973), all the Low er D evonian 二丈 stages still aw ait new boundary definitions. The decision on the nom enclature of the D evonian stages also contains the sta te m en t tha t th e cla ssic a reas of the L ow er D e vo n ia n in the A rdenno-R henish R egion (B elgium 一W est G erm any) are no longer acceptable as satisfactory for L ow er D evonian 吓 stage boundaries. D ecisions on the low er levels of the Pragian and Em sian stages w ill be based on different regions W P 1 7 3 七 in the next few years. 1 2 0 } T he decision on the L ow er-M iddle D evonian Series boundary (see below ) also em phasizes the fact that E ifelian is the nam e 一奋嚓票 of the first M iddle D evonian stage. T he low er level of the } - p " 1 - 刃 G ivetian Stage needs further studies prior to its form al W P 1 d e fin itio n . F ig ur e 1 ： L oc al i ty m a ps of th e si t e o f th e boundary stratotyp e of the pa些些U三-boundary at the W et te lda rf R ich tsch n i tt , E i fe l Hi ll s , F .R .G . B o tto m s ec tio n sh ow s si te of o l d t ren ch e s （＝ so li d b la ck l in e ) an d 19 82 tr en ch （＝ p ar a lle l lin e w ith h a tc he s a t b o th en d s ) ； WP 1 -1 73 ＝ m e as ur ed un i ts ; d a sh ed oblique line between patulus Zone and partitus Zone ＝ 〕 5 0 1 0 O } Lo we r -Mi dd le D e von i an S er ie s B o und ar y . H . -F m . ＝ ． · ， r 一 。 I He is do rf F orm a ti on , W .-Fm . ＝ W et te ld ar f Fo rm a tion . 1 0 4 Episodes, Vol. 8, N o. 2, June 1985 目 山 卜 曰 O e 拭 O 囚 t } M . 1 ,t } , - d - t , H 2 s e l} ted g c n 旧fi t. } 目 0 山 卜 厂一一一－ ｝— 11 ｝ The low er lim it of the U pper D evonian Series coincides w ith 工 叭 沪 击 1 囚 黔 。n 三 生 乏 叻 U o’u 。 的 一 刁 ． 了 ﹂ 二 ︸ n the low er lim it of the Frasnian Stage; the definition of 0 一 细 气 臼0 ～ ，湘 D ‘ ‘‘︸ rL 沪 ︸ 0 曰 0‘ 口si ‘ 山 D ， ﹄1 二 ‘ e chronostratigraphic level is discussed in the follow ing. T he 的 ︺ 的刃 。 l 1” 川 一﹂ 搜 n Q． 。︾ 哎 “ 艺﹄ U了 于 匕 low er lim it of the second U pper D evonian Stage, the 山 了sir D O 峨 dl ，引 江 U 酬引 一－ 乞 F am ennian Stage is also new ly defined. 詹 L O W E R - M ID D L E D E V O N IA N S E R IE S B O U N D A R Y 扛 D e fin it io n 一 的 奉 乳 价1 门 The boundary betw een the L ow er and M iddle D evonian Series u ‘ 1 川 己 0 以 ︸ ， 注 全 0 户 曰 is coincident w ith the low er boundary of the Eifelian Stage. o ︸ 。 叨 少 ︸ n 川 U 。 们 曰 The exact boundary level is chosen to coincide w ith the first 叼 ‘今0 屯 ，︺1 品 ． 们 岁 o 触 几 ， 0 五r oc cu rren ce o f th e co no do n t c o st a tu s a 邵曰 司 阔 6 盯。〔e 「。一仲5 0 「0 ‘ partitus 引刽 川 o 甲 户 u 0夏：｛ M a s h k o v a l 动 峋 圈 K lapper, Ziegler and boundary). 0一 州川 一1 引 江 层～ 全1 升 叻 This stratigraphic level is the low er lim it of the partitu 。 u 到 四 ，的 ︶ 创 ‘刻 叶 口 引 国 中。 Zone, a zonal subdivision of the conodont standard zonation ，1 里 ︸ 引 叭 。1 ． 柑 山 1 ﹄ 击 。 田弓 目 1 叹 －1 ． 的J ﹄一 ︺ 为今 目 D that w as established during the 1970s (K Iapper, 1971; ｜十 u n u es 。︸︸ 。曰 o ﹃ U 叫 只n U 明 ～ W eddige and Ziegler, 1977; W eddige, 1977; W eddige et al., u D 川 － ‘ 工护 争‘ ‘ 注 团 ， 舒 ︺ ，比 份 二 ． U 川 箱曰 ‘ D ‘ 一 1979; K lapper et al., 1978; K lapper and Ziegler, 1979). D 一51 1 D u 民 1 工 浇‘ ︸ 们 U － 叭 a l 戏 ︺ ‘ ‘ 的 ． 仍 仍 户 户1 ‘ 识 0 ︸ 乳︸ Boundary Stratotype 州c 一 仁 u 石 艺︹ 曰 哑 r ‘～ ， u es es The holostratotype of the 巴些 tus boundary is in the section 。 飞 曰乳 ． F 扩 es exposed in the W etteldorf R ichtschnitt, near the tow n of es L ︸ Schbneeken-W etteldorf, Eifel H ills, Federal R epublic of 日 m Fi g u re 3 : P a ra st ra to t yp e co l um n a r sec ti on o f 石o w e r - m i d d l e D evo n ian S er ie s B o un da ry , a t Pr as ta v q u a r r y , n ea r P r ag ue , Cz ech o s lo vak ia ． N umb er ed in ter va l s ar e b e d s 。 n的 nl G erm any (Schdriecken m apsheet 1:25000, r 33 765 h 57 130; 7 0 l d门 1 see F ig. 1). T he R ichtschnitt section is in a trench that w as o工 n的 u L ib ra 土 ︸ 之 first dug in 1937 (R . R ichter, 1942; G . Solle, 1942) follow ing 1门 － 的 q二 an interna tio na l co n fe re nc e h eld in D iisseldo rf on the L o w er- uo 明 的 的 的 un ． M iddle D evonian Series boundary.