Variations in lowstand systems tracts: Constraints on exploration

Conference · Fri Mar 01 04:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:6007196

Brown, Jr, L F

Results of worldwide exploration of lowstand systems tracts support continued application and evaluation of Exxon's cyclic sequence concepts but indicate the need for a better understanding of erosional and depositional variations possible along ancient lowstand coastlines. Exxon's idealized siliciclastic (type 1) model applies where a major highstand fluvial system was entrenched during falling relative sea level, eroding canyons and contributing sediments to lowstand depositional systems. Canyons and incised valleys were filled by late lowstand and retrogradational (transgressive) systems. Not explicit in Exxon's scenario are lowstand tracts at sites of minor entrenched coastal-plain streams or along interdeltaic or nondeltaic margins. A spectrum of systems tracts, identified along ancient basin margins, provides clues for predicting lowstand targets. In the absence of rivers, basin-floor sediments were supplied locally by headward-slumping submarine canyons and erosion of contributary valleys into subaerially exposed highstand shelf and/or strandline systems. Submarine erosion typically continued during subsequent rise and highstand of sea level, and sediments may have been introduced to basin floors through canyons from active retrogradational and highstand longshore systems. Headwardly eroded canyons and valleys were not always filled during subsequent transgression and highstand, leading to long-term multiple erosional/depositional cycles to produce some of the world's major ancient canyon complexes. The type and distribution of highstand systems tracts strongly influenced the quality and distribution of sandstone reservoir potential in subsequent lowstand tracts and, therefore, may help guide deep-water exploration along ancient basin margins.

• OSTI ID: 6007196
• Report Number(s): CONF-910403--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 75:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000 -- Geosciences
CONTINENTAL MARGIN
DEPOSITION
EROSION
EXPLORATION
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GEOLOGY
GLOBAL ASPECTS
LEVELS
MINERAL RESOURCES
NATURAL GAS DEPOSITS
ORIGIN
PETROLEUM DEPOSITS
RESOURCES
SEA LEVEL
SEDIMENTARY BASINS
STRATIGRAPHY
SUBMARINE CANYONS