[First Hit]

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Oscar A. Abbink1, Roel M.C.H. Verreussel1, Jan Willem Weegink1
(1) LPP, Utrecht, Netherlands

Abstract: Palynological Identification of Previous HitSystemsNext Hit Previous HitTractsNext Hit in Jurassic Paralic Deposits in the North Previous HitSeaNext Hit Basin

Paralic depositional sequences in the Jurassic of the North Previous HitSeaNext Hit form an important economic objective. In these sequences, palynomorphs are the most abundant (micro)fossil group and palynology is increasingly challenged to identify Previous HitsystemsNext Hit Previous HittractsNext Hit and parasequences.

Based on the general ecologies of aquatic palynomorphs and on a recently developed Sporomorph EcoGroup model it can be demonstrated that (1) the interplay of the distribution patterns of brackish-marine, freshwater and terrestrial palynomorphs, and (2) distribution patterns of even solely terrestrial palynomorphs (grouped in six Sporomorph EcoGroups(SEGs), viz. Upland, Lowland, River, Pioneer, Coastal, and Tidally-influenced SEG), can be used for the recognition of Previous HitseaNext Hit-Previous HitlevelNext Hit fluctuations in paralic settings

The Previous HitseaNext Hit-Previous HitlevelNext Hit changes recognized based on the SEG model allow the identification of discrete palynological Previous HitseaNext Hit-Previous HitlevelNext Hit induced units (Previous HitSeaNext Hit-Previous HitlevelNext Hit Induced Palynomorph Succession;SIPS). Within the SIPS, four phases can be distinguished: (1) a "wet" Lowland SEG Previous HitphaseNext Hit, (2) a Previous HitphaseNext Hit with maximum abundance of Upland, Coastal and/or Tidally-influenced SEGs and a high marine/terrestrial ratio, (3) a Coastal SEG Previous HitphaseNext Hit, and (4) a "dry" Lowland SEG Previous HitphaseNext Hit. These Previous HitphaseTop are considered to correlate to the (1) late LST and TST, (2) MFS, (3) early HST, and (4) late HST. The boundary of between SIPSs reflects the abrupt shift from a regressional to a transgressional regime and is considered to approximately correlate to the SB.

AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana