Berthierine in the Mid dle Ju ras sic si der it ic rocks from south ern Po land
Aleksandra KOZŁOWSKA1, * and Anna MALISZEWSKA1
1 Pol ish Geo log i cal In sti tute – Na tional Re search In sti tute, Rakowiecka 4, 00-975 Warszawa, Po land,
Kozłowska, A., Maliszewska, A., 2015. Berthierine in the Mid dle Ju ras sic si der it ic rocks from south ern Po land. Geo log i cal Quar terly, 59 (3): 551–564, doi: 10.7306/gq.1231
A char ac ter is tic green and yel low-brown clay min eral from si der it ic rocks was stud ied from 14 bore holes pen e trat ing the Mid - dle Ju ras sic strata of the northeast ern mar gin of the Holy Cross Moun tains and Częstochowa re gion, us ing po lar iz ing and scan ning elec tron mi cro scopes, cathodoluminescence and X-ray anal y sis and re veal ing the pres ence of berthierine. In these si der it ic rocks, berthierine oc curs mainly in Lower and Mid dle Bathonian strata de pos ited in shoreface and deltaic en vi - ron ments of the northeast ern mar gin of the Holy Cross Moun tains, and in Up per Bajocian de pos its of both ar eas stud ied. It forms the clay ce ment of si der it ic rocks, fills voids in bioclasts and is also pres ent in ooids. Ooids con sist ing of berthierine have been af fected by me chan i cal com pac tion and mainly car bon ate re place ment. Berthierine ooids, re placed by sideroplesite, pistomesite, Fe-cal cite or an ker ite, and rarely by py rite and al tered by kaolinite, oc cur com monly. Berthierine ooids of the Bathonian si der it ic rocks are typ i cally better pre served, com pared to those from the Bajocian and Aalenian.
Berthierine crys tal lised in the eodiagenesis stage in suboxic con di tions be low the wa ter-sed i ment in ter face, where iron-bear - ing fresh wa ter mixed with sea wa ter. It is chem i cally and struc tur ally un sta ble and, dur ing the mesodiagenetic stage at higher tem per a tures, could trans form to chamosite by recrystallisation.
Key words: berthierine, si der it ic rocks, Mid dle Ju ras sic, Holy Cross Moun tains, Częstochowa re gion.
INTRODUCTION
Berthierine is a 1:1 layer fer rous-fer ric alu mi no sili cate from the ser pen tine sub group (Brindley and Brown, 1984). Its chem i - cal com po si tion is iden ti cal to that of iron-rich leptochlorite, com monly re ferred to as chamosite. It may also be sim i lar to the com po si tion of an other iron alu mi no sili cate – odinite (Horni - brook and Longstaffe, 1996). Berthierine (like chamosite) is gen er ally con sid ered to be char ac ter is tic of ma rine de pos its (Tay lor and Curtis, 1995; Ryan and Hill ier, 2002; Tay lor et al., 2002), al though it has also been re ported in de pos its of brack - ish bas ins (Tay lor, 1990), in laterites (Fritz and Toth, 1997), and even in hy dro ther mal de pos its (Rivas-Sanchez et al., 2006).
Hy poth e ses con cern ing the gen e sis of berthierine are based on the source of iron. The po ten tial sources for the iron might be:
weath er ing (see Young and Tay lor, 1989), vol ca nism (Dreesen, 1989; Kimberley, 1994; Sturesson et al., 2000; García-Frank et al., 2012) or hy dro ther mal pro cesses (Rivas-Sanchez et al., 2006). Some au thors think that berthierine is an early dia - genetic min eral (e.g., Young, 1989; Tay lor and Curtis, 1995), and oth ers sug gest that one model of berthierine for ma tion does not nec es sar ily ex clude the other (e.g., Young, 1989;
Reolid et al., 2008).
Berthierine can be con sid ered a geothermometer. The ex - per i ments of Hornibrook and Longstaffe (1996), car ried out on berthierine from Lower Cre ta ceous oil-bear ing sands of the Clearwater For ma tion, Al berta, Can ada, have shown that it crys tal lised from fresh or brack ish wa ters at a tem per a ture of 25–45°C in the early diagenetic stage. Berthierine can trans - form to chamosite at 70°C, and is com monly con sid ered its pre - cur sor (e.g., Iijima and Matsumoto, 1982; Longstaffe and Ayalon, 1987). Re place ment of berthierine by chamosite can thus point to a >70°C tem per a ture dur ing diagenetic al ter ation in sed i men tary rocks (Velde, 1995; Hornibrook and Longstaffe, 1996; Meunier, 2005).
The aim of the study was to de ter mine the phase com po si - tion of a green or yel low-brown clay min eral found in Aalenian to Bathonian si der it ic, siliciclastic rocks of Po land. Cus tom arily, it has been called chamosite. In the de scrip tion of si der it ic coquinas from the Łęczyca-Kłodawa re gion (Cen tral Po land;
Fig. 1), Turnau-Morawska (1961) sug gested that the green clay min eral may be chamosite, turingite or berthierine in com po si - tion. In the early stud ies of these si der it ic rocks (Maliszewska et al., 2005, 2006), the green min eral was pro vi sion ally called chamosite, but sub se quently was iden ti fied as berthierine (Maliszewska et al., 2007). In this pa per we de scribe the oc cur - rence of berthierine in a range of re cently stud ied Mid dle Ju ras - sic si der it ic rocks in south ern Po land, and sug gest its pos si ble gen e sis. The re sults of our ob ser va tions us ing po lar iz ing mi cro - scope, cathodoluminescence, and XRD and SEM-EDS anal y - ses are aimed at the ques tion: is the oc cur rence of berthierine in these Mid dle Ju ras sic de pos its re lated to a spe cific depositional en vi ron ment and/or pe riod of time?
* Corresponding author, e-mail: aleksandra.kozlowska@pgi.gov.pl Received: November 22, 2014; accepted: March 26, 2015; first published online: May 15, 2015
GEOLOGICAL SETTING
The study con cerns Mid dle Ju ras sic rocks from the south - ern part of the Pol ish epicontinental ba sin (Fig. 1), which was the east ern arm of the Cen tral Eu ro pean Ba sin Sys tem (Pieńkowski et al., 2008). The Pol ish Ba sin was sur rounded from the north-east and south-west by lands that served as a source area for clastic ma te rial (Feldman-Olszewska, 1997, 1998).
Lithological-strati graphi cal stud ies of the Ju ras sic suc ces - sion in the south east ern mar gin of the Holy Cross Moun tains, which be gan be fore World War II (e.g., Passendorfer, 1927, 1928; Kuźniar, 1928; Samsonowicz, 1932), pro vided much new data af ter the War, thanks to, among oth ers, work by Kobyłecki (1948), Cieśla (1958) and Daniec (1963, 1970). The great est thick nesses of Mid dle Ju ras sic de pos its of about 800 m were found on the north ern part of the mar gin. It de creases to wards the south-east to ap prox i mately 180 m in the Wyszmontów re - gion (Daniec, 1970). These are mainly Aalenian, Bajocian and Bathonian de pos its rep re sented by sand stones and mudstones with interbeds of claystone and si der it ic iron ore (Fig. 2A). The Callovian de pos its, about 20 m thick, are com posed of car bon - ate and car bon ate-si li ceous de pos its.
Lithological-strati graphi cal stud ies of Mid dle Ju ras sic rocks in the Częstochowa re gion be gan in the late 19th cen tury (fide
Kopik and Marcinkiewicz, 1997) and con tin ued in the 20th cen - tury (Kopik and Marcinkiewicz, 1997). The thick ness of the Mid - dle Ju ras sic in the Częstochowa re gion is about 184 m in the north ern area, and it de creases to ap prox i mately 85 m in the south (Kopik, 1998). The lithological sec tion is rep re sented largely by Bajocian and Bathonian sandy claystones and mud - stones lo cally con tain ing dark claystones with sid er ite, cus tom - arily re ferred to as ore-bear ing clays (Kopik, 1998; Fig. 2B). The Callovian is only sev eral metres thick and is rep re sented by sandy-car bon ate de pos its. In the last few years, much new in - for ma tion on the sed i men tary con di tions and en vi ron ments has been pro vided by the re sults of petrographic and litholo - gical-strati graphi cal stud ies (Gedl et. al., 2006) as well as by geo chem i cal anal y ses per formed by Marynowski et al. (2007), Szczepanik et al. (2007), Wierzbowski and Joachimski (2007) and Zatoń et al. (2009). The sed i men tary struc tures in these de - pos its (in clud ing storm-gen er ated struc tures) have been de - scribed by Leonowicz (2012, 2013). The mech a nism of the for - ma tion of sid er ite and phos phate con cre tions in the ore-bear ing clays from Gnaszyn (dis trict of Częstochowa) with re gard to sed i men tary con di tions and diagenetic pro cesses was stud ied by Witkowska (2012).
The dif fer ence in the thick ness of Mid dle Ju ras sic de pos its be tween these two ar eas re sults from their palaeogeographic po si tion within the epicontinental ba sin. It is thought that the north east ern mar gin of the Holy Cross Moun tains oc cu pied its Fig. 1. Lo ca tion map of the bore holes in cluded in this study
Grey poly gon – ex tent of the Mid dle Ju ras sic in Po land af ter Lott et al. (2010)
cen tral part, whereas the Częstochowa re gion lay in its mar - ginal part (Feldman-Olszewska, 1998).
Cur rently, we have fo cused on min er al og i cal-petrographic in ves ti ga tions of clayey siderites and si der it ic sand stones, and partly also si der it ic con glom er ates and coquinas, con tain ing a va ri ety of coated grains and berthierine, due to their com plex and in ter est ing gen e sis. Ac cord ing to Feldman-Olszewska (pers. comm., 2013), these rocks rep re sent var i ous Mid dle Ju -
ras sic sed i men tary en vi ron ments, in clud ing: off shore, tran si tion zone, shoreface, deltaic and estuarine en vi ron ments and spo - rad i cally, car bon ate ramp and Aalenian flu vial en vi ron ments (Ta bles 1–4). Sid er ite lay ers and con cre tions, and si der it ic sand stones are ob served mainly in the Aalenian, Bajocian and Bathonian rocks of the north east ern mar gin of the Holy Cross Moun tains and in the Bajocian and Bathonian rocks of the Częstochowa re gion (Fig. 2).
Fig. 2. Stra tig ra phy of the Mid dle Ju ras sic de pos its from: A – north east ern mar gin of the Holy Cross Moun tains (af - ter Daniec, 1970) with lithological pro file of the Gutwin bore hole (af ter Feldman-Olszewska, pers. comm., 2008), and B – Częstochowa re gion (af ter Kopik, 1998) with lithological pro file of the Łutowiec 135Ż bore hole (af ter Feldman-Olszewska, pers. comm., 2013)
MATERIAL AND METHODS
The rock sam ples stud ied orig i nated from 14 bore holes drilled along the north east ern mar gin of the Holy Cross Moun - tains and in the Częstochowa re gion (Fig. 1) in the pe riod 1955–1989. The bore holes were drilled for iron ore min ing in both ar eas, where in ten sive min ing de vel op ment dates from the 17th cen tury and came to an end in the 1980s.
Rock sam ples were col lected from all si der it ic interlayers and con cre tions that were found in the bore holes in ves ti gated.
A to tal num ber of 276 thin sec tions was made, which were stud - ied us ing a po lar iz ing mi cro scope Nikon Eclipse LV 100 Pol.
De tailed anal y sis was per formed on 82 thin sec tions of si der it ic rocks in which berthierine was iden ti fied (Ta bles 1–4). The de -
scrip tion of coated grains is based on a scheme used by Turnau-Morawska (1961) and the def i ni tion of Flügel (2010), ac cord ing, with some mod i fi ca tions, to the clas si fi ca tion of coated grains by Kears ley (1989). Thin sec tions were stained with the Evamy’s so lu tion to iden tify car bon ate min er als. Seven sam ples con tain ing cal cite or an ker ite were sub jected to catho - do luminescence anal y sis us ing the so-called “cold cath o de”, CITL MK5 type from Cam bridge Im age Tech nol ogy Ltd.
The min er al og i cal com po si tion of the <2 µm frac tion of the sed i ment (clay min er als) from 10 sam ples (Ta ble 5) was de ter - mined by X-ray dif frac tion anal y sis us ing a Philips X’Pert PW 3020 diffractometer (Cu Ka ra di a tion and semi con duc tor de tec - tor). Sam ples were crushed and ground to ob tain par ti cles of less than 0.063 mm in size. The anal y sis was per formed on ori - ented air-dried sam ples, which were sub se quently glycolized Clayey sid er ite sam ples con tain ing berthierine
Area Bore hole Depth
[m] Age Berth.
ce ment Bert.
ooids Other ooids
Sec ond ary min er als
in ooids
Per cent age of ooids
in rock [vol.%]
Method
Northeast ern mar gin of the Holy Cross Moun - tains
Gutwin 191.1 Bj2 + Sd 2.0 PL
Justynów PIG 1 20.3 Bj2(?) + + Sd, Kl 1.0 PL
Mniszków IG 1
958.0 Bt1-2 + + + Ak 1.0 PL
959.5 Bt1-2 + + + Sd 0.7 PL
961.0 Bt1-2 + + + Sd 1.0 PL, X-ray
Mołdawa 274.1 Bj2 + + Sd 3.0 PL, SEM
401.3 Bj2 + + + Sd 0.3 PL
Omięcin XI/2
36.0 Bj2 + + Sd, Kl tr PL
67.7–68.2 Bj2 + + Sd 1.7 PL
116.0–116.2 Aa1? + + Sd, Pt 0.7 PL
Omięcin XI/3 132.2 Bj2 + + Sd 1.7 PL
184.4 Bj2 + + Sd tr PL
Wąglany k/Opoczna
395.2 Bt1-2 + + Sd, Ca 18.0 PL, SEM
412.4 Bt1-2 + + Sd, Ca 1.7 PL, SEM
597.2 Aa1 + + Pt, Kl 9.3 PL, SEM
Wyszmontów 1 80.5 Bt1-2 + + Sd 11.0 PL, SEM
129.3 Bj2 + + Ca 1.0 PL
Częstochowa re gion
Biskupice 25BN
58.1 Bt3 + + + Sd, Ca, Py 6.0 PL
132.4 Bt1 + + Sd 1.0 PL
190.1 Bj2 + + + Sd, Kl 1.0 PL, SEM
190.6 Bj2 + + + Sd, Kl 2.0 PL
Łutowiec 135Ż 178.9 Bj1 + + + Sd 2.0 PL, SEM
Parkoszowice 58BN
34.5 Bt3 + + Ca, Sd 3.3 PL, SEM
101.0 Bj2 + + Ca, Ak 15.0 PL, SEM, CL
101.2 Bj2 + + Sd, Ca, Ak 25.0 PL
104.1 Bj2 + + Sd 15.0 PL, SEM
Zrębice 33BN 297.8 Bt1 + + Sd, Ca, Py 2.7 PL, CL
353.4 Bj2 + PL
Aa1 – Lower Aalenian, Cl – Callovian, Aa2 – Up per Aalenian, Bj1 – Lower Bajocian, Bj2 – Up per Bajocian, Bt1 – Lower Bathonian, Bt2 – Mid - dle Bathonian, Bt3 – Up per Bathonian; Ak – an ker ite, Ca – cal cite, Kl – kaolinite, Sd – sideroplesite, Pt – pistomesite, Py – py rite; tr – trace;
PL – po lar iz ing mi cro scope; SEM – scan ning elec tron mi cro scope; CL – cathodoluminescence; X-ray – X-ray dif frac tion anal y sis; * – no berthierine, chlorite pres ent
En vi ron ments
off shore tran si tion zone shoreface deltaic es tu ary car bon ate ramp flu vial
T a b l e 2 Si der it ic sand stone sam ples con tain ing berthierine
Area Bore hole Depth
[m] Age Berth.
ce ment Berth.
ooids Other ooids
Sec ond ary min er als
in ooids
Per cent age of ooids
in rock [vol.%]
Method
North east ern mar gin of the Holy Cross Moun tains
Gutwin
124.2 Bt1-2 + + 4.4 PL, X-ray, SEM
167.6 Bj2 + + 1.3 PL
191.5 Bj2 + + Sd 3.0 PL
Mniszków IG 1 962.0 Bt1-2 + + tr PL
Mołdawa
73.2 Bt3-Cl + + 3.0 PL
94.9 Bt2-3 + + tr. PL
109.0 Bt1-2 + + 2.3 PL
113.4 Bt1-2 + + + Ak, Py 1.7 PL
123.6 Bt1-2 + + 10.7 PL
168.7 Bt1-2 + + Ca tr PL
208.0 Bt1-2 + + + Sd, Ca 1.7 PL, X-ray
216.7 Bt1-2 + + + Sd 0.7 PL
229.6 Bt1-2 + PL
250.75 Bt1-2 + + + Sd, Ak 44.7 PL, CL
281.5 Bj2 + + + Ca, Sd, Kl 3.3 PL
308.0 Bj2 + + Sd 17.0 PL
313.4 Bj2 + + Sd, Pt, Kl 5.4 PL
321.8 Bj2 + + + Sd, Pt 7.3 PL
347.0 Bj2 + + Ak, Kl 6.7 PL, CL
352.0 Bj2 + + Ak 0.3 PL
354.3 Bj2 + Sd 0.7 PL, SEM
387.7 Bj2 + + + Ak 55.7 PL
Omięcin XI/2
77.9–78.9 Bj2 + + Sd 0.7 PL
104.4 Bt1-2 * PL, X-ray
105.4 Bt1-2 + + + Ca 1.3 PL
172.9 Bj2 + + + Ca, Ak 3.0 PL, X-ray, SEM
202.9 Bj1 + + + Ca, Kl, Ak 0.3 PL
225.0 Aa1? + + Sd 4.3 PL
Wąglany k/Opoczna
482.7 Bj2 + + Py, Kl, Sd 4.0 PL
643.8 Aa1 + + Pt 5.3 PL, SEM
Władysław 166.8 Bt1-2 + + tr PL
200.5 Bt1-2 + + + Ca 3.7 PL, SEM
Wyszmontów 1 91.6 Bj2 + + Ca 16.7 PL
Zalesie Antoniowskie
278.5 Aa2 + + Kl, Py 24.3 PL, X-ray
279.3 Aa2 + + Kl, Py 16.0 PL
Area Bore hole Depth
[m] Age Berth.
ce ment Berth.
ooids Other ooids
Sec ond ary min er als
in ooids
Per cent age of ooids
in rock [vol.%]
Method
Częstochowa re gion
Biskupice 25BN
190.1 Bj2 + + + Sd, Kl tr PL, SEM
190.6 Bj2 + + + Sd 2.0 PL
192.4 Bj2 + + 3.0 PL, X-ray
199.1 Bj2 + + 0.7 PL
Łutowiec 135Ż
172.6 Bj2 + + Sd, Kl, Ak 3.0 PL, SEM, CL
180.6 Bj1 + + 6.3 PL, X-ray, SEM
183.5 Bj1 + + 1.7 Pl
Zrębice 33BN
301.2 Bt1 + + + Ca 1.0 PL
307.7 Bt1 + PL
353.95 Bj2 + + + Kl, Sd 2.0 PL
355.0 Bj2 + + 1.0 PL, X-ray
372.7 Bj2 + + + Sd 0.3 PL, SEM
For ex pla na tions see Ta ble 1
and heated at 550°C. They were stud ied in an gu lar range 1–26°2q (Figs. 3 and 4).
The chem i cal com po si tion of clay min er als was de ter mined on four car bon-cov ered thin sec tions us ing a LEO scan ning elec tron mi cro scope (SEM) with en ergy dispersive X-ray an a - lyzer (Ta ble 6). Ad di tion ally, the chem i cal com po si tion of car - bon ate min er als was de ter mined on 15 sam ples. Back-scat - tered elec tron im ages (BSE) were also made.
RESULTS
Berthierine was iden ti fied in clayey siderites, si der it ic sand - stones and con glom er ates, and also in two co quina sam ples.
This min eral mainly com prises ooids but also oc curs as the ce - ment and fills voids in bioclasts (Fig. 5). Sid er ite, which is the main com po nent of the si der it ic rocks, is rep re sented mostly by its Mg-rich va ri ety – sideroplesite, rarely pistomesite; pure sid - er ite is also pres ent (Kozłowska et al., 2008, 2011, 2013).
CLAYEY SIDERITES (TABLE 1)
The main com po nent of the clayey siderites is sideroplesite in the form of micrite and microspar, or oc ca sion ally as spar.
Clay pelite, silt-sized and sand-sized quartz grains, to gether with Fe-cal cite and an ker ite oc cur in vary ing amounts. The per - cent age of clay pelite, lo cally im preg nated by or ganic mat ter or Si der it ic co quina sam ples con tain ing berthierine
Area Bore hole Depth
[m] Age Berth.
ce ment Berth.
ooids Other ooids
Sec ond ary min er als
in ooids
Per cent age of ooids
in rock [vol.%]
Method
Northeast ern mar gin of the
Holy Cross Moun tains Władysław 157.5 Bt1-2 + + Sd, Ca 2.3 PL, CL
194.0 Bt1-2 + + + Ca 2.3 PL, X-ray, CL
For ex pla na tions see Ta ble 1
T a b l e 4 Si der it ic con glom er ate sam ples con tain ing berthierine
Area Bore hole Depth
[m] Age Berth.
ce ment Berth.
ooids Other ooids
Sec ond ary min er als in
ooids
Per cent age of ooids
in rock [vol.%]
Method
Northeast ern mar gin of the Holy Cross Moun tains
Justynów PIG 1 26.0 BJ2 (?) + + + Ca tr PL
Mołdawa
153.1 Bt1-2 + + + Ca 1.0 PL
303.9 Bj2 + + + Ca, Sd 4.0 PL
326.6 Bj2 + + Ca, Kl 18.7 PL
Omięcin XI/3 109.1 Bt1-2 + + + Ca 2.0 PL
For ex pla na tions see Ta ble 1
T a b l e 5 Re sults of X-ray dif frac tion anal y sis of se lected sam ples
Area Bore hole Depth
[m] Age Rock type Clay frac tion
North east ern mar gin of the Holy Cross Moun tains
Berthierine Kaolinite Illite Chlorite
Gutwin 124.2 Bt1-2 si der it ic sand stone + + – –
Mniszków IG 1 961.0 Bt1-2 clayey si der it ic + + + –
Mołdawa 208.0 Bt1-2 si der it ic sand stone + + – –
Omięcin XI/3 104.4 Bt1-2 si der it ic sand stone – + + +
172.9 Bj2 si der it ic sand stone + + – –
Władysław 194.0 Bt1-2 si der it ic co quina + – – –
Zalesie Antoniowskie 278.5 Aa2 si der it ic sand stone – + – –
Częstochowa re gion
Biskupice 25BN 192.4 Bj2 si der it ic sand stone + – – –
Łutowiec 135Ż 180.6 Bj1 si der it ic sand stone + – + –
Zrębice 33B 355.0 Bj2 si der it ic sand stone + – – –
For ex pla na tions see Ta ble 1
iron hy drox ides, var ies from 0 to 30%. Clay min er als oc cur ring in the form of colour less, very fine, low-birefringent flakes are rep re sented mainly by kaolinite. Green and yel low ag gre gates of clay min er als have been rec og nized as berthierine and illite.
The mi cro scopic ob ser va tions have been con firmed by X-ray stud ies (Ta ble 5 and Fig. 3). On the XRD pat tern, berthierine is a min eral char ac ter ized by an in tense re flec tion at 7.05 and two re flec tions of lesser in ten sity at 4.66 and 3.52 (Stoch, 1974). In con trast, chlorites are re cog nised by the basal re flec - tion at 14.0–14.3. Low-iron va ri et ies are char ac ter ized by the
basal re flec tions of the first five or ders with strong or me dium in - ten sity. High-iron chlorites are char ac ter ized by the pres ence of strong re flec tions at 7.09 and 3.53, and rel a tively weak re flec - tions at 14.25, 4.73 and 2.84 (Stoch, 1974; Wil son, 1987). Ac - ces sory com po nents in clude feld spar grains, mica flakes, zir - con, py rite, he ma tite and or ganic mat ter. Calcitic, lo cally pyritized fau nal frag ments (bi valves, brachi o pods, gas tro pods, echinoderms and foraminifers) are com mon. Iron-rich, car bon - ate and clay-rich ooids were ob served in some of the sam ples;
their size var ies from 0.2 to 2.5 mm. Berthierine ooids in clayey Fig. 3. XRD di a gram of clay frac tion in clayey sid er ite
Mniszków IG 1 bore hole, depth 961.0 m
Fig. 4. XRD di a gram of clay frac tion in si der it ic sand stone Łutowiec 135Ż bore hole, depth 180.6 m; for other ex pla na tions see Fig ure 3
siderites are rare (Fig. 5A). A sam ple from the Biskupice 25BN bore hole was ana lysed for the chem i cal com po si tion of berthierine in an ooid (Ta ble 6). Ooids, formed as a re sult of re - place ment of berthierine ooids by car bon ate min er als (sidero - plesite, pistomesite, Fe-cal cite and an ker ite; Fig. 5B, C) and py - rite or al tered to kaolinite, are more fre quent. In the same sam - ple, the de gree of berthierine re place ment by sec ond ary min er - als var ied. The great est per cent age of berthierine ooids (11%) was ob served in a sam ple from the Wyszmontów 1 bore hole (depth 80.5 m), and the great est pro por tion of ooids com posed of the car bon ate min er als sideroplesite, cal cite and an ker ite (25%) was found in a sam ple from the Parkoszowice 58BN bore hole (depth 101.2 m) (Ta ble 1).
SIDERITIC SANDSTONES (TABLE 2)
The si der it ic sand stones are rep re sented by fine- to me - dium-grained quartz arenites. De tri tal ma te rial is dom i nated by quartz grains. Feld spars, micas and zir con oc cur in mi nor per - cent ages. Shell frag ments of bi valves, echinoderms, gas tro - pods and foraminifers and ooids were ob served in vari able amounts. The bioclasts are com monly com posed of cal cite, oc - ca sion ally of an ker ite, sid er ite and kaolinite. Lo cally, the voids in bioclasts are filled with a green min eral, prob a bly berthierine.
The ooids are oval, rarely sphe roi dal grains, 0.1 to 1.2 mm in size. They are com posed of a green or yel low-brown min eral.
The XRD anal y sis re vealed this min eral to be berthierine (Ta ble 5). The nu clei of the ooids are com monly rep re sented by quartz grains or small bioclasts (Fig. 5D). Some of the ooids seem to be de void of for eign ob jects, which is prob a bly due to the cross-sec tion be ing cut obliquely in re la tion to the cen tre. The cor tex of the berthierine ooids re veals a sub tle con cen tric struc - ture (Fig. 5D–F). Some of the ooids are flat tened as a re sult of me chan i cal com pac tion (Fig. 5E). The ooids were fre quently sub jected to carbonatization; berthierine has been partly or com pletely re placed by ei ther Fe-cal cite (Fig. 5F), an ker ite (Fig.
5E), sideroplesite or pistomesite. Ad di tion ally, the berthierine ooids have also been re placed by py rite and al tered to kaolinite (Fig. 5G). Ooids are rel a tively fre quent in the si der it ic sand - stones. The great est per cent age of berthierine ooids (16.7%) was found in a sam ple from the Wyszmontów 1 bore hole (depth 91.6 m), and of ooids re placed by car bon ates – an ker ite (55.7%
of rock vol ume) – in the Mołdawa bore hole (depth 387.7 m) (Ta - ble 2). The sand stones are ce mented by micritic and micro - sparitic sideroplesite, sparitic sideroplesite, pistomesite, an ker -
ite, Fe-cal cite and clay min er als (Fig. 5H). As re gards clay min - er als, the XRD anal y sis con firmed the pres ence of kaolinite, berthierine, illite (Ta ble 5 and Fig. 4) and oc ca sional chlorites. In ad di tion to illite and kaolinite, chlorites were iden ti fied in the ce - ment of sand stone from the Omięcin XI/3 bore hole, depth 104.4 m, which does not con tain berthierine (Ta ble 5). Chlorites pro vide a strong re flec tion peak at 7.15 and two peaks of lesser in ten sity at 14.29 and 3.52. This may sug gest that the min eral called “chlorite” is a ferruginous va ri ety. Based on ob - ser va tions made us ing a po lar iz ing mi cro scope, the yel low- brown min eral that forms the ce ment was pre lim i nar ily iden ti fied as berthierine.
SIDERITIC COQUINA (TABLE 3)
The two sam ples of si der it ic co quina (bioclasts – 20% of rock vol ume) from the Władysław bore hole are com posed mainly of silt- or sand-sized quartz grains and bioclasts – frag ments of echinoderms, bi valves, brachi o pods, gas tro pods, bryo zoans and serpulid tubes. Berthierine ooids, feld spars and rock clasts oc cur in smaller amounts. Some of the berthierine ooids have been re - placed to a vari able de gree by Fe-cal cite and sideroplesite (20–80%). The ce ment is com posed of sidero plesite, Fe-cal cite and clay min er als – berthierine. XRD anal y sis of the clay frac tion re vealed the pres ence of berthierine (Ta ble 5).
SIDERITIC CONGLOMERATE (TABLE 4)
The three sam ples of si der it ic con glom er ate from the Moł dawa bore hole are of polymictic paraconglomerate (see Jawo rowski, 1987). Psephite clasts are rep re sented by quartz grains and rock frag ments of cal cite- or berthierine-ce mented sand stones, quartzites and car bon ates. Among bioclasts, the most com mon are echinoderms, bi valves, gas tro pods and cor - als. The ma trix has a com po si tion of sand stone with ooids ce - mented by berthierine, microsparitic sideroplesite and Fe -cal cite.
The sam ple from the Justynów PIG 1 bore hole is a poly - mictic paraconglomerate. Psephite clasts are rep re sented by frag ments of quartz ite and car bon ate, and an ker ite- or berthie - rine-ce mented sand stone and polycrystalline quartz. The ma - trix has a com po si tion of si der it ic sand stone with some frag - ments of echinoderms, bi valves and foraminifers, as well as berhierine ooids re placed by Fe-cal cite ce mented mainly by micrite siderolpesite, lo cally by berthierine.
Re sults of anal y ses of berthierine in ooids
Bore hole Rock type
Depth
[m] Age SiO2
[wt.%]
Al2O3
[wt.%]
FeO [wt.%]
MnO [wt.%]
CaO [wt.%]
MgO [wt.%]
K2O [wt.%]
P2O5
[wt.%]
To tal [wt.%]
Gutwin 124.0 Bt1-2 33.52 21.70 25.59 0.44 1.13 0.00 0.00 0.00 89.08
Si der it ic sand stone 35.41 20.80 26.87 0.32 1.08 5.44 0.00 0.00 89.91
Omięcin XI/3 172.9 Bj2 31.42 28.40 26.01 0.00 0.55 5.40 0.00 0.00 91.76
Si der it ic sand stone 34.28 25.79 29.29 0.05 0.08 3.52 0.00 0.00 93.00
Biskupice 25BN 190.1 Bj2 26.93 23.16 33.48 0.00 0.00 3.07 0.29 0.00 86.92
Clayey sid er ite 27.14 22.96 36.04 0.00 0.00 2.68 0.08 0.00 88.91
Łutowiec 135Ż Si der it ic sand stone
180.6 Bj1 20.78 21.64 38.05 0.00 0.39 1.14 0.27 1.36 83.63
For ex pla na tions see Ta ble 1
Fig. 5. Pho to graphs in po lar iz ing mi cro scope (PL) and scan ning elec tron mi cro scope (BSE) A – berthierine ooid (Be) partly re placed by Fe-cal cite (Ca) in clayey sid er ite (Parkoszowice 58BN bore hole, depth 34.5 m, PL – crossed polars); B – sideroplesite ooids (Sdp) in clayey sid er ite com posed of sideroplesite microsparite; berthierine (Be) relicts (Wąglany k/Opoczna bore hole, depth 395.4 m, BSE im age); C – ooids com posed of Fe-cal cite (Ca) and an ker ite (Ak) in clayey sid er ite com posed of sideroplesite micrite; berthierine (Be) relicts (Parkoszowice 58BN bore hole, depth 101.0 m, BSE im age); D – berthierine ooid (Be) with con cen - tric lamellae and quartz (Q) nu cleus in si der it ic sand stone (Łutowiec 135Ż bore hole, depth 180.6 m, PL – one po lar); E – flat tened berthierine ooid (Be) with con cen tric lamellae, partly re placed by an ker ite (Ak), in si der it ic sand stone (Gutwin bore hole, depth 124.0 m, BSE im age); F – berthierine ooid (Be) partly re placed by Fe-cal - cite (Ca) in si der it ic sand stone (Omięcin XI/3 bore hole, depth 105.4 m, PL – crossed polars); G – berthierine ooid (Be) al tered to kaolinite (Kl) in si der it ic sand stone com posed of sideroplesite micrite (Sdp) (Zrębice 33BN bore hole, depth 353.95 m, PL – crossed polars); H – si der it ic sand stone with berthierine (Be) and sidero plesite (Sdp) ce ments (Łutowiec 135Ż bore hole, depth 180.6 m, PL – one po lar)
conglomerate. Psephite clasts are rep re sented by frag ments of cal cite-sid er ite-ce mented sand stones with a few frag ments of bi valves and echinoderms, and berthierine ooids ce mented by fine-crys tal line sideroplesite and berthierine oc ca sion ally.
INTERPRETATION AND DISCUSSION
OCCURRENCE OF BERTHIERINE
Berthierine forms the clay ce ment of these si der it ic rocks, fills voids in bioclasts, and oc curs in ooids. Large inter gra nu lar spaces filled with the berthierine ce ment in di cate its pre cip i ta - tion in the sed i ment be fore or at the be gin ning of me chan i cal com pac tion. The fill ing of voids in bioclasts by berthierine shows its early pre cip i ta tion. The berthierine ooids ob served in the Mid dle Ju ras sic rocks of the re gion stud ied be long to class B, ac cord ing to the Kears ley (1989) clas si fi ca tion. Sub class B2 is the most com mon and is rep re sented by pure berthierine ooids with well-de fined con cen tric cor ti cal laminae which are of - ten well-pre served (Fig. 5D). These coated grains formed di - rectly by eodiagenetic crystallisation from so lu tion or gel. There is also some ev i dence that con cen tric berthierine (and phos - phate) ooids de vel oped by in situ ac cre tion in iron-rich muds in quiet-wa ter la goons and then were in cor po rated into sandy sed i ments dur ing off shore storms (Knox, 1970; Pufahl and Grimm, 2003). Some berthierine and kaolinite ooids be long to sub class B4. They are clearly soft and the ef fects of compa - ctional de for ma tion are vis i ble in the form of squashed grains (Fig. 5E). The gen e sis of these ooids is diagenetic, and kaolinite is a sec ond ary min eral in them. Ooids from sub class B5 have also been ob served. They rep re sent com pact berthie - rine ooids with bioclast cores, but of berthierine com po si tion.
Ac cord ing to Kears ley (1989), they prob a bly formed as a re sult of diagenetic re place ment of pri mary ar agon ite ooids.
It is ob served that berthierine was com monly re placed by sid er ite and sideroplesite which, in turn, were re placed by Fe-cal cite and an ker ite. Berthierine in ooids was also re placed by car bon ate min er als and py rite, and al tered to kaolinite. Ac - cord ing to the Kears ley (1989) clas si fi ca tion, the car bon ate ooids be long to class C and sub classes from C1 to C4. They rep re sent sec ond ary sid er ite and cal cite ooids pro duced by the re place ment of ear lier phyllosilicate ooids. Re place ment pro - cesses lo cally lead to com plete oblit er a tion of the orig i nal con - cen tric struc ture (Fig. 5C). This is caused by the cir cu la tion of Fe-, Ca- and Mg-rich pore flu ids in the rock vol ume dur ing the late stage of diagenetic pro cesses.
In the area stud ied, berthierine has been found in ma rine strata de pos ited in shoreface to off shore and deltaic en vi ron - ments, in a pe riod span ning the Early Bajocian through the Late Bathonian (Feldman-Olszewska, pers. comm., 2013; Ta bles 1–4). There is no con sen sus about the cli ma tic con di tions in Mid dle Ju ras sic times in Po land. Dudek (2012) sug gested a cool cli mate with me chan i cal weath er ing dom i nant; how ever, Gedl and Ziaja (2012) pro posed a warm cli mate dur ing Bathonian de po si tion in the Częstochowa re gion. Ac cord ing to Hal lam (2001), the Mid dle Ju ras sic cli mate in Eu rope was sim i - lar to the re cent one. Odin (1990) sug gested that berthierine forms pri mar ily in trop i cal to sub trop i cal seas. In the Często - chowa re gion, the Bathonian fine siliciclastic de pos its ac cu mu - lated in a ma rine en vi ron ment in the off shore zone, most likely be low the storm wave base (Leonowicz, 2012), and in suboxic con di tions (Leonowicz, 2013). The oc cur rence of berthierine in both ma rine and deltaic de pos its of the study area, in places of
changes. The de gree of sa lin ity of the ba sin is a cru cial fac tor in berthierine crystallisation.
Bathonian (mainly Lower and Mid dle Bathonian) si der it ic rocks with berthierine oc cur pre dom i nantly along the north east - ern mar gin of the Holy Cross Moun tains (Ta bles 1–4). They are rep re sented by si der it ic sand stones de pos ited in shoreface and deltaic en vi ron ments, and rarely by clayey siderites of the shoreface en vi ron ment. Two sam ples are rep re sented by si der - it ic con glom er ates de pos ited in the shoreface en vi ron ment, and two si der it ic co quina sam ples are re lated to deltaic and car bon - ate ramp de pos its. The ooids in these rocks are in cluded in ooid sub classes B2, lo cally B5 and B4. Deltaic ooids are com monly better pre served, com pared to those de pos ited in the shoreface en vi ron ment. It is ob served that berthierine is partly re placed in ooids by Fe-cal cite and sideroplesite, and rarely by an ker ite and py rite.
Berthierine from the Bajocian si der it ic rocks has been found in both study ar eas (Ta bles 1, 2 and 4). Most of the sam ples are Late Bajocian in age and are rep re sented by si der it ic sand - stones, lo cally con glom er ates de pos ited in the shoreface, lo - cally off shore and deltaic en vi ron ments, and by clayey siderites de pos ited in the off shore, tran si tion and shoreface zones. The most com mon ooids are of type C, rep re sented by partly or com pletely re placed ooids, likely of sub class B2. Berthierine in these ooids has been re placed by sideroplesite, pistomesite, Fe-cal cite and an ker ite, and py rite. Sec ond ary kaolinite is also pres ent in these ooids. Three si der it ic sand stone sam ples and one clayey sid er ite sam ple are Early Bajocian in age. They rep - re sent deltaic de pos its in which ooids of sub classes B2 and B4 are well-pre served in the Częstochowa re gion. Whereas, in the north east ern mar gin of the Holy Cross Moun tains, berthierine in ooids is oc ca sion ally com pletely re placed mainly by Fe-cal cite and, to a lesser ex tent, by an ker ite, and al tered to kaolinite.
In a few rock sam ples of Aalenian de pos its, from the north - east ern mar gin of the Holy Cross Moun tains only, sec ond ary ooids with traces of berthierine have been found (Ta bles 1 and 2). The Up per Aalenian is rep re sented by si der it ic sand stone con tain ing about 20 vol.% ooids and de pos ited in the off shore en vi ron ment. The ooids are partly filled with py rite and in cluded in sub class B2. X-ray anal y sis pro vided no ev i dence for the pres ence of berthierine. In ad di tion to sid er ite and py rite, kaolinite has also been iden ti fied (Ta ble 6). It is likely that kaolinite is a sec ond ary min eral af ter berthierine. The Lower Aalenian flu vial and estuarine si der it ic sand stone, as well as the clayey sid er ite de pos ited in the shoreface zone, con tain min er - als the orig i nal ma te rial of which, prob a bly berthierine, has been com pletely re placed by sideroplesite and pistomesite.
In the si der it ic rocks, berthierine oc curs pri mar ily in those de pos ited in the shoreface and deltaic en vi ron ments of the Early and Middle Bathonian along the northeast ern mar gin of the Holy Cross Moun tains, and of the Late Bajocian of both ar - eas. In the rocks ex am ined, berthierine ooids are better pre - served in the Bathonian de pos its, com pared with those in the Bajocian and Aalenian. Diagenetic pro cesses of re place ment and al ter ation of berthierine de vel oped most in tensely in clayey siderites. In the Bathonian of the northeast ern mar gin of the Holy Cross Moun tains, ma rine de pos its of pre dom i nantly shoreface en vi ron ment con tain ooids in which berthierine is re - placed by Fe- cal cite and sideroplesite, and rarely by an ker ite.
Berthierine ooids from the Bathonian deltaic de pos its are com - monly well-pre served. The Up per Bajocian shoreface de pos its con tain pre dom i nantly sec ond ary ooids in which berthierine has lo cally been com pletely re placed by sideroplesite, pistomesite, Fe-cal cite, an ker ite and py rite, and al tered to kaolinite. These pro cesses were more poorly de vel oped in the Częstochowa re -
gion com pared to the northeast ern mar gin of the Holy Cross Moun tains. Sim i lar vari abil ity in the ef fects of diagenetic pro - cesses, in both the study ar eas, has been no ticed in the Lower Bajocian deltaic de pos its. In the northeast ern mar gin of the Holy Cross Moun tains, the Aalenian si der it ic rocks of var i ous en vi ron ments contain only secondary ooids composed of kaolinite, pyrite, sideroplesite and pistomesite.
ORIGIN OF BERTHIERINE
The oc cur rence of berthierine in the rocks ex am ined shows that the min eral was formed dur ing the early stage of diage - nesis – the eodiagenesis stage (diagenetic stages af ter Cho - quette and Pray, 1970).
Dur ing eodiagenesis, the es sen tial fac tor was a cir cu la tion of pore wa ter con tain ing land-de rived or ganic mat ter and iron com pounds. Hornibrook and Longstaffe (1996) have shown that berthierine crys tal lised at a tem per a ture of 25–45°C. Ac - cord ing to Worden and Morad (2003) and Wil son (2013) the for - ma tion of berthierine took place in trop i cal, off shore and deltaic en vi ron ments where iron-bear ing fresh wa ter mixed with sea wa ter. In ma rine sed i ments with a sig nif i cant fresh wa ter in flux, berthierine forms close to the sed i ment sur face but re quires iso la tion from ox i dized wa ter to pres ent re-ox i da tion (Odin and Mat ter, 1981). It crystallises us ing re duced iron (Fe2+) in the methanogenic zone un der con di tions of very low sed i men ta tion rates (Odin, 1988). Ac cord ing to Tay lor (1998), berthierine crys - tal lised within the suboxic diagenetic zone in ma rine con di tions.
García-Frank et al. (2012) also sug gested pre cip i ta tion of berthie rine in suboxic con di tions in the ear li est stages of dia - genesis, prob a bly be low the ac tive sed i ment-wa ter in ter face. It seems that the most prob a ble source of iron for berthie rine in the study area is river wa ter car ry ing ma te rial orig i nat ing from weath er ing pro cesses on land. A vol ca nic-or i gin of iron should be ex cluded be cause there was no vol ca nic ac tiv ity in ad ja cent ar eas in Ju ras sic times. Odin (1988) has de scribed three fa cies of Fe-clay min er ali sa tion, from which two – verdin and oolitic iron stone – could have ex isted in the Mid dle Ju ras sic in the area stud ied. Both of these fa cies are as so ci ated with points of lo cal flu vial dis charge into the ma rine en vi ron ment. Due to con tact be tween fresh wa ter and sea wa ter, the sa lin ity of the for mer in - creases caus ing the floc cu la tion of iron and its de po si tion in an amor phous, highly re ac tive state (Ehrenberg, 1993).
Berthierine forms by diagenetic recrystallisation of odinite or pre cur sor min er als sim i lar to it (Odin et al., 1988). The for ma - tion of berthierine re quires re duc ing con di tions in which the ac - tiv ity of sulphides and bi car bon ate is low (Tay lor, 1990; Fritz and Toth, 1997; Shel don and Retallack, 2002). Ad di tion ally, Fritz and Toth (1997) re port that berthierine pre cip i ta tion is as - so ci ated with low ac tiv ity of sil ica in so lu tion, be cause oth er wise kaolinite would form. Lo cally, the amount of sil ica must have in - creased in some ooids and berthierine was trans formed to kaolinite (Fig. 5G). Kaolinite forms in an acidic en vi ron ment (Osborne et al., 1994) where a sig nif i cant role is played by me - te oric wa ters, slightly acidic due to dis so lu tion of CO2 and or - ganic ac ids (Giles and de Boer, 1990). Dur ing the change from suboxic to anoxic con di tions, berthierine is re placed by py rite in the zone of sul phate re duc tion. Un der con di tions of fresh wa ter in flow, methanogenic bac te ria trans form or ganic mat ter to pro - duce CO2 and CH4 (Claypool and Kaplan, 1974). In the ox y - gen-de fi cient en vi ron ment, in sed i ments rich in re ac tive min er - als con tain ing iron, and at a low con cen tra tion of dis solved sulphates, berthierine is re placed by pre cip i tat ing sid er ite (Browne and Kingston, 1993; Morad, 1998). In the rocks ex am - ined, this is sid er ite en riched with mag ne sium – pre dom i nantly
sideroplesite (Kozłowska et al., 2008, 2011, 2013; Witkowska, 2012). In the eodiagenesis stage, berthierine ooids un der went de for ma tion, es pe cially flat ten ing, as a re sult of me chan i cal com pac tion (Fig. 5E). The ef fects of me chan i cal com pac tion are best man i fested in sand stones. They in clude close pack ing of de tri tal ma te rial, re duc tion in pri mary po ros ity, frac tur ing of grains, de for ma tion of clay-mud laminae and, lo cally, bend ing of mica flakes.
In the sub se quent diagenetic stage – mesodiagenesis – berthierine ooids were re placed to a vari able ex tent by car bon - ate min er als that pen e trated into the grains from the out side (Fig. 5F). These min er als were crystallising around the ooid and, grad u ally grow ing into its cen tral point, were re plac ing berthierine. Due to an ac tive cir cu la tion of flu ids, the fol low ing pre cip i ta tion se quence oc curred: sideroplesite, pistomesite, Fe - cal cite and an ker ite. The crystallising sideroplesite and pistomesite are char ac ter ised by a high mag ne sium con tent com pared with early diagenetic sideroplesite, and they are of - ten rhombohedral in shape (Kozłowska et al., 2008, 2011, 2013). Stud ies of fluid in clu sions in sideroplesite and pisto - mesite crys tals in di cate that their crystallisation tem per a ture was >60°C (Kozłowska, 2014). Next, Fe-cal cite and an ker ite for med, fill ing the space be tween sid er ite, sideroplesite and pisto mesite crys tals, show ing that they crys tal lised later.
Early diagenetic berthierine is chem i cally and struc tur ally un sta ble. With in creas ing tem per a ture and depth of burial, this min eral trans formed to chlorite. The trans for ma tion pro cess was grad ual and mixed-lay er ing chlorite/ser pen tine re cords its in ter me di ate stage (Wil son, 2013). Ac cord ing to Jahren and Aagaard (1989), berthierine is trans formed to chamosite as a re sult of crystallisation at a tem per a ture of about 70°C. The trans for ma tion of berthierine to chamosite is a dis so lu tion-pre - cip i ta tion re ac tion in closed or semi-closed sys tems (Aagaard et al., 2000). Berthierine may have been the pre cur sor of ferru - ginous chlorites found in some sam ples. The ce ment of sand - stone from a sam ple taken at a depth of 104.4 m in the Omięcin XI/3 bore hole (Ta ble 2) is com posed of a yel low-brown min eral.
Based on mi cro scopic ob ser va tions, the min eral was iden ti fied as berthierine, how ever, X-ray anal y sis re vealed that it was chlorite. This may sug gest that, dur ing their diagenetic his tory, the rocks could at tain tem per a tures >60°C. This is also con - firmed by the re sults of anal y sis of fluid in clu sions in some sideroplesite and pistomesite crys tals, in di cat ing the tem per a - tures of their crystallisation was 62–137°C.
BERTHIERINE AND OTHER CLAY MINERALS
The re sults of XRD (Ta ble 5) and point chem i cal anal y ses (Ta ble 6) of clay min er als from si der it ic rocks in both study ar - eas con firm the pres ence of berthierine. In the sam ples ana - lysed, the green and yel low-brown min eral that mostly com - prises ooids, but which also oc curs in the ce ment and fills voids in bioclasts, has been iden ti fied as berthierine. In some sam - ples, berthierine is ac com pa nied by kaolinite or illite.
XRD stud ies of the Lower and Mid dle Bathonian rocks along the northeast ern mar gin of the Holy Cross Moun tains re - veal the pres ence in the clay frac tion of berthierine, kaolinite, illite, with mi nor chlorites. Sin gle sam ples of Up per Bajocian rock con tain berthierine and kaolinite while Aalenian rocks con - tain kaolinite. It seems that, in this area, kaolinite pre dom i nates over the other clay min er als. Anal y sis of se lected rock sam ples from the Częstochowa re gion, con tain ing the clay frac tion, has re vealed the pres ence of berthierine (Up per Bajocian) and berthierine and illite (Lower Bajocian).
clay min er als in the Częstochowa area shows that illite pre vails over kaolinite and chlorites (Dudek, 2012). Vari abil ity in the com po si tion of clay min er als within de pos its of dif fer ent ages in the Mid dle Ju ras sic may sug gest changes in the cli ma tic con di - tions of the area stud ied.
The chem i cal anal y sis of berthierine in di cates a re gional dif - fer en ti a tion. Berthierine from the northeast ern mar gin of the Holy Cross Moun tains typ i cally shows a higher con tent of SiO2, CaO and MgO and a lower con tent of FeO as com pared with berthierine from the Częstochowa re gion. This may be in dic a - tive of a greater sup ply of iron from land to the Middle Ju ras sic (Bajocian) ba sin in the Częstochowa area com pared to the northeast ern mar gin of the Holy Cross Moun tains.
The re sults of anal y ses that iden ti fied berthierine among clay min er als of these Mid dle Ju ras sic si der it ic rocks are con - sis tent with the re sults of stud ies by Maliszewska et al. (2007) from the Pol ish Low lands. They con firm the pres ence of berthierine in the Mid dle Ju ras sic de pos its, and not only of chamosite, as was pre vi ously com monly thought. The smaller amount of kaolinite in the Częstochowa ores com pared to the Starachowice ores (Fig. 1) was re ported by Jaskólski (1928).
Re cently pub lished pa pers re port the oc cur rence of both illite and kaolinite from the de pos its of the Mid dle and Up per Bathonian in the Częstochowa re gion (Szczepanik et al., 2007;
Dudek, 2012; Witkowska, 2012).
CONCLUSIONS
1. Berthierine is a green or yel low-brown clay min eral, the pres ence of which in Mid dle Ju ras sic si der it ic siliciclastic rocks has been con firmed by XRD and SEM anal y ses. It com prises mostly ooids and also oc curs less com monly in the ce ment of si der it ic sand stones, con glom er ates, coquinas and clayey side - rites, and fills voids in bioclasts. Berthierine in ooids is char ac - ter ized by FeO con tent of up to about 29 wt.% in the northeast - ern mar gin of the Holy Cross Moun tains, and up to ap prox i - mately 38 wt.% in the Częstochowa re gion. This may sug gest a greater sup ply of iron from land to the Middle Ju ras sic (Bajocian) ba sin in the Częstochowa area com pared with the northeast ern margin of the Holy Cross Mountains.
2. Among the clay min er als, apart from berthierine, also illite, kaolinite and chlorites have been iden ti fied in the si der it ic rocks. Vari abil ity in the com po si tion of clay min er als within de - pos its of dif fer ent ages in the Mid dle Ju ras sic could sug gest changes in cli ma tic con di tions in both of the areas studied.
3. Berthierine ooids were ob served mainly in si der it ic sand - stones, rarely in clayey siderites, and in a few sam ples of si der - it ic con glom er ate and co quina. Their state of pres er va tion var -
pac tion, re place ment and al ter ation. Berthierine was re placed by car bon ate min er als and py rite, and al tered to kaolinite.
Ooids, which are com posed of the car bon ate min er als sidero - plesite, pistomesite, Fe-cal cite and an ker ite, and lo cally of py rite and kaolinite, are com mon com po nents of si der it ic rocks. They are always secondary after berthierine ooids.
4. In the si der it ic rocks, berthierine oc curs pri mar ily in those de pos ited in the shoreface and deltaic en vi ron ments of the Early and Middle Bathonian of the northeast ern mar gin of the Holy Cross Moun tains, and of the Late Bajocian of both study ar eas. Berthierine ooids from the Bathonian si der it ic rocks are char ac ter ized by a better de gree of pres er va tion com pared to those from the Bajocian and Aalenian de pos its. The ef fects of diage netic pro cesses are better de vel oped in the ma rine si der it - ic sand stones, con glom er ates and coquinas, de pos ited mostly in the shoreface zone, com pared to those ob served in deltaic de pos its. The stron gest ef fects of the pro cesses of berthierine re place ment and al ter ation have been found in clayey siderites de pos ited in a ma rine en vi ron ment, in clud ing shoreface to off - shore. In the Częstochowa re gion, the ef fects of diagenetic re - place ment and al ter ation pro cesses are more poorly de vel oped com pared to those observed in the northeastern margin of the Holy Cross Mountains.
5. Berthierine was formed in the early diagenetic stage (eodiagenesis) in suboxic con di tions where iron-bear ing fresh - wa ter mixed with sea wa ter prob a bly at a tem per a ture of about 25–45°C. This min eral is chem i cally and struc tur ally un sta ble, caus ing its trans for ma tion to chamosite as a re sult of recry - stallisation pro cess at a tem per a ture of 70°C. Berthierine may have been the pre cur sor of ferruginous chlorites found in some sam ples. This may show that, dur ing their diagenetic his tory, the rocks could lo cally at tain tem per a tures >60°C, which is sug - gested by the re sults of anal y sis of fluid in clu sions in some sideroplesite and pistomesite crys tals, in di cat ing the tem per a - tures of their crystallisation to be 62–137°C.
Ac knowl edge ments. The au thors are grate ful to Re view - ers A. García-Frank, P. Leonowicz and J. Powell for their sug - ges tions and com ments that greatly im proved an ear lier ver sion of this manu script. Pro fes sor T. Peryt, GQ Ed i tor-in-Chief, is thanked for fi nal ed it ing of the manu script. Spe cial thanks are due to A. Feldman-Olszewska for al low ing us to use the re sults of her un pub lished sedimentological study. This pa per is a part of the pro jects No. N N307 330339 fi nanced by the Min is try of Sci ence and Higher Ed u ca tion, and No. 61.2201.0604.00.0 of the Pol ish Geo log i cal In sti tute – Na tional Re search In sti tute.
XRD anal y sis was per formed by W. Narkiewicz, and the SEM ex am i na tion by L. Giro and E. Starnawska.
REFERENCES
Aagard, P., Jahren, J.S., Harstad, A.O., Nilsen, O., Ramm, M., 2000. For ma tion of grain-coat ing chlorite in sand stones. Lab o - ra tory syn the size vs. nat u ral oc cur rences. Clay Min er als, 35:
261–269.
Brindley, G.W., Brown, G., 1984. Crys tal Struc tures of Clay Min er als and Their X-ray Iden ti fi ca tion. Min er al og i cal So ci ety, Lon don.
Browne, G.H., Kingston, D.M., 1993. Early diagenetic spherulitic siderites from Penn syl va nian palaeosols in the Boss Point For - ma tion, Mar i time Can ada. Sedimentology, 40: 467–474.
Choquette, P.W., Pray, L.C., 1970. Geo logic no men cla ture and clas si fi ca tion of po ros ity in sed i men tary car bon ates. AAPG Bul - le tin, 54: 207–220.
Cieśla, E., 1958. Nowe dane o przebiegu północnej części anty kliny inowłodzkiej (in Pol ish). Przegląd Geologiczny, 3: 144–145.
Claypool, G.E., Kaplan, I.R., 1974. The or i gin and dis tri bu tion of meth ane in ma rine sed i ments. Ma rine Sci ence, 3: 97–139.
Daniec, J., 1963. The Dogger of the mid dle part of the north east ern sur round ing cover of the Święty Krzyż Moun tains (in Pol ish with Eng lish sum mary). Biuletyn Instytutu Geologicznego, 168:
37–86.
Daniec, J., 1970. Mid dle Ju ras sic (in Pol ish with Eng lish sum mary).
Prace Instytutu Geologicznego, 56: 99–134.
Dreesen, R., 1989. Oolitic iron stones as event-strati graphi cal marker beds within the Up per De vo nian of the Ardeno-Rhenish Mas sif. Geo log i cal So ci ety Spe cial Pub li ca tions, 46: 65–78.
Dudek, T., 2012. Clay min er als as palaeoenvironmental in di ca tors in the Bathonian (Mid dle Ju ras sic) ore-bear ing clays from Gna - szyn, Kraków-Silesia Homocline. Acta Geologica Polonica, 62:
297–305.
Ehrenberg, S.N., 1993. Pres er va tion of an oma lously high po ros ity in deeply bur ied sand stones by grain-coat ing chlorite: ex am ples from the Nor we gian Con ti nen tal Shelf. AAPG Bul le tin, 77:
1260–1286.
Feldman-Olszewska, A., 1997. Depositional ar chi tec ture of the Pol ish epicontinental Mid dle Ju ras sic ba sin. Geo log i cal Quar - terly, 41 (4): 491–508.
Feldman-Olszewska, A., 1998. Palaeo geo graphi cal maps of Mid - dle Ju ras sic, pl. 36–47. In: Palaeo geo graphi cal At las of the Epicontinental Perm ian and Me so zoic in Po land (eds. R.
Dadlez, S. Marek and J. Pokorski). Państwowy Instytut Geolo - giczny, Warszawa.
Flügel, E., 2010. Microfacies of Car bon ate Rocks. Springer-Verlag, Berlin–Hei del berg.
Fritz, S.J., Toth, T.A., 1997. An Fe-berthierine from a Cre ta ceous laterite: part II. Es ti ma tion of Eh, ph and pCO2 con di tions of for - ma tion. Clays and Clay Min er als, 45: 590–586.
García-Frank, A., Ureta, S., Mas, R., 2012. Iron-coated par ti cles from con densed Aalenian-Bajocian de pos its: evo lu tion ary model (Ibe rian Ba sin, Spain). Jour nal of Sed i men tary Re search, 82: 953–968.
Gedl, P., Boczarowski, A., Dudek, T., Kaim, A., Kędzierski, M., Leonowicz, P., Smoleń, J., Szczepanik, P., Witkowska, M., Ziaja, J., 2006. Biostratigraphical frame work from Bajocian to Oxfordian. Stop B1.7 – Gnaszyn Clay pit (Mid dle Bathonian - -low er most Up per Bathonian). Li thol ogy, fos sil as sem blages and palaeoenvironment. In: Ju ras sic of Po land and Ad ja cent Slovakian Carpathians (eds. A. Wierzbowski, R. Aubrecht, J.
Golonka, J. Gutowski, M. Krobicki, B.A. Matyja, G. Pieńkowski and A. Uchman): 155–156. Field Trip Guide book. 7th In ter na - tional Con gress on the Ju ras sic Sys tem, Sep tem ber 6–18, Kraków, Po land.
Gedl, P., Ziaja, J., 2012. Palynofacies from Bathonian (Mid dle Ju - ras sic) ore-bear ing clays at Gnaszyn, Kraków-Silesian Homo - cline, Po land, with spe cial em pha sis on sporomorph eco- groups. Acta Geologica Polonica, 62: 325–349.
Giles, M.R., de Boer, R.B., 1990. Or i gin and sig nif i cance of redis - tributional sec ond ary po ros ity. Ma rine and Pe tro leum Ge ol ogy, 7: 378–397.
Hal lam, A., 2001. A re view of the broad pat tern of Ju ras sic sea-level changes and their pos si ble causes in the light of cur rent knowl - edge. Palaeo ge ogra phy, Palaeoclimatology, Palaeo ec ol ogy, 167: 23–37.
Hornibrook, E.R.C., Longstaffe, F.J., 1996. Berthierine from the Lower Cre ta ceous Clearwater For ma tion, Al berta, Can ada.
Clays and Clay Min er als, 44: 1–21.
Iijima, A., Matsumoto, R., 1982. Berthierine and chamosite in coal mea sures of Ja pan. Clays and Clay Min er als, 30: 264–274.
Jahren, J.S., Aagaard, P., 1989. Compositional vari a tions in dia - genetic chlorites and illites and re la tion ships with for ma tion-wa - ter chem is try. Clay Min er als, 24: 157–170.
Jaskólski, S., 1928. Die oolitischen Toneisenerzlagerstätten der Gegend von Częstochowa (in Pol ish with Ger man sum mary).
Rocznik Polskiego Towarzystwa Geologicznego, 4: 1–91.
Jaworowski, K., 1987. Petrographic canon of the most com mon sed i men tary rocks (in Pol ish). Przegląd Geologiczny, 35:
205–209.
Kears ley, A.T., 1989. Iron-rich ooids, their min er al ogy and micro - fabric: clues to their or i gin and evo lu tion. Geo log i cal So ci ety Spe cial Pub li ca tions, 46: 141–164.
Kimberley, M.M., 1994. De bate about iron stone: has sol ute sup ply been surficial weath er ing, hy dro ther mal con vec tion, or ex ha la - tion of deep flu ids? Terra Nova, 6: 116–132.
Knox, R.W.O’B., 1970. Chamosite ooliths from the Win ter Gill iron - stone (Ju ras sic) of York shire, Eng land. Jour nal of Sed i men tary Pe trol ogy, 40: 1216–1225.
Kobyłecki, M., 1948. Ju ras sic clay iron ores of Tychów Belt be - tween Rogów and Ćmielów (in Pol ish with Eng lish sum mary).
Biuletyn Państwowego Instytutu Geologicznego, 41: 8–42.
Kopik, J., 1998. Lower and Mid dle Ju ras sic of the north-east ern mar gin of the Up per Silesian Coal Ba sin (in Pol ish with Eng lish sum mary). Prace Państwowego Instytutu Geologicznego, 378:
67–131.
Kopik, J., Marcinkiewicz, T., 1997. The Mid dle Ju ras sic. Biostra - tigraphy (in Pol ish with Eng lish sum mary). Prace Państwowego Instytutu Geologicznego, 153: 236–263.
Kozłowska, A., 2014. Diagenesis of the Mid dle Ju ras sic sid er ite rocks south of Tomaszów Mazowiecki (in Pol ish). Przewodnik wycieczek terenowych, abstrakty i artykuły, Jurassica XI, 50.
Kozłowska, A., Feldman-Olszewska, A., Kuberska, M., Malisze - wska, A., 2008. The Mid dle Ju ras sic siderites from the north ern edge of the Holy Cross Moun tains. Schriftenreihe der Deuts - chen Gesellschaft für Geowissenschaften, 58: 158.
Kozłowska, A., Feldman-Olszewska, A., Kuberska, M., Malisze - wska, A., 2011. Sed i men tary en vi ron ments and diagenesis of the Mid dle Ju ras sic siderites in the North Mar gin of the Holy Cross Moun tains, Po land. Ab stracts, 28th IAS Meet ing of Sedimen - tology, 5–8 July, Zaragossa, Spain, 522, Abstracts28thIAS.pdf Kozłowska, A., Kuberska, M., Feldman-Olszewska, A., Jarmoło -
wicz-Szulc, K., Maliszewska, A., 2013. The Mid dle Ju ras sic sid er ite iron ore de pos its in South ern Po land. Acta Mineralogica Sinica, 33: 5.
Kuźniar, C., 1928. Les minerais de fer oolitique ´ Parczów, prÀs d'Opoczno (in Pol ish with French sum mary). Sprawozdania Państwo wego Instytutu Geologicznego, 4: 710–755.
Leonowicz, P., 2012. Sedimentology and ichnology of Bathonian (Mid dle Ju ras sic) ore-bear ing clays at Gnaszyn, Kraków- Silesian Homocline, Po land. Acta Geologica Polonica, 62: 281–296.
Leonowicz, P., 2013. The sig nif i cance of mudstone fab ric com bined with palaeo eco logi cal ev i dence in de ter min ing sed i men tary pro - cesses – an ex am ple from the Mid dle Ju ras sic of south ern Po - land. Geo log i cal Quar terly, 57 (2): 243–260.
Longstaffe, F.J., Ayalon, A., 1987. Ox y gen-iso tope stud ies of clastic diagenesis in the Lower Cre ta ceous Vi king For ma tion, Al berta: im pli ca tion for the role of me te oric wa ter. Geo log i cal So - ci ety Spe cial Pub li ca tions, 36: 277–296.
Lott, G., Wong, T., Dusar, M., Andsbjerg, J., Monnig, E., Feldman -Olszewska, A., Verreussel, R., 2010. Ju ras sic. In:
Pe tro leum Geo log i cal At las of the South ern Perm ian Ba sin Area (eds. H. Doornenbal and A. Stevenson): 173–193. EAGE Pub li - ca tions, Houten.
Maliszewska, A., Kozłowska, A., Kuberska, M., 2005. Min er al ogy of Mid dle Ju ras sic siderites of the Kujawy re gion (Pol ish Low - lands) – pre lim i nary re sults. Schriftenreihe der Deutschen Gesellschaft für Geowissenschaften, 38: 100.
Maliszewska, A., Kozłowska, A., Kuberska, M., 2006. Or i gin of the Mid dle Ju ras sic sid er ite rocks from Cen tral Po land. Volu - mina Jurassica, 4: 95–96.
Maliszewska, A., Kozłowska, A., Kuberska, M., 2007. Diagenesis of the Mid dle Ju ras sic sideritic rocks from Cen tral and NW Po - land (in Pol ish). Przegląd Geologiczny, 55: 297–298.
Marynowski, L., Zatoń, M., Simoneit, B.R.T., Otto, A., Jędrysek, M.O., Grelowski, C., Kurkiewicz, S., 2007. Com po si tions, sources and depositional en vi ron ments of or ganic mat ter from the Mid dle Ju ras sic clays of Po land. Ap plied Geo chem is try, 22:
2456–2485.
Meunier, A., 2005. Clays. Berlin, Springer.
tion pat terns and geo chem i cal evo lu tion. IAS Spe cial Pub li ca - tion, 26: 1–26.
Odin, G.S., 1988. The verdine fa cies from the la goon of New Cal - edo nia. De vel op ments in Sedimentology, 45: 57–82.
Odin, G.S., 1990. Clay min eral for ma tion at the con ti nen tal-ocean bound ary: the verdin fa cies. Clay Min er als, 25: 477–483.
Odin, G.S., Mat ter, A., 1981. De glauconarium origine. Sedimen - tology, 28: 611–641.
Odin, G.S., Knox R.W.O’B., Gygi, R.A., Guerrak, S., 1988. Green ma rine clays from the oolithic iron stone fa cies. De vel op ments in Sedimentology, 45: 29–52.
Osborne, M., Haszeldine, R.S., Fallick, A.E., 1994. Vari a tion in kaolinite mor phol ogy with growth tem per a ture in iso to pi cally mixed pore-flu ids, Brent Group, UK North Sea. Clay Min er als, 29: 591– 608.
Passendorfer, E., 1927. Compte-rendu des recherches g¾olo - giques ex¾cut¾es en 1926 pour la feuille Przedbórz (in Pol ish).
Posiedzenia Naukowe Państwowego Instytutu Geologicznego, 16: 10–11.
Passendorfer, E., 1928. Compte-rendu des recherches g¾olo - giques ex¾cut¾es en 1927 pour la feuille Opoczno (in Pol ish).
Posiedzenia Naukowe Państwowego Instytutu Geologicznego, 19/20: 5–8.
Pieńkowski, G., Schudack, M.E. (co-ordinators), Bosák, P., Enay, R., Feldman-Olszewska, A., Golonka, J., Gutowski, J., Herngreen, G.F.W., Jor dan, P., Krobicki, M., Lathuiliere, B., Leinfelder, R.R., Michalík, J., Mönnig, E., Noe-Nygaard, N., Pálfy, J., Pint, A., Rasser, M.W., Reisdorf, A.G., Schmid, D.U., Schweigert, G., Surlyk, F., Wetzel, A., Wong, T.E., 2008.
Ju ras sic. In: The Ge ol ogy of Cen tral Eu rope. Vol ume 2: Me so - zoic and Ce no zoic (ed. T. McCann): 823–922. Geo log i cal So ci - ety of Lon don.
Pufahl, P.K., Grimm, K.A., 2003. Coated phos phate grains: proxy for phys i cal, chem i cal, and eco log i cal changes in sea wa ter. Ge - ol ogy, 31: 801–804.
Reolid, M., Abad, I., Mar tin-García, J.M., 2008. Paleoenviron - mental im pli ca tions of ferruginous de pos its re lated to a Mid - dle-Up per Ju ras sic dis con ti nu ity (Prebetic Zone, Betic Cor dil - lera, South ern Spain). Sed i men tary Ge ol ogy, 203: 1–16.
Rivas-Sanchez, M.L., Alva-Valdivia, L.M., Are nas-Alatorre, J., Urrutia-Fucugauchi, J., 2006. Berthierine and chamosite hy dro - ther mal: ge netic guides un the Peńa Colorada mag ne tite- bear ing ore de posit, Mex ico. Earth Plan ets Space, 58: 1389–1400.
Ryan, P.C., Hill ier, S., 2002. Berthierine/chamosite, corrensite, and dis crete chlorite from evolved verdine and evap o rate-as so ci - ated fa cies in the Ju ras sic Sundance For ma tion, Wy o ming.
Amer i can Min er al o gist, 87: 1607–1615.
Samsonowicz, J., 1932. Sur le trac¾ et le caractÀre de la limite en tre le Jurassigue et le Cr¾tac¾ sur le versant nord-est du Mas sif de Ste Croix (in Pol ish with French summary). Sprawo zdania Państwowego Instytutu Geologicznego, 7: 208–226.
Shel don, N.D., Retallack, G.J., 2002. Low ox y gen lev els in ear li est Tri as sic soils. Ge ol ogy, 30: 919–922.
Stoch, L., 1974. Minerały ilaste (in Pol ish). Wyd. Geol., Warszawa.
leo zoic iron ooids; a sim i lar vol ca nic or i gin. Sed i men tary Ge ol - ogy, 136: 137–146.
Szczepanik, P., Witkowska, M., Sawłowicz, Z., 2007. Geo chem is - try of Mid dle Ju ras sic mudstones (Kraków-Częstochowa area, south ern Po land): in ter pre ta tion of the depositional re dox con di - tions. Geo log i cal Quar terly, 51 (1): 57–66.
Tay lor, K.G., 1990. Berthierine from the non-ma rine Wealden (Early Cre ta ceous) sed i ments of south-east Eng land. Clay Min er als, 25: 391–399.
Tay lor, K.G., 1998. Spa tial and tem po ral vari a tions in early diage - netic or ganic mat ter ox i da tion path ways in Lower Ju ras sic mud - stones of east ern Eng land. Chem i cal Ge ol ogy, 145: 47–60.
Tay lor, K.G., Curtis, C.D., 1995. Sta bil ity and fa cies as so ci a tion of early diagenetic min eral as sem blages: an ex am ple from a Ju - ras sic iron stone-mudstone suc ces sion, U.K. Jour nal of Sed i - men tary Re search, A65: 358–368.
Tay lor, K.G., Simo, T.J.A., Yocum, D., Leckie, D.A., 2002. Strati - graphic sig nif i cance of ooidal iron stone from the Cre ta ceous west ern in te rior sea way: the Peace River For ma tion, Al berta, Can ada, and the Castlegate Sand stone, Utah, U.S.A. Jour nal of Sed i men tary Re search, 72: 316–327.
Turnau-Morawska, M., 1961. Petrographic char ac ter of the iron - stone of the Vesulian in the Łęczyca re gion (in Pol ish with Eng - lish sum mary). Biuletyn Instytutu Geologicznego, 172: 5–69.
Velde, B., 1995. Com pac tion and diagenesis. In: Or i gin and Min er - al ogy of Clays: Clays and En vi ron ment (ed. B. Velde): 220–246.
Springer-Verlag.
Wierzbowski, H., Joachimski, M., 2007. Re con struc tion of late Bajocian – Bathonian ma rine palaeoenvironments us ing car bon and ox y gen iso tope ra tios of cal car e ous fos sils from the Pol ish Jura Chain (cen tral Po land). Palaeo ge ogra phy, Palaeo clima - tology, Palaeo ec ol ogy, 254: 523–540.
Wil son, M.J., 1987. X-ray pow der dif frac tion meth ods. In: A Hand - book of De ter mi na tive Meth ods in Clay Min er al ogy (ed. M.J. Wil - son): 26–98. Blackie, New York.
Wil son, M.J., 2013. Sheet silicicates: clay min er als. Rocks-form ing min er als, 3C. The Geo log i cal So ci ety, Lon don.
Witkowska, M., 2012. Palaeoenvironmental sig nif i cance of iron car bon ate con cre tions from the Bathonian (Mid dle Ju ras sic) ore-bear ing clays at Gnaszyn, Kraków-Silesian Homocline, Po - land. Acta Geologica Polonica, 62: 307–324.
Worden, R.H., Morad, S., 2003. Clay min er als in sand stones: con - trols on for ma tion, dis tri bu tion ad evo lu tion. IAS Spe cial Pub li - ca tion, 34: 3–41.
Young, T.P., 1989. Eustatically con trolled ooidal iron stone de po si - tion: fa cies re la tion ships of the Or do vi cian open-shelf iron - stones of West ern Eu rope. Geo log i cal So ci ety Spe cial Pub li ca - tions, 46: 51–63.
Young, T.P., Tay lor, W.E.G., 1989. Phanerozoic iron stones. Geo - log i cal So ci ety Spe cial Pub li ca tions, 46.
Zatoń, M., Marynowski, L., Szczepanik, P., Bond, D.P.G., Wignall, P.B., 2009. Re dox con di tions dur ing sed i men ta tion of the Mid dle Ju ras sic (Up per Bajocian-Bathonian) clays of the Pol ish Jura (south-cen tral Po land). Fa cies, 55: 103–114.
