PBDB Collection

Umbarka IX Borehole, Zone No. II (Cretaceous to of Egypt)

Where: Western Desert, Egypt (30.8° N, 26.5° E: paleocoordinates 8.9° N, 22.9° E)

• coordinate stated in text

When: Zone No. II. Aptian pollen zone, Aptian to Aptian (125.0 - 100.5 Ma)

• Age determination and environment of deposition of zone No. II.

•From the above results it is clear that the microlloral assemblages

•recovered from the sediments included in zone No. II are devoid of

•Angiosperms and characterized by dominance of Gymnosperms particularly

•Classopollis and Inaperturopollenites. Characteristic Jurassic

•sporomorphs are completely absent. The presence of characteristic

•spores like Balmeisporiles, Elaterosporites and Reticulatasporites

•emphasizes its relation to Aptian or Aptian-Albian age, as such

•age, in many African and South American countries contain such

•spores.

Environment/lithology: coastal; lithified, medium-grained, dolomitic, brown, gray, green, argillaceous, calcareous shale and lithified, white, calcareous dolomite

• Striking similarities exist between the present microllora and that

•of Aptian-Albian recovered from the formation of Dcqueen, Pike

•County, Arkansas, described by Bo:\'D (1972). Both assemblages are

•marine, containing such forms like Gonyaulacysta, Hystrichosphaeridium

•and Microforaminifera. They lack Angiosperms and are rich

•in Classopollis pollen. Nearly the same pteridophytic spores are present

•in both. In conclusion zone No. II is most probably related to

•Aptian or Aptian-Albian age. The high frequency of Classopollis

•pollen and marine microflora in these sediments of zone No. II

•indicates that deposition look place in coastal region under the

•influence of marine water current. The high percentage of Ephedripites

•pollen in these sediments indicates aridity of environmental

•conditions prevailing during this age.

• Sample 16, 9090-9012 ft.:Shale, flaky, med. Hard, dark gray, slightly dolomitic with sandstone of calcareous cement/ Samples 14-15, 9270-9330 ft: Shale, dark gray, flky med. Hard, greenish gray, with dolomite, hard cryptocrystalline/ Sample 13, 9330-9360 ft.: Shale, dark gray, flaky, med. hard and greenish gray with dolomite, hard crystalline brown in colour and gray with s.s. colourless fine grains./ Sample 12, 9510-9540 ft.: Shale, dark gray flaky med, hard with s.s. med. hard to hard grains. colouress. Sample 11, 9720-9750 ft.: Dolomite, white hard cryptocrystalline and shale, gray flaky med. hard./Sample 10, 9930-10230: Shale, dark gray, med. hard brown s.s. colourless fine to med. grains fairly porous.

Size class: microfossils

Preservation: soft parts, original sporopollenin

Collection methods: chemical, hydrochloric, hydroflouric, sieve

Primary reference: S. I. Saad. 1978. Plynological studie in the Egyptian Western Desert: Umbarka IX Borehole. Pollen et Spores 20(2):261-301 [C. Jaramillo/G. Doria/A. Cardenas ]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 144965: authorized by Carlos Jaramillo, entered by Gabriela Doria on 24.05.2013

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names

unclassified
-	Camarazonosporites insignis, Cictricosisporites "Type AH" Camarazonosporites insignis Cictricosisporites "Type AH"
Equisetopsida
Pinidae - Pinidae	Classopollis classoides, Balmeisporites aegyptiaca, Balmeisporites auriculatus Classopollis classoides Pflug 1953 Balmeisporites aegyptiaca Balmeisporites auriculatus Hall 1963
Gymnospermopsida
-	Singhia sp. Singhia sp. Srivastava 1967
Reticulatasporites
-	Reticulatasporites jardinus Reticulatasporites jardinus
Cycadopsida
Gnetales -	Elaterosporites klaszi Elaterosporites klaszi Jardiné 1967 elaterate
Ginkgoopsida
Ephedrales -	Ephedripites spp. Ephedripites spp. Bolkhovitina and Potonié 1958
Concavissimisporites
-	Concavissimisporites asper Concavissimisporites asper

Coniferales -	Circulina parva Circulina parva Brenner 1963
Concavisporites
-	Concavisporites twentianus Concavisporites twentianus
Murospora
-	Murospora sp. Murospora sp. Somers 1952
Polypodiopsida
- Osmundaceae	Baculatisporites sp. Baculatisporites sp. Thomson and Pflug 1953
- Gleicheniaceae	Gleicheniidites senonicus Gleicheniidites senonicus Ross 1949
Salviniales - Polypodiidae	Ariadnaesporites sp. Ariadnaesporites sp. Potonié 1956
Pteridopsida
-	Deltoidospora "Type A", Cyathidites australis, Cyathidites minor, Todisporites minor Deltoidospora "Type A" Miner 1935 Cyathidites australis Couper 1953 Cyathidites minor Couper 1953 Todisporites minor Couper 1953
Converrucosisporites
-	Converrucosisporites proxigranulatus Converrucosisporites proxigranulatus Brenner 1963
Perotriletes
-	Perotriletes aegyptiaca Perotriletes aegyptiaca