Provenance (geology)
Provenance, also known as geographic attribution, in geology refers to the origins or sources of particles within sediment and sedimentary rocks.
Modern geological provenance research specifically refers to the application of compositional analyses to determine sedimental origins.
This is often used in conjunction with the study of exhumation histories, forward-modeling of paleo-earth systems, and interpretation of drainage networks and their evolution.
In combination, these help to characterize the "source to sink" journey of clastic sediments from the hinterland to sedimentary basin.
[5] Provenance (from French provenir 'to come from/forth')[6] describes the history in detail of a certain object, with respect to its creation, ownership, custody, and location.
The term is commonly used by art historians and archivists, who use it to authenticate a work, document, or other signifigant object.
[7][8] The study of sedimentary provenance involves several geological disciplines, including mineralogy, geochemistry, geochronology, sedimentology, and petrology.
The earliest provenance studies were based on paleocurrent and petrographic analysis (composition and texture of sandstone and conglomerate).
[10] In the 1970s, provenance studies expanded to include tectonic settings (i.e. magmatic arcs, collision orogens and continental blocks) using sandstone composition.
Inductively coupled plasma spectrometry (ICP-MS) and sensitive high-resolution ion microprobe (SHRIMP) enabled researchers to analyze single mineral grains.
[12][13] The goal of sedimentary provenance studies is to reconstruct and interpret the history of sediment from parent rocks at a source area to detritus at a burial place.
[14] Sedimentary provenance analysis can also be a powerful tool to track landscape evolution and changes in sediment dispersal pathways through time.
[15] The goal of provenance studies is to investigate the characteristics of a source area by analyzing the composition and texture of sediments.
[18][19][20] After detritus are eroded from source area, they are transported and deposited in river, foreland basin or flood plain.
To avoid this problem, samples can be collected close to the mountain front, upstream from which there is no significant sediment storage.
Examples of petrological methods include QFL ternary diagram, heavy mineral assemblages (apatite–tourmaline index, garnet zircon index), clay mineral assemblages and illite crystallinity, reworked fossils and palynomorphs, and stock magnetic properties.
This method is based on the following considerations: "(1) the source areas are characterized by rocks with different tectonic histories recorded by distinctive crystallization and cooling ages; (2) the source rocks contain the selected mineral;" [30] (3) Detrital mineral like zircon is ultra-stable which means it is capable of surviving multiple phases of physical and chemical weathering, erosion and deposition.
This property make these detrital mineral ideal to record long history of crystallization of tectonically complex source area.
Then we can interpret that sediments of Amile formation are mainly derived from the Lesser Himalaya, and rocks yield ago of Paleoproterozoic and Archean are from the Indian craton.
U–Pb geochronology of zircons was conducted by laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICPMS).
Depend on properties of Sm–Nd radioactive isotope system can provide age estimation of sedimentary source rocks.
The upper plot (a), bold line shows the evolution of the bulk earth or CHUR(chondritic uniform reservoir).
The lower plot (b) shows evolution of bulk earth (CHUR) crust and mantle, 143Nd/144Nd is transformed to εNd.
[74] For finer-grained sediments, where loss of paragenetic information is a concern, only a limited range of analytical methods are appropriate.
Data acquisition approaches for provenance study fall into the following three categories: (1) analyzing bulk composition to extract petrographic, mineralogical, and chemical information.
Then measurement of major and trace and rare-earth (REE) elements are conducted by using instruments like atomic absorption spectroscopy (AAS), X-ray fluorescence (XRF), neutron activation analysis (NAA) etc.
Single-grain methods can be divided into the following three groups: (1) Microscopic-morphological techniques, which are used to observe shape, color and internal structures in minerals.
This results in a preferential enrichment of specific materials in a certain range of grain-size, and sediment composition tends to be a function of grain size.
In the development stage, mineralogical and chemical techniques are used to estimate reservoir zonation and correlation of stratigraphy.
For example, they are used to assess permeability variations and well decline rate resulting from spatial variability in diagenesis and depositional facies [83]
