What is paleocurrent data?
Paleocurrents are sedimentological features contained in all sedimentary deposits, enabling the direction of movement of the sediment and the containing fluid at the time of deposition to be determined.
How do you determine paleocurrent?
The paleocurrent direction can be determined by analyzing the direction of permeability. The permeability direction can be determined by using imaging logging data. Permeability direction of fluvial sand bodies and channel sand bodies is consistent with paleocurrent direction.
Which of the following sedimentary structures can be used as paleocurrent direction indicator?
Paleocurrent indicators. Sedimentary structures that may contain useful paleocurrent information include: Ripple marks (q.v.) and crossbedding (see Cross-lamination). Dune and ripple crests are typically oriented transverse to flow, while the foresets of crossbed structures normally dip in a downstream direction.
What causes cross bedding?
Cross-bedding is formed by the downstream migration of bedforms such as ripples or dunes in a flowing fluid. The fluid flow causes sand grains to saltate up the stoss (upstream) side of the bedform and collect at the peak until the angle of repose is reached.
What is provenance study?
Provenance studies involve the interpretation of the lithologic source of sediments and/or sedimentary rocks.
What is Rose diagram?
A rose diagram shows the circular distribution of directional data. The diagram plots lines at each of the 360 degrees of a compass distribution, with the length proportional to the number of values in that direction. With small data sets, directions can be binned.
How do you read a rose diagram?
The wind rose located in the top right corner of each data map shows the general wind direction and speed for each sampling period. The circular format of the wind rose shows the direction the winds blew from and the length of each “spoke” around the circle shows how often the wind blew from that direction.
What causes cross-bedding?
What cross-bedding tells us?
Cross bedding forms on a sloping surface such as ripple marks and dunes, and allows us to interpret that the depositional environment was water or wind. Examples of these are ripples, dunes, sand waves, hummocks, bars, and deltas.
How heavy a mineral is?
In geology, a heavy mineral is a mineral with a density that is greater than 2.9 g/cm3, most commonly referring to dense components of siliciclastic sediments. A heavy mineral suite is the relative percentages of heavy minerals in a stone.
What do mud cracks tell us?
3. What do mud cracks tell about the environment of deposition of a sedimentary rock? They indicate an environment in which sediment got wet and then dried out. Such an environment could be a flood plain, or tidal flat.
What are the two types of ripple marks?
There are two types of ripples: asymmetric and symmetric.
What do Rose plots show?
What is the purpose of a paleocurrent analysis?
Paleocurrent analysis. Yields information about the flow directions of rivers, longshore currents, sediment gravity flows, and paleowinds Provides direction of initial dip or paleoslope Yields clues to the provenance of sediment supply Aids in determining geologic setting to which it was placed Provides info on paleogeography.
What are paleocurrent indicators?
Definition Paleocurrent- The study of ancient flow Paleocurrent indicators- oriented sedimentary structures interpreted to have been deposited by ancient flows 4. Paleocurrent Indicators Include…
What is an example of paleocurrent data?
Collection of Paleocurrent Data. A wide range of sedimentary structures can be used in paleocurrent analysis. Some structures yield only the sense of current flow, others yield both sense and direction. Examples of the first group include groove marks, channels, washouts and parting lineation.
What is paleocurrent in geology?
Definition Paleocurrent- The study of ancient flow Paleocurrent indicators- oriented sedimentary structures interpreted to have been deposited by ancient flows 4. Paleocurrent Indicators Include… Cross-beds clast imbrication/fabric tool marks groove casts and molds ripple crest orientation 5. Paleocurrent Analysis….